Methods of using macrocyclic modulators of the ghrelin receptor

Abstract

The present invention provides novel conformationally-defined macrocyclic compounds that have been demonstrated to be selective modulators of the ghrelin receptor (growth hormone secretagogue receptor, GHS-R1a and subtypes, isoforms and variants thereof). Methods of synthesizing the novel compounds are also described herein. These compounds are useful as agonists of the ghrelin receptor and as medicaments for treatment and prevention of a range of medical conditions including, but not limited to, metabolic and/or endocrine disorders, gastrointestinal disorders, cardiovascular disorders, obesity and obesity-associated disorders, central nervous system disorders, genetic disorders, hyperproliferative disorders and inflammatory disorders.

Description

RELATED APPLICATION INFORMATION

This application is

• • wherein d and e are each independently 0, 1, 2, 3, 4 or 5; Y and Z are each optionally present; U is —CR₂₁R₂₂— or —C(═O)— and is bonded to X of formula I; W, Y and Z are each independently selected from the group consisting of—O—, —NR₂₃—, —S—, —SO—, —SO₂—, —C(═O)—O—, —O—C(═O)—, —C(═O)—NH—, —NH—C(═O)—, —SO₂—NH—, —NH—SO₂—, —CR₂₄R₂₅—, —CH═CH— with the configuration Z or E, and the ring structures below:

##STR00002##

• • • wherein G₁ and G₂ are each independently a covalent bond or a bivalent radical selected from the group consisting of —O—, —NR₃₉—, —S—, —SO—, —SO₂—, —C(═O)—, —C(═O)—O—, —O—C (═O)—, —C(═O)NH—, —NH—C(═O)—, —SO₂—NH—, —NH—SO₂—, —CR₄₀R₄₁—, —CH═CH— with the configuration Z or E, and —C≡C—; with G₁ being bonded closest to the group U; wherein any carbon atom in the rings not otherwise defined, is optionally replaced by N, with the proviso that the ring cannot contain more than four N atoms; K₁, K₂, K₃, K₄ and K₅ are each independently O, NR₄₂ or S, wherein R₄₂ is as defined below;
    • R₂₁ and R₂₂ are each independently hydrogen, lower alkyl, or substituted lower alkyl, or alternatively R₂, and R₂₂ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N, wherein the ring is optionally substituted with R₈ as defined above;
    • R₂₃, R₃₉ and R₄₂ are each independently hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, formyl, acyl, carboxyalkyl, carboxyaryl, amido, amidino, sulfonyl or sulfonamido;
    • R₂₄ and R₂₅ are each independently hydrogen, lower alkyl, substituted lower alkyl, R_AA, wherein R_AA is a side chain of an amino acid such as a standard or unusual amino acid, or alternatively R₂₄ and R₂₅ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N; or alternatively one of R₂₄ or R₂₅ is hydroxy, alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino while the other is hydrogen, lower alkyl or substituted lower alkyl, except when the carbon to which R₂₄ and R₂₅ are bonded is also bonded to another heteroatom;
    • R₂₆, R₃₁, R₃₅ and R₃₈ are each optionally present and, when present, are substituted for one or more hydrogen atoms on the indicated ring and each is independently selected from the group consisting of halogen, trifluoromethyl, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, cyano, nitro, mercapto, sulfinyl, sulfonyl and sulfonamido; R₂₇ is optionally present and is substituted for one or more hydrogen atoms on the indicated ring and each is independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and sulfonamido;
    • R₂₈, R₂₉, R₃₀, R₃₂, R₃₃, R₃₄, R₃₆ and R₃₇ are each optionally present and, when no double bond is present to the carbon atom to which it is bonded in the ring, two groups are optionally present, and when present, is substituted for one hydrogen present in the ring, or when no double bond is present to the carbon atom to which it is bonded in the ring, is substituted for one or both of the two hydrogen atoms present on the ring and each is independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl, sulfonamido and, only if a double bond is present to the carbon atom to which it is bonded, halogen; and
    • R₄₀ and R₄₁ are each independently hydrogen, lower alkyl, substituted lower alkyl, R_AA as defined above, or alternatively R₄₀ and R₄₁ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N wherein the ring is optionally substituted with R₈ as defined above, or alternatively one of R₄₀ and R₄₁ is hydroxy, alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino, while the other is hydrogen, lower alkyl or substituted lower alkyl, except when the carbon to which R₄₀ and R₄₁ are bonded is also bonded to another heteroatom;
      with the proviso that T is not an amino acid residue, dipeptide fragment, tripeptide fragment or higher order peptide fragment comprising standard amino acids;

##STR00003##
or an optical isomer, enantiomer, diastereomer, racemate or stereochemical mixture thereof,
wherein:

R₅₀ is —(CH₂)_ssCH₃, —CH(CH₃)(CH₂)_ttCH₃, —(CH₂)_uuCH(CH₃)₂, —C(CH₃)₃, —(CHR₅₅)_vv—R₅₆, or —CH(OR₅₇)CH₃, wherein ss is 1, 2 or 3; tt is 1 or 2; uu is 0, 1 or 2; and vv is 0, 1, 2, 3 or 4; R₅₅ is hydrogen or C₁-C₄ alkyl; R₅₆ is amino, hydroxy, alkoxy, cycloalkyl or substituted cycloalkyl; and R₅₇ is hydrogen, alkyl, acyl, amino acyl, sulfonyl, carboxyalkyl or carboxyaryl;

R₅₁ is hydrogen, C₁-C₄ alkyl or C₁-C₄ alkyl substituted with hydroxy or alkoxy;

R₅₂ is —(CHR₅₈)_wwR₅₉, wherein ww is 0, 1, 2 or 3; R₅₈ is hydrogen, C₁-C₄ alkyl, amino, hydroxy or alkoxy; R₅₉ is aryl, substituted aryl, heteroaryl, substituted heteroaryl, cycloalkyl or substituted cycloalkyl;

R₅₃ is hydrogen or C₁-C₄ alkyl;

X₂ is O, NR₉ or N(R₁₀)₂⁺;

• • wherein R₉ is hydrogen, lower alkyl, substituted lower alkyl, sulfonyl, sulfonamido or amidino and R₁₀ is hydrogen, lower alkyl, or substituted lower alkyl;

Z₅ is O or NR₁₂, wherein R₁₂ is hydrogen, lower alkyl, or substituted lower alkyl; and

T₂ is a bivalent radical of formula V:
—U_a—(CH₂)_d—W_a—Y_a-Z_a-(CH₂)₃—  (V)

• • wherein d and e are independently 0, 1, 2, 3, 4 or 5; Y_a and Z_a are each optionally present; U_a is —CR₆₀R₆₁— or —C(═O)— and is bonded to X₂ of formula II, wherein R₆₀ and R₆₁ are each independently hydrogen, lower alkyl, or substituted lower alkyl, or alternatively R₂₁ and R₂₂ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N, wherein the ring is optionally substituted with R₈ as defined above: W_a, Y_a and Z_a are each independently selected from the group consisting of: —O—, —NR₆₂—, —S—, —SO—, —SO₂—, —C(═O)—O—, —O—C(═O)—, —C(═O)—NH—, —NH—C(═O)—, —SO₂—NH—, —NH—SO₂—, —CR₆₃R₆₄—, —CH═CH— with the configuration Z or E, —C≡C—, and the ring structures depicted below:

##STR00004##

• • • wherein G₁ and G₂ are as defined above, and wherein any carbon atom in the ring is optionally replaced by N, with the proviso that the aromatic ring cannot contain more than four N atoms and the cycloalkyl ring cannot contain more than two N atoms;
      • R₆₂ is hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, formyl, acyl, carboxyalkyl, carboxyaryl, amido, amidino, sulfonyl or sulfonamido;
      • R₆₃ and R₆₄ are each independently hydrogen, lower alkyl, substituted lower alkyl or R_AA; or alternatively R₆₃ and R₆₄ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N; or alternatively one of R₆₃ and R₆₄ is hydroxy, alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino, while the other is hydrogen, lower alkyl or substituted lower alkyl, except when the carbon to which R₆₃ and R₆₄ are bonded is also bonded to another heteroatom; and R_AA indicates the side chain of an amino acid such as a standard or unusual amino acid;
      • R₆₅ and R₆₈ are each optionally present, and, when present are substituted for one or more hydrogen atoms on the ring and each is independently halogen, trifluoromethyl, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidine, ureido, amidino, cyano, nitro, mercapto, sulfinyl, sulfonyl or sulfonamido;
      • R₆₆ and R₆₇ are each optionally present, and when no double bond is present to the carbon atom to which it is bonded in the ring, two groups are optionally present, and, when present, each is substituted for one hydrogen present in the ring, or when no double bond is present to the carbon atom to which it is bonded in the ring, is substituted for one or both of the two hydrogen atoms present on the ring and each is independently alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl, sulfonamido and, only if a double bond is present to the carbon atom to which it is bonded, halogen;
      • R₆₉ is optionally present, and when present is substituted for one or more hydrogen atoms on the ring and each is independently alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl or sulfonamido;
      • K₆ is O or S; and
      • ff is 1, 2, 3, 4 or 5;
    • with the proviso that T₂ is not an amino acid residue, dipeptide fragment, tripeptide fragment or higher order peptide fragment comprising standard amino acids;
    • or

##STR00005##
or an optical isomer, enantiomer, diastereomer, racemate or stereochemical mixture thereof, wherein:

R₇₀ is hydrogen, C₁-C₄ alkyl or alternatively R₇₀ and R₇₁ together form a 4-, 5-, 6-, 7- or 8-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R_8a as defined below;

R₇₁ is hydrogen, —(CH₂)_aaCH₃, —CH(CH₃) (CH₂)_bbCH₃, —(CH₂)_ccCH(CH₃)₂, —(CH₂)_dd—R₇₆ or —CH(OR₇₇)CH₃ or, alternatively R₇₁ and R₇₀ together form a 4-, 5-, 6-, 7- or 8-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R_8a as defined below; wherein aa is 0, 1, 2, 3, 4 or 5; bb is 1, 2 or 3; cc is 0, 1, 2 or 3; and dd is 0, 1, 2, 3 or 4; R₇₆ is aryl, substituted aryl, heteroaryl, substituted heteroaryl, cycloalkyl or substituted cycloalkyl; R₇₇ is hydrogen, alkyl, acyl, amino acyl, sulfonyl, carboxyalkyl or carboxyaryl;

R₇₂ is C₁-C₄ alkyl; or alternatively R₇₂ and R₇₃ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O or S atom in the ring, wherein the ring is optionally substituted with R_8b as defined below;

R₇₃ is hydrogen, or alternatively R₇₃ and R₇₂ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or N atom in the ring, wherein the ring is optionally substituted with R_8b as defined below;

R₇₄ is hydrogen or C₁-C₄ alkyl or alternatively R₇₄ and R₇₅ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R_8c, as defined below;

R₇₅ is —(CHR₇₈)R₇₉ or alternatively R₇₅ and R₇₄ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R_8c as defined below; wherein R₇₈ is hydrogen, C₁-C₄ alkyl, amino, hydroxy or alkoxy, and R₇₉ is selected from the group consisting of the following structures:

##STR00006##

• • wherein E, E₂, E₃, E₄ and E₅ are each optionally present and when present are each independently selected from the group consisting of halogen, trifluoromethyl, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, cyano, sulfinyl, sulfonyl and sulfonamido, and represent substitution at one or more available positions on the monocyclic or bicyclic aromatic ring, wherein said substitution is made with the same or different selected group member, and J₁ and J₂ are each independently O or S;

R_8a, R_8b and R_8c are each independently substituted for one or more hydrogen atoms on the 3-, 4-, 5-, 6-, 7- or 8-membered ring structure and are independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, halogen, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and sulfonamido, or, alternatively. R_8a, R_8b and R_8c are each independently a fused cycloalkyl, a substituted fused cycloalkyl, a fused heterocyclic, a substituted fused heterocyclic, a fused aryl, a substituted fused aryl, a fused heteroaryl or a substituted fused heteroaryl ring when substituted for hydrogen atoms on two adjacent atoms;

X₃ is O, NR₉ or N(R₁₀)₂⁺;

• • wherein R₉ is hydrogen, lower alkyl, substituted lower alkyl, sulfonyl, sulfonamido or amidino and R₁₀ is hydrogen, lower alkyl, or substituted lower alkyl;

Z₁₀ is O or NR₁₂, wherein R₁₂ is hydrogen, lower alkyl, or substituted lower alkyl; and

T₃ is the same as defined for T₂ with the exception that U_a is bonded to X₃ of formula III.

According to further aspects of the present invention, the compound is a ghrelin receptor agonist or a GHS-R1a receptor agonist.

Further aspects of the present invention provide pharmaceutical compositions comprising: (a) a compound of the present invention; and (b) a pharmaceutically acceptable carrier, excipient or diluent.

Additional aspects of the present invention provide kits comprising one or more containers containing pharmaceutical dosage units comprising an effective amount of one or more compounds of the present invention packaged with optional instructions for the use thereof.

Aspects of the present invention further provide methods of stimulating gastrointestinal motility, modulating GHS-R1a receptor activity in a mammal and/or treating a gastrointestinal disorder comprising administering to a subject in need thereof an effective amount of a modulator that modulates a mammalian GHS-R1a receptor. In particular embodiments, interaction of the modulator and the GHS-R1a receptor does not result in a significant amount of growth hormone release. In still other embodiments, the modulator is a compound of formula I, II and/or III.

Additional aspects of the present invention provide methods of diagnosing tumors and/or acromegaly, comprising administering compounds of the present invention and a radiolabeled metal binding agent and detecting the binding of the composition to a biological target, and treating tumors and/or acromegaly comprising administering a therapeutically effective amount of a composition comprising a compound of the present invention.

Further aspects of the present invention relate to methods of making the compounds of formula I, II and/or III.

Aspects of the present invention further relate to methods of preventing and/or treating disorders described herein, in particular, gastrointestinal disorders, including post-operative ileus, gastroparesis, such as diabetic and post-surgical gastroparesis, opioid-induced bowel dysfunction, chronic intestinal pseudo-obstruction, short bowel syndrome, emesis such as caused by cancer chemotherapy, constipation such as associated with the hypomotility phase of irritable bowel syndrome (IBS), delayed gastric emptying associated with wasting conditions, gastroesophageal reflux disease (GERD), gastric ulcers, Crohn's disease, gastrointestinal disorders characterized by dysmotility and other diseases and disorders of the gastrointestinal tract.

The present invention also relates to compounds of formula I, II and/or III used for the preparation of a medicament for prevention and/or treatment of the disorders described herein.

The foregoing and other aspects of the present invention are explained in greater detail in the specification set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a scheme presenting a general synthetic strategy to provide conformationally-defined macrocycles of the present invention.

FIG. 2 shows a general thioester strategy for making macrocyclic compounds of the present invention.

FIG. 3 shows a general ring-closing metathesis (RCM) strategy for macrocyclic compounds of the present invention.

FIG. 4 (panels A through E) shows competitive binding curves for binding of exemplary compounds of the present invention to the hGHS-R1a receptor.

FIG. 5 (panels A through E) shows concentration-response curves for activation of the hGHS-R1a receptor by exemplary compounds of the present invention.

FIG. 6 shows graphs depicting pharmacokinetic parameters for exemplary compounds of the present invention, specifically after oral administration of 8 mg/kg compound 298 (panel A), after subcutaneous injection of 2 mg/kg compound 298 with cyclodextrin (panel B), after intravenous administration of 2 mg/kg compound 25 with cyclodextrin (panel C) and after intravenous administration of 2 mg/kg compound 298 with cyclodextrin (panel D).

FIG. 7 (panels A and B) shows graphs presenting effects on gastric emptying for exemplary compounds of the present invention.

FIG. 8 shows a graph presenting effects on postoperative ileus for an exemplary compound of the present invention.

FIG. 9 (panels A through D) shows graphs depicting the effect on pulsatile growth hormone release for an exemplary compound of the present invention.

FIG. 10 shows a competitive binding curve for binding of an exemplary compound of the present invention to the hGHS-R1a receptor.

FIG. 11 shows an activation curve demonstrating the agonism of an exemplary compound of the present invention.

FIG. 12 shows a graph depicting the lack of effect on ghrelin-induced growth hormone release for an exemplary compound of the present invention.

FIG. 13 shows graphs depicting receptor desentization associated with binding of exemplary compounds of the present invention to the hGHS-R1a receptor.

FIG. 14 (panels A and B) shows graphs presenting effects on gastric emptying for an exemplary compound of the present invention.

FIG. 15 shows a graph presenting effects on postoperative ileus for an exemplary compound of the present invention.

FIG. 16 shows graphs depicting reversal of morphine-delayed gastric emptying (panel A) and morphine-delayed gastrointestinal transit (panel B) for an exemplary compound of the present invention.

FIG. 17 (panels A and B) shows graphs depicting effects on gastroparesis for exemplary compounds of the present invention.

DETAILED DESCRIPTION

The foregoing and other aspects of the present invention will now be described in more detail with respect to other embodiments described herein. It should be appreciated that the invention can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Additionally, as used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

All publications, U.S. patent applications, U.S. patents and other references cited herein are incorporated by reference in their entireties.

The term “alkyl” refers to straight or branched chain saturated or partially unsaturated hydrocarbon groups having from 1 to 20 carbon atoms, in some instances 1 to 8 carbon atoms. The term “lower alkyl” refers to alkyl groups containing 1 to 6 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, isopropyl, tert-butyl, 3-hexenyl, and 2-butynyl. By “unsaturated” is meant the presence of 1, 2 or 3 double or triple bonds, or a combination of the two. Such alkyl groups may also be optionally substituted as described below.

When a subscript is used with reference to an alkyl or other hydrocarbon group defined herein, the subscript refers to the number of carbon atoms that the group may contain. For example, C₂-C₄ alkyl indicates an alkyl group with 2, 3 or 4 carbon atoms.

The term “cycloalkyl” refers to saturated or partially unsaturated cyclic hydrocarbon groups having from 3 to 15 carbon atoms in the ring, in some instances 3 to 7, and to alkyl groups containing said cyclic hydrocarbon groups. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclopropylmethyl, cyclopentyl, 2-(cyclohexyl)ethyl, cycloheptyl, and cyclohexenyl. Cycloalkyl as defined herein also includes groups with multiple carbon rings, each of which may be saturated or partially unsaturated, for example decalinyl, [2.2.1]-bicycloheptanyl or adamantanyl. All such cycloalkyl groups may also be optionally substituted as described below.

The term “aromatic” refers to an unsaturated cyclic hydrocarbon group having a conjugated pi electron system that contains 4n+2 electrons where n is an integer greater than or equal to 1. Aromatic molecules are typically stable and are depicted as a planar ring of atoms with resonance structures that consist of alternating double and single bonds, for example benzene or naphthalene.

The term “aryl” refers to an aromatic group in a single or fused carbocyclic ring system having from 6 to 15 ring atoms, in some instances 6 to 10, and to alkyl groups containing said aromatic groups. Examples of aryl groups include, but are not limited to, phenyl, 1-naphthyl, 2-naphthyl and benzyl. Aryl as defined herein also includes groups with multiple aryl rings which may be fused, as in naphthyl and anthracenyl, or unfused, as in biphenyl and terphenyl. Aryl also refers to bicyclic or tricyclic carbon rings, where one of the rings is aromatic and the others of which may be saturated, partially unsaturated or aromatic, for example, indanyl or tetrahydronaphthyl (tetralinyl). All such aryl groups may also be optionally substituted as described below.

The term “heterocycle” or “heterocyclic” refers to saturated or partially unsaturated monocyclic, bicyclic or tricyclic groups having from 3 to 15 atoms, in some instances 3 to 7, with at least one heteroatom in at least one of the rings, said heteroatom being selected from O, S or N. Each ring of the heterocyclic group can contain one or two O atoms, one or two S atoms, one to four N atoms, provided that the total number of heteroatoms in each ring is four or less and each ring contains at least one carbon atom. The fused rings completing the bicyclic or tricyclic heterocyclic groups may contain only carbon atoms and may be saturated or partially unsaturated. The N and S atoms may optionally be oxidized and the N atoms may optionally be quaternized. Heterocyclic also refers to alkyl groups containing said monocyclic, bicyclic or tricyclic heterocyclic groups. Examples of heterocyclic rings include, but are not limited to, 2- or 3-piperidinyl, 2- or 3-piperazinyl, 2- or 3-morpholinyl. All such heterocyclic groups may also be optionally substituted as described below

The term “heteroaryl” refers to an aromatic group in a single or fused ring system having from 5 to 15 ring atoms, in some instances 5 to 10, which have at least one heteroatom in at least one of the rings, said heteroatom being selected from O, S or N. Each ring of the heteroaryl group can contain one or two O atoms, one or two S atoms, one to four N atoms, provided that the total number of heteroatoms in each ring is four or less and each ring contains at least one carbon atom. The fused rings completing the bicyclic or tricyclic groups may contain only carbon atoms and may be saturated, partially unsaturated or aromatic. In structures where the lone pair of electrons of a nitrogen atom is not involved in completing the aromatic pi electron system, the N atoms may optionally be quaternized or oxidized to the N-oxide. Heteroaryl also refers to alkyl groups containing said cyclic groups. Examples of monocyclic heteroaryl groups include, but are not limited to pyrrolyl, pyrazolyl, pyrazolinyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, thiadiazolyl, isothiazolyl, furanyl, thienyl, oxadiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl. Examples of bicyclic heteroaryl groups include, but are not limited to indolyl, benzothiazolyl, benzoxazolyl, benzothienyl, quinolinyl, tetrahydroisoquinolinyl, isoquinolinyl, benzimidazolyl, benzopyranyl, indolizinyl, benzofuranyl, isobenzofuranyl, chromonyl, coumarinyl, benzopyranyl, cinnolinyl, quinoxalinyl, indazolyl, purinyl, pyrrolopyridinyl, furopyridinyl, thienopyridinyl, dihydroisoindolyl, and tetrahydroquinolinyl. Examples of tricyclic heteroaryl groups include, but are not limited to carbazolyl, benzindolyl, phenanthrollinyl, acridinyl, phenanthridinyl, and xanthenyl. All such heteroaryl groups may also be optionally substituted as described below.

The term “hydroxy” refers to the group —OH.

The term “alkoxy” refers to the group —OR_a, wherein R_a is alkyl, cycloalkyl or heterocyclic. Examples include, but are not limited to methoxy, ethoxy, tert-butoxy, cyclohexyloxy and tetrahydropyranyloxy.

The term “aryloxy” refers to the group —OR_b wherein R_b is aryl or heteroaryl. Examples include, but are not limited to phenoxy, benzyloxy and 2-naphthyloxy.

The term “acyl” refers to the group —C(═O)—R_c wherein R_c is alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl. Examples include, but are not limited to, acetyl, benzoyl and furoyl.

The term “amino acyl” indicates an acyl group that is derived from an amino acid.

The term “amino” refers to an —NR_dR_e group wherein R_d and R_e are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic, aryl and heteroaryl. Alternatively, R_d and R_e together form a heterocyclic ring of 3 to 8 members, optionally substituted with unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and optionally containing one to three additional heteroatoms selected from O, S or N.

The term “amido” refers to the group —C(═O)—NR_fR_g wherein R_f and R_g are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic, aryl and heteroaryl. Alternatively, R_f and R_g together form a heterocyclic ring of 3 to 8 members, optionally substituted with unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and optionally containing one to three additional heteroatoms selected from O, S or N.

The term “amidino” refers to the group —C(═NR_h)NR_iR_j wherein R_h is selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic, aryl and heteroaryl; and R_i and R_j are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic, aryl and heteroaryl. Alternatively, R_i and R_j together form a heterocyclic ring of 3 to 8 members, optionally substituted with unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and optionally containing one to three additional heteroatoms selected from O, S or N.

The term “carboxy” refers to the group —CO₂H.

The term “carboxyalkyl” refers to the group —CO₂R_k, wherein R_k is alkyl, cycloalkyl or heterocyclic.

The term “carboxyaryl” refers to the group —CO₂R_m, wherein R_m is aryl or heteroaryl.

The term “cyano” refers to the group —CN.

The term “formyl” refers to the group —C(═O)H, also denoted —CHO.

The term “halo,” “halogen” or “halide” refers to fluoro, fluorine or fluoride, chloro, chlorine or chloride, bromo, bromine or bromide, and iodo, iodine or iodide, respectively.

The term “oxo” refers to the bivalent group ═O, which is substituted in place of two hydrogen atoms on the same carbon to form a carbonyl group.

The term “mercapto” refers to the group —SR_n wherein R_n is hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl.

The term “nitro” refers to the group —NO₂.

The term “trifluoromethyl” refers to the group —CF₃.

The term “sulfinyl” refers to the group —S(═O)R_p wherein R_p is alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl.

The term “sulfonyl” refers to the group —S(═O)₂—R_q1 wherein R_q1 is alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl.

The term “aminosulfonyl” refers to the group —NR_q2—S (═O)₂—R_q3 wherein R_q2 is hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl; and R_q3 is alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl.

The term “sulfonamido” refers to the group —S(═O)₂—NR_rR_s wherein R_r and R_s are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl. Alternatively, R_r and R_s together form a heterocyclic ring of 3 to 8 members, optionally substituted with unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and optionally containing one to three additional heteroatoms selected from O, S or N.

The term “carbamoyl” refers to a group of the formula —N(R_t)—C(═O)—OR_u wherein R_t is selected from hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl; and R_u is selected from alkyl, cycloalkyl, heterocylic, aryl or heteroaryl.

The term “guanidino” refers to a group of the formula —N(R_v)—C(═NR_w)—NR_xR_y wherein R_v, R_w, R_x and R_y are independently selected from hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl. Alternatively, R_x and R_y together form a heterocyclic ring or 3 to 8 members, optionally substituted with unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and optionally containing one to three additional heteroatoms selected from O, S or N.

The term “ureido” refers to a group of the formula —N(R_z)—C(═O)—NR_aaR_bb wherein R_z, R_aa and R_bb are independently selected from hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl. Alternatively, R_aa and R_bb together form a heterocyclic ring of 3 to 8 members, optionally substituted with unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and optionally containing one to three additional heteroatoms selected from O, S or N.

The term “optionally substituted” is intended to expressly indicate that the specified group is unsubstituted or substituted by one or more suitable substituents, unless the optional substituents are expressly specified, in which case the term indicates that the group is unsubstituted or substituted with the specified substituents. As defined above, various groups may be unsubstituted or substituted (i.e., they are optionally substituted) unless indicated otherwise herein (e.g., by indicating that the specified group is =substituted).

