WO2009153566A1 - Cyp26 inhibitors - Google Patents

Abstract

A compound of formula (I) wherein X is selected from O, S, NH or CH₂; R^d and R^p are optional naphthyl group substituents; R^Het is imidazolyl, triazolyl or pyridyl; and R^c is C_1-4 alkyl substituted by a group selected from: hydroxy, amino, amido, carboxy, C_1-7 alkyl ester, C_5-7 aryl-C_1-2 alkyl ester, sulfonamino, sulfinamino, hydroxamino and tetrazolyl.

Description

CYP26 INHIBITORS

The present invention relates to compounds which act as an inhibitor of CYP26, their use and synthesis.

Retinoic acid (RA) is a naturally occurring retinoid, the main biologically active derivative of vitamin A (retinol). Retinoic acid regulates cell growth and differentiation in a variety of cell types. RA binds to transcription-regulatory factors in the cell nucleus known as RAR (retinoic acid receptor) and RXR (retinoid X receptor), each having subtypes α, β and γ. RA controls transcription by binding to RAR/RXR dimers, which locally modifies chromatin structure. RA exists in several isomeric forms, including a\\-trans retinoic acid (ATRA), 13- cis retinoic acid (13cisRA) and to a lesser extent 9-c/s retinoic acid (9cisRA). ATRA is the natural ligand for the retinoic acid receptors (RARs: α, β and γ) while 9cisRA binds both RARs and retinoid X receptors (RXRs: α, β and γ). All RA isomers will readily isomerise in biological systems but conversion to ATRA is thermodynamically favoured. Unless otherwise specified herein, the terms "retinoic acid" or "RA" refer to any isomeric form of retinoic acid, or a mixture thereof.

As a key signalling molecule, RA's intracellular concentrations are regulated by negative feedback controls tightly coupled to requirements for signalling in relation to cell differentiation and morphogenesis.

RA has been used in a number of clinical situations, including oncology, for example acute promyelocytic leukemia (Estey, E. H., ef al., M. Blood, 94, 2230 (1999); Fenaux, P.; et al., L. Blood , 94, 1192 (1999); neuroblastoma (Matthay, K.K., ef al., New England Journal of Medicine, 341, 1165-1173 (1999); Veal, G. J., et al., British Journal of Cancer, 96, 424-431 (2007)); and prostate cancer (Debruyne, F.J. M., et al., Urology, 52, 72-81 (1998)). RA has also been used in dermatology (acne, psoriasis (Ahmad, N. and Mukhtar, H.J. Investig. Dermatol., 123, 417 (2004), Brecher, A.R. and Orlow, S.J., J. Am. Acad. Dermatol., 49, 171 (2003))).

RA may improve the efficacy of other treatments such as radiation, cisplatin and interferon therapies (Weiss, G. R., et al., Gynecol. Oncol., 71 , 386 (1998); Pettersson, F., et al., Pancreas, 23, 273. (2001)). Biochemical results also support lower retinoid supply, synthesis, impaired transport, and hypofunction as contributing factors to late onset Alzheimer's disease (LOAD) (Goodman, A.B. and Pardee, A.B., Proc. Nat. Acad. Sci. USA, 100, 2901 (2003)) suggesting that increasing endogenous levels of RA may modify memory performance via the promotion of both adult neurogenesis and adult synaptic plasticity (Jacobs, S., et a/., Proc. Nat. Acad. Sci. USA, 103, 3902 (2006)).

However, natural and induced resistance to RA as well as local and systemic toxicity limit the potential of RA in the treatment of these diseases and as a therapeutic strategy for a wider range of diseases e.g. other cancers.

AW-trans RA has a short half-life and its potency is reduced when administered systemically, owing to metabolism by several human liver and intestine cytochrome P450 enzymes to the inactive 4-hydroxy-RA and then by dehydrogenases to the partially active 4-keto-RA and the inactive polar metabolites.

The low stability and metabolism of ATRA result in poor pharmacokinetic properties in vivo and necessitate the use of ATRA at doses which can result in significant toxicity. Evidence (Giannini, F., et al., International Journal of Cancer, 70, 194-200 (1997); Tsukada, M., et ai, Journal of Investigative Dermatology, 115, 321-327 (2000); Veal, G. J. et ai, Biochemical Pharmacology, 63, 207-215 (2002); Pontham, F., et a/., Medical Pediatric Oncology, 36,

127-131 (2001); Armstrong, J. L., et al., Biochemical Pharmacology, 69, 1299-1306 (2005)) supports the hypothesis that 13cisRA acts as a pro-drug, generating ATRA through isomerisation. 13cisRA is more stable in plasma and used therapeutically for children with neuroblastoma as a result of its lower toxicity. However, while the use of 13cisRA can reduce the problem of poor pharmacokinetic properties of ATRA, the metabolism of ATRA resulting from negative feedback controls within target cells is an important factor limiting its clinical potential.

The endogenous metabolism of ATRA occurs primarily via oxidation, with C-4 hydroxylation of the cyclohexenyl ring leading to formation of 4-hydroxy-ATRA, the most prominent metabolite. A number of cytochrome P450 enzymes, primarily CYP2C8, CYP3A4 and CYP2C9, can perform this oxidation but their contribution to RA metabolism may be relatively minor due to with high K_m values. The main route of RA catabolism, likely to represent the main negative feedback control of intracellular RA concentrations, is via a family of RA-inducible P450s, P450RAI or CYP26. In living tissues, a\\-trans RA administration induces CYP26, which recognizes only RA as its substrate, and the expression of this isozyme can be induced by ATRA both in vitro and in vivo. The induction of CYP26 has been reported in a wide range of cells and tissues after RA treatment and RA-treated cells transfected with full length CYP26 accumulate polar metabolites at an increased rate. Evidence is growing that RA resistance is related to up- regulation of CYP26 resulting in accelerated metabolism of RA. For example, a relationship between induction of ATRA metabolism and drug resistance has been demonstrated in acute promyelocytic leukaemia (APL) patients.

Three members of the CYP26 family have now been identified: CYP26A1 and CYP26B1 which metabolise ATRA in the embryo and adult, and more recently, CYP26C1 that may have a role in the specific metabolism of both a\\-trans and 9-c/s isomers of RA. The dose- dependent induction of CYP26 mRNA has been used as a sensitive marker of retinoid response: in SH-SY5Y neuroblastoma cells, CYP26 mRNA is normally undetectable but treatment with ATRA results in the dose-dependent induction of CYP26A1 and CYP26B1 mRNA and increased metabolism of ATRA within 24 hours.

An inhibitor of the metabolism of endogenous RA, limiting the negative feedback control, would be expected to have a beneficial effect on cell growth and differentiation, as a RA- mimetic, with considerable therapeutic potential.

Knockdown of CYP26 expression using silencing RNA in vitro inhibits ATRA metabolism and this emphasizes the role of CYP26 in ATRA metabolism and the potential for the development of RA metabolism blocking agents (RAMBAs) specifically targeting CYP26 for clinical use in cancer and other diseases.

CYP26 inhibitors have proven to be effective in blocking catabolic effects on ATRA and have demonstrated an increase in endogenous ATRA levels. Therefore administering a CYP26 inhibitor alone or in conjunction with exogenously administered ATRA would both be therapeutically beneficial.

Potentiating endogenous ATRA through inhibition of CYP26 may avoid the frequency and severity of complications associated with intensive high dose ATRA therapy and may provide an effective means of treatment following relapses in cases where resistance emerges due to CYP26 upregulation.

A number of retinoic acid metabolism blocking agents (RAMBAs) have been described, and have recently been reviewed by Njar (Njar, V.C.O., ef a/., J. Bioorg. Med. Chem., 14, 4323 (2006)).

The following compound, liarozole:

developed by Janssen Pharmaceuticals (and disclosed in EP 0 260 744), has been evaluated clinically in prostate cancer. While clinical results were initially promising, liarozole in this context has been discontinued owing to adverse side effects which have been attributed to a lack of CYP isoform specificity. R115866 and R116010:

also developed by Janssen Pharmaceuticals (and disclosed in WO 97/49704), are potent and selective inhibitors of retinoic acid metabolism. R115866 increases endogenous RA levels in rats after a single oral dose (Stoppie, P., ef a/., Journal of Pharmacology & Experimental Therapeutics, 293, 304-312 (2000)) and recent data indicate that R115866 is beneficial in the treatment of acne and psoriasis (Verfaille, CJ. ; Steijlen, P.M.; van der Kerkhof, P.C.M.; Stoppie, P.; Van Wauwe, J. P.; van Rossem, K. (2007) R115866 (rambazole): a potential alternative for retinoids in the treatment of psoriasis. Journal of the European Academy of Dermatology and Venereology 21 : 21-21 Suppl. 1.; Bovenschen, H.J., ef a/., British Journal of Dermatology, 156, 263-270 (2007)). R116010 inhibits ATRA metabolism in neuroblastoma both in vitro and in vivo (Armstrong, J. L., ef a/., British Journal of Cancer, 92, 696-704 (2005); Armstrong ,J.L, et al., British Journal of Cancer, 96, 1675- 168 (2007)). The present inventors have discovered CYP26 inhibitors which can therefore act as retinoic acid metabolism blocking agents (RAM BAs). The compounds may possess improved biological activity over known CYP26 inhibitors, and/or greater selectivity for CYP26 over other CYPs.

Accordingly, the first aspect of the invention provides a compound of formula (I):

(or an isomer, salt, solvate, chemically protected form or prodrug thereof) wherein

X is selected from O, S₁ NH or CH₂;

R^d and R^p are optional naphthyl group substituents;

R^Het is imidazolyl, triazolyl or pyridyl,

R^c is C₁-4 alkyl substituted by a group selected from: hydroxy, amino, amido, carboxy, C_1-7 alkyl ester, C_5-7 aryl-C_1-2 alkyl ester, sulfonamino, sulfinamino, hydroxamino and tetrazolyl.

The compound of formula (I) can be of formula Ia or Ib:

The optional naphthyl group substituents may be selected from, but not limited to, C₁-₇ alkyl, C₃-₂₀ heterocyclyl, C₅-₂₀ aryl, halo, hydroxy, ether, nitro, cyano, acyl, ester, amido, amino, acylamido, ureido, acyloxy, thiol, thioether, sulfoxide, sulfonyl, thioamido, sulfonamino, sulfinamino and hydroxamino. A second aspect of the invention provides a composition comprising a compound of the first aspect of the invention and a pharmaceutically acceptable carrier or diluent.

A third aspect of the invention provides a compound of the first aspect of the invention or a composition of the second aspect of the invention for use in a method of therapy.

A fourth aspect of the invention provides the use of a compound of the first aspect of the invention or a composition of the second aspect of the invention in the preparation of a medicament for treating diseases which are ameliorated by the inhibition of CYP26 mediated retinoic acid metabolism. The fourth aspect of the invention also provides a compound of the first aspect of the invention or a composition of the second aspect of the invention for use in the treatment of diseases which are ameliorated by the inhibition of CYP26 mediated retinoic acid metabolism

A fifth aspect of the invention provides the use of a compound of the first aspect of the invention or a composition of the second aspect of the invention in combination with RA in the preparation of a medicament for treating diseases which are ameliorated by administration of RA. The fifth aspect of the invention also provides a compound of the first aspect of the invention or a composition of the second aspect of the invention in combination with RA for use in the treatment of diseases which are ameliorated by administration of RA.