The term “substituted” when used with the terms alkyl, cycloalkyl, heterocyclic, aryl and heteroaryl refers to an alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl group having one or more of the hydrogen atoms of the group replaced by substituents independently selected from unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, halo, oxo, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino, ureido and groups of the formulas —NR_ccC(═O)R_dd, —NR_eeC (═NR_ff)R_gg, —OC(═O)NR_hhR_ii, —OC(═O)R_jj, —OC (═O)OR_kk, —NR_mmSO₂R_nn, or —NR_ppSO₂NR_qqR_rr wherein R_cc, R_dd, R_ee, R_ff, R_gg, R_hh, R_ii, R_jj, R_mm, R_pp, R_qq and R_rr are independently selected from hydrogen, unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl or unsubstituted heteroaryl; and wherein R_kk and R_nn are independently selected from unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl or unsubstituted heteroaryl. Alternatively, R_gg and R_hh, R_jj and R_kk or R_pp and R_qq together form a heterocyclic ring of 3 to 8 members, optionally substituted with unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and optionally containing one to three additional heteroatoms selected from O, S or N. In addition, the term “substituted” for aryl and heteroaryl groups includes as an option having one of the hydrogen atoms of the group replaced by cyano, nitro or trifluoromethyl.

A substitution is made provided that any atom's normal valency is not exceeded and that the substitution results in a stable compound. Generally, when a substituted form of a group is present, such substituted group is preferably not further substituted or, if substituted, the substituent comprises only a limited number of substituted groups, in some instances 1, 2, 3 or 4 such substituents.

When any variable occurs more than one time in any constituent or in any formula herein, its definition on each occurrence is independent of its definition at every other occurrence. Also, combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.

A “stable compound” or “stable structure” refers to a compound that is sufficiently robust to survive isolation to a useful degree of purity and formulation into an efficacious therapeutic agent.

The term “amino acid” refers to the common natural (genetically encoded) or synthetic amino acids and common derivatives thereof, known to those skilled in the art. When applied to amino acids, “standard” or “proteinogenic” refers to the genetically encoded 20 amino acids in their natural configuration. Similarly, when applied to amino acids, “unnatural” or “unusual” refers to the wide selection of non-natural, rare or synthetic amino acids such as those described by Hunt, S. in Chemistry and Biochemistry of the Amino Acids, Barrett, G. C., Ed., Chapman and Hall: New York, 1985.

The term “residue” with reference to an amino acid or amino acid derivative refers to a group of the formula:

##STR00007##
wherein R_AA is an amino acid side chain, and n=0, 1 or 2 in this instance.

The term “fragment” with respect to a dipeptide, tripeptide or higher order peptide derivative indicates a group that contains two, three or more, respectively, amino acid residues.

The term “amino acid side chain” refers to any side chain from a standard or unnatural amino acid, and is denoted R_AA. For example, the side chain of alanine is methyl, the side chain of valine is isopropyl and the side chain of tryptophan is 3-indolylmethyl.

The term “agonist” refers to a compound that duplicates at least some of the effect of the endogenous ligand of a protein, receptor, enzyme or the like.

The term “antagonist” refers to a compound that inhibits at least some of the effect of the endogenous ligand of a protein, receptor, enzyme or the like.

The term “growth hormone secretagogue” (GHS) refers to any exogenously administered compound or agent that directly or indirectly stimulates or increases the endogenous release of growth hormone, growth hormone-releasing hormone, or somatostatin in an animal, in particular, a human. A GHS may be peptidic or non-peptidic in nature, in some instances, with an agent that can be administered orally. In some instances, the agent can induce a pulsatile response.

The term “modulator” refers to a compound that imparts an effect on a biological or chemical process or mechanism. For example, a modulator may increase, facilitate, upregulate, activate, inhibit, decrease, block, prevent, delay, desensitize, deactivate, down regulate, or the like, a biological or chemical process or mechanism. Accordingly, a modulator can be an “agonist” or an “antagonist.” Exemplary biological processes or mechanisms affected by a modulator include, but are not limited to, receptor binding and hormone release or secretion. Exemplary chemical processes or mechanisms affected by a modulator include, but are not limited to, catalysis and hydrolysis.

The term “variant” when applied to a receptor is meant to include dimers, trimers, tetramers, pentamers and other biological complexes containing multiple components. These components can be the same or different.

The term “peptide” refers to a chemical compound comprised of two or more amino acids covalently bonded together.

The term “peptidomimetic” refers to a chemical compound designed to mimic a peptide, but which contains structural differences through the addition or replacement of one of more functional groups of the peptide in order to modulate its activity or other properties, such as solubility, metabolic stability, oral bioavailability, lipophilicity, permeability, etc. This can include replacement of the peptide bond, side chain modifications, truncations, additions of functional groups, etc. When the chemical structure is not derived from the peptide, but mimics its activity, it is often referred to as a “non-peptide peptidomimetic.”

The term “peptide bond” refers to the amide [—C(═O)—NH—] functionality with which individual amino acids are typically covalently bonded to each other in a peptide.

The term “protecting group” refers to any chemical compound that may be used to prevent a potentially reactive functional group, such as an amine, a hydroxyl or a carboxyl, on a molecule from undergoing a chemical reaction while chemical change occurs elsewhere in the molecule. A number of such protecting groups are known to those skilled in the art and examples can be found in “Protective Groups in Organic Synthesis,” Theodora W. Greene and Peter G. Wuts, editors, John Wiley & Sons, New York, 3^rd edition, 1999 [ISBN 0471160199]. Examples of amino protecting groups include, but are not limited to, phthalimido, trichloroacetyl, benzyloxycarbonyl, tert-butoxycarbonyl, and adamantyloxycarbonyl. In some embodiments, amino protecting groups are carbamate amino protecting groups, which are defined as an amino protecting group that when bound to an amino group forms a carbamate. In other embodiments, amino carbamate protecting groups are allyloxycarbonyl (Alloc), benzyloxycarbonyl (Cbz), 9-fluorenylmethoxycarbonyl (Fmoc), tertbutoxycarbonyl (Boc) and α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl (Ddz). For a recent discussion of newer nitrogen protecting groups: Theodoridis, G. Tetrahedron 2000, 56, 2339-2358. Examples of hydroxyl protecting groups include, but are not limited to, acetyl, tert-butyldimethylsilyl (TBDMS), trityl (Trt), tert-butyl, and tetrahydropyranyl (THP). Examples of carboxyl protecting groups include, but are not limited to methyl ester, tert-butyl ester, benzyl ester, trimethylsilylethyl ester, and 2,2,2-trichloroethyl ester.

The term “solid phase chemistry” refers to the conduct of chemical reactions where one component of the reaction is covalently bonded to a polymeric material (solid support as defined below). Reaction methods for performing chemistry on solid phase have become more widely known and established outside the traditional fields of peptide and oligonucleotide chemistry.

The term “solid support,” “solid phase” or “resin” refers to a mechanically and chemically stable polymeric matrix utilized to conduct solid phase chemistry. This is denoted by “Resin,” “P-” or the following symbol:

##STR00008##

Examples of appropriate polymer materials include, but are not limited to, polystyrene, polyethylene, polyethylene glycol, polyethylene glycol grafted or covalently bonded to polystyrene (also termed PEG-polystyrene, TentaGel™, Rapp, W.; Zhang, L.; Bayer, E. In Innovations and Persepctives in Solid Phase Synthesis, Peptides, Polypeptides and Oligonucleotides; Epton, R., Ed.; SPCC Ltd.: Birmingham, UK; p 205), polyacrylate (CLEAR™), polyacrylamide, polyurethane, PEGA [polyethyleneglycol poly(N,N-dimethylacrylamide) co-polymer, Meldal, M. Tetrahedron Lett, 1992, 33, 3077-3080], cellulose, etc. These materials can optionally contain additional chemical agents to form cross-linked bonds to mechanically stabilize the structure, for example polystyrene cross-linked with divinylbenezene (DVB, usually 0.1-5%, preferably 0.5-2%). This solid support can include as non-limiting examples aminomethyl polystyrene, hydroxymethyl polystyrene, benzhydrylamine polystyrene (BHA), methylbenzhydrylamine (MBHA) polystyrene, and other polymeric backbones containing free chemical functional groups, most typically, —NH₂ or —OH, for further derivatization or reaction. The term is also meant to include “Ultraresins” with a high proportion (“loading”) of these functional groups such as those prepared from polyethyleneimines and cross-linking molecules (Barth, M.; Rademann, J. J. Comb. Chem. 2004, 6, 340-349). At the conclusion of the synthesis, resins are typically discarded, although they have been shown to be able to be reused such as in Frechet, J. M. J.; Hague, K. E. Tetrahedron Lett. 1975, 16, 3055.

In general, the materials used as resins are insoluble polymers, but certain polymers have differential solubility depending on solvent and can also be employed for solid phase chemistry. For example, polyethylene glycol can be utilized in this manner since it is soluble in many organic solvents in which chemical reactions can be conducted, but it is insoluble in others, such as diethyl ether. Hence, reactions can be conducted homogeneously in solution, then the product on the polymer precipitated through the addition of diethyl ether and processed as a solid. This has been termed “liquid-phase” chemistry.

The term “linker” when used in reference to solid phase chemistry refers to a chemical group that is bonded covalently to a solid support and is attached between the support and the substrate typically in order to permit the release (cleavage) of the substrate from the solid support. However, it can also be used to impart stability to the bond to the solid support or merely as a spacer element. Many solid supports are available commercially with linkers already attached.

Abbreviations used for amino acids and designation of peptides follow the rules of the IUPAC-IUB Commission of Biochemical Nomenclature in J. Biol. Chem. 1972, 247, 977-983. This document has been updated: Biochem. J., 1984, 219, 345-373; Eur. J. Biochem., 1984, 138, 9-37; 1985, 152, 1; Internat. J. Pept. Prot. Res., 1984, 24, following p 84; J. Biol. Chem., 1985, 260, 14-42; Pure Appl. Chem., 1984, 56, 595-624; Amino Acids and Peptides, 1985, 16.387-410; and in Biochemical Nomenclature and Related Documents, 2nd edition, Portland Press, 1992, pp 39-67. Extensions to the rules were published in the JCBN/NC-IUB Newsletter 1985, 1986, 1989; see Biochemical Nomenclature and Related Documents, 2nd edition, Portland Press, 1992, pp 68-69.

The term “effective amount” or “effective” is intended to designate a dose that causes a relief of symptoms of a disease or disorder as noted through clinical testing and evaluation, patient observation, and/or the like, and/or a dose that causes a detectable change in biological or chemical activity. The detectable changes may be detected and/or further quantified by one skilled in the art for the relevant mechanism or process. As is generally understood in the art, the dosage will vary depending on the administration routes, symptoms and body weight of the patient but also depending upon the compound being administered.

Administration of two or more compounds “in combination” means that the two compounds are administered closely enough in time that the presence of one alters the biological effects of the other. The two compounds can be administered simultaneously (concurrently) or sequentially. Simultaneous administration can be carried out by mixing the compounds prior to administration, or by administering the compounds at the same point in time but at different anatomic sites or using different routes of administration. The phrases “concurrent administration”, “administration in combination”, “simultaneous administration” or “administered simultaneously” as used herein, means that the compounds are administered at the same point in time or immediately following one another. In the latter case, the two compounds are administered at times sufficiently close that the results observed are indistinguishable from those achieved when the compounds are administered at the same point in time.

The term “pharmaceutically active metabolite” is intended to mean a pharmacologically active product produced through metabolism in the body of a specified compound.

The term “solvate” is intended to mean a pharmaceutically acceptable solvate form of a specified compound that retains the biological effectiveness of such compound. Examples of solvates, without limitation, include compounds of the invention in combination with water, isopropanol, ethanol, methanol, DMSO, ethyl acetate, acetic acid, or ethanolamine.

1. Compounds

Novel macrocyclic compounds of the present invention include macrocyclic compounds comprising a building block structure including a tether component that undergoes cyclization to form the macrocyclic compound. The building block structure can comprise amino acids (standard and unnatural), hydroxy acids, hydrazino acids, aza-amino acids, specialized moieties such as those that play a role in the introduction of peptide surrogates and isosteres, and a tether component as described herein. The tether component can be selected from the following:

##STR00009##

wherein (Z₂) is the site of a covalent bond of T to Z₂, and Z₂ is as defined below for formula I, and wherein (X) is the site of a covalent bond of T to X, and X is as defined below for formula I; L₇ is —CH₂— or —O—; U₁ is —CR₁₀₁R₁₀₂— or —C(═O)—; R₁₀₀ is lower alkyl; R₁₀₁ and R₁₀₂ are each independently hydrogen, lower alkyl or substituted lower alkyl; xx is 2 or 3; yy is 1 or 2; zz is 1 or 2; and aaa is 0 or 1.

Macrocyclic compounds of the present invention further include those of formula I, formula II and/or formula III:

##STR00010##
or an optical isomer, enantiomer, diastereomer, racemate or stereochemical mixture thereof.

wherein:

R₁ is hydrogen or the side chain of an amino acid, or alternatively R₁ and R₂ together form a 4-, 5-, 6-, 7- or 8-membered ring, optionally comprising an O, S or N atom in the ring, wherein the ring is optionally substituted with R₈ as defined below, or alternatively R₁ and R₉ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or additional N atom in the ring, wherein the ring is optionally substituted with R₈ as defined below;

R₂ is hydrogen or the side chain of an amino acid, or alternatively R₁ and R₂ together form a 4-, 5-, 6-, 7- or 8-membered ring, optionally comprising an O, S or N atom in the ring, wherein the ring is optionally substituted with R₈ as defined below; or alternatively R₂ and R₉ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or additional N atom in the ring, wherein the ring is optionally substituted with R₈ as defined below;

R₃ is hydrogen or the side chain of an amino acid, or alternatively R₃ and R₄ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O or S atom in the ring, wherein the ring is optionally substituted with R₈ as defined below, or alternatively, R₃ and R₇ or R₃ and R₁₁ together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic ring, optionally comprising an O, S or additional N atom in the ring, wherein the ring is optionally substituted with R₈ as defined below;

R₄ is hydrogen or the side chain of an amino acid, or alternatively R₄ and R₃ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O or S atom in the ring, wherein the ring is optionally substituted with R₈ as defined below, or alternatively R₄ and R₇ or R₄ and R₁₁ together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic ring, optionally comprising an O, S or additional N atom in the ring, wherein the ring is optionally substituted with R₈ as defined below;

R₅ and R₆ are each independently hydrogen or the side chain of an amino acid or alternatively R₅ and R₆ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or N atom in the ring, wherein the ring is optionally substituted with R₈ as defined below;

R₇ is hydrogen, lower alkyl, substituted lower alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, or a substituted heterocyclic group, or alternatively R₃ and R₇ or R₄ and R₇ together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic ring optionally comprising an O, S or additional N atom in the ring, wherein the ring is optionally substituted with R₈ as described below;

R₈ is substituted for one or more hydrogen atoms on the 3-, 4-, 5-, 6-, 7- or 8-membered-ring structure and is independently selected from the group consisting of alkyl, substituted cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, halogen, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and sulfonamido, or, alternatively, R₈ is a fused cycloalkyl, a substituted fused cycloalkyl, a fused heterocyclic, a substituted fused heterocyclic, a fused aryl, a substituted fused aryl, a fused heteroaryl or a substituted fused heteroaryl ring when substituted for hydrogen atoms on two adjacent atoms:

X is O, NR₉ or N(R₁₀)₂⁺;

• • wherein R₉ is hydrogen, lower alkyl, substituted lower sulfonyl, sulfonamido or amidino and R₁₀ is hydrogen, lower alkyl, or substituted lower alkyl, or alternatively R₉ and R₁ together form a 3-. 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or additional N atom in the ring, wherein the ring is optionally substituted with R₈ as defined above;

Z₁ is O or NR₁₁,

• • wherein R₁₁ is hydrogen, lower alkyl, or substituted lower alkyl, or alternatively R₃ and R₁₁ or R₄ and R₁₁ together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic ring, optionally comprising an O, S or additional N atom in the ring, wherein the ring is optionally substituted with R₈ as defined above;

Z₂ is O or NR₁₂, wherein R₁₂ is hydrogen, lower alkyl, or substituted lower alkyl;

m, n and p are each independently 0, 1 or 2;

T is a bivalent radical of formula IV:
—U—(CH₂)_d—W—Y-Z-(CH₂)_e—  (IV)

• • wherein d and e are each independently 0, 1, 2, 3, 4 or 5; Y and Z are each optionally present; U is —CR₂₁R₂₂— or —C(═O)— and is bonded to X of formula I; W, Y and Z are each independently selected from the group consisting of —O—, —NR₂₃—, —S—, —SO—, —SO₂—, —C(═O)—, —O—C(═O)—, —C(═O)NH—, —NH—C(═O)—, —SO₂—NH—, —NH—SO₂—, —CR₂₄R₂₅—, —CH═CH— with the configuration Z or E, —C≡C— and the ring structures below:

##STR00011##

• • • wherein G₁ and G₂ are each independently a covalent bond or a bivalent radical selected from the group consisting of —O—, —NR₃₉—, —S—, —SO—, —SO₂—, —C(═O)—, —C(═O)—, —O—C (═O)—, —C(═O)NH—, —NH—C(═O)—, —SO₂—NH—, —NH—SO₂—, —CR₄₀R₄₁—, —CH═CH— with the configuration Z or E, and —C≡C—; with G_I being bonded closest to the group U; wherein any carbon atom in the rings not otherwise defined, is optionally replaced by N, with the proviso that the ring cannot contain more than four N atoms; K₁, K₂, K₃, K₄ and K₅ are each independently O, NR₄₂ or S, wherein R₄₂ is as defined below;
    • R₂₁ and R₂₂ are each independently hydrogen, lower alkyl, or substituted lower alkyl, or alternatively R₂, and R₂₂ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N, wherein the ring is optionally substituted with R₈ as defined above;
    • R₂₃, R₃₉ and R₄₂ are each independently hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, formyl, acyl, carboxyalkyl, carboxyaryl, amido, amidino, sulfonyl or sulfonamido;
    • R₂₄ and R₂₅ are each independently hydrogen, lower alkyl, substituted lower alkyl, R_AA, wherein R_AA is a side chain of an amino acid such as a standard or unusual amino acid, or alternatively R₂₄ and R₂₅ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N; or alternatively one of R₂₄ or R₂₅ is hydroxy, alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino while the other is hydrogen, lower alkyl or substituted lower alkyl, except when the carbon to which R₂₄ and R₂₅ are bonded is also bonded to another heteroatom;
    • R₂₆, R₃₁, R₃₅ and R₃₈ are each optionally present and, when present, are substituted for one or more hydrogen atoms on the indicated ring and each is independently selected from the group consisting of halogen, trifluoromethyl, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, cyano, nitro, mercapto, sulfinyl, sulfonyl and sulfonamido;
    • R₂₇ is optionally present and is substituted for one or more hydrogen atoms on the indicated ring and each is independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and sulfonamido;
    • R₂₈, R₂₉, R₃₀, R₃₂, R₃₃, R₃₄, R₃₆ and R₃₇ are each optionally present and, when no double bond is present to the carbon atom to which it is bonded in the ring, two groups are optionally present, and when present, is substituted for one hydrogen present in the ring, or when no double bond is present to the carbon atom to which it is bonded in the ring, is substituted for one or both of the two hydrogen atoms present on the ring and each is independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl, sulfonamido and, only if a double bond is present to the carbon atom to which it is bonded, halogen; and
    • R₄₀ and R₄₁ are each independently hydrogen, lower alkyl, substituted lower alkyl, R_AA as defined above, or alternatively R₄₀ and R₄₁, together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N wherein the ring is optionally substituted with R₈ as defined above, or alternatively one of R₄₀ and R₄₁ is hydroxy, alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino, while the other is hydrogen, lower alkyl or substituted lower alkyl, except when the carbon to which R₄₀ and R₄₁ are bonded is also bonded to another heteroatom:
  • with the proviso that T is not an amino acid residue, dipeptide fragment, tripeptide fragment or higher order peptide fragment comprising standard amino acids;

##STR00012##
or an optical isomer, enantiomer, diastereomer, racemate or stereochemical mixture thereof,
wherein:

R₅₀ is —(CH₂)_ssCH₃, —CH(CH₃)(CH₂)_ttCH₃, —(CH₂)_uuCH(CH₃)₂, —C(CH₃)₃, —(CHR₅₅)_vv—R₅₆, or —(CH(OR₅₇)CH₃, wherein ss is 1, 2 or 3; tt is 1 or 2; uu is 0, 1 or 2; and vv is 0, 1, 2, 3 or 4; R₅₅ is hydrogen or C₁-C₄ alkyl; R₅₆ is amino, hydroxy, alkoxy, cycloalkyl or substituted cycloalkyl; and R₅₇ is hydrogen, alkyl, acyl, amino acyl, sulfonyl, carboxyalkyl or carboxyaryl;

R₅₁ is hydrogen, C₁-C₄ alkyl or C₁-C₄ alkyl substituted with hydroxy or alkoxy;

R₅₂ is —(CHR₅₈)_wwR₅₉, wherein ww is 0, 1, 2 or 3; R₅₈ is hydrogen, C₁-C₄ alkyl, amino, hydroxy or alkoxy; R₅₉ is aryl, substituted aryl, heteroaryl, substituted heteroaryl, cycloalkyl or substituted cycloalkyl;

R₅₃ is hydrogen or C₁-C₄ alkyl;

X₂ is O, NR₉ or N(R₁₀)₂⁺;

• • wherein R₉ is hydrogen, lower alkyl, substituted lower alkyl, sulfonyl, sulfonamido or amidino and R₁₀ is hydrogen, lower alkyl, or substituted lower alkyl;

Z₅ is O or NR₁₂, wherein R₁₂ is hydrogen, lower alkyl, or substituted lower alkyl; and

T₂ is a bivalent radical of formula V:
—U_a—(CH₂)_d—W_a—Y_a-Z_a-(CH₂)_e—  (V)

• • wherein d and e are independently 0, 1, 2, 3, 4 or 5; Y_a and Z_a are each optionally present; U_a is —CR₆₀R₆₁— or —C(═O)— and is bonded to X₂ of formula II, wherein R₆₀ and R₆₁ are each independently hydrogen, lower alkyl, or substituted lower alkyl, or alternatively R₂₁ and R₂₂ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N, wherein the ring is optionally substituted with R₈ as defined above; W_a, Y_a and Z_a are each independently selected from the group consisting of: —O—, —NR₆₂—, —S—, —SO—, —SO₂—, —C(═O)—O—, —C(═O)—, —C(═O)—NH—, —NH—C(═O)—, —SO₂—NH—, —NH—SO₂—, —CR₆₃R₆₄—, —CH═CH— with the configuration Z or E, —C≡C—, and the ring structures depicted below:

##STR00013##

• • • wherein G₁ and G₂ are as defined above, and wherein any carbon atom in the ring is optionally replaced by N, with the proviso that the aromatic ring cannot contain more than four N atoms and the cycloalkyl ring cannot contain more than two N atoms;
      • R₆₂ is hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, formyl, acyl, carboxyalkyl, carboxyaryl, amido, amidino, sulfonyl or sulfonamido;
      • R₆₃ and R₆₄ are each independently hydrogen, lower alkyl, substituted lower alkyl or R_AA; or alternatively R₆₃ and R₆₄ together form a 3- to 12-membered cyclic ring optionally comprising one or more heteroatoms selected from the group consisting of O, S and N; or alternatively one of R₆₃ and R₆₄ is hydroxy, alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino, while the other is hydrogen, lower alkyl or substituted lower alkyl, except when the carbon to which R₆₃ and R₆₄ are bonded is also bonded to another heteroatom; and R_AA indicates the side chain of a standard or unusual amino acid;
      • R₆₅ and R₆₈ are each optionally present, and, when present are substituted for one or more hydrogen atoms on the ring and each is independently halogen, trifluoromethyl, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, cyano, nitro, mercapto, sulfinyl, sulfonyl or sulfonamido;
      • R₆₆ and R₆₇ are each optionally present, and when no double bond is present to the carbon atom to which it is bonded in the ring, two groups are optionally present, and, when present, each is substituted for one hydrogen present in the ring, or when no double bond is present to the carbon atom to which it is bonded in the ring, is substituted for one or both of the two hydrogen atoms present on the ring and each is independently alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl, sulfonamido and, only if a double bond is present to the carbon atom to which it is bonded, halogen;
      • R₆₉ is optionally present, and when present is substituted for one or more hydrogen atoms on the ring and each is independently alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl or sulfonamido;
      • K₆ is O or S; and
      • ff is 1, 2, 3, 4 or 5;

with the proviso that T₂ is not an amino acid residue, dipeptide fragment, tripeptide fragment or higher order peptide fragment comprising standard amino acids; or

##STR00014##
or an optical isomer, enantiomer, diastereomer, racemate or stereochemical mixture thereof, wherein:

R₇₀ is hydrogen, C₁-C₄ alkyl or alternatively R₇₀ and R₇₁ together form a 4-, 5-, 6-, 7- or 8-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R_8a as defined below;

R₇₁ is, hydrogen, —(CH₂)_aaCH₃, —CH(CH₃)(CH₂)_bbCH₃, —(CH₂)_ccCH(CH₃)₂, —(CH₂)_dd—R₇₆ or —CH(OR₇₇) CH₃ or, alternatively R₇₁ and R₇₀ together form a 4-, 5-, 6-, 7- or 8-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R_8a as defined below; wherein aa is 0, 1, 2, 3, 4 or 5; bb is 1, 2 or 3; cc is 0, 1, 2 or 3; and dd is 0, 1, 2, 3 or 4; R₇₆ is aryl, substituted aryl, heteroaryl, substituted heteroaryl, cycloalkyl or substituted cycloalkyl; R₇₇ is hydrogen, alkyl, acyl, amino acyl, sulfonyl, carboxyalkyl or carboxyaryl;

R₇₂ is C₁-C₄ alkyl; or alternatively R₇₂ and R₇₃ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O or S atom in the ring, wherein the ring is optionally substituted with R_8b as defined below;

R₇₃ is hydrogen, or alternatively R₇₃ and R₇₂ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or N atom in the ring, wherein the ring is optionally substituted with R_8b as defined below;

R₇₄ is hydrogen or C₁-C₄ alkyl or alternatively R₇₄ and R₇₅ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R_8c as defined below;

R₇₅ is —(CHR₇₈)R₇₉ or alternatively R₇₅ and R₇₄ together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, N or S atom in the ring, wherein the ring is optionally substituted with R₈, as defined below: wherein R₇₈ is hydrogen, C₁-C₄ alkyl, amino, hydroxy or alkoxy, and R₇₉ is selected from the group consisting of the following structures:

##STR00015##

• • wherein E₁, E₂, E₃, E₄ and E₅ are each optionally present and when present are each independently selected from the group consisting of halogen, trifluoromethyl, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, cyano, sulfinyl, sulfonyl and sulfonamido, and represent substitution at one or more available positions on the monocyclic or bicyclic aromatic ring, wherein said substitution is made with the same or different selected group member, and J₁ and J₂ are each independently O or S;

R_8a, R_8b and R_8c are each independently substituted for one or more hydrogen atoms on the 3-, 4-, 5-, 6-, 7- or 8-membered ring structure and are independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a substituted heterocyclic group, aryl, substituted aryl, heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, halogen, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and sulfonamido, or, alternatively, R_8a, R_8b and R_8c are each independently a fused cycloalkyl, a substituted fused cycloalkyl, a fused heterocyclic, a substituted fused heterocyclic, a fused aryl, a substituted fused aryl, a fused heteroaryl or a substituted fused heteroaryl ring when substituted for hydrogen atoms on two adjacent atoms;

X₃ is O, NR₉ or N(R₁₀)₂⁺;

• • wherein R₉ is hydrogen, lower alkyl, substituted lower alkyl, sulfonyl, sulfonamido or amidino and R₁₀ is hydrogen, lower alkyl, or substituted lower alkyl;

Z₁₀ is O or NR₁₂, wherein R₁₂ is hydrogen, lower alkyl, or substituted lower alkyl; and

T₃ is the same as defined for T₂ with the exception that U_a is bonded to X₃ of formula III.

In some embodiments of the present invention, the compound can have one of the following structures:

##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020## ##STR00021##
or an optical isomer, enantiomer, diastereomer, racemate or stereochemical mixture thereof.

The present invention includes isolated compounds. An isolated compound refers to a compound that, in some embodiements, comprises at least 10%, at least 25%, at least 50% or at least 70% of the compounds of a mixture. In some embodiments, the compound, pharmaceutically acceptable salt thereof or pharmaceutical composition containing the compound exhibits a statistically significant binding and/or antagonist activity when tested in biological assays at the human ghrelin receptor.

In the case of compounds, salts, or solvates that are solids, it is understood by those skilled in the art that the inventive compounds, salts, and solvates may exist in different crystal or polymorphic forms, all of which are intended to be within the scope of the present invention and specified formulas.

The compounds of formula I, II and/or III disclosed herein have asymmetric centers. The inventive compounds may exist as single stereoisomers, racemates, and/or mixtures of enantiomers and/or diastereomers. All such single stereoisomers, racemates, and mixtures thereof are intended to be within the scope of the present invention. In particular embodiments, however, the inventive compounds are used in optically pure form. The terms “S” and “R” configuration as used herein are as defined by the IUPAC 1974 Recommendations for Section E, Fundamentals of Stereochemistry (Pure Appl. Chem. 1976, 45, 13-30.)

Unless otherwise depicted to be a specific orientation, the present invention accounts for all stereoisomeric forms. The compounds may be prepared as a single stereoisomer or a mixture of stereoisomers. The non-racemic forms may be obtained by either synthesis or resolution. The compounds may, for example, be resolved into the component enantiomers by standard techniques, for example formation of diastereomeric pairs via salt formation. The compounds also may be resolved by covalently bonding to a chiral moiety. The diastereomers can then be resolved by chromatographic separation and/or crystallographic separation. In the case of a chiral auxiliary moiety, it can then be removed. As an alternative, the compounds can be resolved through the use of chiral chromatography. Enzymatic methods of resolution could also be used in certain cases.

As generally understood by those skilled in the art, an “optically pure” compound is one that contains only a single enantiomer. As used herein, the term “optically active” is intended to mean a compound comprising at least a sufficient excess of one enantiomer over the other such that the mixture rotates plane polarized light. Optically active compounds have the ability to rotate the plane of polarized light. The excess of one enantiomer over another is typically expressed as enantiomeric excess (e.e.). In describing an optically active compound, the prefixes D and L or R and S are used to denote the absolute configuration of the molecule about its chiral center(s). The prefixes “d” and “l” or (+) and (−) are used to denote the optical rotation of the compound (i.e., the direction in which a plane of polarized light is rotated by the optically active compound). The “l” or (−) prefix indicates that the compound is levorotatory (i.e., rotates the plane of polarized light to the left or counterclockwise) while the “d” or (+) prefix means that the compound is dextrarotatory (i.e., rotates the plane of polarized light to the right or clockwise). The sign of optical rotation, (−) and (+), is not related to the absolute configuration of the molecule, R and S.

A compound of the invention having the desired pharmacological properties will be optically active and, can be comprised of at least 90% (80% e.e.), at least 95% (90% e.e.), at least 97.5% (95% e.e.) or at least 99% (98% e.e.) of a single isomer.

Likewise, many geometric isomers of double bonds and the like can also be present in the compounds disclosed herein, and all such stable isomers are included within the present invention unless otherwise specified. Also included in the invention are tautomers and rotamers of formula I, II and/or III.

The use of the following symbols at the right refers to substitution of one or more hydrogen atoms of the indicated ring

##STR00022##
with the defined substituent R.

The use of the following symbol indicates a single bond or an optional double bond: ═

Embodiments of the present invention further provide intermediate compounds formed through the synthetic methods described herein to provide the compounds of formula I, II and/or III. The intermediate compounds may possess utiltity as a therapeutic agent for the range of indications described herein and/or a reagent for further synthesis methods and reactions.

2. Synthetic Methods

The compounds of formula I, II and/or II can be synthesized using traditional solution synthesis techniques or solid phase chemistry methods. In either, the construction involves four phases: first, synthesis of the building blocks comprising recognition elements for the biological target receptor, plus one tether moiety, primarily for control and definition of conformation. These building blocks are assembled together, typically in a sequential fashion, in a second phase employing standard chemical transformations. The precursors from the assembly are then cyclized in the third stage to provide the macrocyclic structures. Finally, the post-cyclization processing fourth stage involving removal of protecting groups and optional purification provides the desired final compounds. Synthetic methods for this general type of macrocyclic structure are described in Intl. Pat. Appls, WO 01/25257, WO 2004/111077, WO 2005/012331 and WO 2005/012332, including purification procedures described in WO 2004/111077 and WO 2005/012331.

In some embodiments of the present invention, the macrocyclic compounds of formula I, II and/or III may be synthesized using solid phase chemistry on a soluble or insoluble polymer matrix as previously defined. For solid phase chemistry, a preliminary stage involving the attachment of the first building block, also termed “loading,” to the resin must be performed. The resin utilized for the present invention preferentially has attached to it a linker moiety, L. These linkers are attached to an appropriate free chemical functionality, usually an alcohol or amine, although others are also possible, on the base resin through standard reaction methods known in the art, such as any of the large number of reaction conditions developed for the formation of ester or amide bonds. Some linker moieties for the present invention are designed to allow for simultaneous cleavage from the resin with formation of the macrocycle in a process generally termed “cyclization-release.” (van Maarseveen, J. H. Solid phase synthesis of heterocycles by cyclization/cleavage methodologies. Comb. Chem. High Throughput Screen. 1998, 1, 185-214; Ian W. James, Linkers for solid phase organic synthesis. Tetrahedron 1999, 55, 4855-4946; Eggenweiler, H.-M. Linkers for solid-phase synthesis of small molecules: coupling and cleavage techniques. Drug Discovery Today 1998, 3, 552-560; Backes, B. J.; Ellman, J. A. Solid support linker strategies. Curr. Opin. Chem. Biol. 1997, 1, 86-93. Of particular utility in this regard for compounds of the invention is the 3-thiopropionic acid linker. (Hojo, H.; Aimoto, S. Bull. Chem. Soc. Jpn. 1991, 64, 111-117; Zhang, L.; Tam, J. J. Am. Chem. Soc. 1999, 121, 3311-3320.)

Such a process provides material of higher purity as only cyclic products are released from the solid support and minimal contamination with the linear precursor occurs as would happen in solution phase. After sequential assembly of all the building blocks and tether into the linear precursor using known or standard reaction chemistry, base-mediated intramolecular attack on the carbonyl attached to this linker by an appropriate nucleophilic functionality that is part of the tether building block results in formation of the amide or ester bond that completes the cyclic structure as shown (Scheme 1). An analogous methodology adapted to solution phase can also be applied as would likely be preferable for larger scale applications.

##STR00023##

Although this description accurately represents the pathway for one of the methods of the present invention, the thioester strategy, another method of the present invention, that of ring-closing metathesis (RCM), proceeds through a modified route where the tether component is actually assembled during the cyclization step. However, in the RCM methodology as well, assembly of the building blocks proceeds sequentially, followed by cyclization (and release from the resin if solid phase). An additional post-cyclization processing step is required to remove particular byproducts of the RCM reaction, but the remaining subsequent processing is done in the same manner as for the thioester or analogous base-mediated cyclization strategy.

Moreover, it will be understood that steps including the methods provided herein may be performed independently or at least two steps may be combined. Additionally, steps including the methods provided herein, when performed independently or combined, may be performed at the same temperature or at different temperatures without departing from the teachings of the present invention.

Novel macrocyclic compounds of the present invention include those formed by a novel process including cyclization of a building block structure to form a macrocyclic compound comprising a tether component described herein. Accordingly, the present invention provides methods of manufacturing the compounds of the present invention comprising (a) assembling building block structures, (b) chemically transforming the building block structures, (c) cyclizing the building block structures including a tether component, (d) removing protecting groups from the building block structures, and (e) optionally purifiying the product obtained from step (d). In some embodiments, assembly of the building block structures may be sequential. In further embodiments, the synthesis methods are carried out using traditional solution synthesis techniques or solid phase chemistry techniques.

A. Amino Acids

Amino acids, Boc- and Fmoc-protected amino acids and side chain protected derivatives, including those of N-methyl and unnatural amino acids, were obtained from commercial suppliers [for example Advanced ChemTech (Louisville, Ky., USA), Bachem (Bubendorf, Switzerland), ChemImpex (Wood Dale, Ill., USA), Novabiochem (subsidiary of Merck KGaA, Darmstadt, Germany), PepTech (Burlington, Mass., USA), Synthetech (Albany, Oreg., USA)] or synthesized through standard methodologies known to those in the art. Ddz-amino acids were either obtained commercially from Orpegen (Heidelberg, Germany) or Advanced ChemTech (Louisville, Ky., USA) or synthesized using standard methods utilizing Ddz-OPh or Ddz-N₃. (Birr, C.; Lochinger, W.; Stahnke, G.; Lang, P. The α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl (Ddz) residue, an N-protecting group labile toward weak acids and irradiation. Justus Liebigs Ann. Chem. 1972, 763, 162-172.) Bts-amino acids were synthesized by known methods. (Vedejs, E.; Lin, S.; Klapara, A.; Wang, J. “Heteroarene-2-sulfonyl Chlorides (BtsCl, ThsCl): Reagents for Nitrogen Protection and >99% Racemization-Free Phenylglycine Activation with SOCl₂.” J. Am. Chem. Soc. 1996, 118, 9796-9797. Also WO 01/25257, WO 2004/111077) N-Alkyl amino acids, in particular N-methyl amino acids, are commercially available from multiple vendors (Bachem, Novabiochem, Advanced ChemTech, ChemImpex). In addition, N-alkyl amino acid derivatives were accessed via literature methods. (Hansen, D. W., Jr.: Pilipauskas, D. J. Org. Chem. 1985, 50, 945-950.)

B. Tethers

Tethers were obtained from the methods previously described in Intl. Pat. Appl. WO 01/25257, WO 2004/111077, WO 2005/012331 and U.S. Provisional Patent Application Ser. No.

Results are depicted in the graph in FIG. 8 and indicate that Compound 298 at 100 μg/kg (i.v. n=5) significantly improves postoperative ileus in comparison to POI+vehicle treated rats. Further results are presented in the Examples below,

G. Growth Hormone Response to Test Compounds

The compounds of the invention likewise can be tested in a number of animal models for their effect on GH release. For example, rats (Bowers, C. Y.; Momany, F.; Reynolds, G. A.; Chang, D.; Hong, A.; Chang, K. Endocrinology 1980, 106, 663-667), dogs (Hickey, G.; Jacks, T.; Judith, F.; Taylor, J.; Schoen, W. R.; Krupa, D.; Cunningham, P.; Clark, J.; Smith, R. G. Endocrinology 1994, 134, 695-701; Jacks, T.; Hickey, G.; Judith, F.; Taylor, J.; Chen, H.; Krupa, D.; Feeney, W.; Schoen, W. R.; Ok, D.; Fisher, M.; Wyvratt, M.; Smith, R. J. Endocrinology 1994, 143, 399-406; Hickey, G. J.; Jacks, T. M.; Schleim, K. D.; Frazier, E.; Chen, H. Y.; Krupa, D.; Feeney, W.; Nargund, R. P.; Patchett, A. A.; Smith, R. G. J. Endocrinol. 1997, 152, 183-192), and pigs (Chang, C. H.; Rickes, E. L.; Marsilio, F.; McGuire, L.; Cosgrove, S.; Taylor, J.; Chen, H. Y.; Feighner, S.; Clark, J. N.; Devita, R.; Schoen, W. R.; Wyvratt, M.; Fisher, M.; Smith, R. G.; Hickey, G. Endocrinology 1995, 136, 1065-1071; Peschke, B.; Hanse, B. S. Bioorg. Med. Chem. Lett. 1999, 9, 1295-1298) have all been successfully utilized for the in vivo study of the effects of GHS and would likewise be applicable for investigation of the effect of ghrelin agonists on GH levels. The measurement of ghrelin of GH levels in plasma after appropriate administration of compounds of the invention can be performed using radioimmunoassay via standard methods known to those in the art. (Deghenghi, R.; et al. Life Sciences 1994, 54, 1321-1328.) Binding to tissue can be studied using whole body autoradiography after dosing of an animal with test substance containing a radioactive label. (Ahnfelt-Rønne, I.; Nowak, J.; Olsen, U. B. Do growth hormone-releasing peptides act as ghrelin secretagogues? Endocrine 2001, 14, 133-135.)

The following method is employed to determine the temporal pattern and magnitude of the growth hormone (GH) response to test compounds, administered either systemically or centrally. Results for compound 298 demonstrating its lack of effect on GH release are presented in FIG. 9. Compound 25 gave similar results. Further results are presented in the Examples below.

Dosing and Sampling Procedures for In Vivo Studies of GH Release

Adult male Sprague Dawley rats (225-300 g) were purchased from Charles River Canada (St. Constant, Canada) and individually housed on a 12-h light, 12-h dark cycle (lights on, time: 0600-1800) in a temperature (22±1° C.)- and humidity-controlled room. Purina rat chow (Ralston Purina Co., St. Louis, Mo.) and tap water were freely available. For these studies, chronic intracerebroventricular (icy) and intracardiac venous cannulas were implanted under sodium pentobarbital (50 mg/kg, ip) anesthesia using known techniques. The placement of the icy cannula was verified by both a positive drinking response to icy carbachol (100 ng/110 μl) injection on the day after surgery and methylene blue dye at the time of sacrifice. After surgery, the rats were placed directly in isolation test chambers with food and water freely available until body weight returned to preoperative levels (usually within 5-7 d). During this time, the rats were handled daily to minimize any stress associated with handling on the day of the experiment. On the test day, food was removed 1.5 h before the start of sampling and was returned at the end. Free moving rats were iv injected with either test sample at various levels (3, 30, 300, 1000 μg/kg) or normal saline at two different time points during a 6-h sampling period. The times 1100 and 1300 were chosen because they reflect typical peak and trough periods of GH secretion, as previously documented. The human ghrelin peptide (5 μg, Phoenix Pharmaceuticals, Inc., Belmont, Calif.) was used as a positive control in the experiments and was diluted in normal saline just before use. To assess the central actions of test compounds on pulsatile GH release, a 10-fold lower dose of the test sample or normal saline was administered icy at the same time points, 1100 and 1300. Blood samples (0.35 mL) were withdrawn every 15 min over the 6-h sampling period (time: 1000-1600) from all animals. To document the rapidity of the GH response to the test compound, an additional blood sample was obtained 5 min after each injection. All blood samples were immediately centrifuged, and plasma was separated and stored at −20° C. for subsequent GH assay. To avoid hemodynamic disturbance, the red blood cells were resuspended in normal saline and returned to the animal after removal of the next blood sample. All animal studies were conducted under procedures approved by an animal care oversight committee.

GH Assay Method

Plasma GH concentrations were measured in duplicate by double antibody RIA using materials supplied by the NIDDK Hormone Distribution Program (Bethesda, Md.). The averaged plasma GH values for 5-6 rats per group are reported in terms of the rat GH reference preparation. The standard curve was linear within the range of interest; the least detectable concentration of plasma GH under the conditions used was approximately 1 ng/mL. All samples with values above the range of interest were reassayed at dilutions ranging from 1:2 to 1:10. The intra- and interassay coefficients of variation were acceptable for duplicate samples of pooled plasma containing a known GH concentration.

4. Pharmaceutical Compositions

The macrocyclic compounds of the present invention or pharmacologically acceptable salts thereof according to the invention may be formulated into pharmaceutical compositions of various dosage forms. To prepare the pharmaceutical compositions of the invention, one or more compounds, including optical isomers, enantiomers, diastereomers, racemates or stereochemical mixtures thereof, or pharmaceutically acceptable salts thereof as the active ingredient is intimately mixed with appropriate carriers and additives according to techniques known to those skilled in the art of pharmaceutical formulations.

A pharmaceutically acceptable salt refers to a salt form of the compounds of the present invention in order to permit their use or formulation as pharmaceuticals and which retains the biological effectiveness of the free acids and bases of the specified compound and that is not biologically or otherwise undesirable. Examples of such salts are described in Handbook of Pharmaceutical Salts: Properties, Selection, and Use, Wermuth, C. G. and Stahl, P. H. (eds.), Wiley-Verlag Helvetica Acta, Züirich, 2002 [ISBN 3-906390-26-8]. Examples of such salts include alkali metal salts and addition salts of free acids and bases. Examples of pharmaceutically acceptable salts, without limitation, include sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, phosphates, monohydrogenphosphates, dihydrogenphosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, propionates, decanoates, caprylates, acrylates, formates, isobutyrates, caproates, heptanoates, propiolates, oxalates, malonates, succinates, suberates, sebacates, fumarates, maleates, butyne-1,4-dioates, hexyne-1,6-dioates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates, citrates, lactates, γ-hydroxybutyrates, glycollates, tartrates, methanesulfonates, ethane sulfonates, propanesulfonates, toluenesulfonates, naphthalene-1-sulfonates, naphthalene-2-sulfonates, and mandelates.

If an inventive compound is a base, a desired salt may be prepared by any suitable method known to those skilled in the art, including treatment of the free base with an inorganic acid, such as, without limitation, hydrochloric acid, hydrobromic acid, hydroiodic, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, and the like, or with an organic acid, including, without limitation, formic acid, acetic acid, propionic acid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonic acid, pyruvic acid, oxalic acid, stearic acid, ascorbic acid, glycolic acid, salicylic acid, pyranosidyl acid, such as glucuronic acid or galacturonic acid, alpha-hydroxy acid, such as citric acid or tartaric acid, amino acid, such as aspartic acid or glutamic acid, aromatic acid, such as benzoic acid or cinnamic acid, sulfonic acid, such as p-toluene-sulfonic acid, methanesulfonic acid, ethanesulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, cyclohexyl-aminosulfonic acid or the like.

If an inventive compound is an acid, a desired salt may be prepared by any suitable method known to the art, including treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary, or tertiary); an alkali metal or alkaline earth metal hydroxide; or the like. Illustrative examples of suitable salts include organic salts derived from amino acids such as glycine, lysine and arginine; ammonia; primary, secondary, and tertiary amines such as ethylenediamine, N,N′-dibenzylethylenediamine, diethanolamine, choline, and procaine, and cyclic amines, such as piperidine, morpholine, and piperazine; as well as inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum, and lithium.

The carriers and additives used for such pharmaceutical compositions can take a variety of forms depending on the anticipated mode of administration. Thus, compositions for oral administration may be, for example, solid preparations such as tablets, sugar-coated tablets, hard capsules, soft capsules, granules, powders and the like, with suitable carriers and additives being starches, sugars, binders, diluents, granulating agents, lubricants, disintegrating agents and the like. Because of their ease of use and higher patient compliance, tablets and capsules represent the most advantageous oral dosage forms for many medical conditions.

Similarly, compositions for liquid preparations include solutions, emulsions, dispersions, suspensions, syrups, elixirs, and the like with suitable carriers and additives being water, alcohols, oils, glycols, preservatives, flavoring agents, coloring agents, suspending agents, and the like. Typical preparations for parenteral administration comprise the active ingredient with a carrier such as sterile water or parenterally acceptable oil including polyethylene glycol, polyvinyl pyrrolidone, lecithin, arachis oil or sesame oil, with other additives for aiding solubility or preservation may also be included. In the case of a solution, it can be lyophilized to a powder and then reconstituted immediately prior to use. For dispersions and suspensions, appropriate carriers and additives include aqueous gums, celluloses, silicates or oils.

The pharmaceutical compositions according to embodiments of the present invention include those suitable for oral, rectal, topical, inhalation (e.g., via an aerosol) buccal (e.g., sub-lingual), vaginal, topical (i.e., both skin and mucosal surfaces, including airway surfaces), transdermal administration and parenteral (e.g., subcutaneous, intramuscular, intradermal, intraarticular, intrapleural, intraperitoneal, intrathecal, intracerebral, intracranially, intraarterial, or intravenous), although the most suitable route in any given case will depend on the nature and severity of the condition being treated and on the nature of the particular active agent which is being used.

Compositions for injection will include the active ingredient together with suitable carriers including propylene glycol-alcohol-water, isotonic water, sterile water for injection (USP), emulPhorm™-alcohol-water, cremophor-EL™ or other suitable carriers known to those skilled in the art. These carriers may be used alone or in combination with other conventional solubilizing agents such as ethanol, propylene glycol, or other agents known to those skilled in the art.

Where the macrocyclic compounds of the present invention are to be applied in the form of solutions or injections, the compounds may be used by dissolving or suspending in any conventional diluent. The diluents may include, for example, physiological saline, Ringer's solution, an aqueous glucose solution, an aqueous dextrose solution, an alcohol, a fatty acid ester, glycerol, a glycol, an oil derived from plant or animal sources, a paraffin and the like. These preparations may be prepared according to any conventional method known to those skilled in the art.

Compositions for nasal administration may be formulated as aerosols, drops, powders and gels. Aerosol formulations typically comprise a solution or fine suspension of the active ingredient in a physiologically acceptable aqueous or non-aqueous solvent. Such formulations are typically presented in single or multidose quantities in a sterile form in a sealed container. The sealed container can be a cartridge or refill for use with an atomizing device. Alternatively, the sealed container may be a unitary dispensing device such as a single use nasal inhaler, pump atomizer or an aerosol dispenser fitted with a metering valve set to deliver a therapeutically effective amount, which is intended for disposal once the contents have been completely used. When the dosage form comprises an aerosol dispenser, it will contain a propellant such as a compressed gas, air as an example, or an organic propellant including a fluorochlorohydrocarbon or fluorohydrocarbon.

Compositions suitable for buccal or sublingual administration include tablets, lozenges and pastilles, wherein the active ingredient is formulated with a carrier such as sugar and acacia, tragacanth or gelatin and glycerin.

Compositions for rectal administration include suppositories containing a conventional suppository base such as cocoa butter.

Compositions suitable for transdermal administration include ointments, gels and patches.

Other compositions known to those skilled in the art can also be applied for percutaneous or subcutaneous administration, such as plasters.

Further, in preparing such pharmaceutical compositions comprising the active ingredient or ingredients in admixture with components necessary for the formulation of the compositions, other conventional pharmacologically acceptable additives may be incorporated, for example, excipients, stabilizers, antiseptics, wetting agents, emulsifying agents, lubricants, sweetening agents, coloring agents, flavoring agents, isotonicity agents, buffering agents, antioxidants and the like. As the additives, there may be mentioned, for example, starch, sucrose, fructose, dextrose, lactose, glucose, mannitol, sorbitol, precipitated calcium carbonate, crystalline cellulose, carboxymethylcellulose, dextrin, gelatin, acacia, EDTA, magnesium stearate, talc, hydroxypropylmethylcellulose, sodium metabisulfite, and the like.

In some embodiments, the composition is provided in a unit dosage form such as a tablet or capsule.

In further embodiments, the present invention provides kits including one or more containers comprising pharmaceutical dosage units comprising an effective amount of one or more compounds of the present invention.

The present invention further provides prodrugs comprising the compounds described herein. The term “prodrug” is intended to mean a compound that is converted under physiological conditions or by solvolysis or metabolically to a specified compound that is pharmaceutically active. The “prodrug” can be a compound of the present invention that has been chemically derivatized such that, (i) it retains some, all or none of the bioactivity of its parent drug compound, and (ii) it is metabolized in a subject to yield the parent drug compound. The prodrug of the present invention may also be a “partial prodrug” in that the compound has been chemically derivatized such that, (i) it retains some, all or none of the bioactivity of its parent drug compound, and (ii) it is metabolized in a subject to yield a biologically active derivative of the compound. Known techniques for derivatizing compounds to provide prodrugs can be employed. Such methods may utilize formation of a hydrolyzable coupling to the compound.

The present invention further provides that the compounds of the present invention may be administered in combination with a therapeutic agent used to prevent and/or treat metabolic and/or endocrine disorders, gastrointestinal disorders, cardiovascular disorders, obesity and obesity-associated disorders, central nervous system disorders, genetic disorders, hyperproliferative disorders and inflammatory disorders. Exemplary agents include analgesics (including opioid analgesics), anesthetics, antifungals, antibiotics, antiinflammatories (including nonsteroidal anti-inflammatory agents), anthelmintics, antiemetics, antihistamines, antihypertensives, antipsychotics, antiarthritics, antitussives, antivirals, cardioactive drugs, cathartics, chemotherapeutic agents (such as DNA-interactive agents, antimetabolites, tubulin-interactive agents, hormonal agents, and agents such as asparaginase or hydroxyurea), corticoids (steroids), antidepressants, depressants, diuretics, hypnotics, minerals, nutritional supplements, parasympathomimetics, hormones (such as corticotrophin releasing hormone, adrenocorticotropin, growth hormone releasing hormone, growth hormone, thyrptropin-releasing hormone and thyroid stimulating hormone), sedatives, sulfonamides, stimulants, sympathomimetics, tranquilizers, vasoconstrictors, vasodilators, vitamins and xanthine derivatives.