Diseases which are ameliorated by the inhibition of CYP26 mediated retinoic acid metabolism and diseases which are ameliorated by administration of RA may include, but are not limited to: (a) Cancer, e.g. acute promyelocytic leukaemia, neuroblastoma, acute myelogenous leukaemia, basal cell and squamous cell carcinomas, prostate cancer, breast cancer; which may include combination with radiotherapy, and chemotherapy;

(b) Dermatological disorders, e.g. acne, psoriasis, ichthyosis;

(c) Late onset Alzheimer's disease (LOAD).

A sixth aspect of the invention provides an active compound as described herein for use in a method of treatment of the human or animal body, preferably in the form of a pharmaceutical composition. A seventh aspect of the invention provides a method of inhibiting metabolism of retinoic acid by CYP26 in vitro or in vivo, comprising contacting a cell with an effective amount of an active compound as described herein.

Definitions

Alkyl: The term "alkyl" as used herein, pertains to a monovalent moiety obtained by removing a hydrogen atom from a carbon atom of a hydrocarbon compound having from 1 to 20 carbon atoms (unless otherwise specified), which may be aliphatic or alicyclic, and which may be saturated or unsaturated (e.g. partially unsaturated, fully unsaturated). Thus, the term "alkyl" includes the sub-classes alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cylcoalkynyl, etc., discussed below.

In the context of alkyl groups, the prefixes (e.g. C_1-4, C_1-7, Ci_-2o, C_2-7, C3-7, etc.) denote the number of carbon atoms, or range of number of carbon atoms. For example, the term "C₁.₄ alkyl", as used herein, pertains to an alkyl group having from 1 to 4 carbon atoms. Examples of groups of alkyl groups include Ci_-4 alkyl ("lower alkyl"), Ci_-7 alkyl, d.₁₀ alkyl and C_L20 alkyl. Note that the first prefix may vary according to other limitations; for example, for unsaturated alkyl groups, the first prefix must be at least 2; for cyclic alkyl groups, the first prefix must be at least 3; etc.

Examples of (unsubstituted) saturated alkyl groups include, but are not limited to, methyl (C₁), ethyl (C₂), propyl (C₃), butyl (C₄), pentyl (C₅), hexyl (C₆), heptyl (C₇), octyl (C₈), nonyl (C₉), decyl (C₁0), undecyl (C₁₁), dodecyl (C₁₂), tridecyl (C₁₃), tetradecyl (C₁₄), pentadecyl (C₁₅), and eicodecyl (C₂₀).

Examples of (unsubstituted) saturated linear alkyl groups include, but are not limited to, methyl (C₁), ethyl (C₂), n-propyl (C₃), n-butyl (C₄), n-pentyl (amyl) (C₅), n-hexyl (C₆), and n- heptyl (C₇).

Examples of (unsubstituted) saturated branched alkyl groups include iso-propyl (C₃), iso-butyl (C₄), sec-butyl (C₄), tert-butyl (C₄), iso-pentyl (C₅), and neo-pentyl (C₅).

Alkenyl: The term "alkenyl", as used herein, pertains to an alkyl group having one or more carbon-carbon double bonds. Examples of groups of alkenyl groups include C_2-4 alkenyl, C_2-7 alkenyl, C_2-2O alkenyl. Examples of (unsubstituted) unsaturated alkenyl groups include, but are not limited to, ethenyl (vinyl, -CH=CH₂), 1-propenyl (-CH=CH-CH₃), 2-propenyl (allyl, -CH-CH=CH₂), isopropenyl (1-methylvinyl, -C(CH₃)=CH₂), butenyl (C₄), pentenyl (C₅), and hexenyl (C₆).

Alkynyl: The term "alkynyl", as used herein, pertains to an alkyl group having one or more carbon-carbon triple bonds. Examples of groups of alkynyl groups include C_2-4 alkynyl, C_2-7 alkynyl, C_2-20 alkynyl.

Examples of (unsubstituted) unsaturated alkynyl groups include, but are not limited to, ethynyl (ethinyl, -C≡CH) and 2-propynyl (propargyl, -CH₂-C≡CH).

Cycloalkyl: The term "cycloalkyl", as used herein, pertains to an alkyl group which is also a cyclyl group; that is, a monovalent moiety obtained by removing a hydrogen atom from an alicyclic ring atom of a carbocyclic ring of a carbocyclic compound, which carbocyclic ring may be saturated or unsaturated (e.g. partially unsaturated, fully unsaturated), which moiety has from 3 to 20 carbon atoms (unless otherwise specified), including from 3 to 20 ring atoms. Thus, the term "cycloalkyl" includes the sub-classes cycloalkenyl and cycloalkynyl. Preferably, each ring has from 3 to 7 ring atoms. Examples of groups of cycloalkyl groups include C₃.₂o cycloalkyl, C_3-15 cycloalkyl, C_3-10 cycloalkyl, C_3-7 cycloalkyl.

Examples of cycloalkyl groups include, but are not limited to, those derived from: saturated monocyclic hydrocarbon compounds: cyclopropane (C₃), cyclobutane (C₄), cyclopentane (C₅), cyclohexane (C₆), cycloheptane (C₇), methylcyclopropane (C₄), dimethylcyclopropane (C₅), methylcyclobutane (C₅), dimethylcyclobutane (C₆), methylcyclopentane (C₆), dimethylcyclopentane (C₇), methylcyclohexane (C₇), dimethylcyclohexane (C₈), menthane (C₁₀); unsaturated monocyclic hydrocarbon compounds: cyclopropene (C₃), cyclobutene (C₄), cyclopentene (C₅), cyclohexene (C₆), methylcyclopropene (C₄), dimethylcyclopropene (C₅), methylcyclobutene (C₅), dimethylcyclobutene (C₆), methylcyclopentene (C₆), dimethylcyclopentene (C₇), methylcyclohexene (C₇), dimethylcyclohexene (C₈); saturated polycyclic hydrocarbon compounds: thujane (C₁₀), carane (C₁₀), pinane (C₁₀), bornane (C₁₀), norcarane (C₇), norpinane (C₇), norbornane (C₇), adamantane (C₁₀), decalin (decahydronaphthalene) (C₁₀); unsaturated polycyclic hydrocarbon compounds: camphene (Ci₀), limonene (Ci₀), pinene (C₁₀); polycyclic hydrocarbon compounds having an aromatic ring: indene (C₉), indane (e.g., 2,3-dihydro-1 H-indene) (C₉), tetraline (1 ,2,3,4-tetrahydronaphthalene) (Ci₀), acenaphthene (Ci₂), fluorene (Ci₃), phenalene (C13), acephenanthrene (Ci₅), aceanthrene (Ci₆), cholanthrene (C₂o).

Heterocyclyl: The term "heterocyclyl", as used herein, pertains to a monovalent moiety obtained by removing a hydrogen atom from a ring atom of a heterocyclic compound, which moiety has from 3 to 20 ring atoms (unless otherwise specified), of which from 1 to 10 are ring heteroatoms. Preferably, each ring has from 3 to 7 ring atoms, of which from 1 to 4 are ring heteroatoms.

In this context, the prefixes (e.g. C₃.₂o, C_3-7, C_5-6, etc.) denote the number of ring atoms, or range of number of ring atoms, whether carbon atoms or heteroatoms. For example, the term "C₅-₆heterocyclyl", as used herein, pertains to a heterocyclyl group having 5 or 6 ring atoms. Examples of groups of heterocyclyl groups include C_3-2O heterocyclyl, C_5-20 heterocyclyl, C₃.i₅ heterocyclyl, C₅.i₅ heterocyclyl, C_3-I2 heterocyclyl, C_5-I2 heterocyclyl, C_3-10 heterocyclyl, C_5-i₀ heterocyclyl, C_3-7 heterocyclyl, C_5-7 heterocyclyl, and C₅.₆ heterocyclyl.

Examples of monocyclic heterocyclyl groups include, but are not limited to, those derived from:

Ni: aziridine (C₃), azetidine (C₄), pyrrolidine (tetrahydropyrrole) (C₅), pyrroline (e.g.,

3-pyrroline, 2,5-dihydropyrrole) (C₅), 2H-pyrrole or 3H-pyrrole (isopyrrole, isoazole) (C₅), piperidine (C₆), dihydropyridine (C₆), tetrahydropyridine (C₆), azepine (C₇);

O₁: oxirane (C₃), oxetane (C₄), oxolane (tetrahydrofuran) (C₅), oxole (dihydrofuran) (C₅), oxane (tetrahydropyran) (C₆), dihydropyran (C₆), pyran (C₆), oxepin (C₇);

Sv thiirane (C₃), thietane (C₄), thiolane (tetrahydrothiophene) (C₅), thiane

(tetrahydrothiopyran) (C₆), thiepane (C₇); O₂: dioxolane (C₅), dioxane (C₆), and dioxepane (C₇);

O₃: trioxane (C₆);

N₂: imidazolidine (C₅), pyrazolidine (diazolidine) (C₅), imidazoline (C₅), pyrazoline

(dihydropyrazole) (C₅), piperazine (C₆); N₁O₁: tetrahydrooxazole (C₅), dihydrooxazole (C₅), tetrahydroisoxazole (C₅), dihydroisoxazole (C₅), morpholine (C₆), tetrahydrooxazine (C₆), dihydrooxazine (C₆), oxazine (C₆);

NiS₁: thiazoline (C₅), thiazolidine (C₅), thiomorpholine (C₆); N₂Oi: oxadiazine (C₆);

UIS₁ : oxathiole (C₅) and oxathiane (thioxane) (C₆); and, N₁O₁Si: oxathiazine (C₆).

Examples of substituted (non-aromatic) monocyclic heterocyclyl groups include those derived from saccharides, in cyclic form, for example, furanoses (C₅), such as arabinofuranose, lyxofuranose, ribofuranose, and xylofuranse, and pyranoses (C₆), such as allopyranose, altropyranose, glucopyranose, mannopyranose, gulopyranose, idopyranose, galactopyranose, and talopyranose.

C_5-2O aryl: The term "C_5-20 aryl" as used herein, pertains to a monovalent moiety obtained by removing a hydrogen atom from an aromatic ring atom of a C₅.₂o aromatic compound, said compound having one ring, or two or more rings (e.g., fused), and having from 5 to 20 ring atoms, and wherein at least one of said ring(s) is an aromatic ring. Preferably, each ring has from 5 to 7 ring atoms.

The ring atoms may be all carbon atoms, as in "carboaryl groups" in which case the group may conveniently be referred to as a "C_5-20 carboaryl" group.

Examples of C_5-20 aryl groups which do not have ring heteroatoms (i.e. C_5-20 carboaryl groups) include, but are not limited to, those derived from benzene (i.e. phenyl) (C₆), naphthalene (Ci₀), anthracene (Ci₄), phenanthrene (C1₄), and pyrene (Ci₆).

Alternatively, the ring atoms may include one or more heteroatoms, including but not limited to oxygen, nitrogen, and sulfur, as in "heteroaryl groups". In this case, the group may conveniently be referred to as a "C_5-20 heteroaryl" group, wherein "C_5-20" . denotes ring atoms, whether carbon atoms or heteroatoms. Preferably, each ring has from 5 to 7 ring atoms, of which from 0 to 4 are ring heteroatoms.