Subjects suitable to be treated according to the present invention include, but are not limited to, avian and mammalian subjects, and are preferably mammalian. Mammals of the present invention include, but are not limited to, canines, felines, bovines, caprins, equines, ovines, porcines, rodents (e.g. rats and mice), lagomorphs, primates, humans, and the like, and mammals in utero. Any mammalian subject in need of being treated according to the present invention is suitable. Human subjects are preferred. Human subjects of both genders and at any stage of development (i.e., neonate, infant, juvenile, adolescent, adult) can be treated according to the present invention.

Illustrative avians according to the present invention include chickens, ducks, turkeys, geese, quail, pheasant, ratites (e.g., ostrich) and domesticated birds (e.g., parrots and canaries), and birds in ovo.

The present invention is primarily concerned with the treatment of human subjects, but the invention can also be carried out on animal subjects, particularly mammalian subjects such as mice, rats, dogs, cats, livestock and horses for veterinary purposes, and for drug screening and drug development purposes.

In therapeutic use for treatment of conditions in mammals (i.e. humans or animals) for which a modulator, such as an agonist, of the ghrelin receptor is effective, the compounds of the present invention or an appropriate pharmaceutical composition thereof may be administered in an effective amount. Since the activity of the compounds and the degree of the therapeutic effect vary, the actual dosage administered will be determined based upon generally recognized factors such as age, condition of the subject, route of delivery and body weight of the subject. The dosage can be from about 0.1 to about 100 mg/kg, administered orally 1-4 times per day. In addition, compounds can be administered by injection at approximately 0.01-20 mg/kg per dose, with administration 1-4 times per day. Treatment could continue for weeks, months or longer. Determination of optimal dosages for a particular situation is within the capabilities of those skilled in the art.

5. Methods of Use

The compounds of formula I, II and/or III of the present invention can be used for the prevention and treatment of a range of medical conditions including, but not limited to, metabolic and/or endocrine disorders, gastrointestinal disorders, cardiovascular disorders, obesity and obesity-associated disorders, central nervous system disorders, genetic disorders, hyperproliferative disorders, inflammatory disorders and combinations thereof where the disorder may be the result of multiple underlying maladies. In particular embodiments, the disease or disorder is irritable bowel syndrome (IBS), non-ulcer dyspepsia, Crohn's disease, gastroesophogeal reflux disorders, constipation, ulcerative colitis, pancreatitis, infantile hypertrophic pyloric stenosis, carcinoid syndrome, malabsorption syndrome, diarrhea, diabetes including diabetes mellitus (type II diabetes), obesity, atrophic colitis, gastritis, gastric stasis, gastrointestinal dumping syndrome, postgastroenterectomy syndrome, celiac disease, an eating disorder or obesity. In other embodiments, the disease or disorder is congestive heart failure, ischemic heart disease or chronic heart disease. In still other embodiments, the disease or disorder is osteoporosis and/or frailty, congestive heart failure, accelerating bone fracture repair, metabolic syndrome, attenuating protein catabolic response, cachexia, protein loss, impaired or risk of impaired wound healing, impaired or risk of impaired recovery from burns, impaired or risk of impaired recovery from surgery, impaired or risk of impaired muscle strength, impaired or risk of impaired mobility, alterted or risk of altered skin thickness, impaired or risk of impaired metabolic homeostasis or impaired or risk of impaired renal homeostasis. In other embodiments, the disease or disorder involves facilitating neonatal development, stimulating growth hormone release in humans, maintenance of muscle strength and function in humans, reversal or prevention of frailty in humans, prevention of catabolic side effects of glucocorticoids, treatment of osteoporosis, stimulation and increase in muscle mass and muscle strength, stimulation of the immune system, acceleration of wound healing, acceleration of bone fracture repair, treatment of renal failure or insufficiency resulting in growth retardation, treatment of short stature, treatment of obesity and growth retardation, accelerating the recovery and reducing hospitalization of burn patients, treatment of intrauterine growth retardation, treatment of skeletal dysplasia, treatment of hypercortisolism, treatment of Cushing's syndrome, induction of pulsatile growth hormone release, replacement of growth hormone in stressed patients, treatment of osteochondrodysplasias, treatment of Noonans syndrome, treatment of schizophrenia, treatment of depression, treatment of Alzheimer's disease, treatment of emesis, treatment of memory loss, treatment of reproduction disorders, treatment of delayed wound healing, treatment of psychosocial deprivation, treatment of pulmonary dysfunction, treatment of ventilator dependency; attenuation of protein catabolic response, reducing cachexia and protein loss, treatment of hyperinsulinemia, adjuvant treatment for ovulation induction, stimulation of thymic development, prevention of thymic function decline, treatment of immunosuppressed patients, improvement in muscle mobility, maintenance of skin thickness, metabolic homeostasis, renal homeostasis, stimulation of osteoblasts, stimulation of bone remodeling, stimulation of cartilage growth, stimulation of the immune system in companion animals, treatment of disorders of aging in companion animals, growth promotion in livestock, and/or stimulation of wool growth in sheep.

According to a further aspect of the invention, there is provided a method for the treatment of post-operative ileus, cachexia (wasting syndrome), such as that caused by cancer, AIDS, cardiac disease and renal disease, gastroparesis, such as that resulting from type I or type II diabetes, other gastrointestinal disorders, growth hormone deficiency, bone loss, and other age-related disorders in a human or animal patient suffering therefrom, which method comprises administering to said patient an effective amount of at least one member selected from the compounds disclosed herein having the ability to modulate the ghrelin receptor. Other diseases and disorders treated by the compounds disclosed herein include short bowel syndrome, gastrointestinal dumping syndrome, postgastroenterectomy syndrome, celiac disease, and hyperproliferative disorders such as tumors, cancers, and neoplastic disorders, as well as premalignant and non-neoplastic or non-malignant hyperproliferative disorders. In particular, tumors, cancers, and neoplastic tissue that can be treated by the present invention include, but are not limited to, malignant disorders such as breast cancers, osteosarcomas, angiosarcomas, fibrosarcomas and other sarcomas, leukemias, lymphomas, sinus tumors, ovarian, uretal, bladder, prostate and other genitourinary cancers, colon, esophageal and stomach cancers and other gastrointestinal cancers, lung cancers, myelomas, pancreatic cancers, liver cancers, kidney cancers, endocrine cancers, skin cancers and brain or central and peripheral nervous (CNS) system tumors, malignant or benign, including gliomas and neuroblastomas.

In particular embodiments, the macrocyclic compounds of the present invention can be used to treat post-operative ileus. In other embodiments, the compounds of the present invention can be used to treat gastroparesis. In still other embodiments, the compounds of the present invention can be used to treat diabetic gastroparesis. In another embodiment, the compounds of the present invention can be used to treat opioid-induced bowel dysfunction. In further embodiments, the compounds of the present invention can be used to treat chronic intestinal pseudoobstruction.

The present invention further provides methods of treating a horse or canine for a gastrointestinal disorder comprising administering a therapeutically effective amount of a modulator having the structure of formula I, II and/or III. In some embodiments, the gastrointestinal disorder is ileus or colic.

As used herein, “treatment” is not necessarily meant to imply cure or complete abolition of the disorder or symptoms associated therewith.

The compounds of the present invention can further be utilized for the preparation of a medicament for the treatment of a range of medical conditions including, but not limited to, metabolic and/or endocrine disorders, gastrointestinal disorders, cardiovascular disorders, obesity and obesity-associated disorders, genetic disorders, hyperproliferative disorders and inflammatory disorders.

Further embodiments of the present invention will now be described with reference to the following examples. It should be appreciated that these examples are for the purposes of illustrating embodiments of the present invention, and do not limit the scope of the invention.

EXAMPLE 1

Synthesis of Tethers

A. Standard Procedure for the Synthesis of Tether T9

##STR01185##

Step T9-1: To a solution of 2-iodophenol (9-0, 200 g, 0.91 mol, 1.0 eq) in DMF (DriSolv®, 560 mL) is added sodium hydride 60% in mineral oil (3.64 g, 0.091 mol, 0.1 eq) by portions (hydrogen is seen to evolve). The reaction is heated for 1 h at 100° C. under nitrogen, then ethylene carbonate is added and the reaction mixture heated O/N at 100° C. The reaction is monitored by TLC (conditions: 25/75 EtOAc/hex; R_f: 0.15. detection: UV, CMA). The reaction mixture is allowed to cool, then the solvent evaporated under reduced pressure. The residual oil is diluted in Et₂O (1.5 L), then washed sequentially with 1 N sodium hydroxide (3×) and brine (2×), dried with MgSO₄, filtered and the filtrate evaporated under reduced pressure. The crude product is distilled under vacuum (200 μm Hg) at 110-115° C. to provide 9-1.

Step T9-2: A solution of 9-1 (45.1 g, 0.171 mol, 1.0 eq) and Ddz-propargylamine (9-A, synthesized by standard protection procedures, 59.3 g, 0.214 mol, 1.25 eq) in acetonitrile (DriSolv®, 257 mL) was degassed by passing argon through the solution for 10-15 min. To this was added Et₃N (85.5 mL, stirred O/N with CaH₂, then distilled) and the mixture was again purged by bubbling with argon, this time for 5 min. Recrystallized copper (I) iodide (1.14 g, 0.006 mol, 0.035 eq) and trans-dichloro-bis(triphenylphosphine) palladium (II) (Strem Chemicals, 3.6 g, 0.0051 mol, 0.03 eq) are added and the reaction mixture stirred for 4 h under argon at rt. After 5-10 min, the reaction mixture turned black. The reaction was monitored by TLC (conditions: 55/45 EtOAc/hex). When complete, the solvent was removed under reduced pressure until dryness, then the residual oil diluted with 1 L of a 15% DCM in Et₂O solution. The organic phase is washed with citrate buffer pH 4-5 (3×), saturated aqueous sodium bicarbonate (2×), and brine (1×), then dried with MgSO₄, filtered and the filtrate evaporated under reduced pressure. The crude product thus obtained is purified by a dry pack column starting with 30% EtOAc/Hex (4-8 L) then increasing by 5% EtOAc increments until 55% EtOAc/Hex to give 9-2 as a brown syrup (yield: 65.8 g, 93.2%).

Step T9-3: To a solution of Ddz-amino-alcohol 9-2 (65.8 g, 0.159 mol, 1.0 eq) in 95% ethanol under nitrogen was added Platinum (IV) oxide (3.6 g, 0.016 mol, 0.1 eq) and then hydrogen gas bubbled into the solution for 2 h. The mixture was stirred O/N, maintaining an atmosphere of hydrogen using a balloon. The reaction was monitored by ¹H NMR until completion. When the reaction is complete, nitrogen was bubbled for 10 min to remove the excess hydrogen. The solvent is evaporated under reduced pressure, then diluted with EtOAc, filtered through a silica gel pad and the silica washed with EtOAc until no further material was eluted as verified by TLC. (55/45 EtOAc/hex) The combined filtrates were concentrated under reduced pressure. The residue is diluted in DCM (500 mL) and 4 eq of scavenger resin was added and the suspension stirred O/N. For this latter step, any of three different resins were used. MP-TMT resin (Argonaut Technologies, Foster City, Calif., 0.73 mmol/g) is preferred, but others, for example, PS-TRIS (4.1 mmol/g) and Si-Triamine (Silicycle, Quebec City, QC, 1.21 mmol/g) can also be employed effectively. The resin was filtered and washed with DCM, the solvent evaporated under reduced pressure, then dried further under vacuum (oil pump) to provide the product. The yield of Ddz-T9 from 9-0 on a 65 g scale was 60.9 g (91%)

¹H NMR (CDCl₃): δ 7.19-7.01, (m, 2H), 6.92-9.83 (m, 2H), 6.53 (bs, 2H), 6.34 (t, 1H), 5.17 (bt, 1H), 4.08 (m, 2H), 3.98 (m, 2H), 3.79 (s, 6H), 3.01 (bq, 2H), 2.66 (t, 3H), 1.26 (bs, 8H);

¹³CNMR(CDCl₃): δ 160.9, 156.8, 155.6, 149.6, 130.4, 127.5, 121.2, 111.7, 103.2, 98.4, 80.0, 69.7, 61.6, 55.5, 40.3, 30.5, 29.3, 27.4 ppm.

Tether T9 can also be synthesized from another tether molecule by reduction as in step T9-3 or with other appropriate hydrogenation catalysts known to those in the art.

B. Standard Procedure for the Synthesis of Tether T33a T33b

##STR01186##

The construction to the (R)-isomer of this tether (T33a) was accomplished from 2-iodophenol (33-0) and (S)-methyl lactate (33-A). Mitsunobu reaction of 33-0 and 33-A proceeded with inversion of configuration in excellent yield to give 33-1. Reduction of the ester to the corresponding alcohol (33-2) also occurred in high yield and was followed by Sonagashira reaction with Ddz-propargylamine (33-B). The alkyne in the resulting coupling product, 33-3, was reduced with catalytic hydrogenation. Workup with scavenger resin provided the desired product, Ddz-T33a.

The synthesis of the (S)-enantiomer (Ddz-T33b) was carried out in an identical manner in comparable yield starting from (R)-methyl lactate (33-B)

##STR01187##
C. Standard Procedure for the Synthesis of Tether Precursor RCM-T_A1

##STR01188##

Step A1-1. To a solution of diol A 1-0 (50 g, 567 mmol, 1.0 eq) in CH₂Cl₂ (1.5 L) were added Et₃N (34.5 mL, 341 mmol, 0.6 eq) and DMAP (1.73 g, 14.2 mmol, 0.025 eq). TBDMSC1 (42.8 g, 284 mmol. 0.5 eq) in CH₂Cl₂ (100 mL) was added to this mixture at rt over 4 h with a syringe pump. The reaction was monitored by TLC [EtOAc/hexanes (30:70); detection: KMnO₄; R_f=0.39], which revealed starting material, mono-protected compound and di-protected compound. The mixture was stirred O/N, washed with H₂O, saturated NH₄Cl (aq) and brine, then dried over MgSO₄, filtered and evaporated under reduced pressure. The residue was purified by flash chromatography (EtOAc/hexanes, 30:70) to give the desired mono-protected alcohol A1-1 (yield: 31%).

Step A1-2. To a solution of alcohol A1-1 (26.5 g, 131 mmol, 1.0 eq) in THF (130 mL) at 0° C. was added PPh₃ (44.7 g, 170 mmol, 1.3 eq). A freshly prepared and titrated 1.3 M solution of HN₃ (149 mL, 157 mmol, 1.5 eq) was added slowly to this mixture, then DIAD (32 mL, 163 mmol, 1.25 eq) also added slowly. This was an exotheric reaction. The resulting mixture was stirred at 0° C. for 1 h with monitoring of the reaction by TLC [EtOAc/hexanes (30:70); detection: KMnO₄; R_f=0.77]. Compound A1-2 was obtained, but was not isolated and instead used directly for the next step in solution.

Step A1-3. PPh₃ (51 g, 196 mmol, 1.5 eq) was added by portion to the solution of A1-2 and the resulting mixture was stirred at 0° C. for 2 h, allowed to warm to rt and maintained there for 3 h, then H₂O (24 mL, 1331 mmol, 10 eq) added.

##STR01189##
This mixture was heated at 60° C. O/N. The reaction was monitored by TLC [EtOAc/hexanes (1:9); detection: KMnO₄; R_f=baseline]. After cooling, a solution of 2 N HCl (327 mL, 655 mmol, 5.0 eq) was added and the resulting mixture stirred at rt for 2 h to obtain compound A1-3 in solution, which was used directly in the next step. TLC [DCM/MeOH/30% NH₄OH (7:3:1); detection: KMnO₄; R_f=0.32].

Step A1-4. For the next transformation, THF was evaporated under reduced pressure from the above reaction mixture and the remaining aqueous phase extracted with Et₂O (5×150 mL) and CHCl₃ (3×150 mL). The organic phases were monitored by TLC and if any A1-3 was observed, the organic phase was then extracted with 2 N HCl. The aqueous phase was neutralized cautiously to pH 8 with 10 N NaOH. CH₃CN (400 mL) was added to this aqueous solution and Fmoc-OSu (41.9 g, 124 mmol, 0.95 eq) in CH₃CN (400 mL) added slowly over 50 min. The solution was stirred at rt O/N. The reaction progress was monitored by TLC [EtOAc/hexanes (1:1); detection: ninhydrin; R_f=0.27]. The aqueous phase was extracted with Et₂O, then the combined organic phase dried over MgSO₄ and concentrated under reduced pressure. The solid residue obtained was mixed with H₂O (120 mL), stirred 30 min, filtered (to remove succinimide byproduct) and dried O/N under vacuum (oil pump). The solid was purified by flash chromatography [gradient: EtOAc/hexanes (50:50) to EtOAc/hexanes (70:30), with the change of eluent once Fmoc-OSu was removed as indicated by TLC] to give compound T_A1 as a white solid (yield: 71%).

¹H NMR (CDCl₃, ppm): 7.8 (d, 2H), 7.6 (d, 2H), 7.4 (t, 2H), 7.3 (t, 2H), 5.9-5.7 (1H, m), 5.6-5.5 (1H, m), 5.0 (1H, broad), 4.4 (2H, d), 4.2 (2H, d), 3.9 (2H, broad), 2.1 (1H, broad).

¹³C NMR (CDCl₃, ppm): 156.8, 144.1, 141.5, 131.9, 128.3, 127.9, 127.3, 125.2, 120.2, 67.0, 58.0, 47.4, 38.0.

D. Standard Procedure for the Synthesis of Tether Precursor RCM-T_A2

This material was accessed through application of the cross metathesis reaction shown to construct the carbon backbone. The resulting nitrile was reduced to the amine, which was protected in situ with Fmoc or other appropriate protecting group prior to attachment to the resin, which was performed using standard solid phase chemistry procedures known to those in the art. This standard procedure would also be applicable to homologues of T_A2

E. Standard Procedure for the Synthesis of Tether Precursor RCM-T_B1

##STR01190##

Step B1-1. To 2-bromobenzyl alcohol (B1-0, 30 g, 160 mmol) in DCM (DriSolv®, 530 mL) as an approximately 0.3 M solution, was added dihydropyran (B1-A, 22 mL, 241 mmol). Pyridinium p-toluenesulfonate (PPTS, 4.0 g, 16 mmol) was added and the reaction mixture stirred vigorously at rt O/N. A saturated solution of Na₂CO₃ (aq, 200 mL) was then added and the mixture stirred for 30 min. The DCM layer was separated, washed successively with saturated Na₂CO₃ (aq, 2×100 mL) and brine (2×50 mL), and dried over anhydrous MgSO₄. The solvent was evaporated under reduced pressure and the crude residue was purified by dry-pack silica-gel column. [EtOAc/hexanes (1:9); before loading the crude material, the silica was neutralized by flushing with 1% Et₃N in DCM] This afforded B1-1 as a colorless oil (42 g, 97%). TLC [EtOAc/hexanes (1:9); R_f=0.56]

Step B1-2. Magnesium turnings (2.21 g, 90 mmol) were added to an approximately 0.8 M solution of B1-1 (from which several portions of toluene were evaporated to remove traces of water, 22.14 g, 81.8 mmol) in anhydrous THF (distilled from sodium benzopheneone ketyl, 100 mL) under an atmosphere of nitrogen. The reaction was initiated by adding iodine chips (50 mg, 0.002 equiv). The reaction mixture was heated to reflux for 2 h, during which time most of the Mg turnings disappeared. The reaction was allowed to cool to rt. In a separate flame-dried round-bottomed flask, freshly distilled allyl bromide (6.92 mL, 81.8 mmol) was diluted with anhydrous THF (50 mL) under a nitrogen atmosphere and cooled to 0° C. using an ice-water bath. To this was gradually transferred the now cooled Grignard solution over a period of 20-30 min using a cannula ensuring that the unreacted magnesium turnings remained in the source flask. The contents of the Grignard preparation flask were washed (2×5 mL dry THF) and the washings transferred via cannula to the allyl bromide solution as well. The resulting mixture was stirred O/N under N₂ while allowing it to gradually warm to rt. The reaction was quenched by adding saturated NH₄Cl (aq) solution, then diluted with 100 mL Et₂O and the layers separated. The aqueous phase was extracted with Et₂O (3×100 mL) and the combined organic layers dried over MgSO₄, then concentrated under reduced pressure to provide B1-2 (18.54 g, 98%). TLC [EtOAc/hexanes (1:9), R_f=0.53]. This material was utilized in the next step without further purification.

Step B1-3. 2-(2-Propenyl)benzyl alcohol (T_B1). The crude THP ether B1-2 (18.54 g, 80 mmol) was dissolved in MeOH (160 mL) and p-toluenesulfonic acid monohydrate (PTSA, 1.52 g, 8 mmol) added. The resulting mixture was stirred at rt O/N, then concentrated under reduced pressure and the residue diluted with Et₂O (100 mL). The organic layer was sequentially washed with 5% NaHCO₃ (aq) solution (3×50 mL) and brine (1×50 mL), then dried over MgSO₄. The solvent was evaporated under reduced pressure and the residue purified by flash chromatography (EtOAc/hexanes, 1:9), to obtain T_B1 as a pale-yellow oil (9.2 g, 78%). TLC [EtOAc/hexanes (1:9), detection: UV, PMA; R_f=0.24]

F. Standard Procedure for the Synthesis of Tether Precursor RCM-T_B2

##STR01191##

Step B2-1. To a suspension of MePPh₃Br (85.7 g, 240 mmol, 2.2 eq) in THF (500 mL) was added t-BuOK in portions (26.9 g, 240 mmol, 2.2 eq) and the resulting mixture stirred at rt for 2 h during which time it became yellow. The reaction mixture was cooled to −78° C., 2-hydroxybenzaldehyde (B2-0, 11.6 mL, 109 mmol, 1.0 eq) added over 10 min, then it was stirred O/N at rt. The reaction progress was monitored by TLC [EtOAc/hexanes (20:80); detection: UV, CMA: R_f=0.25]. A saturated NH₄Cl (aq) solution was added and the resulting aqueous phase extracted with Et₂O (3×). The combined organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (EtOAc/hexanes, 30:70) to give B2-1 as a yellow oil. The identity and purity were confirmed by ¹H NMR (yield: 100%).

Step B2-2. To a solution of alcohol B2-1 (2.0 g, 16.7 mmol, 1.0 eq) in DMF at 0° C. was added cesium carbonate (1.1 g, 3.34 mmol, 0.2 eq) and the mixture stirred at 0° C. for 15 min. The reaction was warmed to 100° C. and ethylene carbonate added. The resulting mixture was stirred at 100° C. O/N. The reaction was monitored by TLC [EtOAc/hexanes (30:70); detection: UV, CMA; R_f=0.21]. The solution was cooled to rt and H₂O added. The resulting aqueous phase was extracted with Et₂O (3×). The organic phase was extracted with brine (3×), dried with MgSO₄, filtered and concentrated under reduced pressure. A yellow syrup (T_B2) was obtained (yield: 96%), which was of sufficient purity (as assessed by NMR) for further use without additional purification. Note that this product proved to be unstable in the presence of acid.

¹H NMR (CDCl₃, ppm): 7.50 (1H, dd, Ph), 7.22 (1H, td, Ph), 7.05 (dd, 1H, PhCH═CH₂), 6.98 (1H, t, Ph), 7.90 (1H, d, Ph), 5.75 (1H, dd, PhCH═CHH), 5.30 (1H, dd, PhCH═CHH), 4.15-4.10 (2H, m, PhOCH₂CH₂OH), 4.05-3.95 (2H, m, PhOCH₂CH₂OH), 2.05 (1H, s, OH).

G. Standard Procedure for the Synthesis of Tether Precursor RCM-T_B3

##STR01192##

To a solution of 2′-bromophenethylalcohol (B3-0, 2.0 mL, 14.9 mmol, 1.0 eq) in toluene (50 mL) were added tetrakis (triphenylphosphine)palladium(0) [Pd(PPh₃)₄, 347 mg, 0.30 mmol, 0.02 eq) and vinyltributyltin (6.5 mL, 22.4 mmol, 1.5 eq). The resulting mixture was stirred at reflux for 24 h under N₂. Monitoring reaction progress by TLC was difficult since the starting material and product possessed the same R_f [EtOAc/hexanes (30:70)]. The reaction mixture was cooled to rt and saturated KF (aq) solution added at which time a precipitate was formed. The solid was optionally removed by filtration and the aqueous phase extracted with DCM (4×). The combined organic phase was extracted with brine, dried over MgSO₄ and concentrated under reduced pressure. The residue was purified by flash chromatography (EtOAc/hexanes, 30:70) to give T_B3 as a colorless oil. The identity and purity were confirmed by ¹H NMR (yield: 100%).

¹H NMR (CDCl₃, ppm): 7.57-7.45 (1H, m, Ph), 7.30-7.15 (3H, m, Ph), 7.05 (dd, 1H, PhCH═CH₂), 5.65 (1H, dd, PhCH═CHH), 5.32 (1H, dd, PhCH═CHH), 4.85 (2H, t, PhCH₂CH₂OH), 2.98 (2H, t, PhCH₂CH₂OH), 1.50 (1H, s, O H.

H. Standard Procedure for the Synthesis of Tether Precursor RCM-T_B4

##STR01193##

Step B4-1. 1,2-Dihydronaphthalene (B4-0, 5.0 g, 38.4 mmol, 1.0 eq) was dissolved in 200 mL of DCM:MeOH (1:1) and the solution cooled to −78° C. Ozone (O₃) was bubbled through the solution until a blue color developed. The reaction was monitored by TLC [EtOAc/hexanes (30:70); detection: UV, CMA; R_f=0.25]. Excess O₃ was then removed by bubbling N₂ through the solution until the blue color had dissipated. Sodium borohydride (2.9 g, 76.8 mmol, 2.0 eq) was added slowly to the mixture, then it was stirred at rt for 1 h. The reaction was monitored by TLC [EtOAc/hexanes (30:70); detection: UV, CMA; R_f=0.06]. A saturated NH₄Cl (aq) solution was added slowly, then the aqueous phase was extracted with DCM (3×). The combined organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. B4-1 was obtained as a yellow oil (yield: 100%). The identity and purity of the compound was confirmed by NMR analysis and typically was of sufficient purity to be used without further manipulation.