Examples of C_5-20 heteroaryl groups include, but are not limited to, C₅ heteroaryl groups derived from furan (oxole), thiophene (thiole), pyrrole (azole), imidazole (1 ,3-diazole), pyrazole (1 ,2-diazole), triazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, tetrazole and oxatriazole; and C₆ heteroaryl groups derived from isoxazine, pyridine (azine), pyridazine (1 ,2-diazine), pyrimidine (1 ,3-diazine; e.g., cytosine, thymine, uracil), pyrazine (1 ,4-diazine) and triazine.

The heteroaryl group may be bonded via a carbon or hetero ring atom.

Examples of C₅.₂o heteroaryl groups which comprise fused rings, include, but are not limited to, C₉ heteroaryl groups derived from benzofuran, isobenzofuran, benzothiophene, indole, isoindole; C₁₀ heteroaryl groups derived from quinoline, isoquinoline, benzodiazine, pyridopyridine; d₄ heteroaryl groups derived from acridine and xanthene.

The above alkyl, heterocyclyl, and aryl groups, whether alone or part of another substituent, may themselves optionally be substituted with one or more groups selected from themselves and the additional substituents listed below.

Halo: -F, -Cl, -Br, and -I.

Hydroxy: -OH.

Ether: -OR, wherein R is an ether substituent, for example, a C_1-7 alkyl group (also referred to as a C_1-7 alkoxy group), a C₃.₂o heterocyclyl group (also referred to as a C_3-2O heterocyclyloxy group), or a C_5-2O aryl group (also referred to as a C_5-2O aryloxy group), preferably a Ci_-7 alkyl group.

Nitro: -NO₂.

Cyano (nitrile, carbonitrile): -CN.

Acyl (keto): -C(=O)R, wherein R is an acyl substituent, for example, H, a C_1-7 alkyl group (also referred to as Ci_-7 alkylacyl or Ci.₇ alkanoyl), a C_3-2O heterocyclyl group (also referred to as C₃.₂₀ heterocyclylacyl), or a C_5-2O aryl group (also referred to as C_5-20 arylacyl), preferably a C₁.7 alkyl group. Examples of acyl groups include, but are not limited to, -C(=O)CH₃ (acetyl), -C(=O)CH₂CH₃ (propionyl), -C(=O)C(CH₃)₃ (butyryl), and -C(=O)Ph (benzoyl, phenone).

Carboxy (carboxylic acid): -COOH. Ester (carboxylate, carboxylic acid ester, oxycarbonyl): -C(=O)OR, wherein R is an ester substituent, for example, a Ci_₇ alkyl group, a C₃.₂o heterocyclyl group, or a C₅.₂₀aryl group, preferably a C_1-7 alkyl group. Examples of ester groups include, but are not limited to, -C(=O)OCH₃, -Cf=O)OCH₂CH₃, -C(=O)OC(CH₃)₃, and -C(=O)OPh. Where R is a C_1-2 alkyl group substituted by a C₅.₆ aryl group, the ester is termed a C_5-6 aryl-Ci.₂ alkyl ester.

Amido (carbamoyl, carbamyl, aminocarbonyl, carboxamide): -C(=0)NR¹R², wherein R¹ and R² are independently amino substituents, as defined for amino groups. Examples of amido groups include, but are not limited to, -C(=O)NH₂, -C(=0)NHCH₃, -C(=O)N(CH₃)₂,

-C(=O)NHCH₂CH₃, and -C(=O)N(CH₂CH₃)₂, as well as amido groups in which R¹ and R², together with the nitrogen atom to which they are attached, form a heterocyclic structure as in, for example, piperidinocarbonyl, morpholinocarbonyl, thiomorpholinocarbonyl, and piperazinylcarbonyl.

Amino: -NR¹R², wherein R¹ and R² are independently amino substituents, for example, hydrogen, a Ci_-7 alkyl group (also referred to as C^ alkylamino or di-C^ alkylamino), a C₃.₂₀ heterocyclyl group, or a C_5-20 aryl group, preferably H or a C_1-7 alkyl group, or, in the case of a "cyclic" amino group, R¹ and R², taken together with the nitrogen atom to which they are attached, form a heterocyclic ring having from 4 to 8 ring atoms. Examples of amino groups include, but are not limited to, -NH₂, -NHCH₃, -NHCH(CH₃)₂, -N(CH₃J₂, -N(CH₂CH₃)₂, and -NHPh. Examples of cyclic amino groups include, but are not limited to, aziridinyl, azetidinyl, pyrrolidinyl, piperidino, piperazinyl, perhydrodiazepinyl, morpholino, and thiomorpholino. The cylic amino groups may be substituted on their ring by any of the substituents defined here, for example carboxy, carboxylate and amido.

Acylamido (acylamino): -NR¹C(=O)R², wherein R¹ is an amide substituent, for example, hydrogen, a Ci_-7 alkyl group, a C_3-20 heterocyclyl group, or a C_5-20 aryl group, preferably H or a C_1-7 alkyl group, most preferably H, and R² is an acyl substituent, for example, a Ci_-7 alkyl group, a C_3-20 heterocyclyl group, or a C_5-20 aryl group, preferably a C_1-7 alkyl group. Examples of acylamide groups include, but are not limited to, -NHC(=O)CH₃ , -NHC(=O)CH₂CH₃, and -NHC(=O)Ph. R¹ and R² may together form a cyclic structure, as in, for example, succinimidyl, maleimidyl, and phthalimidyl:

succinimidyl maleimidyl

Ureido: -N(R¹)CONR²R³ wherein R² and R³ are independently amino substituents, as defined for amino groups, and R1 is a ureido substituent, for example, hydrogen, a C_1-7alkyl group, a C₃.2oheterocyclyl group, or a C₅-₂oaryl group, preferably hydrogen or a Ci_-7alkyl group. Examples of ureido groups include, but are not limited to, -NHCONH₂, -NHCONHMe, -NHCONHEt, -NHCONMe₂, -NHCONEt₂, -NMeCONH₂, -NMeCONHMe, -NMeCONHEt, - NMeCONMe₂, -NMeCONEt₂ and -NHC(=0)NHPh.

Acyloxy (reverse ester): -OC(=O)R, wherein R is an acyloxy substituent, for example, a Ci_-7 alkyl group, a C_3-20 heterocyclyl group, or a C_5-20 aryl group, preferably a C_1-7 alkyl group. Examples of acyloxy groups include, but are not limited to, -0C(=0)CH₃ (acetoxy), - OC(=O)CH₂CH₃, -OC(=O)C(CH₃)₃, -OC(=O)Ph, -OC(=O)C₆H₄F, and -OC(=O)CH₂Ph.

Thiol : -SH.

Thioether (sulfide): -SR, wherein R is a thioether substituent, for example, a Ci_-7 alkyl group (also referred to as a C_1-7 alkylthio group), a C_3-20 heterocyclyl group, or a C₅.₂₀ aryl group, preferably a C1.₇ alkyl group. Examples of Ci_-7 alkylthio groups include, but are not limited to, -SCH₃ and -SCH₂CH₃.

Sulfoxide (sulfinyl): -S(=O)R, wherein R is a sulfoxide substituent, for example, a Ci_-7 alkyl group, a C_3-20 heterocyclyl group, or a C_5-20 aryl group, preferably a C_1-7 alkyl group. Examples of sulfoxide groups include, but are not limited to, -S(=0)CH₃ and -S(=O)CH₂CH₃.

Sulfonyl (sulfone): -S(=0)₂R, wherein R is a sulfone substituent, for example, a Ci-₇ alkyl group, a C_3-20 heterocyclyl group, or a C_5-20 aryl group, preferably a Ci_-7 alkyl group. Examples of sulfone groups include, but are not limited to, -S(=O)₂CH₃ (methanesulfonyl, mesyl), -S(=O)₂CF₃, -S(=O)₂CH₂CH₃, and 4-methylphenylsulfonyl (tosyl). Thioamido (thiocarbamyl): -C(=S)NR¹R², wherein R¹ and R² are independently amino substituents, as defined for amino groups. Examples of amido groups include, but are not limited to, -C(=S)NH₂, -C(=S)NHCH₃, -C(=S)N(CH₃)₂, and -C(=S)NHCH₂CH₃.

Sulfonamino: -NR¹S(=O)₂R, wherein R¹ is an amino substituent, as defined for amino groups, and R is a sulfonamino substituent, for example, a Ci-₇alkyl group, a C₃. 2oheterocyclyl group, or a C₅-2oaryl group, preferably a d-₇alkyl group. Examples of sulfonamino groups include, but are not limited to, -NHS(=O)₂CH₃, -NHS(=O)₂Ph and -N(CH₃)S(=O)₂C₆H₅.

Sulfinamino: -NR¹S(=O)R, wherein R¹ is an amino substituent, as defined for amino groups, and R is a sulfinamino substituent, for example, a C^alkyl group, a C₃.₂₀heterocyclyl group, or a C₅-₂oaryl group, preferably a C^alkyl group. Examples of sulfinamino groups include, but are not limited to, -NHS(=O)CH₃, -NHS(O)Ph and -N(CH₃)S(=O)C₆H₅.

Hydroxamino (hydroxamic acid): -C(=O)NR¹OH, wherein R¹ is an amide substituent, for example, hydrogen, a Ci_-7 alkyl group, a C₃.₂o heterocyclyl group, or a C_5-20 aryl group, preferably H or a Ci_-7 alkyl group, most preferably H. Examples of hydroxamino groups include, but are not limited to, -C(=O)NHOH , -C(=O)N(CH₃)OH, and -C(=O)N(Ph)OH.

As mentioned above, the groups that form the above listed substituent groups, e.g. C₁._? alkyl, C₃.₂o heterocyclyl and C_5-20 aryl, may themselves be substituted. Thus, the above definitions cover substituent groups which are substituted.

Further Embodiments

The following preferences may apply to each aspect of the invention, and may be combined where appropriate.

X In some embodiment, X is O. In other embodiments, X is S. In other embodiments, X is NH. In further embodiments, X is CH₂.

Naphthyl group substituents R^d and R^p are optional naphthyl group substituents. There can be one, two or three R^p groups on the proximal naphthyl ring, which may be the same or selected independently from the possible substituent groups. The substituents may be at any available ring position. In some embodiments, there are no substituents on the proximal naphthyl ring. In other embodiments, there is a single substituent on the proximal naphthyl ring, which may be in any available ring position.

There can be one, two, three or four R^d groups on the distal naphthyl ring, which may be the same or selected independently from the possible substituent groups. In some embodiments, there are no substituents on the distal naphthyl ring. In other embodiments, there is a single substituent on the distal naphthyl ring, which may be in any available ring position. In further embodiments, there are two substituents on the distal naphthyl ring, which may be in any available ring position.

When there is a single substituent on the distal naphthyl ring, it may in the position indicated in the formulae below:

In some embodiments, there are no substituents on the naphthyl group. In other embodiments, there may be one or two substituents on the naphthyl group, and they may be on either the proximal and/or the distal ring.

The optional naphthyl group substituents may be selected from, but not limited to, Ci_-7 alkyl, C3-20 heterocyclyl, C5-₂0 aryl, halo, hydroxy, ether, nitro, cyano, acyl, ester, amido, amino, acylamido, ureido, acyloxy, thiol, thioether, sulfoxide, sulfonyl, thioamido and sulfonamino.