Step B4-2. To a solution of the diol B4-1 (6.38 g, 38.4 mmol, 1.0 eq) in benzene (200 mL) was added MnO₂ (85%, 16.7 g. 192 mmol, 5.0 eq) and the resulting mixture stirred 1 h at rt. The reaction was monitored by TLC [EtOAc/hexanes (50:50); detection: UV, CMA; R_f=0.24] and more MnO₂ (5 eq) added each 1 h period until the reaction was completed, typically this required 2-3 such additions. The MnO₂ was filtered through a Celite pad, which was then washed with EtOAc. The combined filtrate and washes were evaporated under reduced pressure to give B4-2. A ¹H NMR was taken to check the purity of the resulting compound, which typically contained small amounts of impurities. However, this was sufficiently pure for use in the next step, which was preferably performed on the same day as this step since the aldehyde product (B4-2) had limited stability.

Step B4-3. To a suspension of MePPh₃Br (30.2 g, 84.5 mmol, 2.2 eq) in THF (200 mL) was added t-BuOK in portions (9.5 g, 84.5 mmol, 2.2 eq) and the resulting mixture stirred at rt for 2 h during which time the solution became yellow. The reaction mixture was cooled to −78° C., B4-2 [6.3 g, 38.4 mmol, 1.0 eq (based on the theoretical yield)] added over 10 min, then the mixture stirred O/N at rt. The reaction was monitored by TLC [EtOAc/hexanes (50:50); detection: UV, CMA; R_f=0.33]. A saturated NH₄Cl (aq) solution was added and the resulting aqueous phase extracted with EtOAc (3×). The combined organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (EtOAc/hexanes, 40:60) to give T_B4 as a yellow oil. NMR was used to confirm the identity and purity of the product (yield: 73%, 2 steps).

¹H NMR (CDCl₃, ppm): 7.55-7.45 (1H, m, Ph), 7.25-7.10 (3H, m, Ph), 7.05 (dd, 1H, PhCH═CH₂), 5.65 (1H, dd, PhCH═CHH), 5.30 (1H, dd, PhCH═CHH), 3.70 (2H, t, PhCH₂CH₂CH₂OH), 2.80 (2H, t, PhCH₂CH₂CH₂OH), 1.90-1.80 (2H, m, PhCH₂CH₂CH₂OH), 1.45 (1H, s, OH).

I. Standard Procedure for the Synthesis of Tether T45

##STR01194##

The protected version of this tether was obtained through standard transformations involving monoprotection of triethyleneglycol (45-0) followed by conversion of the remaining alcohol to a mesylate, displacement with azide and catalytic reduction in the presence of di-t-butyl dicarbonate.

J. Standard Procedure for the Synthesis of Tether T65

##STR01195##

See the preparation of T9-2 as this tether is actually an intermediate in the synthesis of tether T9.

¹H NMR (CDCl₃): δ 7.38-7.35 (bd, 1H), 7.30-7.19 (m, 1H), 6.92 (dd, 2H), 4.88 (bs, 1H), 4.16-4.11 (bt, 4H), 3.98-3.95 (t, 2H), 1.46 (s, 9H).

¹³C NMR (CDCl₃): δ 156.7. 155.8, 133.6, 130.0, 121.3, 114.8, 113.1, 112.9, 90.2, 70.8, 61.4, 28.6

K. Standard Procedure for the Synthesis of Tether T66

##STR01196##

To a solution of alkyne (Boc-T65, 13.1 g, 45.1 mmol, 1.0 eq) in EtOH/AcOEt (5:1) under N₂ is added quinoline (106 μl, 0.9 mmol. 0.02 eq) and the Lindlar catalyst (1.3 g, 10% wt), then hydrogen is bubbled into the mixture. The reaction is monitored (each 30-40 min) by ¹H NMR until the reaction is complete. Then, the reaction is filtered through a Celite pad and rinsed with AcOEt until there is no more material eluting. The solvent is removed under reduced pressure. The crude product is purified by flash chromatography with 15% AcOEt/Hex to 40% AcOEt/Hex to give Boc-T66 an oil. (Yield: 7.8 g, 59%) TLC (45/55AcOEt/Hex): R_f: 0.15; detection: UV, KMnO₄.

¹H NMR (CDCl₃): , 7.27-7.21 (td, 1H), 7.15-7.10 (dd, 1H), 7.00.6.85, (m, 2H), 6.62-6.58 (bd, 1H), 5.77-5.70 (dt, 1H), 4.13-4.03 (m, 2H), 3.97-3.95 (m, 2H), 3.9-3.88 (bd, 2H), 1.46, (s, 9H)

L. Standard Procedure for the Synthesis of Tether T67

##STR01197##

To a solution of Et₂Zn (1 M hexanes, 153 mL, 153.6 mmol, 3.0 eq) in CH₂Cl₂ (150 mL) at −20° C. was added CH₂I₂ (12.4 mL, 153.6 mmol, 3.0 eq) (CAUTION: Pressure can develop.) and the mixture stirred at −20° C. for 15 min. Boc-T8 (15.0 g, 51.2 mmol, 1.0 eq) in CH₂Cl₂ (100 mL) was then added and the mixture stirred at room temperature O/N. The reaction was monitored by TLC [(60% AcOEt: 40% hexane); detection: UV and CMA; R_f=0.39]. The solution was treated with aqueous NH₄Cl (saturated) and the aqueous phase was extracted with CH₂Cl₂. The organic phase was dried over MgSO₄ and concentrated under reduced pressure. The residue was purified by flash chromatography (60% AcOEt: 40% hexane) to give Boc-T67 as a yellow oil (yield: 57%.

¹H NMR (CDCl₃, ppm): 7.18 (1H, t), 7.03 (1H, d), 6.88 (2H, t), 4.23-4.04 (4H, m), 3.73-3.70 (2H, m), 1.48 (1H, broad), 1.28 (9H, s), 1.12-1.06 (1H, m), 1.0-0.93 (1H, m), 0.76 (2H, dt).

M. Standard Procedure for the Synthesis of Tether T68

##STR01198##

To a solution of Et₂Zn (1 M in hexanes, 49.2 mL, 49.2 mmol, 3.0 eq) in CH₂Cl₂ (30 mL) at −20° C. was added CH₂I₂ (3.9 mL. 49.2 mmol, 3.0 eq) and the mixture stirred at −20° C. for 15 min. The alkene (Boc-T66, 4.8 g, 16.4 mmol, 1.0 eq) in CH₂Cl₂ (50 mL) was then slowly added and the mixture stirred at room temperature for 2 h. The solution was treated with aqueous NH₄Cl (saturated) and the aqueous phase extracted with CH₂Cl₂ (1×) then washed with brine (1×). The organic phase was dried over MgSO₄, filtered and the solvent removed under reduced pressure. The crude product is purified by flash chromatography (gradient: 40%, then 50% and finally 60% AcOEt in hexanes) to give Boc-T68 as a yellow oil (yield: 90.7%). TLC (60% AcOEt: 40% hexanes): R_f: 0.4; detection: UV, ninhydrin.

¹H NMR (CDCl₃): δ 7.32-7.20 (td, 2H), 7.10-6.85, (m, 2H), 4.25-4.13 (m, 2H), 4.10-3.99 (m, 2H), 3.41-3.36 (dd, 1H), 2.15-2.02 (m, 1H), 1.38 (s, 9H), 1.04-0.96 (dq, 1H), 0.78-0.73 (q, 1H)

¹³CNMR(CDCl₃): δ 158.0, 130.7, 130.4, 127.9, 127.5, 127.1, 121.2, 121.0, 111.6, 111.2, 79.5 69.8, 61.5, 28.7, 17.8, 16.8, 7.2

N. Standard Procedure for the Synthesis of Tether T69

##STR01199##

TLC (25/75 AcOEt/Hex): R_f: 0.03; detection: UV, ninhydrin

¹H NMR (CDCl₃): δ 7.06-7.00 (bt, 1H), 6.61-6.52 (m, 4H), 6.35 (m, 1H), 5.12 (bt, 1H), 4.03 (m, 2H), 3.95 (m, 2H), 3.77 (s, 6H), 3.11-3.04 (bq, 2H), 2.60 (bt, 2H), 1.75 (m, 8H)

¹³C NMR (CDCl₃): δ 163.9, 160.9, 160.6, 157.6, 157.5, 155.6, 149.5, 130.8, 130.6, 125.9, 107.26, 106.9, 103.2, 98.4, 80.8, 77.5, 69.9, 61.3, 60.9, 60.6, 55.4. 40.3, 30.4, 29.3, 26.9,

LC-MS (Grad_A4) t_R: 8.37 min

O. Standard Procedure for the Synthesis of Tether T70

##STR01200##

TLC (25/75 AcOEt/Hex): R_f: 0.03; detection: UV, ninnydrin

¹H NMR (CDCl₃): δ 6.84-6.75 (m, 31-1), 6.52 (bs, 2H), 6.34 (m, 1H), 5.17 (bt, 1H), 4.01 (m, 2H), 3.93 (m, 2H), 3.77 (s, 6H), 3.10 (bq, 2H), 2.63 (bt, 2H), 1.74 (m, 8H)

¹³C NMR (CDCl₃): δ 160.9, 158.9, 155.8, 155.6, 152.9, 152.9, 149.5, 132.4, 132.3, 117.1, 116.8, 112.7, 112.6, 103.2, 98.4, 80.8, 70.4, 61.6, 55.5, 40.2, 30.3, 29.3, 27.4.

LC-MS (Grad_A4) t_R: 8.29 min

P. Standard Procedure for the Synthesis of Tether T71

##STR01201##

TLC (25/75 AcOEt/Hex): R_f: 0.03; detection: UV, ninhydrin

¹H NMR (CDCl₃): δ 7.12-7.08 (hd, 2H), 6.76-6.73 (d, 1H), 6.52 (m, 2H), 6.33 (bs, 1H), 5.15 (bt, 1H), 4.02 (m, 2H), 3.95 (m, 2H), 3.79 (s, 6H), 3.09 (bq, 2H), 2.61 (bt, 2H), 1.74 (m, 8H)

¹³C NMR (CDCl₃): δ 160.8, 155.6, 155.4, 149.5, 132.4. 130.1, 127.0, 126.0, 112.8, 103.2, 98.4, 80.8, 70.0, 61.4, 55.5, 40.3, 30.2, 29.3, 24.5, 27.4

LC-MS (Grad_A4) t_R: 9.60 min

Q. Standard Procedure for the Synthesis of Tether T72

##STR01202##

TLC (1/1, Hex/AcOEt): R_f: 0.16

¹H NMR (ppm): 1.49 (Boc), 1.8 (CH2), 2.7 (CH2), 3.1 (CH2), 4.0 (CH2), 4.1 (CH2), 4.9 (NH), 6.9 (CH aromatic), 7.35 (CH aromatic), 7.4 (CH aromatic)

¹³C NMR (ppm): 29, 30, 40, 61, 70, 110, 124, 128, 132, 160

R. Standard Procedure for the Synthesis of Tether T73

##STR01203##

TLC (60/40 AcOEt/Hex): R_f: 0.11; detection: UV, ninhydrin

¹H NMR (CDCl₃): δ 7.06-6.99, (m, 2H), 6.84-6.81 (m, 1H), 6.5 (m, 2H), 6.32 (m, 1H), 5.11 (bt, 1H), 4.07 (m, 2H), 3.90 (bt, 2H), 3.79 (s, 6H), 3.39 (s, 3H), 3.09 (bt, 2H), 2.64 (bt, 2H), 1.85-1.74 (m, 8H), 1.46 (bs, 9H)

¹³C NMR (CDCl₃): δ 160.8, 157.1, 155.6, 151.9, 149.5, 131.3, 131.0, 128.43, 128.37, 111.6, 103.2, 98.4, 84.8, 80.8, 69.9, 61.4, 60.6, 55.5, 41.8, 40.2, 30.0, 29.3, 28.1, 27.3 ppm.

LC-MS (Grad_A4) t_R: 8.26 min.

S. Standard Procedure for the Synthesis of Tether T74

##STR01204##

TLC (50/50 AcOEt/Hex): R_f: 0.09; Detection: UV, CMA

¹H NMR (DMSO-d₆): δ 7.14 (bd, 1H), 6.76-6.71 (m, 2H), 6.53 (m, 2H), 6.33 (bs, 1H), 5.15 (bt, 1H), 4.08 (m, 2H), 3.95 (m, 2H), 3.79 (s, 6H), 3.41 (s, 3H), 3.01 (bq, 2H), 2.64 (bt, 2H), 1.75 (m, 8H), 1.47 (s, 9H)

¹³C NMR (DMSO-d₆): δ 156.1, 152.3, 150.8, 147.0, 144.7, 129.8, 126.9, 125.6, 116.8, 108.4, 98.5, 93.6, 80.3, 76.1, 65.1, 56.7, 50.7, 37.1, 35.6, 25.3, 24.5, 23.4, 22.6

LC-MS (Grad_A4) t_R: 8.21 min

T. Standard Procedure for the Synthesis of Tether T75a and T75b

##STR01205##

The synthesis of the fluorinated derivative, tether T75, was carried out in an analogous matter to that of the related tether T33 starting from 33-A [(S)-methyl lactate] and appropriately substituted phenol 75-0 to provide 4.1 g of Ddz-T75a as a pale yellow solid. Although the first two steps, Mitsunobu reaction and DIBAL reduction, were high yielding, 91% and 98% respectively, isolation of the final product proved difficult after Sonagashira coupling and hydrogenation, lowering the overall yield to 17%. Again, the corresponding (R)-enantiomer, Ddz-T75b, is accessible by substituting (R)-methyl lactate (33-B) in the above procedure.

##STR01206##
U. Standard Procedure for the Synthesis of Tether T76

##STR01207##

Step T76-1. 3-Bromo-2-hydroxy-benzaldehyde. In a manner analogous to that of the literature (Hofslokken et al. Acta. Chemica Scand. 1999, 53, 258), a stirred suspension of 2-bromophenol (76-0, 3.5 g, 20 mmol) and paraformaldehyde (8.1 g, 270 mmol) in 100 mL of dry acetonitrile at room temperature was treated with MgCl₂ (2.85 g, 30 mmol) and triethylamine (TEA, 10.45 ml, 75 mmol). The mixture was stirred vigorously at reflux O/N. After this period of time, the mixture was cooled to room temperature, then 30 mL of 5% HCl was added and the product extracted with Et₂O to give 4.0 g (95%) of 76-1.

TLC (hexanes/dichloromethane, 3:1): R_f=0.3; detection: CMA and UV

Step T76-2. 2-Bromo-6-vinyl-phenol. To a stirred solution of CH₃PPh₃Br (72 g, 0.033 mol) at room temperature was added, over 5 min, a solution of tBuOK (4.1 g, 0.03 mol) in THF (50 mL). The mixture was cooled to −78° C. and 76-1 (3 g, 0.015 mol) was added dropwise over 15 min. The reaction mixture was allowed to warm to room temperature and stirred for 24 h. After this time, the solvent was removed in vacuo and the residue purified by flash chromatography using hexanes/dichloromethane (3:1) as eluent to afford 76-2 as a colorless oil (2.2 g, 75%).

TLC (hexanes/dichloromethane, 3:1): R_f=0.5; detection: CMA and UV

Step T76-3. The tosylate 76-A was synthesized using the literature method (Buono et al. Eur. J. Org. Chem. 1999, 1671)and then utilized for 76-3 (Manhas, M.S. J. Am. Chem. Soc. 1975, 97, 461-463. Nakano, J. Heterocycles 1983, 20, 1975-1978). To a solution of 76-2 (2.5 g, 12 mmol), Ph₃P (4.6 g, 18 mmol) and 76-A (4.3 g, 18 mmol) in 150 mL of THF was slowly added diethylazodicarboxylate (DEAD, 3.5 mL, 18 mmol) at room temperature. The mixture was stirred at room temperature for 6 h until the reaction was complete as indicated by TLC analysis (hexanes/ethyl acetate, 8:2; R_f=0.6; detection: CMA and UV). The solvent was removed under high vacuum and the residue was purified by flash chromatography to obtain 76-3 as a pale brown liquid (4.6 g, 88%).

Step T76-4. 76-3 (3.4 g, 8 mmol) was treated with second generation Grubbs catalyst (0.02 mol %) in 50 mL of DCM (Grubbs, R. J. Org. Chem. 1998, 63, 864-866. Gross. J. Tet. Lett. 2003, 44, 8563-8565. Hoveyda, A. J. Am. Chem. Soc. 1998, 120, 2343-2351). The resulting mixture was stirred at room temperature for 12 h The solvent was then removed under high vacuum and the residue purified by flash column chromatography to obtain 76-4 as a pale brown liquid (2.15 g, 70%). TLC (hexanes/ethyl acetate, 8:2; R_f=0.4; detection: CMA and UV).

Step T76-5. To a solution of 76-4 (1.43 g, 0.023 mol) in dry DMF (50 mL) was added cesium acetate (2.09 g, 0.0109 mol) under an argon atmosphere. The solution was stirred at 50° C. O/N. After this time, the solvent was removed under high vacuum and the residue purified by flash chromatography to obtain 76-5 as a pale brown liquid (0.7 g, 70%). TLC (hexanes/ethyl acetate, 8:2; R_f=0.6; detection: CMA and UV).

Step T76-6 (8-Bromo-2H-chromen-2-yl)-methanol. To a solution of 76-5 (5.5 g, 0.023 mol) in dry MeOH (150 mL) was added sodium metal in a catalytic amount under an argon atmosphere. The solution was then stirred at room temperature for 60 min. After this time, Amberlite IRA-120 (H⁺) resin was added to neutralize (pH=7) excess sodium methoxide and the mixture was vigorously stirred for 10 min. The resin was removed by filtration and the filtrate evaporated in vacuo. Pure compound 76-6 was recovered as a colorless oil (4.5 g, 98%).

TLC (hexanes/ethyl acetate, 7:3): R_f=0.3; detection: CMA andUV

Step T76-7. 76-6 (4.5 g, 18 mmol) and Ddz-propargyl amine (76-B, 15.16 g, 55.8 mmol) were dissolved in dioxane (150 mL) and diisopropylamine (27 mL). The reaction mixture was degassed by bubbling argon through the solution. PdCl₂PhCN)₂ (430 mg, 1.11 mmol. 0.06 eq), CuI (220 mg, 1.11 mmol, 0.06 eq) and tributylphosphine (10% in hexane, 4.4 mL, 2.23 mmol) were added and the mixture was warmed to 70° C. and stirred O/N. The solvent was removed under high vacuum and the residue purified by flash column chromatography to obtain 76-7 as a pale brown liquid (3.2 g, 80%).

TLC (hexanes/ethyl acetate, 1:1): R_f=0.3; detection: CMA and UV

Step T76-8. The acetylene 76-7 (4.5 g, 0.2 mol) was dissolved in EtOH (150 mL), then purged with nitrogen for 10 min. PtO₂ (10 mol %, 450 mg) was added, and the mixture purged with a balloon full of hydrogen gas. The mixture was then charged into a Parr bomb, flushed with hydrogen (simply fill with hydrogen at 60 psi, then release and refill, repeat this fill-release-refill cycle 3×), and reacted with hydrogen at 60 psi at room temperature O/N. The reaction mixture was filtered through a pad of Celite (use methanol for washing the pad) and the filtrate concentrated to afford a practically pure (clean by ¹H NMR), but colored sample of Ddz-T76 in quantitative yield. Further purification was achieved by subjecting this material to flash chromatography. TLC (hexanes/ethyl acetate, 1:1; R_f=0.3; detection: CMA and UV). Since the product Ddz-T76 has the same R_f as the starting material (76-7), ¹H NMR is the best way to distinguish them.

¹H NMR (CDCl₃): δ 1.73 (s. 6H), 1.75-1.95 (m, 4H), 2.60 (m, 2H), 2.70-2.90 (m, 2H), 3.10 (m, 2H), 3.72 (s, 6H), 3.75 (m, 2H), 4.12 (m, 1H), 5.20 (m, 1H), 6.35 (s, 1H), 6.50 (s, 2H), 6.80 (m, 1H), 6.90 (m, 2H).

¹³C NMR (CDCl₃): δ 23.93 (CH₂), 24.97 (CH₂), 27.07 (CH₂), 29.35 (CH₃), 30.45 (CH₂), 40.23 (CH₂), 55.47 (CH₃), 65.76 (CH₂), 80.72 (CH), 98.44 (CH), 103.22 (CH), 120.29 (CH), 121.90 (Cq), 127.76 (CH), 128.14 (CH), 129.42 (Cq), 149.56 (Cq), 152.55 (Cq), 155.56 (Cq), 160.84 (Cq).

LC-MS (Grad_A4): t_R: 9.46 min; Mass found: 443

V. Standard Procedure for the Synthesis of Tether T77

##STR01208##

Step T77-1. 3-Bromo-pyridin-2-ol. A stirred suspension of 2-pyridone (77-0, 19 g, 200 mmol) in 200 mL of 1 M aqueous KBr at room temperature was treated over 15 min with bromine (32 g, 200 mmol; CAUTION: Large quantities of Br₂ should be handled carefully!) in 200 mL of 1 M aqueous KBr, then stirred vigorously at room temperature O/N. After 24 h, this solution deposited crystals which were filtered off and then recrystallized from acetonitrile to give 27.2 g (78%) of 3-bromo-pyridin-2-ol. (77-1) [J. Am. Chem. Soc. 1982, 104, 4142-4146; Bioorg Med. Chem. Lett. 2002, 12, 197-200; J Med. Chem. 1979, 22, 1284-1290.]

Molecular weight calcd. for C₅H₄BrNO: 173; (M+H)⁺ found: 174

Step T77-2. To a solution of 3-bromo-pyridin-2-ol (77-1, 5 g, 0.028 mol), Ph₃P (11 g, 0.04 mol) and 2-(tert-butyldimethylsilanyloxy)-ethanol (77-A, 7 g, 0.04 mol) in 50 mL of THF was slowly added diethylazodicarboxylate (8.1 g, 0.04 mol) at room temperature. The progress of the reaction was easily monitored by TLC [hexanes/ethyl acetate (4:1); R_f=0.5; detection: CMA]. The mixture was stirred at room temperature for 24 h at which point the reaction was complete by TLC analysis. The solvent was removed under high vacuum and the residue purified by flash chromatography to obtain 77-2 as a pale brown liquid (6.3 g, 68%). [Tetrahedron Lett. 1994, 35, 2819-2822; Tetrahedron Lett. 1995, 36, 8917-8920; Synlett, 1995, 845-846. Heetrocycles 1990, 31, 819-824.

Molecular weight calcd. for C₁₃H₂₂BrNO₂Si 331; (M+H)⁺ found: 332

Step T77-3. The protected alcohol 77-2 (3 g, 9.1 mmol) was dissolved in diisopropylamine (50 mL) and the reaction mixture degassed by bubbling argon through the solution. PdCl₂(PPh₃)₂ (410 mg, 0.61 mmol, 0.06 eq), CuI (74 mg, 0.4 mmol, 0.04 eq) and triphenylphosphine (310 mg, 1.12 mmol) were added, then the mixture was warmed to 70° C. and stirred O/N. The solvent was removed under high vacuum and the residue was purified by flash chromatography to obtain 77-3 as a pale brown liquid (3.36 g, 70%) [Org. Lett. 2003, 5, 2441-2444; J. Chem. Soc. Perkin. Trans I 1999, 1505-1510; J. Org. Chem. 1993, 58, 2232-2243; J. Org. Chem. 1999, 58, 95-99; Org. Lett. 2000, 2, 2291-2293; Org. Lett. 2002, 4, 2409-2412]

TLC (hexanes/ethyl acetate, 1:3): R_f: =0.3; detection: CMA

Molecular weight calcd. for C₂₈H₄₀N₂O₆Si: 528; (M+H)⁺ found: 529

Step T77-4. The acetylene 77-3 (3 g, 5.67 mmol) was dissolved in EtOH (30 mL) and purged with nitrogen for 10 min. PtO₂ (10 mol %, 300 mg) was added and the mixture purged with a balloon full of hydrogen gas. The mixture was then charged into a Parr bomb, flushed with hydrogen (fill with hydrogen at 80 psi then release and refill, repeat this fill-release-refill cycle 3×), and maintained with hydrogen at 80 psi at room temperature O/N. The reaction mixture was filtered through a pad of Celite (use methanol for washing the residue on the Celite) and the filtrate plus washings was concentrated under reduced pressure to afford a practically pure (clean ¹H NMR), but colored sample of 77-4 in a quantitative yield. Further purification was achieved by subjecting this material to flash chromatography. The product 77-4 has the same R_f as the starting material (77-3), hence, ¹H NMR is the best way to distinguish them.

TLC [(hexanes/ethyl-acetate, 1:3); R_f=0.3 detection: CMA]

Molecular weight calcd. for C₂₈H₄₄N₂O₆Si: 532, (M+H)⁺ found: 533

Step T77-5. 77-4 (3 g, 5.6 mmol) was dissolved in anhydrous THF (200 mL). To the clear solution was added TBAF (6.7 mmol, 7 mL) and the mixture stirred for 2 h at room temperature. The solution was then poured into ice water. The aqueous solution was extracted with dichloromethane (3×200 mL). The organic layer was washed sequentially with saturated citrate buffer (1×200 mL), water (200 mL) and brine (200 mL). The washed organic extract was dried over anhydrous sodium sulfate, filtered and evaporated to dryness under reduced pressure to give an oily residue. This syrup was purified by flash chromatography (hexanes/AcOEt, 1:2) to give Ddz-T77 as a syrup (2.10 g, yield 90%). TLC (hexanes/AcOEt, 1:2): R_f=0.3; detection: ninhydrin

¹H NMR (CDCl₃): δ 1.73 (s, 6H), 1.75 (m, 2H), 2.65 (m, 2H), 3.15 (m, 2H), 3.75 (s, 6H), 3.90 (m, 2H), 4.50 (m, 2H), 5.01 (sb, 1H), 6.30 (s, 1H), 6.50 (s, 2H), 6.80 (m, 1H), 7.40 (m, 1H), 8.01 (m, 1H).

¹³C NMR (CDCl₃): δ 27.23 (CH₂), 29.24 (CH₃), 29.71 (CH₂), 40.17 (CH₂), 55.44 (CH₃), 62.76 (CH₂), 69.11 (CH₂), 80.76 (Cq), 98.24 (CH), 103.24 (CH), 117.54 (CH), 124.68 (Cq), 138.82 (CH), 144.17 (CH), 149.45 (Cq), 155.50 (Cq), 160.84 (Cq), 162.03 (Cq).

Molecular weight calcd. for C₂₂H₃₀N₂O₆: 418; (M+H)⁺ found: 419

EXAMPLE 2

Synthesis of Representative Macrocyclic Compounds

The following are provided as representative examples for the macrocyclic compounds of the invention. For solid phase methods, all yields are reported starting from 300-325 mg of PS-aminomethyl resin (loading 2.0 mmol/g) unless otherwise noted. Attachment of the first building block, BB₃, varies from 100% to 55% for the more difficult residues, typically sterically crowded structures such as Ile or Val. The remaining couplings for BB₂ and BB, proceed in an average yield of 80-90%. Attachment of the tether using the Mitsunobu reaction yields from 50-90% of the desired linear precursor. The macrocyclization itself proceeds in an average yield of 20-50%. Minimal loss of yield occurs in post-cyclization processing.

All the retention time values presented herein are based on the UV portion of the HPLC data. In the HPLC procedure, ELSD and CLND data (not listed) were also procured to further assess purity of the final products, and for quantification (CLND). All compounds were analyzed using the same HPLC conditions. The details for the HPLC procedure used was as follows: Column: XTerra MS C18 4.6×50 mm, 3.5 μm, from Waters, HPLC: Alliance 2695 from Waters; MS: Platform LC from Micromass/Waters; CLND: 8060 from Antek; PDA: 996 from Waters; Gradient_B4: (i) 0 to 50% MeOH: 0.1% aqueous TFA in 6 min, (ii) 3 min at 50% MeOH: 0.1% aqueous TFA; (iii) 50 to 90% MeOH:0.1% aqueous TFA in 5 min; (iv) 3 min at 90% MeOH:0.1% aqueous TFA. Retention time (t_R) for the compound is listed.

Modifications were made to the standard methods for compounds 58, 99, 201, 203 and 215.

Compound 1

Yield: 33.4 mg pure macrocycle was obtained (CLND quantification).

¹H NMR (300 MHz, DMSO-d₆): δ 8.53, 8.41, 8.34 (doublets J=8.7 Hz for all, 1H); 8.13-8.06, 7.82-7.75 (multiplets, 1H); 7.30-7.05 (m, 8H); 6.90-6.77 (m, 2H); 4.58-4.46, 4.40-4.29, 4.27-4.16 (multiplets, 1H); 4.09-3.99, 3.97-3.82 (multiplets, 2H); 3.77-3.44 (m, 2H); 3.37-3.19 (m, 4H); 3.15, 3.08 (2s, 2H); 2.98-2.86 (m, 5H); 2.52 (s, 3H); 1.94-1.75, 1.60-1.30 (multiplets, 2H); 1.22 (br s, 4H); 0.86-0.75 (m, 3H).

HRMS talc. for C₂₉H₄₀N₄O₄; 508.3049; found 508.3040±0.0015.

HPLC t_R=8.94 min.

Compound 3

Yield: 33.0 mg pure macrocycle was obtained (CLND quantification).

¹H NMR (300 MHz, DMSO-d₆): δ 8.54 (d, J=9.4 Hz), 8.43-8.36 (m), and 8.12 (br t, J=5.65 Hz) (1H); 7.90 (d, J=6.6 Hz), 7.79-7.72 (m) (1H); 7.30-7.05 (m, 6H); 6.90-6.76 (m, 3H); 4.60-4.50 (m), 4.43 (d, J=18.3 Hz), 4.26-4.16 (m) (1H); 4.13-4.02 (m, 1H); 4.01-3.84 (m, 2H); 3.74-3.41 (m, 2H); 3.17, 3.09 (2s, 3H); 2.99-2.86 (m, 5H); 2.43-2.18 (m, 1H); 1.97-1.75 (m, 3H); 1.72-1.39 (m, 1H); 0.96 (d, 5.76 Hz, 3H); 0.93-0.77 (m, 2H); 0.68 (d, 5.76 Hz, 3H).

HRMS calc. for C₂₈H₃₈N₄O₄; 494.2893; found 494.2888±0.0015.

HPLC t_R=8.11 min.

Compound 4

Yield: 15.3 mg pure macrocycle was obtained (CLND quantification).

¹H NMR (300 MHz, CD₃CN): δ 7.48-7.19 (m, 6H); 7.13-6.98 (m, 3H); 4.71-4.51 (m, 3H); 4.48-4.32 (m, 1H); 4.26-4.01 (m, 1H); 3.79-3.57 (m, 2H); 3.48-3.20 (m, 3H); 3.19-3.06 (m, 5H); 3.01-2.89 (m, 2H); 2.80-2.62 (m, 2H); 2.09-1.96 (m, 3H); 1.94-1.70 (m, 1H); 1.57-1.36 (m, 4H); 1.32-1.26 (m, 1H); 1.08-0.97 (m, 3H).

HRMS calcd for C₂₉H₄₀N₄O₄; 508.3049; found 508.3045±0.0015

HPLC t_R=8.37 min

Compound 6

Yield: 28.2 mg macrocycle was obtained (CLND quantification).

¹H NMR (300 MHz, DMSO-d₆): δ 10.80 (s, 1H); 8.46 (d, J=9.65 Hz), 8.36-8.28 (m), 8.14-8.07 (m), and 8.02 (d, J=9.65 Hz) (1H); 7.73-7.65 (m), 7.59 (d, 8.2 Hz), and 7.51 (d, J=8.2 Hz) (1H); 7.3 (d, J=8.2 Hz, 1H); 7.16-6.91 (m, 5H); 6.89-6.76 (m, 2H); 4.62-4.49 (m) and 4.42-4.24 (m) (1H); 4.15-3.81 (m, 2H); 3.77-3.43 (m, 2H); 3.41-3.19 (m, 6H); 3.22-2.85 (m, 6H); 2.52 (s, 3H); 1.89-1.69 (m, 1H); 1.59-1.02 (m, 4H); 0.88-0.74 (m, 3H).

HRMS calc. for C₃₀H₃₉N₅O₄; 533.3002; found 533.2990±0.0016.

HPLC t_R=8.22 min.

Compound 8

Yield: 74.9 mg pure macrocycle was obtained (CLND quantification) from 600-650 mg starting resin

¹H NMR (300 MHz, DMSO-d₆): δ 9.47 (br s), 9.07 (s) (1H) and 8.32 (br s) (2H); 7.94 (d, 6.6 Hz, 1H); 7.60-7.42 (m, 2H); 7.38 (d, 9.0 Hz, 1H); 7.28-7.04 (m, 7H); 6.93 (t, 8.1 Hz, 1H); 6.60 (d, J=14.4 Hz) and 6.39-6.27 (m) (1H); 4.51-4.38 (m, 1H); 4.29-4.08 (m, 2H); 3.87-3.63 (m, 2H); 3.40-3.13 (m, 2H); 2.94 (t, J=14.1 Hz, 1H); 2.53-2.50 (m, 1H); 2.32-2.17 (m, 1H); 1.86-1.06 (m, 10H); 0.95-0.79 (m, 6H).

HRMS calc. for C₃₂H₄₂N₄O₄; 546.3206; found 546.3198±0.0016.

HPLC t_R=9.02 min.

Compound 9

Yield: 33.7 mg pure macrocycle was obtained (CLND quantification).

¹H NMR (300 MHz, DMSO-d₆): δ 8.48 (s, 1H); 7.92 (d, J=5.3 Hz, 1H); 7.81 (d, 3=8.5 Hz, 1H); 7.26-7.08 (m, 7H); 6.88-6.75 (m, 2H); 4.30 (br t, J=10.1 Hz, 1H); 4.0 (t, J=8.6 Hz, 1H); 3.87 (br d, J=8.6 Hz, 1H); 3.70-3.58 (m, 1H); 3.4-3.25 (m, 1H); 3.04-2.85 (m, 3H); 2.73 (d, 7.67 Hz, 1H); 2.53 (s, 3H); 2.35-2.09 (m, 2H); 1.92-1.44 (m, 8H); 1.42-1.18 (m, 2H); 0.85, 0.81 (2 doublets, J=6.76 Hz, 6H).

¹³C NMR (75 MHz, DMSO-d₆): δ 176.15; 173.20; 171.27; 157.18; 140.08; 130.72; 130.52; 129.71; 128.64; 127.87; 126.62; 120.88; 111.44; 68.29; 67.10; 66.99; 55.24; 48.42; 41.11; 41.03; 39.36; 36.93; 35.77; 34.65; 32.38; 30.55; 29.96; 23.83; 22.65; 19.87.

HRMS calc. for C₃₁H₄₂N₄O₄; 534.3206; found 534.2139±0.0016.

HPLC t_R=9.29 min.

Compound 10

Yield: 19.2 mg pure macrocycle was obtained (CLND quantification).

¹H NMR (300 MHz, DMSO-d₆): δ 8.53. 8.41, 8.38 (doublets, J=8.8, 8.5, 8.5 Hz, 1H); 8.16-8.05, 7.87-7.71 (multiplets, 1H); 7.31-7.04 (m, 7H); 6.91-6.75 (m, 2H); 4.60-4.45, 4.39-4.30, 4.28-4.16 (m, 1H), 4.10-4.00, 3.97-3.83 (m, 2H); 3.73-3.46 (m, 2H): 3.22-3.20 (m 1H), 3.16, 3.09 (2 s, 3H), 2.45-2.39 (m, 1H); 2.99-2.86 (m, 1H); 2.85-2.58 (m, 5H); 2.48-2.22 (m, 1H); 2.07 (s, 1H), 1.95-1.78 (m, 1H),1.75-1.42 (m, 1H), 1.42-1.17 (m, 4H), 0.88-0.77 (m, 3H).

HRMS calc. for C₂₈H₃₈N₄O₄; 494.2893; found 494.2888±0.0015 HPLC t_R=8.27 min.

Compound 221

Yield: 50.3 mg macrocycle was obtained (CLND quantification).

¹H NMR (300 MHz, DMSO-d₆): δ 7.86 (d, J=6.7 Hz) and 7.65-7.58 (m) (1H); 7.28-7.06 (m, 7H); 6.88 (d, 8.06 Hz, 1H); 6.81 (t, J=6.7 Hz, 1H); 4.07-3.91 (m, 3H); 3.77-3.65 (m, 1H); 3.56-3.38 (m, 2H); 3.35-3.25 (m, 3H); 3.25-3.07 (m, 2H); 3.04-2.63 (m, 3H); 2.52 (s, 3H); 2.01-1.71 (m, 4H); 1.66-1.49 (m, 2H); 1.47-1.17 (m. 4H); 0.90-0.78 (m, 3H).

¹³C NMR (75 MHz, DMSO-d₆): δ 172.15; 170.81; 170.74; 157.29; 139.62; 130.76; 130.56; 129.56; 128.82; 61.73; 59.29; 56.37; 47.90; 41.11; 41.03; 39.36; 35.81; 35.43; 30.23; 30.03; 29.63; 25.12; 19.15; 14.66.

HRMS calc. for C₃₀H₄₀N₄O₄; 520.3049; found 520.3041±0.0016.

HPLC t_R=8.30 min.

EXAMPLE 3

Alternative Synthetic Strategies

Alternative synthetic strategies amenable to larger scale synthesis of compounds of the present invention are discussed below.

A. Method LS1 for Representative Large Scale Synthesis of Compounds of the Invention

##STR01209##

##STR01210##

##STR01211##

Step LS1-A: Synthesis of LS1-8

##STR01212##

To alcohol Cbz-T33a (2.4 g, 7.0 mmol, 1.0 eq) in CH₂Cl₂ (50 mL) were added NBS (1.5 g, 8.4 mmol, 1.2 eq) and PPh₃ (2.2 g, 8.4 mmol, 1.2 eq). The mixture was stirred at room temperature O/N and a saturated aqueous NH₄Cl solution was added. The aqueous phase was extracted with CH₂Cl₂ (2×) and the combined organic phases were extracted with a saturated aqueous NH₄Cl solution to remove succinimide byproduct. The organic phase was dried over MgSO₄ and concentrated under reduced pressure. The residue was purified by flash chromatography (20% AcOEt, 80% hexanes) to give bromide LS1-8a as a yellow oil (2.6 g, 91%).

TLC (30% AcOEt, 70% hexanes): R_f=0.56; detection: UV and CMA

¹H NMR (CDCl₃): δ 7.37-7.26 (5H, m, Ph), 7.19-7.13 (2H, m, Ph), 6.90 (1H, t, Ph), 6.83 (1H, d, Ph), 5.10 (2H, s, NHC (O)OCH—)Ph), 4.96 (1H, broad, NHCbz), 4.59 (1H, sextuplet, PhOCH(CH₃)CH₂Br), 3.58-3.47 (2H, m, CH₂Br), 3.19 (2H, q, CHNHCbz), 2.67 (2H, t, PhCH₂CH₂), 1.78 (2H, quint, PhCH₂CH₂), 1.44 (3H, d, CHCH₃).

LC/MS (Grad_A4): t_R=11.15 min

Step LS1-B1: Synthesis of LS1-10

##STR01213##

The hydrochloride salt of H-Nva-OMe was dissolved in an aqueous solution of Na₂CO₃ (1 M) and saturated with NaCl to ensure extraction of all of the free amine. The aqueous solution was extracted with AcOEt (3×). The combined organic phases were extracted with brine, dried over MgSO₄, filtered and concentrated under reduced pressure. The free amine, H-Nva-OMe, was recovered in 90% yield. It is important to perform the alkylation with the free amine (H-Nva-OMe) to eliminate chloride formation (OTs to Cl) as a side reaction. In a dried round-bottomed flask, bromide LS1-8a (740 mg, 1.83 mmol, 1.0 eq) and H-Nva-OMe (479 mg, 3.60 mmol, 2.0 eq) were added. Degassed (by stirring under vacuum for 30 min) DMF (3.7 mL), anhydrous Na₂CO₃ (232 mg, 2.19 mmol, 1.2 eq) and KI (61 mg, 0.37 mmol, 0.2 eq) were added and the mixture stirred at 110° C. O/N. Water was added and the aqueous phase was extracted with Et₂O (3×). The combined organic phases were extracted with water (2×), then brine (1×). The organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (30% AcOEt: 70% hexanes) to give secondary amine LS1-10 as a yellow oil (709 mg, 85%).

TLC (30% AcOEt, 70% hexanes): R_f=0.32; detection: UV and CMA

¹H NMR (CDCl₃): δ 7.35-7.29 (5H, m, Ph), 7.17-7.12 (2H, m, Ph), 6.91-6.84 (2H, m, Ph), 5.51 (1H, broad, CH₂N HCHRR′), 5.09 (2H, s, OCH₂Ph), 4.67-4.51 (1H, m, PhOC H(CH₃)R), 3.65 (3H, s, C(O)OCH₃), 3.24-3.10 (3H, m, NHC H(Pr)CO₂Me and CH₂NHCbz), 2.87-2.41 (4H, m, PhC H₂CH₂ and NHCH₂CH(Me)OPh), 1.86-1.76 (2H, m, PhC H₂CH₂), 1.70-1.63 (2H, m, CH₃CH₂CH₂), 1.36-1.28 (2H, m, CH₃CH₁CH₂), 1.23 (3H, d, CHCH₃), 0.90 (3H, t, C H₃CH₂CH₂).

¹³C NMR (CDCl₃): δ 176.44, 156,88, 155.58, 137.14, 131.16, 130.57, 128.68, 128.34, 128.21, 127.33, 120.79, 112.62, 73.16, 66.62, 61.30, 54.21, 51.95, 40.86, 36.02, 30.60, 27.88, 19.20, 17.80, 14.07.

LC/MS (Grad_A4): t_R=6.76 min

Step LS1-B2: .Alternative Synthesis of LS1-10

To a solution of alcohol Chz-T33a (8.5 g, 24.7 mmol, 1.0 eq) in CH₂Cl₂ (125 mL) were added Et₃N (10.4 mL, 74.1 mmol, 3.0 eq), TsCl (5.2 g, 27.2 mmol, 1.1 eq) and DMAP (302 mg, 2.47 mmol, 0.1 eq). The mixture was stirred O/N at room temperature and then an aqueous solution of saturated NH₄Cl was added. The aqueous phase was extracted with CH₂Cl₂ (2×) and the combined organic phases were dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (30% AcOEt, 70% hexanes) to give tosylate LS1-8b as an oil (9.4 g, 90%).

TLC (50% AcOEt, 50% hexanes): R_f=0.47; detection: UV and CMA

¹H NMR (CDCl₃): δ 7.74 (2H, d, Ph), 7.36-7.26 (7H, m, Ph), 7.14-7.08 (2H, m, Ph), 6.88 (1H, t, Ph), 6.74 (1H, d, Ph), 5.10 (2H, s, NHC(O)OCH₂Ph), 4.97 (1H, broad, NHCbz), 4.61-4.55 (1H, m, PhOCH(CH₃)CH₂OTs), 4.19-4.05 (2H, m, CH₂OTs), 3.15 (2H, q, CH₂NHCbz), 2.56 (2H, td, PhC H₂CH₂), 2.42 (3H, s, PhCH₃) 1.74 (2H, quint, PhCH₂CH). 1.27 (3H, d, CHCH₃)

¹³C NMR (CDCl₃): δ 156.67, 155.05, 145.20, 137.04, 133.02, 131.16, 130.65, 130.11, 128.72, 128.28, 128.23, 128.10, 127.39, 121.50, 112.87, 71.99, 71.42, 66.68, 40.79, 30.32, 27.57, 21.87, 16.74.

LC-MS (Grad_A4): t_R=11.02 min

Application of the procedure in Step LS1-B1, but substituting the tosylate LS1-8b as alkylating agent gave 73% yield of LS1-10 with 2 eq of H-Nva-OMe.

Step LS1-C1: Synthesis of LS1-7

##STR01214##

To a solution of amine LS1-10 (697 mg, 1.53 mmol, 1.0 eq) in THF/H₂O (1:1, 15 mL) at 0° C. were added Na₂CO₃ (244 mg, 1.68 mmol, 1.5 eq) and (Boc)₂O (366 mg, 1.68 mmol, 1.1 eq), then the mixture stirred at room temperature for 36-48 h. THF was evaporated under reduced pressure and the aqueous phase was extracted with Et₂O (3×). The combined organic phases were extracted with brine, dried over MgSO₄, filtered and concentrated under reduced pressure. The Boc compound was obtained as a yellow oil and used without further purification for the next reaction.

TLC (30% AcOEt, 70% hexane): R_f=0.49; detection: UV and CMA

To a solution of the crude Boc compound in THF/H₂O (1:1, 15 mL) was added LiOH (309 mg, 7.35 mmol, 5.0 eq) and the mixture stirred O/N at rt. THF was evaporated under reduced pressure and the remaining aqueous basic phase was then acidified with 1 M HCl to pH 3 (pH paper). The aqueous phase was extracted with AcOEt and the combined organic phases were extracted with water and brine. The organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. Carboxylic acid LS1-7 was obtained as a yellow oil (687 mg, 83%, 2 steps).

TLC (50% AcOEt, 50% hexane): R_f=0.32; detection: UV and CMA

¹³C NMR (CDCl₃): δ 176.11, 156.81, 155.51, 155.18, 136.93, 131.13, 130.37, 128.72, 128.31, 127.44, 121.20, 113.70, 81.36, 73.40, 66.79, 61.99, 40.80, 32.83, 31.56, 30.33, 28.48, 27.48, 20.10, 17.53, 14.11.

LC/MS (Grad_A4): t_R=12.50 min

Step LS1-C2: Divergent Synthetic Route (No Amine Protection)

##STR01215##

The H-Nva-OtBu-HCl was dissolved in an aqueous solution of Na₂CO₃ (1 M) and saturated with NaCl to ensure extraction of all of the free amine. This aqueous solution was extracted with AcOEt (3×). The combined organic phases were extracted with brine, dried over MgSO₄, flitered and concentrated under reduced pressure. About 90% of the free amine, H-Nva-OtBu, was recovered. It is important to perform the alkylation with the free amine (H-Nva-OtBu) to eliminate chloride side product formation (OTs->Cl).

In a dried round-bottomed flask, tosylate LS1-8b (1.0 g, 2.01 mmol, 1.0 eq) and H-Nva-OtBu (752 mg, 4.02 mmol, 2.0 eq) were added. Degassed (by stirring under vacuum for 30 min) DMF (4 mL) and anhydrous Na₂CO₃ (256 mg, 2.41 mmol, 1.2 eq, note that other bases were less effective) were added and the mixture stirred at 110° C. O/N. Water was added and the aqueous phase extracted with Et₂O (3×). The combined organic phases were extracted with water (2×) and brine (1×). The organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (30% AcOEt: 70% hexanes) to give the amine, LS1-12, as a yellow oil (683 mg, 75%). This crude secondary amine (1.0 eq) was dissolved in 4 M HCl/dioxane (10 eq) and the mixture stirred O/N at room temperature. The solvent was evaporated under reduced pressure and Et₂O added to the residue. A white precipitate was formed upon addition of hexanes to this mixture. The precipitate was filtered and rinsed with cold hexanes to give the desired amino acid, LS1-13, as a white solid.

TLC (50% AcOEt, 50% hexane): R_f=0.71; detection: UV and CMA

LS1-13, despite the presence of the free amine, has been used in the remaining part of the synthetic scheme to successfully access the desired macrocycle.

Step LS1-D: Synthesis of Dipeptide LS1-6

##STR01216##

The tosylate salt of H-(D)Phe-OBn was dissolved in an aqueous solution of 1 M Na₂CO₃ and the aqueous solution extracted with AcOEt (3×). The combined organic phases were extracted with brine, dried over MgSO₄, filtered and concentrated under reduced pressure. The free amine H-(D) Phe-OBn was recovered in 90% yield. To a solution of H-(D) Phe-OBn (3.0 g, 11.76 mmol, 1.0 eq) in THF/CH₂Cl₂ 1/1 (60 mL) were added Boc-(D)NMeAla-OH (2.5 g, 12.35 mmol, 1.05 eq), 6-Cl HOBI (2.0 g, 11.76 mmol, 1.0 eq) and DIPEA (10.2 mL, 58.8 mmol, 5.0 eq). The mixture was cooled to 0° C. and EDCI (2.48 g, 12.94 mmol, 1.1 eq) was added. The mixture was stirred 1 h at 0° C. and at room temperature O/N. Solvent was evaporated under reduced pressure and the residue dissolved in AcOEt. The organic phase was washed sequentially with an aqueous 1 M solution of citrate buffer (pH 3.5, 2×), an aqueous solution of saturated NaHCO₃ (2×) and brine (1×). The organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. The dipeptide was obtained as a yellow oil and used as obtained for the next step (5.3 g, 100%). The dipeptide was dissolved in a solution of HCl/dioxane (4 M, 30 mL, 10 eq), 50 mL of dioxane were then added to facilitate the agitation and the mixture stirred for 1 h at room temperature; a heterogeneous solution was obtained. The mixture was concentrated under reduced pressure and dried further on mechanical vacuum pump. The dipeptide hydrochloride salt LS1-6 was obtained as pale yellow solid (4.4 g, 100%).

¹H NMR (DMSO-d₆): δ 9.40-8.70 (3H, d and 2 broads, C(O)NH and CH₃NH₂⁺Cl⁻), 7.39-7.17 (10H, m, Ph), 5.11 (2H, s, C(O)OCH₂Ph), 4.69-4.61 (1H, m, CHCH₃), 3.69 (1H, dd, CHCH₂Ph), 3.31 (3H, s, CH₃NH₂⁺Cl⁻), 3.17-3.11 and 2.97-2.90 (CHCH₂Ph), 1.28 (3H, d, CHCH₃)

¹³C NMR (DMSO-d₆): δ 171.33, 169.18, 137.63, 136.31, 129.92, 129.11, 128.95, 128.83, 128.63, 127.30, 67.00, 56.57, 54.38, 36.98, 31.11, 16.47.

LC/MS (Grad_A4): t_R=6.17 min

Step, LS1-E: Synthesis of Amino Acid LS1-5

##STR01217##

To a solution of acid LS1-7 (1.45 g, 2.67 mmol, 1.05 eq) in THF/CH₂Cl₂ (1/1, 13 mL) at 0° C. were added hydrochloride salt LS1-6 (958 mg, 2.55 mmol, 1.0 eq), DIPEA (2.2 mL, 12.8 mmol, 5.0 eq) and HATU (1.07 g, 2.81 mmol, 1.1 eq). The mixture was stirred at room temperature O/N. Solvent was evaporated and the residue was dissolved in AcOEt. The organic phase was washed sequentially with an aqueous solution of 1 M citrate buffer (pH=3.5, 2×), aqueous solution of saturated NaHCO₃ (2×), then with brine (1×). The organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (gradient: 20% AcOEt, 80% hexanes to 30% AcOEt, 70% hexanes) to give the desired fully protected tripeptide as a pale yellow gummy foam (1.6 g, 73%).

TLC (50% AcOEt, 50% hexanes): R_f=0.78; detection: UV and CMA

LC/MS (Grad_A4): t_R=15.15 min

To a solution of the protected, alkylated tripeptide (1.5 g, 1.75 mmol, 1.0 eq) in AcOEt (23 mL) was added 10% Pd/C (20% by weight, 315 mg) and then hydrogen was bubbled through the solution, The mixture was stirred O/N under a hydrogen atmosphere. Nitrogen was bubbled through the reaction, then the mixture filtered on a Celite pad and rinsed with AcOEt. The combined filtrate was evaporated under reduced pressure to give LS1-5 as a white solid (1.1 g, quantitative).

TLC (50% AcOEt, 50% hexanes): R_f=0.52; detection: UV and CMA

LCMS (Grad_A4): t_R=8.23 min

Step LS1-F: Macrocyclization and Final Deprotection

##STR01218##

To a solution of cyclization precursor LS1-5 (50 mg, 0.08 mmol, 1.0 eq) in THF (3.2 mL, for a concentration of 25 mM) was added DIPEA (68 μL, 0.39 mmol, 5.0 eq) and DEPBT (28 mg, 0.094 mmol, 1.2 eq) and the mixture stirred at room temperature O/N. Solvent was evaporated under reduced pressure and the residue purified by flash chromatography (1% MeOH, 99% CH₂Cl₂) to give Boc-protected macrocycle LS1-11 as a white solid (40 mg, 0.064 mmol, 80%). On a 1 g scale of precursor LS1-5 at a reaction concentration of 25 mM, the yield was 73%.

TLC (5:95 MeOH:DCM): R_f=0.43; detection: UV and CMA

¹H NMR (DMSO-d_b 60° C.): δ 7.62 (1H, d, NH), 7.47 (1H, broad, NH), 7.27-7.08 (7H, m, Ph), 6.85-6.79 (2H, m, Ph), 4.78 (1H, broad), 4.51-4,38 (1H, m), 4.11-4.02 (2H, m), 3.62-3.56 (1H, m), 3.32-3.04 (5H, m), 2.92 (3H, s, N—C₃), 2.72-2.46 (2H, m), 1.90-1.59 (4H, m), 1.46 (9H, s, C(CH₃)₃), 1.28-1.06 (8H, m), 0.65 (3H, t, CH₂CH₃).