In some embodiments, the optional naphthyl group substituents may be selected from C₁-₄ alkyl, C_5-6 aryl, halo, hydroxy, C_1-4 alkyl ether, C_1-4 alkyl acyl, C₁.₄ alkyl ester, amino, Ci_-4 alkylamino and diC_1-4 alkylamino. In further embodiments, the optional naphthyl group substituents may be selected from hydroxy and Ci_-4 alkyl ether.

In some embodiment, R^Het is imidazolyl. In other embodiments, R^Het is triazolyl. In further embodiments, R^Het is pyridyl.

R^c

In some embodiments, R^c is methyl, which is substituted.

In other embodiments, R^c is ethyl, which is substituted. The substituent may be α to the point at which R^c is bound to the remainder of the compound, i.e. attached to the carbon atom which is attached to the remainder of the molecule.

In further embodiments, R^c is propyl, which is substituted. The propyl group may be branched, i.e. iso-propyl, and the substituent may be α to the point at which R^c is bound to the remainder of the compound, i.e. attached to the carbon atom which is attached to the remainder of the molecule.

The substituent for R^c is selected from hydroxy, amino, amido, carboxy, C_1-7 alkyl esters, C_{5- 7} aryl-C^.₂ alkyl esters, sulfonamino, sulfinamino, hydroxamino and tetrazolyl. In some embodiments, the substituent for R^c is selected from carboxy, amido and sulfonamino. In further embodiments, the substituent for R^c is selected from hydroxy, carboxy, Ci.₇ alkyl esters, C_5-7 aryl-Ci.₂ alkyl esters and amido. In other embodiments, the substituent for R^c is selected from carboxy, Ci_-7 alkyl esters, Cs_-7 aryl-Ci-2 alkyl esters and amido.

If the substituent is amino, then the amino substituents may be selected from H and C_1-4 alkyl (e.g. methyl, ethyl). The amino substituents may also, along with the nitrogen atom to which they are attached, form a heterocyclic ring, such that the optional substituent is e.g. morpholino, piperazinyl, piperidinyl.

If the substituent is amido, then the amino substituents may be selected from H and Ci_-4 alkyl (e.g. methyl, ethyl). The amino substituents may also, along with the nitrogen atom to which they are attached, form a heterocyclic ring, such that the optional substituent is e.g. morpholinocarbonyl, piperazinylcarbonyl, piperidinylcarbonyl. If the substituent is sulfonamino, the amino substituent may be selected from H and Ci_-4 alkyl (e.g. methyl, ethyl). The sulfonamino substituent may be selected from C_1-4 alkyl (e.g. methyl, ethyl) or a C_5-6 aryl group (e.g. phenyl, pyridyl, furanyl, thiophenyl).

If the substituent is sulfinamino, the amino substituent may be selected from H and Ci_-4 alkyl (e.g. methyl, ethyl). The sulfinamino substituent may be selected from Ci_-4 alkyl (e.g. methyl, ethyl) or a C_5-6 aryl group (e.g. phenyl, pyridyl, furanyl, thiophenyl).

If the substituent is hydroxamino, the amide substituent may be selected from H and Ci.₄ alkyl (e.g. methyl, ethyl).

If the substituent is C_1-7 alkyl ester, the C_1-7 alkyl group may in some embodiments be a C_1-4 alkyl ester, in which case the alkyl group may be methyl, ethyl, propyl and butyl. If the alkyl group is a C_1-7 alkyl group, it may also be, for example, a C₅ alkyl group, i.e. pentyl.

If the optional substituent is a C_5-7 aryl-C^ alkyl ester, the alkyl group may be methyl or ethyl. In some embodiments, the group is methyl. The C_5-7 aryl group may be phenyl, pyridyl, furanyl or thiophenyl. In some embodiments, the C_5-7 aryl group is phenyl.

Compounds of particular interest include:

3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester

(4); methyl anf/-3-(1 H-1-imidazolyl)-3-[4-(2-naphthylamino)phenyl]-2-methylpropanoate (7a); methyl syn-3-(1 H-1-imidazolyl)-3-[4-(2-naphthylamino)phenyl]-2-methylpropanoate (7b); methyl 3-(1 H-imidazol-1-yl)-2,3-dimethyl-3-((4-naphthalene-2-yloxy)phenyl) propanoate (10); and methyl 2,2-dimethyl-3-(4-(naphthalen-2-ylamino)phenyl)-3-(1 H- 1 ,2,4-triazol-1-yl) propanoate

(11 ).

Further compounds of particular interest include:

3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid (12);

3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid ethyl ester

(13);

3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid isopropyl ester (14); 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamiπo)-phenyl]-propionic acid butyl ester

(15);

3-imidazol-1-yl-N-isopropyl-2,2-dimethyl-3-t4-(naphthalen-2-ylamino)-phenyl]-propionamide

(16); 2,2-dimethyl-3-(methyl-vinyl-amino)-3-[4-(naphthalen-2-ylamino)-phenyl]-propionamide (17);

3-imidazol-1-yl-2,2,N-trimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionamide (18);

3-irτιidazol-1-yl-2,2,N,N-tetramethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionamide (19);

3-imidazol-1-yl-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2,2-dimethyl-propionic acid methyl ester (21 ); 3-[4-(6-hydroxy-naphthalen-2-ylamino)-phenyl]-3-imidazol-1-yl-2,2-dimethyl-propionic acid methyl ester (22);

3-imidazol-1-yl-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2,2-dimethyl-propan-1-ol

(23);

3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-1-ylamino)-phenyl]-propionic acid methyl ester (25);

3-[4-(2-ethoxy-naphthalen-1 -ylamino)-phenyl]-3-imidazol-1 -yl-2,2-dimethyl-propionic acid methyl ester (27);

3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid benzyl ester

(28); and 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid pentyl ester

(29).

Includes Other Forms

Included in the above are the well known ionic, salt, solvate, and protected forms of these substituents. For example, a reference to carboxylic acid (-COOH) also includes the anionic (carboxylate) form (-COO^'), a salt or solvate thereof, as well as conventional protected forms. Similarly, a reference to an amino group includes the protonated form (-N⁺HR¹R²), a salt or solvate of the amino group, for example, a hydrochloride salt, as well as conventional protected forms of an amino group. Similarly, a reference to a hydroxyl group also includes the anionic form (-0 ), a salt or solvate thereof, as well as conventional protected forms of a hydroxyl group.

Isomers, Salts. Solvates, Protected Forms, and Prodrugs

Certain compounds may exist in one or more particular geometric, optical, enantiomeric, diasteriomeric, epimeric, stereoisomeric, tautomeric, conformational, or anomeric forms, including but not limited to, cis- and transforms; E- and Z-forms; c-, f-, and Λ-forms; endo- and exo-forms; R-, S-, and meso-forms; D- and /.-forms; d- and /-forms; (+) and (-) forms; keto-, enol-, and enolate-forms; syn- and anti-forms; synclinal- and anticlinal-forms; α- and β- forms; axial and equatorial forms; boat-, chair-, twist-, envelope-, and halfchair-forms; and combinations thereof, hereinafter collectively referred to as "isomers" (or "isomeric forms").

If the compound is in crystalline form, it may exist in a number of different polymorphic forms.

Note that, except as discussed below for tautomeric forms, specifically excluded from the term "isomers", as used herein, are structural (or constitutional) isomers (i.e. isomers which differ in the connections between atoms rather than merely by the position of atoms in space). For example, a reference to a methoxy group, -OCH₃, is not to be construed as a reference to its structural isomer, a hydroxymethyl group, -CH₂OH. Similarly, a reference to ortho-chlorophenyl is not to be construed as a reference to its structural isomer, meta- chlorophenyl. However, a reference to a class of structures may well include structurally isomeric forms falling within that class (e.g., C^ alkyl includes n-propyl and /so-propyl; butyl includes n-, iso-, sec-, and terf-butyl; methoxyphenyl includes ortho-, meta-, and para- methoxyphenyl).

The above exclusion does not pertain to tautomeric forms, for example, keto-, enol-, and enolate-forms, as in, for example, the following tautomeric pairs: keto/enol, imine/enamine, amide/imino alcohol, amidine/amidine, nitroso/oxime, thioketone/enethiol, N- nitroso/hyroxyazo, and nitro/aci-nitro.

Note that specifically included in the term "isomer" are compounds with one or more isotopic substitutions. For example, H may be in any isotopic form, including ¹H, ²H (D), and ³H (T); C may be in any isotopic form, including ¹²C, ¹³C, and ¹⁴C; O may be in any isotopic form, including ¹⁶O and ¹⁸O; and the like.

Unless otherwise specified, a reference to a particular compound includes all such isomeric forms, including (wholly or partially) racemic and other mixtures thereof. Methods for the preparation (e.g. asymmetric synthesis) and separation (e.g. fractional crystallisation and chromatographic means) of such isomeric forms are either known in the art or are readily obtained by adapting the methods taught herein, or known methods, in a known manner. Unless otherwise specified, a reference to a particular compound also includes ionic, salt, solvate, and protected forms of thereof, for example, as discussed below, as well as its different polymorphic forms.

It may be convenient or desirable to prepare, purify, and/or handle a corresponding salt of the active compound, for example, a pharmaceutically-acceptable salt. Examples of pharmaceutically acceptable salts are discussed in Berge, et a/., "Pharmaceutically Acceptable Salts", J. Pharm. ScL, 66, 1-19 (1977).

For example, if the compound is anionic, or has a functional group which may be anionic (e.g., -COOH may be -COO^"), then a salt may be formed with a suitable cation. Examples of suitable inorganic cations include, but are not limited to, alkali metal ions such as Na⁺ and K⁺, alkaline earth cations such as Ca²⁺ and Mg²⁺, and other cations such as Al³⁺. Examples of suitable organic cations include, but are not limited to, ammonium ion (i.e., NH₄ ⁺) and substituted ammonium ions (e.g., NH₃R⁺, NH₂R₂ ⁺, NHR₃ ⁺, NR₄ ⁺). Examples of some suitable substituted ammonium ions are those derived from: ethylamine, diethylamine, dicyclohexylamine, triethylamine, butylamine, ethylenediamine, ethanolamine, diethanolamine, piperazine, benzylamine, phenylbenzylamine, choline, meglumine, and tromethamine, as well as amino acids, such as lysine and arginine. An example of a common quaternary ammonium ion is N(CH₃)/.

If the compound is cationic, or has a functional group which may be cationic (e.g., -NH₂ may be -NH₃ ⁺), then a salt may be formed with a suitable anion. Examples of suitable inorganic anions include, but are not limited to, those derived from the following inorganic acids: hydrochloric, hydrobromic, hydroiodic, sulfuric, sulfurous, nitric, nitrous, phosphoric, and phosphorous. Examples of suitable organic anions include, but are not limited to, those derived from the following organic acids: acetic, propionic, succinic, gycolic, stearic, palmitic, lactic, malic, pamoic, tartaric, citric, gluconic, ascorbic, maleic, hydroxymaleic, phenylacetic, glutamic, aspartic, benzoic, cinnamic, pyruvic, salicyclic, sulfanilic, 2-acetyoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethanesulfonic, ethane disulfonic, oxalic, isethionic, valeric, and gluconic. Examples of suitable polymeric anions include, but are not limited to, those derived from the following polymeric acids: tannic acid, carboxymethyl cellulose. It may be convenient or desirable to prepare, purify, and/or handle a corresponding solvate of the active compound. The term "solvate" is used herein in the conventional sense to refer to a complex of solute (e.g. active compound, salt of active compound) and solvent. If the solvent is water, the solvate may be conveniently referred to as a hydrate, for example, a mono-hydrate, a di-hydrate, a tri-hydrate, etc.

It may be convenient or desirable to prepare, purify, and/or handle the active compound in a chemically protected form. The term "chemically protected form," as used herein, pertains to a compound in which one or more reactive functional groups are protected from undesirable chemical reactions, that is, are in the form of a protected or protecting group (also known as a masked or masking group or a blocked or blocking group). By protecting a reactive functional group, reactions involving other unprotected reactive functional groups can be performed, without affecting the protected group; the protecting group may be removed, usually in a subsequent step, without substantially affecting the remainder of the molecule. See, for example, "Protective Groups in Organic Synthesis" (T. Green and P. Wuts; 4th Edition; WileyBlackwell, 2006).

For example, a hydroxy group may be protected as an ether (-OR) or an ester (-OC(=O)R), for example, as: a f-butyl ether; a benzyl, benzhydryl (diphenylmethyl), or trityl (triphenylmethyl) ether; a trimethylsilyl or f-butyldimethylsilyl ether; or an acetyl ester (-OC(=O)CH₃, -OAc).

For example, an aldehyde or ketone group may be protected as an acetal or ketal, respectively, in which the carbonyl group (>C=O) is converted to a diether (>C(OR)₂), by reaction with, for example, a primary alcohol. The aldehyde or ketone group is readily regenerated by hydrolysis using a large excess of water in the presence of acid.

For example, an amine group may be protected, for example, as an amide or a urethane, for example, as: a methyl amide (-NHCO-CH₃); a benzyloxy amide (-NHCO-OCH₂C₆H₅, -NH- Cbz); as a t-butoxy amide (-NHCO-OC(CH₃)₃, -NH-Boc); a 2-biphenyl-2-propoxy amide (- NHCO-OC(CHs)₂C₆H₄C₆H₅, -NH-Bpoc), as a 9-fluorenylmethoxy amide (-NH-Fmoc), as a 6- nitroveratryloxy amide (-NH-Nvoc), as a 2-trimethylsilylethyloxy amide (-NH-Teoc), as a 2,2,2-trichloroethyloxy amide (-NH-Troc), as an allyloxy amide (-NH-Alloc), as a 2(- phenylsulphonyl)ethyloxy amide (-NH-Psec); or, in suitable cases, as an Λ/-oxide (>NO ). For example, a carboxylic acid group may be protected as an ester for example, as: an C_1-7 alkyl ester (e.g. a methyl ester; a f-butyl ester); a Ci.₇ haloalkyl ester (e.g. a Ci.₇ trihaloalkyl ester); a triCi-₇ alkylsilyl-C-i.₇ alkyl ester; or a C_5-2O aryl-Ci_-7 alkyl ester (e.g. a benzyl ester; a nitrobenzyl ester); or as an amide, for example, as a methyl amide.

For example, a thiol group may be protected as a thioether (-SR), for example, as: a benzyl thioether; an acetamidomethyl ether (-S-CH₂NHC(=O)CH₃).

It may be convenient or desirable to prepare, purify, and/or handle the active compound in the form of a prodrug. The term "prodrug", as used herein, pertains to a compound which, when metabolised (e.g. in vivo), yields the desired active compound. Typically, the prodrug is inactive, or less active than the active compound, but may provide advantageous handling, administration, or metabolic properties.

For example, some prodrugs are esters of the active compound (e.g. a physiologically acceptable metabolically labile ester). During metabolism, the ester group (-C(=O)OR) is cleaved to yield the active drug. Such esters may be formed by esterification, for example, of any of the carboxylic acid groups (-C(=O)OH) in the parent compound, with, where appropriate, prior protection of any other reactive groups present in the parent compound, followed by deprotection if required. Examples of such metabolically labile esters include those wherein R is C_1-2O alkyl (e.g. -Me, -Et); d^ aminoalkyl (e.g. aminoethyl; 2-(N₁N- diethylamino)ethyl; 2-(4-morpholino)ethyl); and acyloxy-Ci.₇ alkyl (e.g. acyloxy methyl; acyloxyethyl; e.g. pivaloyloxymethyl; acetoxymethyl; 1-acetoxyethyl; 1-(1-methoxy-1- methyl)ethyl-carbonxyloxyethyl; 1-(benzoyloxy)ethyl; isopropoxy-carbonyloxymethyl; 1-isopropoxy-carbonyloxyethyl; cyclohexyl-carbonyloxymethyl; 1-cyclohexyl- carbonyloxyethyl; cyclohexyloxy-carbonyloxymethyl; 1-cyclohexyloxy-carbonyloxyethyl; (4- tetrahydropyranyloxy) carbonyloxy methyl; 1 -(4-tetrahydropyranyloxy)carbonyloxyethyl; (4-tetrahydropyranyl)carbonyloxymethyl; and 1 -(4-tetrahydropyranyl)carbonyloxyethyl).

Further suitable prodrug forms include phosphonate and glycolate salts. In particular, hydroxy groups (-OH), can be made into phosphonate prodrugs by reaction with chlorodibenzylphosphite, followed by hydrogenation, to form a phosphonate group -O- P(=O)(OH)₂. Such a group can be cleared by phosphotase enzymes during metabolism to yield the active drug with the hydroxy group. Also, some prodrugs are activated enzymatically to yield the active compound, or a compound which, upon further chemical reaction, yields the active compound. For example, the prodrug may be a sugar derivative or other glycoside conjugate, or may be an amino acid ester derivative.

Prodrugs of particular interest in the present invention are of formula (II):

wherein

X, R^d, R^p and R^Het are defined as for formula I; and

R^c is a C_1-4 alkyl ester. R^c may also be a group a selected from C₁.₇ alkyl ester and C₅-₇ aryl-

C_1-2 alkyl ester.

The further embodiments expressed above for compounds of formula (I) apply to compounds of formula (II), where appropriate. Where R^c is a Ci_-4 alkyl group, it may be methyl ester, ethyl ester, propyl ester and butyl ester.

Acronyms For convenience, many chemical moieties are represented using well known abbreviations, including but not limited to, methyl (Me), ethyl (Et), n-propyl (nPr), /so-propyl (iPr), π-butyl (nBu), ferf-butyl (tBu), π-hexyl (nHex), cyclohexyl (cHex), phenyl (Ph), biphenyl (biPh), benzyl (Bn), naphthyl (naph), methoxy (MeO), ethoxy (EtO), benzoyl (Bz), and acetyl (Ac).

For convenience, many chemical compounds are represented using well known abbreviations, including but not limited to, methanol (MeOH), ethanol (EtOH), iso-propanol (i- PrOH), methyl ethyl ketone (MEK), ether or diethyl ether (Et₂O), acetic acid (AcOH)₁ dichloromethane (methylene chloride, DCM), trifluoroacetic acid (TFA), dimethylformamide (DMF), tetrahydrofuran (THF), and dimethylsulfoxide (DMSO). General Synthesis

Compounds of formula (I), and their prodrugs:

can be synthesised from compounds of formula 3:

Formula 3

by reacting with R^Het-H and an activating agent, such as 1 ,1 '-carbonydiimidazole, thionyl chloride or triazole.

Compounds of Formula 3 may be synthesised by coupling a compound of Formula 4:

Formula 4

with a compound of formula 5:

Formula 5

where Q is a boronic acid or ester, using standard conditions.

In the above steps, the napthyl group may derivatised as in the final product or may bear precursor groups that are derived at an appropriate stage. The same may apply to the RC group, which may, in particular, be protected during the transformations described above. The compound of Formula 3 may be formed initially as a ketone and then reduced to the alcohol - the ketone would be formed from a ketone version of a compound of Formula 4. Use

The compounds of the present invention are capable of inhibiting the activity of CYP26, and consequently acting as an RA metabolism blocking agent (RAMBA).

Assays which may conveniently be used in order to assess the inhibition of CYP26 offered by a particular compound are described in the examples below.

The present invention provides a method of inhibiting CYP26 in cells either in vivo or in vitro.

The term "treatment", as used herein in the context of treating a condition, pertains generally to treatment and therapy, whether of a human or an animal (e.g. in veterinary applications), in which some desired therapeutic effect is achieved, for example, the inhibition of the progress of the condition, and includes a reduction in the rate of progress, a halt in the rate of progress, amelioration of the condition, and cure of the condition. Treatment as a prophylactic measure (i.e. prophylaxis) is also included.

Active compounds may also be used as part of an in vitro assay, for example, in order to determine whether a candidate host is likely to benefit from treatment with the compound in question.

Administration

The active compound or pharmaceutical composition comprising the active compound may be administered to a subject by any convenient route of administration, whether systemically/ peripherally or at the site of desired action, including but not limited to, oral (e.g. by ingestion); topical (including e.g. transdermal, intranasal, ocular, buccal, and sublingual); pulmonary (e.g. by inhalation or insufflation therapy using, e.g. an aerosol, e.g. through mouth or nose); rectal; vaginal; parenteral, for example, by injection, including subcutaneous, intradermal, intramuscular, intravenous, intraarterial, intracardiac, intrathecal, intraspinal, intracapsular, subcapsular, intraorbital, intraperitoneal, intratracheal, subcuticular, intraarticular, subarachnoid, and intrasternal; by implant of a depot, for example, subcutaneously or intramuscularly.

The subject may be a eukaryote, an animal, a vertebrate animal, a mammal, a rodent (e.g. a guinea pig, a hamster, a rat, a mouse), murine (e.g. a mouse), canine (e.g. a dog), feline (e.g. a cat), equine (e.g. a horse), a primate, simian (e.g. a monkey or ape), a monkey (e.g. marmoset, baboon), an ape (e.g. gorilla, chimpanzee, orangutang, gibbon), or a human.

Formulations While it is possible for the active compound to be administered alone, it is preferable to present it as a pharmaceutical composition (e.g., formulation) comprising at least one active compound, as defined above, together with one or more pharmaceutically acceptable carriers, adjuvants, excipients, diluents, fillers, buffers, stabilisers, preservatives, lubricants, or other materials well known to those skilled in the art and optionally other therapeutic or prophylactic agents.

Thus, the present invention further provides pharmaceutical compositions, as defined above, and methods of making a pharmaceutical composition comprising admixing at least one active compound, as defined above, together with one or more pharmaceutically acceptable carriers, excipients, buffers, adjuvants, stabilisers, or other materials, as described herein.

The term "pharmaceutically acceptable" as used herein pertains to compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of a subject (e.g. human) without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. Each carrier, excipient, etc. must also be "acceptable" in the sense of being compatible with the other ingredients of the formulation.