¹³C NMR (DMSO-d₆): δ 172.03, 171.07, 155.83, 155.60, 139.69, 131.82, 130.82, 129.69, 128.73, 127.73, 126.75, 121.06, 113.40, 80.66, 74.75, 57.22, 56.66, 50.49, 35.88, 33.72, 32.71, 30.41, 28.68, 19.35, 18.44, 14.95, 14.19.

LC-MS (Grad_A4): t_R=12.82 min

Macrocycle LS1-11 (565 mg, 0.91 mmol, 1.0 eq) was dissolved in a solution of 4 M HCl/dioxane (4.6 mL, 20 eq) and the mixture stirred 2 h at room temperature. The mixture was concentrated under reduced pressure and placed under vacuum (oil pump) to give final macrocycle Compound 410 as a white solid (508 mg, 100%).

Chiral HPLC indicated no racemization when compared to its (L)-antipode at position AA₃.

¹H NMR (DMSO-d₆, 60° C.): δ 9.38 (1H, broad), 8.28 (1H, d), 8.13 (1H, broad), 7.81 (1H, t), 7.28-7.13 (7H, m, Ph), 6.93-6.87 (2H, m, Ph), 4.84-4.77 (1H, m), 4.54-4.40 (3H, m), 3.35-3.07 (6H, m), 2.94 (3H, s, N—CH₃), 2.90-2.81 and 2.64-2.47 (2H, m), 1.85-1.64 (4H, m), 1.38-1.21 (5H, m), 1.10 (3H, d, CH₃), 0.88 (3H, t, CH₂CH₃).

¹³C NMR (CDCl₃): δ 171.92, 171.46, 170.44, 155.11, 139.07, 131.68, 130.47, 129.87, 128.67, 127.54, 126,90, 121.50, 112.94, 69.83, 67.03, 58.14, 56.33, 55.61, 55.29, 53.88, 50.48, 37.29, 32.29, 31.08, 29.70, 28.58, 18.15, 17.89, 15.20, 14.55.

LC-MS (Grad_A4): t_R=6.23 min

LC chiral (Grad35A-05): t_R=26.49 min

LC chiral (Grad40A-05): t_R=26.54 mm

B. Method LS2 for Representative Large Scale Synthesis of Compounds of the Invention

##STR01219##
Step LS2-A: Synthesis of Dipeptide LS2-21

##STR01220##

A stirred suspension of H-(D)Phe-OtBu-HCl (5 g, 0.02 mol, 1 eq) and Z-(D)NMeAla-OH (4.98 g. 0.021 mol, 1.05 eq) in 130 mL of anhydrous THF-DCM (1:1) at room temperature was treated with DIPEA (17.50 mL, 0.1 mol, 5 eq) and 6-Cl-HOBt (3.40 g, 0.02 mol, 1 eq). The mixture was stirred vigorously at room temperature for several minutes, cooled with an ice bath, then EDCI (4.20 g, 0.022 mol, 1.1 eq) was added and the mixture stirred for 1 h. After this period of time, the ice bath was removed and the reaction was stirred at room temperature O/N. The solvent was removed under reduced pressure and the residue dissolved in 100 mL of AcOEt and washed with citrate buffer solution (1 N, 2×100 mL), saturated NaHCO₃ solution (2×100 mL) and brine. The organic layer was dried over anhydrous sodium sulfate, filtered and evaporated to dryness under reduced pressure to give 9.25 g (100%) of a colorless oil, LS2-24.

TLC (hexanes/ethyl acetate, 1:1): R_f=0.3; detection: CMA and UV

H NMR (CDCl₃): δ 1.25 (m, 2H), 1.40 (s, 9H), 2.66 (s, 3H), 2.85 (dd, 1H), 3.15 (dd, 1H), 4.70 (q, 2H), 5.15 (s, 2H), 6.50 (sb, 1H), 7.15 (m, 2H), 7.20 (m, 3H), 7.35 (m, 5H).

¹³C NMR (CDCl₃): δ 28.18, 38.23, 53.61, 53.61, 67.87, 127.12, 128.40, 128.19. 128.40, 128.61, 128.8, 129.53, 170.01.

LC/MS (Grad_A4); t_R=9.73 min; Mass found: 440

Dipeptide LS2-24 (6.9 g, 0.015 mol) was dissolved in AcOEt (100 mL), then purged with nitrogen for 10 min. 10% Pd—C (690 mg) was added and the mixture purged with a balloon full of hydrogen gas. The mixture was then hydrogenated under atmospheric pressure using a H₂ balloon. After 12 h, the reaction mixture was filtered through a short pad of Celite, and the filter cake washed with AcOEt. The combined filtrate and washings were concentrated under reduced pressure to afford practically pure (clean NMR), colorless, solid compound LS2-21 (4.30 g, 90%) which was used directly in the next step without further purification.

TLC (100% AcOEt): R_f=0.1; detection: CMA and UV.

¹H NMR (CDCl₃): δ 1.20 (d J=7.03 Hz, 3H) (s, 9H), 2.40 (s, /H), 3.01-3.20 (m, 3H), 4.80 (q, 1H), 7.20 (m, 5H), 7.60 (m. 1H).

³C NMR (CDCl₃): δ 19.64, 28.18, 35.12, 38.46, 53.06, 60.42, 82.29, 127.05, 128.50, 129.71, 136.61, 170.85, 174.28.

LC-MS (Grad_A4): t_R=5.86 min; Mass found: 306

Step LS2-B: Synthesis of Tripeptide LS2-22

##STR01221##

A stirred suspension of dipeptide LS2-21 (2 g, 6.50 mmol, 1 eq) and Bts-Nva-OH (LS2-28, 2.15 g, 6.85 mmol, 1.05 eq) in 32 mL of anhydrous DCM at 0° C. was treated with DIPEA (4.50 mL, 0.026 mol, 4 eq) and HATU (2.72 g, 7.18 mmol, 1.1 eq). The mixture was stirred vigorously at 0° C. for 1 h. After this period of time, the ice bath was removed and the reaction stirred at room temperature O/N. The solvent was removed in vacuo and the residue dissolved in 30 mL of AcOEt. The organic phase was sequentially washed with 1 N citrate buffer solution (2×30 mL), saturated NaHCO₃ solution (2×30 mL) and brine (1×30 mL). The organic layer was then dried over anhydrous sodium sulfate, filtered and evaporated to dryness under reduced pressure. The residue was purified by flash chromatography [ethyl acetate/hexanes (1/1)] to afford LS2-22 as a colorless solid (3.13 g, 80%).

TLC (hexanes/ethyl acetate, 3:2): R_f=0.3; detection: CMA and UV

¹H NMR (CDCl₃): δ 0.95 (m, 3H), 1.20 (d, 2H), 1.40 (s, 9H), 1.42-1.70 (m, 4H), 2.60 (m, 2H), 2.90 (s, 3H), 4.40 (m, 1H), 4.80 (m, 1H), 4.92 (m, 1H), 6.10 (m, 1H), 6.30 (M, 1H), 6.40 (m, 1H), 6.90 (m, 2H), 7.20 (m, 3H), 7.40-7.60 (m, 2H), 7.90 (m, 1H), 8.10 (m, 1H).

¹³C NMR (CDCl₃): δ 23.42, 26.32, 33.12, 48.63, 49.10, 49.85, 77.56, 117.63, 120.67, 122.35, 122.93, 123.11, 123.80, 124.13, 124.68, 124.75, 131.45, 147.67, 165.16, 165.68, 167.66.

LC-MS (Grad_A4): t_R=11.48 min; Mass found: 602

Step LS2-C: Synthesis of LS2-23

##STR01222##

A stirred suspension of tripeptide LS2-22 (0.4 g, 0.66 mmol) and tether bromide LS2-9 (0.5 g, 1.32 mmol, synthesized as in Step LS1-A for the corresponding Cbz derivative) in 1.33 mL of anhydrous DMF at room temperature was treated with KI (0.12 g, 0.66 mmol) and K₂CO₃ (0.185 g, 1.32 mmol). The mixture was stirred vigorously at 80° C. for 24 h. After this period of time, this mixture was cooled to room temperature, then 20 mL of water was added and the product extracted with Et₂O (3×30 mL). The combined organic layer was washed with brine (2×30 mL), dried over magnesium sulfate and concentrated under vacuum. The residue was purified by flash chromatography [hexanes/ethyl acetate (1:2)] to afford LS2-25 as a white solid (70%).

TLC (hexanes/ethyl acetate. 2:1): R_f=0.4; detection: CMA and UV

¹H NMR (DMSO-d₆): δ 0.5 (m, 1H), 0.70 (m, 1H), 1.01-1.40 (m) 1.60 (m, 3H), 1.80 (m, 1H), 2.55 (m), 2.95 (m, 4H), 3.1 (m, 2), 3.30 (m, 2H), 3.60 (m, 1H), 3.90 (m, 1H), 4.30 (m, 1H), 4.80 (m), 6.80 (m, 3H), 7.05 (m, 6H), 7.60 (2H), 7.95 (m, 1H), 8.20 (m, 1H), 8.25 (m, 1H), 8.90 (s, 2H).

¹³C NMR (CDCl₃): δ 13.84, 15.36, 17.40, 17.70, 19.40, 22.17, 27.52, 28.14, 28.67, 30.29, 31.27, 33.27, 38.01, 40.35, 51.02, 53.08, 54.35, 56.72, 70.25, 73.13, 81.10, 113.49, 120.94, 122.28, 125.44, 127.01, 127.19, 127.19, 127.68, 127.68, 127.79, 128.64, 129.57, 130.06, 136.2, 137.10, 165.10, 170.10, 171.10.

LC-MS (Grad_A4): t_R=15.10 min; Mass found: 892 100 mg of alkylated tripeptide LS2-25 (100 mg, 0.11 mmol) was treated with 2 mL of 50% TFA, 3% triethylsilane (TES) in DCM, then the mixture stirred for 1 h at room temperature. After this period of time, all solvents were removed under reduced pressure. The crude compound LS2-23 was dried using vacuum pump for 1 h and used directly in the next step without further purification.

LC/MS (Grad_A4): t_R=8.55 min; Mass found: 737

Step LS2-D: Synthesis of LS2-26 (Macrolactamization)

##STR01223##

To a stirred suspension of alkylated-tripeptide 23 (0.12 mmol) and DIPEA (0.100 mL, 0.56 mmol) in 11.22 mL of anhydrous THF at room temperature was added DEPBT (41 mg, 0.14 mmol). The mixture was stirred vigorously at room temperature O/N. The reaction was then concentrated to dryness under reduced pressure and the residue dissolved in 10 mL of AcOEt. The organic solution was sequentially washed with citrate buffer solution (1 N, 2×30 mL), saturated NaHCO₃ (2×30 mL) and brine (1×30 mL). The organic layer was dried over anhydrous sodium sulfate, filtered and evaporated to dryness under reduced pressure. The residue was purified by flash chromatography using [ethyl acetate/hexanes (3:1)] to afford LS2-26 (Bts-410) as a white solid (80 mg, 98%).

TLC (ethyl acetate/hexanes, 3:1): R_f=0.3; detection: CMA and UV

H NMR (CDCl₃): δ 0.64 (m, 3H), 0.87 (m, 1H), 1.02 (m, 2H), 1.20 (m, 6H), 1.40 (m, 3H), 1.60 (m, 4H), 1.80 m, 1H0, 2.01 (m, 1H), 2.40 (m, 1H), 2.80 (m, 1H), 3.15 (s, 3H), 3.20 (m, 2H), 3.45 (m, 1H), 3.60-3.80 (m, 2H), 4.40-4.60 (dd, 2H), 4.70 (m, 2H), 5.01 (m, 1H), 5.90 (m, 1H), 6.80 (m, 2H), 6.90 (m, 1H), 7.15-7.25 (m, 7H), 7.60 (m, 2H), 8.01 (m, 1H), 8.10 (m, 1H).

¹³C NMR (CDCl₃): δ 13.28, 13.55, 18.75, 18.98, 28.89, 29.92, 29.92, 33.19, 36.81, 36.98, 39.55, 51.94, 53.83, 55.25, 59.51, 74.64, 111.66, 120.64, 122.51, 125.15, 127.10, 127.37, 127.84, 128.07, 128.86, 129.47, 130.51, 136.55, 137.30, 152.58, 155.86, 165.33, 169.75, 170.09, 171.66.

LC/MS (Grad_A4): t_R=13.17 min; Mass found: 719

LC Chiral (column ODRH, Grad 55A-05): t_R=42.059.

Step LS2-E: Synthesis of Compound 410

##STR01224##

To a stirred suspension of macrocycle LS2-26 (40 mg, 0.003 mmol) in 0.110 mL of DMF was added 23 mg of K₂CO₃ and 10 μl of mercaptopropanoic acid at room temperature, then the reaction left O/N. The reaction was concentrated to dryness under redcued pressure and the crude residue dissolved in 10 mL of AcOEt. The organic solution was washed with a saturated solution of NaHCO₃ (2×30 mL), then brine (1×30 mL). The organic layer was dried over anhydrous sodium sulfate, filtered and evaporated to dryness under reduced pressure. Compound 410 was thus isolated in 90% yield.

TLC (100% AcOEt): R_f=0.2; detection: CMA and UV

¹H NMR (DMSO-d₆): δ 0.79 (m, 3H), 1.20 (m, 9H), 1.30 (M, 1H), 1.60 (m, 1H), 1.90 (m, 1H), 2.10 (Sb, 1H), 2.35 (ddd, J=4.98, 4.95, 4.69 Hz, 1H), 2.56 (Sb, 1H), 2.63 (m, 1H), 2.80 (ddd, J=4.99, 4.69, 4.40 Hz, 1H), 3.01-3.15 (m, 5H), 3.25 (dd, J=4.69, 4.11 Hz, 1H), 3.30 (s, 2H), 3.55 (sb, 1H), 3.95 (q, J=7.33, 7.04 Hz, 1H), 4.50 (sb, 1H), 6.80 (m, 1H), 6.90 (m, 1H), 7.10-7.30 (m, 7H), 7.70 (m, 2H).

¹³C NMR (DMSO-d₆): δ 14.60, 14.84, 18.46, 18.85, 29.80, 29.96, 34.03, 35.84, 36.31, 40.68, 54.79, 55.67, 57.77, 58.11, 73.42, 112.26, 120.58, 126.84, 127.81, 128.80, 129.73, 131.10, 140.10, 158.10, 172.10, 172.40, 176.10.

LC/MS (Grad_A4): t_R=6.19 min; Mass found: 522

EXAMPLE 4

Synthesis and Biological Results for Representative Compound 298

##STR01225## ##STR01226## ##STR01227##

Step LS3-1. Synthesis of cyclopropylglycine methyl ester hydrochloride salt. To a suspension of H—Cpg-OH (LS3-A, 20.0 g, 174 mmol, 1.0 eq) in anhydrous MeOH (350 mL) at 0° C. was slowly added freshly distilled (from PCl₅) acetyl chloride (185 mL, 2.6 mol, 15 eq) over 45 min. The mixture was allowed to warm to room temperature and stirred 16-18 h. The reaction was monitored by TLC [MeOH/NH₄OH/AcOEt (10:2:88); detection: ninhydrin; R_f=0.50]. The mixture was then concentrated under vacuum, azeotroped with toluene (3×) and dried under high vacuum 16-18 h to give LS3-1 as a pale yellow solid (30.0 g, >100% crude yield).

¹H NMR (CD₃OD): δ 4.88 (3H, s, NH₃⁺), 3.85 (3H, s, C H₃O), 3.36-3.33 (1H, d, NH₃⁺CHCH₃O), 1.19-1.10 (1H, m, CH(CH₂)₂), 0.83-0.53 (4H, m, CH(CH₂)₂).

Step LS3-2. Synthesis of tether bromide. To alcohol Cbz-T33a (21.5 g, 62.6 mmol, 1.0 eq) in anhydrous CH₂Cl₂ (250 mL) were added NBS (12.8 g, 72.0 mmol, 1.15 eq, larger amounts of NBS lead to dibrominated side product) and PPh₃ (18.9 g, 72.0 mmol, 1.15 eq). The round bottom flask was protected from light with foil and the mixture stirred at room temperature 16-18 h with monitoring by TLC [AcOEt/Hexanes (3:7); detection: UV and CMA; R_f=0.42]. A saturated aqueous NH₄Cl solution (200 mL) was added and the aqueous phase extracted with CH₂Cl₂ (2×150 mL). The combined organic phases were washed with a saturated aqueous NH₄Cl solution (2×200 mL), dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (AcOEt:hexanes, gradient, 5:95 to 15:85) to give bromide LS3-2 as a slightly yellow oil (22.2 g, 88.4%).

¹H NMR (CDCl₃): δ 7.37-7.26 (5H, m, Ph), 7.19-7.13 (2H, m, Ph), 6.92-6.88 (1H, t, Ph), 6.84-6.81 (1H, d, Ph), 5.10 (2H, s, NHC(O)OCH₂Ph), 4.96 (1H, broad, NHCbz), 4.62-4.56 (1H, sextuplet, PhOCH(CH₃)CH₂Br), 3.58-3.45 (2H, m, C H₂Br), 3.22-3.16 (2H, q, CH₂NHCbz), 2.69-2.64 (2H, t, PhC H₂CH₂), 1.83-1.78 (2H, quint, PhCH₂CH₂), 1.45 (3H, d, CHCH₃).

¹³C NMR (CDCl₃): δ 156.66, 155.08, 136.99, 131.28, 130.77, 128.75, 128.32, 128.28, 127.49, 121.56, 113.03, 73.12, 66.76, 40.69, 36.12, 30.45, 27.48, 19.00.

LC/MS (Grad_A4): t_R=11.04 min

Step LS3-3. The hydrochloride salt LS3-1 was dissolved in an aqueous solution of Na₂CO₃ (1 M, 275 mL, 0.272 mol, 1.5 eq). The basic aqueous phase was saturated with NaCl and extracted with AcOEt/CH₂Cl₂ (2:1) (5×100 mL). TLC [MeOH/NH₄OH/AcOEt (10:2:88); detection: ninhydrin; R_f=0.50]. The combined organic phases were dried over MgSO₄, filtered and concentrated under low vacuum at room temperature to give free amino-ester LS3-3 as a yellow oil (19.1 g, 85%, 2 steps). LS3-3 is volatile and should not be left on a mechanical vacuum pump for extended periods of time. To minimize diketopiperazine formation, Step LS3-4 should occur immediately after isolation of LS3-3.

¹H NMR (CDCl₃): δ 3.70 (3H, s, CH₃O), 2.88-2.85 (1H, d, NH₂CHCH₃O), 1.54 (1H, s, NH₂), 1.04-0.97 (1H, m, C H(CH₂)₂), 0.56-0.27 (4H, m, CH(CH₂)₂).

Step LS3-4. In a dried round-bottom flask, bromide LS3-2 (47.2 g, 117 mmol, 1.0 eq) and freshly prepared LS3-3 (19.1 g, 148 mmol, 1.2 eq) were added. Degassed anhydrous DMF (117 mL), anhydrous Na₂CO₃ (14.8 g, 140 mmol, 1.2 eq) and KI (19.4 g, 117 mmol, 1.0 eq) were added and the mixture was stirred at 100° C. under a nitrogen atmosphere for 16-18 h. Reaction progress was monitored by LC-MS and/or TLC. The mixture was cooled down to room temperature and water (200 mL) added and the aqueous phase extracted with MTBE (3×100 mL). The combined organic phases were washed sequentially with water (2×100 mL) and brine (1×100 mL), dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography [hexanes/AcOEt/DCM, gradient (85:10:5) to (50:45:5)] to give LS3-4 as an orange oil (43.1 g, 81%).

TLC [hexanes/AcOEt (1:1)]: R_f=0.35; detection: UV and CMA

¹H NMR (CDCl₃): δ 7.31-7.22 (5H, m, Ph), 7.07-7.03 (2H, m, Ph), 6.80-6.74 (2H, m, Ph), 5.48 (1H, broad, CH₂N HCHRR′), 5.00 (2H, s, OCH₂Ph), 4.49-4.43 (1H, m, PhOC H(CH₃)R), 3.56 (3H, s, C(O)OCH₃), 3.18-3.11 (3H, m, NHC H(Pr)CO₂Me and CH₂NHCbz), 2.75-2.50 (4H, m, PhC H₂CH₂ and NHCH₂CH(Me)OPh), 1.76-1.68 (2H, m, PhCH₂CH₂), 1.19-1.14 (3H, d, PhOCH(CH₃)R), 0.88-0.80 (1H, m, CH(CH₂)₂), 0.46-0.13 (4H, m, CH(CH₂)₂).

LC/MS (Grad_A4) : t_R=6.63 min

Step LS3-5. To a solution of secondary amine LS3-4 (43.0 g. 94.7 mmol, 1.0 eq) in THF/H₂O (1:1, 475 mL) at 0° C. were added Na₂CO₃ (15.1 g, 113.7 mmol, 1.5 eq) and (Boc)₂O (24.8 g, 142.1 mmol, 1.2 eq). The mixture was allowed to warm to room temperature and stirred 24 h. Reaction was monitored by LC/MS and/or TLC. THF was evaporated under vacuum and the residual aqueous phase was extracted with MTBE (3×100 mL). The combined organic phases were washed with brine (1×100 mL), dried over MgSO₄, filtered and evaporated under vacuum to give the crude LS3-5 as an orange oil (59.1 g, >100% crude yield).

TLC [hexanes/AcOEt (1:1)]: R_f=0.57; detection: UV and CMA

LC/MS (Grad_A4): 12.98 min.

Step LS3-6. To a solution of LS3-5 (52.5 g, 94.7 mmol, 1.0 eq.) in THF/H₂O (1:1, 475 mL) at room temperature was added LiOH monohydrate (19.9 g, 474 mmol, 5.0 eq.). The mixture was stirred 16-18 h at room temperature. The reaction was monitored by LC/MS (Grad_A4): t_R=12.21 min. TLC [Hexanes/AcOEt (1:1); detection: UV and CMA; R_f=baseline]. The reaction mixture was acidified with citrate buffer (1 M, pH 3.5) and THF was then evaporated under vacuum. The residual aqueous phase was extracted with AcOEt (3×150 mL), then the combined organic phases washed with brine (×100 mL), dried over MgSO₄, filtered and concentrated under redcued pressure to give carboxylic acid LS3-6 as a white gummy solid (47.3 g, 93% for 2 steps).

LC/MS (Grad_A4): t_R=12.16 min

Step LS3-7. To a suspension of H-(D)Phe(4F)—OH (LS3-B, 55.6 g, 0.30 mol, 1.0 eq) in benzene (1.2 L) was added p-TSA (69.4 g, 0.37 mol, 1.2 eq) and benzyl alcohol (157 mL, 1.52 mol, 5.0 eq). The mixture was stirred at reflux 16-18 h in a Dean-Stark apparatus during which a homogeneous solution was obtained. The mixture was cooled down to room temperature and a white precipitate formed. The precipitate was diluted with Et₂O (500 mL), filtered and triturated with Et₂O (3×500 mL). The solid was dried under vacuum to give LS3-7 as a white solid (126 g, 93.1%). Substitution of toluene for benzene resulted in reduced reaction time, 2-3 h.

¹H NMR (DMSO-d₆): δ 8.40 (3H, bs, NH₃Cl), 7.47-7.36 (2H, d, Ph), 7.37-7.06 (11H, m, Ph), 5.15 (2H, s, OCH₂Ph), 4.37 (1H, bt, CHCH₂Ph), 3.09-3.05 (2H, m, CHCH₂Ph), 2.27 (3H, s, CH₃Ph).

¹³C NMR (DMSO-d₆): δ 169.52 163.83, 160.62, 140.01, 138.56, 135.48, 132.16, 132.04, 131.33, 131.28, 129.09, 129.05, 128.84, 128.72, 127.09, 126.20, 116.18, 115.89, 67.83, 53.88, 35.83, 21.47.

LC/MS (Grad_A4): t_R=6.12 min

Melting point (uncorrected): 165-167° C.

Step LS3-8._The tosylate salt LS3-7 (122 g) was taken up in an aqueous solution of Na₂CO₃ (1 M, 500 mL). The resulting basic aqueous solution was extracted with AcOEt (4×500 mL) and the combined organic phases were washed with brine (1×250 mL), dried over MgSO₄, filtered and concentrated under redcued pressure to give the amino-ester LS3-8 as a white solid (74.4 g, 99%).

¹H NMR (CDCl₃): δ 7.38-7.28 (5H, m, OCH₂Ph), 7.10-7.06 (2H, m, Ph(4F)), 6.96-6.90 (2H, m, Ph(4F)), 5.13 (2H, d, OCH₂Ph), 3.76-3.71 (1H, t, CHCH₂Ph), (2H, dq, CHC H₂Ph), 1.53 (2H, s, NH₂)

Step LS3-9. To a solution of LS3-8 (74.4 g, 0.27 mol, 1.0 eq) in anhydrous THF/CH₂Cl₂ (1:1, 1120 mL) were added Boc-(D)NMeAla-OH (LS3-C, 57.1 g, 0.28 mol, 1.03 eq), 6-Cl—HOBt (46.2 g, 0.27 mol, 1.0 eq) and DIPEA (238 mL, 1.37 mol, 5.0 eq). The mixture was cooled to 0° C. and EDCI (57.6 g, 0.3 mol, 1.1 eq) was added. The mixture was stirred 1 h at 4° C., allowed to warm to room temperature and stirred 18 h. The solvent was evaporated in vacuo and the residue dissolved in AcOEt (1000 mL). The organic phase was washed sequentially with an aqueous solution of citrate buffer (1 M, pH 3.5, 2×500 mL), H₂O (1×500 mL), an aqueous solution of saturated NaHCO₃ (CAUTION: CO₂ is evolved, 2×500 mL) and brine (1×500 mL). The organic phase was dried over MgSO₄ (180 g), filtered and concentrated under reduced pressure to give crude dipeptide LS3-9 as a yellow oil. (127 g, >100% crude yield).

Step LS3-10. The oil LS3-9 was dissolved in 150 mL of dioxane, then a solution of 4 M HCl in dioxane (1360 mL, 20 eq) added and the mixture stirred for 1 h at room temperature. Reaction was monitored by TLC [AcOEt/Hexanes (3:2)]; R_f=baseline; detection: UV and ninhydrin]. The mixture was concentrated under reduced pressure and the resulting residue co-evaporated with Et₂O (2×500 mL), then dried under vacuum. The crude LS3-10 was obtained as a slightly yellow solid (96 g, 89.7%). This was dissolved in hot 95% EtOH (200 mL), then MTBE (900 mL) added. The mixture was cooled down to room temperature, then put in a freezer (−20° C.) for 18 h. The resulting crystals were collected by filtration and washed with MTBE (2×200 mL), then dried under vacuum to give crystalline dipeptide hydrochloride LS3-10 (62 g, 64.5% recovery).