Suitable carriers, diluents, excipients, etc. can be found in standard pharmaceutical texts. See, for example, "Handbook of Pharmaceutical Additives", 3^rd Edition (eds. M. Ash and I. Ash), 2007 (Synapse Information Resources, Inc.), "Remington's Pharmaceutical Sciences", 21^st edition, 2005 (Lippincott, Williams & Wilkins); and "Handbook of Pharmaceutical Excipients", 5^th edition (eds. R. Rowe, P. Sheskey, S. Owen), 2005 (Pharmaceutical Press)

The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. Such methods include the step of bringing into association the active compound with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active compound with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product. Formulations may be in the form of liquids, solutions, suspensions, emulsions, elixirs, syrups, tablets, losenges, granules, powders, capsules, cachets, pills, ampoules, suppositories, pessaries, ointments, gels, pastes, creams, sprays, mists, foams, lotions, oils, boluses, electuaries, or aerosols.

Formulations suitable for oral administration (e.g., by ingestion) may be presented as discrete units such as capsules, cachets or tablets, each containing a predetermined amount of the active compound; as a powder or granules; as a solution or suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion; as a bolus; as an electuary; or as a paste.

A tablet may be made by conventional means, e.g. compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active compound in a free-flowing form such as a powder or granules, optionally mixed with one or more binders (e.g. povidone, gelatin, acacia, sorbitol, tragacanth, hydroxypropylmethyl cellulose); fillers or diluents (e.g. lactose, microcrystalline cellulose, calcium hydrogen phosphate); lubricants (e.g. magnesium stearate, talc, silica); disintegrants (e.g. sodium starch glycolate, cross-linked povidone, cross-linked sodium carboxymethyl cellulose); surface-active or dispersing or wetting agents (e.g., sodium lauryl sulfate); and preservatives (e.g., methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, sorbic acid). Molded tablets may be made by molding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active compound therein using, for example, hydroxypropylmethyl cellulose in varying proportions to provide the desired release profile. Tablets may optionally be provided with an enteric coating, to provide release in parts of the gut other than the stomach.

Formulations suitable for topical administration (e.g. transdermal, intranasal, ocular, buccal, and sublingual) may be formulated as an ointment, cream, suspension, lotion, powder, solution, past, gel, spray, aerosol, or oil. Alternatively, a formulation may comprise a patch or a dressing such as a bandage or adhesive plaster impregnated with active compounds and optionally one or more excipients or diluents. Formulations suitable for topical administration in the mouth include losenges comprising the active compound in a flavored basis, usually sucrose and acacia or tragacanth; pastilles comprising the active compound in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active compound in a suitable liquid carrier.

Formulations suitable for topical administration to the eye also include eye drops wherein the active compound is dissolved or suspended in a suitable carrier, especially an aqueous solvent for the active compound.

Formulations suitable for nasal administration, wherein the carrier is a solid, include a coarse powder having a particle size, for example, in the range of about 20 to about 500 microns which is administered in the manner in which snuff is taken, i.e. by rapid inhalation through the nasal passage from a container of the powder held close up to the nose. Suitable formulations wherein the carrier is a liquid for administration as, for example, nasal spray, nasal drops, or by aerosol administration by nebuliser, include aqueous or oily solutions of the active compound.

Formulations suitable for administration by inhalation include those presented as an aerosol spray from a pressurised pack, with the use of a suitable propellant, such as dichlorodifluoromethane, trichlorofluoromethane, dichoro-tetrafluoroethane, carbon dioxide, or other suitable gases.

Formulations suitable for topical administration via the skin include ointments, creams, and emulsions. When formulated in an ointment, the active compound may optionally be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active compounds may be formulated in a cream with an oil-in-water cream base. If desired, the aqueous phase of the cream base may include, for example, at least about 30% w/w of a polyhydhc alcohol, i.e., an alcohol having two or more hydroxyl groups such as propylene glycol, butane-1 ,3-diol, mannitol, sorbitol, glycerol and polyethylene glycol and mixtures thereof. The topical formulations may desirably include a compound which enhances absorption or penetration of the active compound through the skin or other affected areas. Examples of such dermal penetration enhancers include dimethylsulfoxide and related analogues. When formulated as a topical emulsion, the oily phase may optionally comprise merely an emulsifier (otherwise known as an emulgent), or it may comprises a mixture of at least one emulsifier with a fat or an oil or with both a fat and an oil. Preferably, a hydrophilic emulsifier is included together with a lipophilic emulsifier which acts as a stabiliser. It is also preferred to include both an oil and a fat. Together, the emulsifier(s) with or without stabiliser(s) make up the so-called emulsifying wax, and the wax together with the oil and/or fat make up the so-called emulsifying ointment base which forms the oily dispersed phase of the cream formulations.

Suitable emulgents and emulsion stabilisers include Tween 60, Span 80, cetostearyl alcohol, myristyl alcohol, glyceryl monostearate and sodium lauryl sulphate. The choice of suitable oils or fats for the formulation is based on achieving the desired cosmetic properties, since the solubility of the active compound in most oils likely to be used in pharmaceutical emulsion formulations may be very low. Thus the cream should preferably be a non-greasy, non-staining and washable product with suitable consistency to avoid leakage from tubes or other containers. Straight or branched chain, mono- or dibasic alkyl esters such as di- isoadipate, isocetyl stearate, propylene glycol diester of coconut fatty acids, isopropyl myristate, decyl oleate, isopropyl palmitate, butyl stearate, 2-ethylhexyl palmitate or a blend of branched chain esters known as Crodamol CAP may be used, the last three being preferred esters. These may be used alone or in combination depending on the properties required. Alternatively, high melting point lipids such as white soft paraffin and/or liquid paraffin or other mineral oils can be used.

Formulations suitable for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter or a salicylate.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active compound, such carriers as are known in the art to be appropriate.

Formulations suitable for parenteral administration (e.g., by injection, including cutaneous, subcutaneous, intramuscular, intravenous and intradermal), include aqueous and nonaqueous isotonic, pyrogen-free, sterile injection solutions which may contain anti-oxidants, buffers, preservatives, stabilisers, bacteriostats, and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents, and liposomes or other microparticulate systems which are designed to target the compound to blood ^N components or one or more organs. Examples of suitable isotonic vehicles for use in such formulations include Sodium Chloride Injection, Ringer's Solution, or Lactated Ringer's Injection. Typically, the concentration of the active compound in the solution is from about 1 ng/ml to about 10 μg/ml, for example from about 10 ng/ml to about 1 μg/ml. The formulations may be presented in unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a freeze-dried (lyophilised) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules, and tablets. Formulations may be in the form of liposomes or other microparticulate systems which are designed to target the active compound to blood components or one or more organs.

Dosage

It will be appreciated that appropriate dosages of the active compounds, and compositions comprising the active compounds, can vary from patient to patient. Determining the optimal dosage will generally involve the balancing of the level of therapeutic benefit against any risk or deleterious side effects of the treatments of the present invention. The selected dosage level will depend on a variety of factors including, but not limited to, the activity of the particular compound, the route of administration, the time of administration, the rate of excretion of the compound, the duration of the treatment, other drugs, compounds, and/or materials used in combination, and the age, sex, weight, condition, general health, and prior medical history of the patient. The amount of compound and route of administration will ultimately be at the discretion of the physician, although generally the dosage will be to achieve local concentrations at the site of action which achieve the desired effect without causing substantial harmful or deleterious side-effects.

Administration in vivo can be effected in one dose, continuously or intermittently (e.g., in divided doses at appropriate intervals) throughout the course of treatment. Methods of determining the most effective means and dosage of administration are well known to those of skill in the art and will vary with the formulation used for therapy, the purpose of the therapy, the target cell being treated, and the subject being treated. Single or multiple administrations can be carried out with the dose level and pattern being selected by the treating physician. In general, a suitable dose of the active compound is in the range of about 100 μg to about 250 mg per kilogram body weight of the subject per day. Where the active compound is a salt, an ester, prodrug, or the like, the amount administered is calculated on the basis of the parent compound and so the actual weight to be used is increased proportionately.

Examples

General Methods

¹H and ¹³C NMR spectra were recorded with a Brucker Avance DPX300 spectrometer operating at 300 and 75 MHz, with Mβ4Si as internal standard. Mass spectra were determined by the EPSRC mass spectrometry centre (Swansea, UK). Microanalyses were determined by Medac Ltd (Surrey, UK). Flash column chromatography was performed with silica gel 60 (230-400 mesh) (Merck) and TLC was carried out on precoated silica plates (kiesel gel 60 F254, BDH). Compounds were visualised by illumination under UV light (254 nm) or by the use of vanillin stain followed by charring on a hotplate. Melting points were determined on an electrothermal instrument and are uncorrected. All solvents were dried prior to use as described by the handbook "Purification of Laboratory Chemicals" and stored over 4A molecular sieves, under nitrogen.

Synthesis Methods

Method A - Suzuki coupling

To aryl boronic acid (30 mmol), 4-aminoaryl derivative (10 mmol), anhydrous cupric acetate (3.63 g, 20 mmol), pyridine (1.58 g, 30 mmol) and 250 mg activated 4A molecular sieves under an atmosphere of air was added dichloromethane (25 mL) and the reaction stirred under air atmosphere at ambient temperature for 3 days. The product was isolated by direct flash column chromatography of the crude reaction mixture.

Method B - Addition of the imidazole ring

To a solution of the carbinol compound (1.8 mmol) in acetonitrile (20 mL) was added imidazole (5.5 mmol) and 1 ,1'-carbonydiimidazole (3.5 mmol). The mixture was then heated under reflux for 1 hour. The reaction mixture was allowed to cool and then extracted with ethyl acetate (150 mL) and water (3 x 100 mL). The organic layer was dried with MgSO₄, filtered and reduced in vacuo. The residue was then purified by flash column chromatography. Method C - NaBH₄ reduction

To a cooled solution of ketone (5 mmol) in anhydrous methanol (10 mL) or a mixture of anhydrous methanol (5 mL) and anhydrous dioxane (5ml_) was added sodium borohydride (10 mmol) and the reactiom stirred under nitrogen at room temperature for the specified time. The solvent was evaporated in vacuo and acetone (1 mL) was added to the residue in order to quench any excess reducing agent. The oil that separated was extracted with dichloromethane (2 x 150 mL), washed with water (3 x 100 mL), then the organic layer was dried with MgSO₄, filtered and reduced in vacuo. The residue was then purified by flash column chromatography.

Method D - Saponification and esterification

To a solution of 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester (4) (1.01 mmol) in ethanol (20 mL) was added potassium hydroxide (0.23 g, 1.05 mmol), and the reaction mixture heated under reflux for 72 hours. The solvent was removed in vacuo, water (10OmL) was added and the unreacted starting materials were extracted with diethyl ether (3 x 50 mL). The aqueous layer was acidified with 1 N HCI to pH 7 and then concentrated to dryness in vacuo. The residue was dissolved in DMF. Alkyl bromide (1.2 mmol) was added and the mixture was heated with stirring at 80⁰C for 2 hours. Water (70 mL) was then added and the aqueous layer was extracted with EtOAc (3 x 50 mL). The organic layer was dried with MgSO₄, filtered and reduced in vacuo. The residue was then purified by flash chromatography.

Method E - Amide formation

EDC (0.1 g, 0.52 mmol), 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]- propionic acid (20), HOBt (70 mg, 0.52 mmol) in DCM (10 mL) were stirred at room temperature under N₂ for 0.5 hours. Amine was added and the reaction mixture was stirred overnight at room temperature. EtOAc (70 mL) was added and the organic layer was washed with 1 M HCI (30 mL), sat. aq. NaHCO₃ (30 mL), brine (30 mL) and water (30 mL). The organic layer was dried with MgSO₄, filtered and concentrated in vacuo. The residue was then purified by flash chromatography. Example 1

(a) 3-(4-aminophenyl)-3-hydroxy-2,2-dimethylpropionic acid methyl ester (2)

Pd/C catalyst (100 mg) was added to a solution of 3-hydroxy-2,2-dimethyl-3-(4-nitrophenyl)- propionic acid methyl ester (1)(1 g, 3.95 mmol) dissolved in EtOH (20 mL) and then the reaction was stirred under a H₂ atmosphere. After 30 minutes the hydrogen balloon was removed and the mixture was filtered through Celite. The solvent was then removed under reduced pressure and the oil formed was extracted with CH₂CI₂ (100 mL), washed with H₂O (2 x 50 mL) and dried (MgSO₄), filtered and evaporated in vacuo. The product was then obtained without further purification to give 3-(4-aminophenyl)-3-hydroxy-2,2- dimethylpropionic acid methyl ester (2) as a yellow solid . Yield: 0.87 g (87 %). t.l.c system: petroleum ether - EtOAc 2:1 v/v, R_F = 0.31 , stain positive.

¹H NMR (DMSO-d₆): δ 0.90 (s, 3H, H-4), 1.02 (s, 3H, H-5), 3.58 (s, 3H, H-1 ), 4.65 (s, 1 H, OH), 4.93 (s, 2H, NH₂), 5.17 (s, 1 H, H-6), 6.50 (d, J= 7.9 Hz, 2H, H-3¹, H-5¹), 6.92 (d, J= 7.8 Hz, 2H, H-2', H-6¹). ¹³C NMR: (DMSO-d₆): δ 18.52 (CH₃, C-4), 19.41 (CH₃, C-5), 47.88 (C, C- 3), 51.30 (CH₃, C-1 ), 76.82 (CH, C-6), 112.84 (CH, C-3¹, C-5¹), 128.01 (CH₁ C-2¹, C-6¹), 128.67 (C, C-1¹), 147.61 (C, C-4¹), 176.76 (C, C-2). Microanalysis: Calculated for C₁₂H₁₇NO₃. 0.2H₂O (226.857); Theoretical: %C= 63.53, %H= 7.55, %N= 6.17; Found: %C= 63.38, %H= 7.75, %N= 5.97. Melting point: 130-132⁰C.

(b) 3-Hydroxy-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester (3)

This was carried out using method A, wherein the aminoraryl derivative was 3-(4- aminophenyl)-3-hydroxy-2,2-dimethylpropionic acid methyl ester (2). The product was isolated by direct flash column chromatography of the crude reaction mixture (petroleum ether - EtOAc 70:30 v/v) to give 3-hydroxy-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]- propionic acid methyl ester (3) as a yellowish brown oil. Yield: 0.64 g (82%), 1. 1. c. system: petroleum ether - EtOAc 2:1 v/v, R_F: 0.59, stain positive. ¹H NMR (CDCI₃): δ 1.18 (s, 3H, H- 4), 1.22 (S, 3H, H-5), 3.15 (s, 1 H, OH), 3.76 (s, 3H, H-1 ), 4.90 (s, 1 H, H-6), 5.98 (s, 1 H, NH), 7.13 (d, J= 7.5 Hz, 2H, H-3', H-5'), 7.23 (s, 1 H, H-2"), 7.26 (d, J= 8.5 Hz, 2H, H-2', H-6¹), 7.33 (t, J= 7.2 Hz, 1 H, H-6"), 7.44 (m, 2H, H-5", H-10"), 7.67 (d, J= 8.2 Hz, 1 H, H-4"), 7.77 (d, J= 8.3 Hz, 2H, H-7", H-9"). ¹³C NMR (CDCI₃): δ 19.18 (CH₃, C-4), 23.05 (CH₃, C-5), 47.91 (C, C-3), 52.10 (CH₃, C-1), 78.52 (CH, C-6), 111.80 (CH, C-2"), 117.27 (CH, C-3', C-5', C-10"), 120.11 (CH, C-6"), 123.56 (CH, C-4"), 12.51 (CH, C-5"), 127.75 (CH, C-7"), 128.73 (CH, C- 9"), 129.19 (CH, C-2', C-6¹), 129.25 (C, C-8"), 132.79 (C, C-1¹), 134.63 (C, C-3"), 140.71 (C, C-4¹), 142.60 (C, C-1 "), 178.30 (C, C-2).HRMS (El): Calculated mass: 372.1570 (M+Na)⁺, Measured mass : 372.1568 (M+Na)⁺.

(c) 3-lmidazol-1-yl-2, 2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester (4)

This was carried out using method B, wherein the carbinol compound was 3-hydroxy- 2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester (3). The product was purified by flash column chromatography (CH₂CI₂ - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol-1-yl-2-methyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester (4) as a light brown solid. Yield 0.25 (54), 1. 1. c. system: CH₂CI₂ - MeOH 97:3 v/v, R_F: 0.61 , stain positive. ¹H NMR (DMSO-d₆): δ 1.21 (s, 6H, H-4, H-5), 3.55 (s, 3H, H-1 ), 5.58 (s, 1 H, H-6), 6.91 (s, 1 H, H-2"), 7.17 (d, J= 8.0 Hz, 2H, H-3¹, H-5¹), 7.28 (m, 2H, H- 6", H-10"), 7.38 (m, 3H, H-2¹, H-6', H-5"), 7.44 (s, 1 H, H-3¹"), 7.50 (s, 1 H, H-2'"), 7.71 (d, J= 8.2 Hz, 1 H, H-4"), 7.77 (m, 2H, H-7", H-9"), 7.83 (s, 1 H, H-1¹"), 8.51 (s, 1 H₁ NH). ¹³C NMR (DMSO-de): δ 22.70 (CH, C-4), 22.90 (CH, C-5), 47.34 (C, C-3), 51.92 (CH, C-1 ), 66.73 (CH, C-6), 109.84 (CH, C-2"), 112.84 (CH, C-10"), 116.20 (CH, C-3¹, C-5¹), 120.10 (CH, C-6". C- 2¹"), 122.98 (CH, C-4"), 126.23 (CH, C-5", C-7"), 127.37 (CH₁ C-9"), 127.96 (C, C-8"), 128.00 (CH, C-3"¹), 128.10 (C, C-1¹), 128.82 (CH, C-1'"), 129.79 (CH, C-2¹, C-6¹), 134.29 (C, C-3"), 140.68 (C, C-4'), 142.99 (C, C-1"), 175.31 (C, C-2). m.p. 190-192⁰C. Anal. Calculated for C₂₅H₂₅N₃O₂-CSH₂O (404.885): C 74.16%, H 6.22%, N 10.38%. Found: C 74.09%, H 6.26%, N 10.11%. Example 2

a) Methyl 3-[4-(2-naphthylamιno)phenyl]-3-hydroxy-2-methyl propanoates (6a and 6b) This was carried out using method A, wherein the aminoraryl derivative was methyl 3-(4- aminophenyl)-3-hydroxy-2-methylpropanoate. The product was isolated by direct flash column chromatography (petroleum ether - EtOAc 100:0 v/v increasing to 70:30 v/v) to give methyl 3-[4-(2-naphthylamino)phenyl]-3-hydroxy-2-methylpropanoate in two forms: anti form (6a) as a brown solid and the syn form (6b) as an oily product in a ratio of 2:1 respectively. Yield: 0.60 g (0.4 g anti (40%) and 0.2 g syn (20%)), 1. 1. c. system: petroleum ether - EtOAc 3:1 v/v, R_F: anti = 0.74 and syn = 0.8.

Anti-form (6a): ¹H NMR (CDCI₃): δ 0.97 (d, 3H, J = 7.2 Hz, CH-CH₂), 2.73-2.79 (m, 2H, CH- CH₃, OH), 3.68 (S, 3H, 0-CH₃), 4.65 (dd, 1 H, J = 3.8 Hz, 8.8 Hz, CH-OH), 5.83 (s, 1 H, NH), 7.05-7.08 (m, 2H, H-3¹, H-5¹), 7.15 (dd, 1H, J = 2.3 Hz₁ 8.7 Hz, H-1"), 7.18-7.25 (m, 3H, H-Z₁ H-6', H-3"), 7.32-7.37 (m, 2H, H-7", H-8"), 7.58 (d, 1 H, J = 8.3 Hz₁ H-4"), 7.66-7.68 (m, 2H, H-6", H-9"). ¹³C NMR (CDCI₃): δ 14.56 (CH₃, C-4), 47.14 (CH₁ C-2), 51.94 (CH₃, C-1¹"), 76.21 (CH, C-3), 112.08 (CH, C-1 "), 117.90 (CH₁ C-3¹, C-5¹, C-3"), 120.15 (CH, C-7"), 123.66 (CH, C-9"), 126.52 (CH, C-8"), 127.66 (CH, C-6"), 127.89 (CH, C-4"), 129.24 (CH, C- 2¹, C-6¹), 129.33 (C, C-5"), 134.24 (C, C-1¹), 134.59 (C, C-10"), 140.54 (C, C-4¹), 142.98 (C, C-2"), 176.37 (C, C-1 ). Anal. Calcd for C₂iH₂iNO₃. 0.8H₂O (349.8) C, 72.10 %; H, 6.51 %; N, 4.00 %. Found: C, 72.14 %; H, 6.44 %; N₁ 3.64 %. Melting point: 124-126°C. Syn-form (6b): ¹H NMR (CDCI₃): δ 1.11 (d, 3H, J = 7.15 Hz, CH-CH₃), 2.69-2.75 (m, 1 H, CH- CH₃), 2.78 (d, 1 H₁ J = 3.3 Hz₁ OH), 3.59 (s, 3H, 0-CH₃), 4.74 (t, 1 H, J = 3.8 Hz, CH-OH)₁ 5.80 (s, 1 H, NH), 7.02-7.05 (m, 2H₁ H-3', H-5¹), 7.11 (dd, 1 H₁ J = 2.3 Hz, 8.75 Hz, H-1"), 7.16-7.23 (m, 3H, H-2', H-6', H-3"), 7.29-7.32 (m, 2H, H-7", H-8"), 7.55 (d, 1 H, J = 8.2 Hz, H- 4"), 7.60-7.71 (m, 2H, H-6", H-9"). ¹³C NMR (CDCI₃): δ 10.15 (CH₃, C-4), 45.52 (CH, C-2), 50.83 (CH₃, C-1"¹), 72.64 (CH, C-3), 110.67 (CH, C-1"), 116.90 (CH, C-3\ C-5¹, C-3"), 119.01 (CH, C-7"), 122.51 (CH₁ C-9"), 125.45 (CH₁ C-8"), 126.14 (CH₁ C-6"), 126.62 (CH₁ C- 4"), 128.16 (CH₁ C-2', C-6¹), 128.20 (C, C-5"), 133.32 (C, C-1¹), 133.59 (C₁ C-10"), 139.74 (C, C-4¹), 141.35 (C₁ C-2"), 175.14 (C, C-1 ). HRMS (El) Calcd for C₂₁H₂₂NO₃ [M + H]⁺ 336.1594. Found 336.1597.