¹H NMR (DMSO-d₆): δ 9.31-9.28 (1H, d, C(O)NH), 7.38-7.26 (7H, m, Ph), 7.09-7.04 (2H, m, Ph), 5.10 (2H, s, C(O)OC H₂Ph), 4.65-4.57 (1H, m, CHCH₃), 3.76-3.69 (1H, d, C HCH₂Ph), 3.15-3.08 and 2.99-2.91 (CHCH₂ Ph), 2.221 (3H, s, CH₃NH₂⁺Cl⁻), 1.31-1.28 (3H, d, CHCH₃).

¹³C NMR (DMSO-d₆): δ 171.33, 169.18, 137.63, 136.31, 129.92, 129.11, 128.95, 128.83, 128.63, 127.30, 67.00, 56.57, 54.38, 36.98, 31.11, 16.47.

LC/MS (Grad_A4): t_R=6.26 min

LC Chiral (Isol00B_—05): t_R=29.6 min, 97% UV

Melting point (uncorrected): 140-142° C.

Step LS3-11. To a solution of carboxylic acid LS3-6 (47.3 g, 87.6 mmol, 1.0 eq) and dipeptide hydrochloride salt LS3-10 (36.2 g, 91.9 mmol, 1.05 eq) in anhydrous THF/CH₂Cl₂ (1:1) (438 mL) at 0° C. were added DIPEA (92 mL, 526 mmol, 6.0 eq) and HATU (34.9 g, 91.9 mmol, 1.05 eq). The mixture was allowed to warm to room temperature and stirred 16-18 h. Reaction was monitored by TLC [AcOEt/Hex (1:1); R_f=0.48; detection: UV and CMA] The mixture was concentrated under reduced pressure and the residue dissolved in AcOEt (250 mL). The organic phase was washed sequentially with an aqueous solution of citrate buffer (1 M, pH 3.5, 3×150 mL), H₂O (1×150 mL), an aqueous solution of saturated NaHCO₃ (2×150 mL) and brine (1×150 mL). The organic phase was dried over MgSO₄, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography [AcOEt:hexanes, gradient (10:90) to (50:50)] to give LS3-11 as a white gummy solid (70.0 g, 90%).

LC/MS (Grad_A4): t_R=15.06 min

Step LS3-12. To a suspension of 10% Pd/C (13.8 g, 20% by weight) in AcOEt (150 mL) was added a solution of alkylated tripeptide LS3-11 (69.0 g, 78.4 mmol, 1.0 eq) in AcOEt (375 mL), then hydrogen was bubbled through the solution for 16-18 h. The reaction was monitored by TLC [AcOEt/hexanes (1:1); R_f=0.22; detection: UV and CMA]. The mixture was purged by nitrogen bubbling, filtered through a Celite pad and rinsed with AcOEt (3×). The combined filtrate and washings were evaporated under reduced pressure to give LS3-12 as a white solid (51.4 g, 100%).

LC/MS (Grad_A4): t_R=8.05 min

Step LS3-13. To LS3-12 (51.4 g, 78.4 mmol, 1.0 eq) was added a solution of 3.0 M HCl in dioxane/H₂O (75:25, 525 mL, 1.57 mol, 20 eq) and the mixture stirred at room temperature 1.5 h. The solvent was evaporated under vacuum, then the residue was azeotroped with toluene (3×) and dried under vacuum to give crude LS3-13 as an off-white solid (58.0 g, >100% yield).

LC/MS (Grad_A4): t_R=5.38 min.

Step LS3-14. To a solution of macrocyclic precursor LS3-13 (78.4 mmol based on LS3-12, 1.0 eq) in anhydrous THF (1.57 L, 50 mM) were added DIPEA (68.0 mL, 392 mmol, 7.0 eq) and DEPBT (25.8 g, 86.2 mmol, 1.1 eq). The mixture was stirred at room temperature 16-18 h. The reaction was monitored by TLC [MeOH/AcOEt (1:9); R_f=0.38; detection: UV and CMA]. At the end of the reaction, significant quantities of DIPEA salts were in suspension in the solution. Prior to evaporation, these salts were filtered and washed with THF to avoid excessive bumping of the solution during evaporation. The solvent was evaporated under vacuum and the residue taken up in an aqueous solution of Na₂CO₃ (1 M, 500 mL) and AcOEt (250 mL). The separated basic aqueous phase was extracted with AcOEt (2×250 mL). The combined organic phases were washed with brine (2×250 mL), dried over MgSO₄, filtered and evaporated under reduced pressure. The crude material so obtained was purified by flash chromatography [AcOEt:MeOH, gradient (100:0) to (90:10)] to give macrocycle compound 298 as a pale yellow solid (35.0 g. 83%, 2 steps).

LC/MS (Grad_A4): t_R=6.19 min

Step LS3-15. To crude compound 298 (18.5 g, 34.4 mmol, 1.0 eq) in anhydrous EtOH (100 mL) was slowly added 1.25 M HCl in EtOH (41.2 mL, 51.5 mmol, 1.5 eq). The mixture was stirred 5 min, cooled down to 0° C. and filtered while still cold. The white precipitate was washed with cold anhydrous EtOH (3×75 mL) and dried under vacuum to give compound 298 hydrochloride as an amorphous white solid (15.3 g, 88% recovery, corrected).

Purification of Compound 298, Amorphous compound 298 hydrochloride (14.2 g, 24.7 mmol) was dissolved in a hot mixture of EtOH/H₂O (9:1, 215 mL). The solution was cooled down to room temperature and then placed in a freezer (−20° C.) for 16-18 h. The crystals were collected by filtration and washed with cold anhydrous EtOH (3×75 mL) to give compound 298 hydrochloride as a crystalline white solid (12.4 g, 86% recovery). Crystalline compound 298 hydrochloride (11.4 g, 19.9 mmol) was taken up in 1 M Na₂CO₃/AcOEt (1:1, 200 mL) and stirred until complete dissolution of the solid. The separated basic aqueous phase was extracted with AcOEt (2×50 mL). The combined organic phases were washed with brine (1×50 mL), dried over MgSO₄, filtered and evaporated under vacuum. The oily residue was dissolved in a minimum amount of AcOEt, then hexanes was added until a white precipitate formed. The mixture was evaporated and dried under vacuum to give compound 298 as a white amorphous solid (11.1 g, 100% recovery).

LC/MS (Grad_A4): 6.18 min; Purity (UV/ELSD/CLND): 100/100/100.

This reaction sequence has been repeated in comparable yields starting from 1 kg Cbz-T33a, 518 g LS3-A and 1 kg LS3-B to yield over 400 g of the desired macrocyclic product compound 298 and/or the corresponding HCl salt form. Similar procedures can be applied for other compounds of the invention.

As an alternative, the t-butyl ester of Cpg (LS3-14), produced under standard conditions, can be utilized as was described in Step LS3-4 to provide alkylated Cpg LS3-15 by reaction with Cbz-T33a. This species, without protection of the secondary amine on LS3-16 (produced by standard acid deprotection of the t-butyl ester of LS3-15), then undergoes chemoselective coupling with dipeptide LS3-10 to prepare LS3-17. Straightforward simultaneous hydrogenolysis of both Cbz and benzyl protecting groups then leads to intermediate LS3-13 in a more efficient approach that avoids two steps.

##STR01228##

Step LS3-17. To the hydrochloride salt of carboxylic acid LS3-16 (2.1 g, 4.41 mmol, 1.0 eq) and LS3-10 (1.7 g, 4.59 mmol, 1.05 eq) in anhydrous THF/CH₂Cl₂ (1:1, 22 mL) at 0° C. were added DIPEA (5.3 mL, 30.6 mmol, 7.0 eq) and HATU (1.7 g, 4.59 mmol, 1.05 eq). The mixture was allowed to warm to room temperature and stirred 16-18 h. The reaction was monitored by LC-MS. The mixture was concentrated under reduced pressure and the residue dissolved in AcOEt (150 mL). The organic phase was washed sequentially with an aqueous solution of citrate buffer (1 M, pH 3.5, 3×25 mL), H₂O (1×25 mL), an aqueous solution of saturated NaHCO₃ (2×25 mL) and brine (1×25 mL). The organic phase was dried over MgSO₄, filtered and concentrated under vacuum to give LS3-17 as a white solid (3.5 g, >100% crude yield).

LC/MS (Grad_A4): t_R=12.09 min.

Step LS3-18. To a suspension of 10% Pd/C (596 mg, 20% by weight) in 95% EtOH (10 mL) was added a solution of alkylated tripeptide LS3-17 (3.0 g, 3.82 mmol, 1.0 eq) in AcOEt (15 mL) and hydrogen bubbled through the solution for 2 h. The mixture was then stirred under a hydrogen atmosphere for 16-18 h. The reaction was monitored by TLC [100% AcOEt; R_f=Baseline; detection: UV and CMA]. The mixture was purged by nitrogen bubbling, filtered through a Celite pad and rinsed with 95% EtOH (3×20 mL). The combined filtrate and rinses were evaporated under reduced pressure to give LS3-13 as a white solid (2.0 g, 94%).

LC/MS (Grad_A4): t_R=5.40 min.

B. Biological Results

1. Radioligand Binding Assay on Ghrelin Receptor (Human Clone, hGHS-R1a)

Objective

• • 1. To demonstrate that compound 298 has a direct, high affinity interaction with hGHS-R1a.
    Key Aspects of Method
  • 1. Binding performed on membranes prepared from HEK293 expressing the transfected, cloned human ghrelin receptor (hGHS-R1a).
  • 2. [¹²⁵I]Ghrelin was used as the radioligand for displacement (K_d=0.01 nM, test concentration=0.007 nM).
  • 3. Ghrelin (unlabeled, 1 μM) was used to determine non-specific binding.
  • 4. Compound 298 tested in duplicate samples over an 11-point concentration curve.
    Results

Compound 298 binding to hGHS-R1a has been run multiple times. A representative binding inhibition curve as shown in FIG. 10 demonstrates that compound 298 binds competitively, reversibly, and with high affinity to hGHS-R1a.

2. Cell-Based, Functional Assays on Ghrelin Receptor (Human Clone, hGHS-R1a)

Objectives

• • 1. To demonstrate that compound 298 is a full agonist at hGHS-R1a.
  • 2. To measure the potency of compound 298 agonist activity at hGHS-R1a.
    Key Aspects of Method
  • 1. Assay performed on CHO—Kl cells expressing the transfected, cloned human ghrelin receptor (hGHS-R1a) and G_α16.
  • 2. Suspended cells incubated O/N with coelenterazine.
  • 3. Stimulation of hGHS-R1a activates G_α16, causing intercellular Ca2+ release which ultimately leads to the oxidation of coelenterazine and the emission of a quantitative luminescent signal.
  • 4. Ghrelin was used as the positive control.
  • 5. Compound 298 tested in duplicate samples over an 8-point concentration curve.
    Results

Compound 298 activates hGHS-R1a with an EC₅₀=25 nM as shown in FIG. 11. Compound 298 is a full agonist based on its similar, maximal efficacy to the ghrelin peptide (positive control).

3. Compound 298 (i.v.) Effect on Growth Hormone (GH) Release in Conscious, Freely-Moving Rats.

Ghrelin (and analogues thereof) is known to potently stimulate GH release from the pituitary in various species including rat following intravenous dosing.

Objectives

• • 1. To determine whether compound 298 stimulates GH release in rat.
  • 2. To determine whether compound 298 modulates ghrelin-induced GH release in rat.
    Method
  • 1. Model adapted from Tannenbaum et al. (2003), Endocrinology 144:967-974.
  • 2. Rats implanted with chronic, intravenous (i.v.) cannulae.
  • 3. Rats allowed to move freely even while dosing drug or sampling blood to minimize stress-induced changes in GH release.
  • 4. Compound 298 administered at GH peak and trough levels to measure:
    • a. Stimulatory effect, if any, on GH release; and
    • b. Whether any stimulatory effect is sustained with repeated dosing.
  • 5. Blood samples are drawn at defined, 15-minute intervals throughout the test day and growth hormone (GH) measured directly by radioimmunoassay.
  • 6. Compound 298 tested at 3, 30, 300, 1000 μg/kg (i.v., N=5-6/rats per group).
  • 7. Ghrelin (positive control) tested at 5 μg (i.v.).
    Results

Compound 298 at doses up to 1000 μg/kg causes no significant difference in pulsatile GH release in comparison to vehicle controls (see FIG. 9 for effects of 30 μg/kg and 300 μg/kg doses). Ghrelin at a dose of 5 μg causes a significant increase in GH release when dosed at both peak and trough levels (positive control). Compound 298 dosed 10 min. prior to ghrelin neither inhibits nor augments ghrelin-induced GH release (FIG. 12). As a secondary indicator of GH release, the effects of compound 298 on the levels of IGF-1 were also examined at the 1000 μg/kg dose. No appreciable changes in IGF-1 levels from control upon treatment with compound 298 were observed.

4. Compound 298 Effect on hGHS-R1a Receptor Desensitization

G-protein coupled receptors can undergo receptor desensitization upon agonist stimulation, where the degree of receptor desensitization is partly characteristic of the agonist. Lesser receptor desensitization is desirable because this correlates with lesser development of tolerance with chronic use of drug. This factor, among others, has been implicated in the poor clinical performance of GHS.

Objective

• • 1. To determine the extent to which Compound 298 causes desensitization of the ghrelin receptor (human clone, hGHS-R1a).
    Method
  • 1. Studies by FLIPR (Fluorometric Imaging Plate Reader, Molecular Devices).
  • 2. Assay performed on HEK293 cells expressing hGHS-R1a.
  • 3. Compound 298 agonist potency was measured using duplicate samples over a 12-point concentration curve; EC₅₀ for compound 298 established.
  • 4. In a separate experiment, cells expressing hGHS-R1a are exposed to a range of concentrations of compound 298 (1, 10, 100, 1000 nM) for 3 minutes. Compound 298 washed out, then cells treated with a concentration of ghrelin (EC₁₀₀) that elicits maximal stimulation at non-desensitized receptors.
  • 5. A DC₅₀ value is calculated. The DC₅₀ value is defined as the pre-treatment concentration of compound 298 that desensitizes the ghrelin (EC₁₀₀) response by 50%.
    Results

Compound 298 is a full agonist (EC₅₀=5 nM; FIG. 13A). Increasing pre-treatment concentrations of compound 298 desensitize the maximal response to EC₁₀₀ ghrelin (DC₅₀=32 nM; FIG. 13B). The DC₅₀ value is >6-fold less potent than the EC₅₀ value, thus compound 298 stimulates the receptor more potently than it desensitizes the receptor. Compound 298 desensitizes the receptor ˜10-fold less potently than other ghrelin agonists (i.e. ghrelin peptide and the GHS capromorelin [Pfizer]; FIG. 13C).

Compound 298 has a favorable desensitization profile since it (1) stimulates the receptor 6-fold more potently that it desensitizes the receptor and (2) elicits desensitization at a 10-fold lower potency than the endogenous ligand (i.e. ghrelin) and alternate, small-molecule ghrelin agonists. Accordingly, compound 298 may elicit less tolerance than alternate ghrelin agonists with chronic dosing.

5. Compound 298 Effect on Gastric Emptying of a Solid Meal in Naïve Rat

Objectives

• • 1. To ascertain data for compound 298 as a prokinetic agent with potent effects on gastric emptying, a model for gastroparesis.
    Methods
  • 1. Overnight-fasted rats (male, Wistar, ˜200 g, N=5/group) were given a meal of methylcellulose (2%) by intragastric gavage. The meal was labeled with phenol red (0.05%).
  • 2. Test articles (i.e, vehicle, compound 298, metoclopramide, etc.) were administered by intravenous injection immediately after meal.
  • 3. Animals were sacrificed 15 minutes later; the stomach was immediately removed and homogenized in 0.1 N NaOH and centrifuged.
  • 4. Total phenol red remaining in the stomach was quantified by a colorimetric method at 560 nm.
  • 5. A >30% increase in gastric emptying, detected based on the phenol red concentration in comparison to the control group, is considered significant.
    Results

Metoclopramide (marketed gastroparesis product), ghrelin and GHRP-6 (reference peptide agonists at hGHS-R1a) all demonstrated significant gastric emptying (FIG. 14A). Compound 298 caused significant gastric emptying in a dose-dependent manner with ˜100-fold superior potency to metoclopramide (FIG. 14B). Compound 298 potently stimulated gastric emptying of a solid meal in naïve rats with a 100-fold superior potency to metoclopramide, a currently used drug with prokinetic activity.

6. Effect of Compound 298 in the Treatment of Post-Operative Ileus in Rat

Objective

To measure the therapeutic utility of compound 298 in a rat model of post-operative ileus (POI).

Methods

• • 1. Model adapted from Kälff et al. (1998), Ann Surg 228: 652-63.
  • 2. Rats (male, Sprague-Dawley, 250-300 g) were implanted with jugular vein catheters to accommodate dosing of test articles.
  • 3. Rats were fasted O/N, anesthetized with isofluorane and subjected to abdominal surgery.
  • 4. Following an abdominal incision, the small intestine caecum and large intestine were eviscerated for a period of 15 min and kept moist with saline.
  • 5. A “running of the bowel” was performed, a clinically-relevant manipulation of the intestines characterized by first pinching the upper small intestine and continuing this manipulation down through the large intestine.
  • 6. Rats are allowed a 15 min recovery beginning after the disappearance of any effects of the isofluorane anesthesia.
  • 7. Rats are dosed with vehicle or compound 298 (30, 100, or 300 μg/kg, i.v., N=6/gp) followed by intragastric gavage of ^99mTc methylcellulose (2%) meal.
  • 8. After 15 min, the rats were euthanized and the stomach and consecutive 10 cm segments of the intestine were isolated. Radioactivity (^99mTc) in each tissue isolate was measured as a means of measuring the transit of the meal.
    Results

In FIG. 15, the distribution of the bars indicates the distribution of the meal in the stomach (‘ST’) and consecutive 10 cm segments of the small intestine at 15 min post-oral gavage. Abdominal surgery coupled with a running of the bowel caused a significant ileus in rats as determined by comparison of the naïve (i.e. unoperated) and POI treatment groups. Compound 298 significantly increased gastric emptying and intestinal transit at test concentrations of 100 and 300 μg/kg (i.v.). The data corresponding to the 100 μg/kg dose is presented in FIG. 15. At 100 μg/kg (i.v.). compound 298 significantly promoted GI transit by 2.7× as measured by the geometric center of the meal in comparison to the POI+vehicle treatment group. Compound 298 significantly improved gastric emptying and intestinal transit in rats with post-operative ileus. Compound 298 can effectively treat an existing, post-surgical ileus; thus, prophylactic use prior to surgery is not required as is the case for opioid antagonists in clinical development.

7. The Effect of Compounds of the Invention on Gastric Emptying and Gastrointestinal Transit in a Model of Opioid-Delayed Gastric Emptying

Opioid analgesics, such as morphine, are well known to delay gastrointestinal transit which is an important side-effect for this class of drugs. The clinical term for this syndrome is opioid bowel dysfunction (OBD). Importantly, patients recovering from abdominal surgery experience post-operative ileus that is further exacerbated by concomitant opioid therapy for post-surgical pain.

Objective

• 1. To determine whether compounds of the invention may have therapeutic utility in the treatment of OBD.
  Methods
• 1. Rats (male, Sprague-Dawley, 250-300 g) are implanted with jugular vein catheters to accommodate dosing of test articles.
• 2. Overnight-fasted rats are administered morphine (3 mg/kg s.c.).
• 3. After 30 min, rats are to be dosed with vehicle or compound 298 (300 or 1000 μg/kg, i.v., n=4-to-6/gp) followed by intragastric gavage of ^99mTc methylcellulose (2%) meal,
• 4. After 15 min, the rats are euthanized and the stomach and consecutive 10 cm segments of the intestine are isolated, Radioactivity (^99mTc) in each tissue isolate is measured as a means of measuring the transit of the meal.
  Results

Morphine (3 mg/kg, s.c.) significantly delayed gastric emptying and intestinal transit in rats (FIG. 16A). Opioid-delayed gastrointestinal transit was effectively reversed in a dose-dependent manner by treatment with compound 298 (i.v.) (FIG. 16B).

8. Metabolic Stability in Human Plasma

Drugs are susceptible to enzymatic degradation in plasma through the action of various proteinases and esterases. Thus, plasma stability is often performed as a metabolic screen in the early phases of drug discovery. The aim of this study was to measure the metabolic stability of compounds of the invention in human plasma.

Experimental Method

The stability of compound 298 in human plasma at 37° C. has been measured at 2 and 24 h. Two forms of compound 298 have been studied: free amine and corresponding HCl salt. Also, the stability of compound 298 has been established in plasma alone and in plasma buffered with phosphate-buffered saline (PBS) where the ratio of plasma to phosphate buffer (pH 7.0) is 20:1. Assays were both performed and analyzed in triplicate samples. Compound 298 was extracted from plasma matrix using an SPE technique (Oasis MCX cartridge). Sample analysis is done using LC-MS in APCI⁺ mode. The level of compound 298 in plasma samples is compared to the level of compound 298 in a spiked sample stored at −60° C. from the same pool of plasma. Results are presented as a percent recovery of compound 298.

TABLE 8
Percent Recovery of Compound 298 Following Incubation in Human
Plasma (37° C.).
		Free Amine +		HCl Salt +
	Free amine	PBS	HCl Salt	PBS
	2	24	2	24	2	24	2	24
	Hours	Hours	Hours	Hours	Hours	Hours	Hours	Hours
Triplicates	(%)	(%)	(%)	(%)	(%)	(%)	(%)	(%)
Assay #1	101.0	105.5	98.3	97.9	100.2	96.6	102.9	97.8
Assay #2	100.3	95.6	100.4	100.8	99.1	104.3	97.4	101.9
Assay #3	101.3	100.9	98.3	101.9	101.6	102.3	99.4	98.5
Mean	100.9	100.7	99.0	100.2	100.3	101.1	99.9	99.4
Standard	0.5	4.9	1.2	2.1	1.3	4.0	2.7	2.2
Deviation
RSD	0.5	4.9	1.3	2.1	1.3	4.0	2.7	2.2

As shown in Table 8, compound 298 is stable in human plasma at 37° C. for at least 24 hours independent of compound form (i.e. free amine or salt) or whether or not the plasma samples are pH buffered with PBS.

9. Compound 298 Interaction Profile at Nine Human Cytochrome P450 Enzyme Subtypes

Compound 298 (0.0457 to 100 μM) has minimal inhibitory activity at all cyp450 enzymes tested, except cyp3A4, and has moderate inhibitory activity at cyp3A4. The inhibitory activity observed for compound 298 at cyp3A4 was not anticipated to be physiologically relevant based on the low doses of compound 298 required for therapeutic activity. Also, there was no indication that compound 298 would undergo a drug-drug interaction with opioid analgesics that may be co-administered to POI patients.

10. Compound 298 Profile in hERG Channel Inhibition

Compound 298 (1, 10 μM) had no significant effect on hERG channel function in comparison to vehicle (0.1% DMSO) controls. E-4031 (positive control) completely inhibited hERG channel currents at 500 nM.

EXAMPLE 5

Gastroparesis Animal Model

High caloric meals are well known to impede gastric emptying. This observation has recently been exploited by Megens, A. A.; et al. (unpublished) to develop a rat model for delayed gastric emptying as experienced in gastroparesis.

Materials

• 1. Wistar rats, male, 200-250 g
• 2. Chocolate test meal: 2 mL Clinutren ISO® (1.0 kcal/mL, Nestle S A, Vevey Switzerland)
  Method

The test meal is given to the subjects by oral gavage at time=0. After 60 min, the subjects are sacrificed, the stomachs excised and the contents weighed. Untreated animals experienced a significant delay in gastric emptying as denoted by the higher residual stomach content.

Test compounds were administered intravenously as aqueous solutions, or solutions in normal saline, at time=0 at three dose levels (0.08 mg/kg; 0.30-0.31 mg/kg, 1.25 mg/kg). When necessary, for example compounds 21, 299 and 415, 10% cyclodextrin (CD) was added to solubilize the material. Test compounds examined utilizing subcutaneous injection are administered at time=−30 min. Four to five (4-5) rats were tested per group, except in the case of the cyclodextrin control in which ten (10) rats comprised the group.

Results are reported as percentage relative to the stomach weight for injection only of solvent as a control as shown in FIGS. 17A and 17B and illustrate the gastric emptying capability of the compounds of the present invention. These results are applicable for the utility of these compounds for the prevention and/or treatment of gastroparesis and/or post-operative ileus.

The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.

Claims

1. A method of stimulating gastrointestinal motility comprising administering to a subject in need thereof an effective amount of a compound selected from the group consisting of the following:

2. The method of claim 1, wherein the compound is administered orally.

3. The method of claim 1, wherein the compound is administered parenterally.

4. The method of claim 3, wherein the compound is administered intracranially.

5. The method of claim 1, wherein the compound is co-administered with an additional agent useful for stimulating gastrointestinal motility.

6. A method of treating a gastrointestinal disorder comprising administering to a subject in need thereof an effective amount of a compound selected from the group consisting of the following:

7. The method of claim 6, wherein the gastrointestinal disorder is characterized by gastrointestinal dysmotility.

8. The method of claim 6, wherein the gastrointestinal disorder is postoperative ileus, gastroparesis, opioid-induced bowel dysfunction, chronic intestinal pseudo-obstruction, short bowel syndrome, emesis, constipation-predominant irritable bowel syndrome (IBS), delayed gastric emptying, gastroesophageal reflux disease (GERD), gastric ulcers, or Crohn's disease.

9. The method of claim 8, wherein the gastroparesis is diabetic gastroparesis.

10. The method of claim 6, wherein the compound is administered orally.

11. The method of claim 6, wherein the compound is co-administered with an additional agent useful for treating a gastrointestinal disorder.

12. A method of treating postoperative ileus in a subject comprising administering to a subject in need thereof an effective amount of a compound selected from the group consisting of the following:

13. The method of claim 12, wherein the compound is administered intravenously.

14. The method of claim 12, wherein the compound is administered subcutaneously.

15. A method of treating gastroparesis in a subject comprising administering to a subject in need thereof an effective amount of a compound selected from the group consisting of the following:

16. The method of claim 15, wherein the gastroparesis is diabetic gastroparesis.

17. The method of claim 15, wherein the compound is administered intravenously.

18. The method of claim 15, wherein the compound is administered subcutaneously.