b)(i) Methyl anti-3-(1H- 1-imidazolyl)-3-[4-(2-naphthylamino)phenyl]-2-methylpropanoate (7a) This was carried out using method B, wherein the carbinol compound was anti-3-[4-(2- naphthylamino)phenyl]-3-hydroxy-2-methylpropanoate (6a). The product was then purified by flash column chromatography (CH₂CI₂ - MeOH 99:1 v/v increasing to 97:3 v/v) to give methyl anti-3-(1 H-1-imidazolyl)-3-[4-(2-naphthylamino)phenyl]-2-methylpropanoate (7a) as a brown solid. Yield: 0.28 g (61 %), 1. 1. c. system: CH₂CI₂ - MeOH 90:10 v/v, R_F: 0.62. ¹H NMR (CDCI₃): δ 1.09 (d, 3H₁ J = 7.0 Hz₁ CH-CH₃), 3.29-3.37 (m, 1 H, CH-CH₃), 3.52 (s, 3H, O- CH₃), 5.16 (d, 1 H, J = 11.3 Hz, CH-imidazole), 5.96 (s, 1 H₁ NH)₁ 6.95-7.04 (m, 2H, H-1 ", H- 6'"), 7.12-7.18 (m, 2H, H-3¹, H-5¹), 7.24-7.27 (m, 3H₁ H-2¹, H-6¹, H-3"), 7.32-7.36 (m, 1 H₁ H- 4"), 7.38-7.39 (m, 2H, H-7", H-8"), 7.53 (s, 1 H₁ H-3¹"), 7.59 (d, 1 H, J = 8.2 Hz₁ H-5¹"), 7.67- 7.69 (m, 2H, H-6", H-9"). ¹³C NMR (CDCI₃): δ 16.04 (CH₃, C-4), 44.99 (CH, C-2), 52.23 (CH₃, C-1¹"), 64.00 (CH, C-3), 113.16 (CH, C-1", C-6¹"), 117.52 (CH, C-3¹, C-5', C-3"), 120.47 (CH, C-7"), 123.96 (CH, C-9"), 126.61 (CH₁ C-8"), 127.68 (CH₁ C-6"), 128.66 (CH₁ C-4", C-5¹"), 129.16 (C, C-5"), 129.32 (CH₁ C-2¹, C-6¹, C-3¹"), 129.60 (C, C-1'), 134.50 (C, C-10"),

139.81.54 (C₁ C-4¹), 143.84 (C, C-2"), 174.47 (C, C-1 ). HRMS (El) Calcd for C₂₄H₂₄N₃O₂ [M + H]⁺ 386.1863. Found 386.1858.

(H) Methyl syn-3-(1H-1-imidazolyl)-3-[4-(2-naphthylamino)phenyl]-2-methylpropanoate (7b) This was carried out using method B, wherein the carbinol compound was syn-3-[4-(2- naphthylamino)phenyl]-3-hydroxy-2-methylpropanoate (6b). The product was then purified by flash column chromatography (CH₂CI₂ - MeOH 99:1 v/v increasing to 97:3 v/v) to give methyl syn-3-(1 H-1-imidazolyl)-3-[4-(2-naphthylamino)phenyl]-2-methylpropanoate (7b) as an oily product. Yield: 0.13 g (57%), 1. 1. c. system: CH₂CI₂ - MeOH 90:10 v/v, R_F: 0.66, stain positive. ¹H NMR (CDCI₃): δ 1.08 (d, 3H, J = 6.95 Hz, CH-CH₃), 3.29-3.37 (m, 1 H₁ CH-CH₃), 3.52 (S, 3H, 0-CH₃), 4.47 (d, 1 H₁ J = 11.3 Hz, CH-imidazole), 5.90 (s, 1 H, NH), 6.94-7.05 (m, 2H, H-1", H-6"¹), 7.13-7.19 (m, 2H, H-3¹, H-5¹), 7.24-7.27 (m, 3H₁ H-2¹, H-6¹, H-3"), 7.33-7.36 (m, 1 H, H-4"), 7.39-7.41 (m, 2H, H-7", H-8"), 7.52 (s, 1 H, H-3"¹), 7.60 (d, 1 H, J = 8.15 Hz, H- 5"¹), 7.67-7.70 (m, 2H, H-6", H-9"). ¹³C NMR (CDCI₃): δ 16.05 (CH₃, C-4), 44.99 (CH, C-2), 52.24 (CH₃, C-1¹"), 63.99 (CH, C-3), 113.19 (CH, C-1", C-6"¹), 117.52 (CH, C-3', C-5', C-3"), 120.47 (CH, C-7"), 123.98 (CH, C-9"), 126.61 (CH, C-8"), 127.68 (CH, C-6"), 128.66 (CH, C- 4", C-5¹"), 129.16 (C, C-5"), 129.32 (CH₁ C-2¹, C-6¹, C-3¹¹¹), 129.60 (C, C-1¹), 134.50 (C, C- 10"), 139.81.54 (C, C-4¹), 143.84 (C, C-2"), 174.47 (C, C-1 ). HRMS (El) Calcd for C₂₄H₂₄N₃O₂ [M + H]⁺ 386.1863. Found 386.1862.

Example 3

8 9 10

(a) Methyl 3-hydroxy-2,2-dimethyl-3-(4-(naphthalene-2-yloxy)phenyl)propanoate (9)

To a mixture of methyl 3-hydroxy-(4-hydroxyphenyl)-2,2-dimethylpropanoate (8)(1.3 g, 5.8 mmol), Cu(OAc)₂ (1.16 g, 6.4 mmol), 2-naphthylboronic acid (2.0 g, 11.6 mmol) and powdered activated 4A molecular sieves (7.5 g) was added CH₂CI₂ (40 mL) followed by Et₃N (4.0 mL, 29.0 mmol) and the reaction mixture stirred vigorously at room temperature for 19 hours. The reaction mixture was filtered through celite and the residue washed well with CH₂CI₂. The filtrate was washed with 1 M aqueous HCI (100 mL), which was back-extracted with CH₂CI₂. The combined organic layers were washed with H₂O (100 mL), brine (100 mL), dried (MgSO₄) and concentrated under reduced pressure to give a brown syrup. Purification by flash column chromatography (petroleum ether-EtOAc 80:20 v/v) gave the required product as a white solid. Yield: 0.82 g (40 %), m.p. 80-82⁰C, t.l.c. system: petroleum ether- ethyl acetate 2:1 v/v, R_F: 0.51. ¹H NMR (CDCI₃): δ 7.74 (d, J = 8.9 Hz, 1 H, Ar), 7.73 (d, J = 7.8 Hz, 1 H, Ar), 7.61 (d, J = 8.2 Hz, 1 H, Ar), 7.32-7.35 (m, 2H, Ar), 7.21-7.23 (m, 1 H, Ar), 7.21 (d, J = 8.6 Hz, 2H, Ar)₁ 7.16-7.18 (m, 1 H, Ar)₁ 6.94 (d, J = 8.7 Hz₁ 2H₁ Ar), 4.82 (d, J = 4.2 Hz, 1 H₁ CHOH), 3.65 (s, 3H, OCH₃), 3.07 (d, J = 4.2 Hz₁ 1 H₁ CHOH), 1.09 (s, 3H, CH₃), 1.05 (s, 3H₁ CH₃). 1³C NMR (CDCI₃); δ 178.2 (C=O)₁ 156.8, 154.9, 135.0, 134.3 and 130.2 (5 x C₁ Ar), 129.9, 129.1 , 127.8, 127.1 , 126.6, 124.8, 120.0, 118.3 and 114.3 (11 x CH₁ Ar), 78.3 (CH₃, OCH₃), 52.1 (CH, CHOH), 47.8 (C, CMe₂), 23.0 (CH₃), 19.2 (CH₃). Anal. Calcd for C₂₂H₂₂O₄ (350.41 ) C, 75.41 %; H, 6.33 %. Found: C, 75.39 %; H, 6.42 %.

(b) Methyl 3-(1H-imidazol-1-yl)-2,3-dimethyl-3-((4-naphthalene-2-yloxy)phenyl) propanoate (10)

This was carried out using method B, wherein the carbinol compound was methyl 3-hydroxy- 2,2-dimethyl-3-(4-(naphthalene-2-yloxy)phenyl)propanoate (9). Purification by flash column chromatography (CH₂CI₂-MeOH 100:0 increasing to 80:20 v/v, then EtOAc-MeOH 80:20 v/v) gave the required product as a white solid. Yield: 0.14 g (16 %), m.p. 124-126°C, t.l.c. system: CH₂CI₂-MeOH 9:1 v/v, R_F: 0.1. ¹H NMR (DMSO-d₆): δ 8.39 (s, 1 H, H-1¹" 7.98 (d, J = 8.9 Hz, 1 H, Ar), 7.93 (d, J = 8.0 Hz, 1 H₁ Ar), 7.84 (d, J = 8.0 Hz, 1 H, Ar)₁ 7.68 (s, 1 H, Ar)₁ 7.46-7.53 (m, 5H, Ar), 7.30 (dd, J = 2.5, 8.9 Hz, 1 H₁ Ar), 7.08-7.13 (m, 3H, Ar)₁ 6.18 (s, 1 H, H-6), 3.64 (s, 3H, OCH₃), 1.27 (s, 3H₁ CH₃), 1.16 (s, 3H₁ CH₃). ¹³C NMR (CDCI₃); δ 174.8 (C=O), 157.2, 153.6, 147.3, 133.9 and 130.0 (5 x C₁ Ar), 130.2, 129.3, 127.7, 127.1 , 126.7, 125.0, 120.0, 117.8, 117.5 and 114.7 (14 x CH, Ar), 82.3 (CH₃, OCH₃), 52.2 (CH₁ CHOH), 46.7 (C, CMe₂), 21.9 (CH₃), 19.7 (CH₃). LRMS (ES⁺) m/z: 401 (M + H)⁺, 369 (M - OCH₃)⁺, 333 (M - imidazole C₃H₃N₂J⁺. HRMS (ES⁺) Calcd for C₂₅H₂₄N₂O₃ [M + H]⁺ 401.1860. Found 401.1857.

Example 4

Methyl 2, 2-dimethyl-3-(4-(naphthalen-2-ylamino)phenyl)-3-(1 H-1 , 2, 4-triazol- 1-yl) propanoate

(11) To a cooled (O⁰C) solution of 1 ,2,4-triazole (6 mmol) in CH₃CN (20 ml_) was added thionyl chloride (3 mmol) in CH₃CN (10 ml_) and the reaction stirred at 10⁰C under N₂ for 1 hour. Potassium carbonate (3 mmol) was then added followed by a solution of 3-hydroxy-2,2- dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester (3)(1.5 mmol) in CH₃CN (10 mL) and the reaction allowed to stir at room temperature for 3 days. The suspension was filtered and the solution concentrated under reduced pressure to produce a mixture, which was extracted with EtOAc (2 x 50 mL) and washed with H₂O (2 x 50 mL). The organic layer was dried (MgSO₄) and the solvent evaporated. Purification by flash- chromatography (CH₂CI₂-MeOH 99:1 increasing to 97:3 v/v) gave the triazole (11 ) as a beige solid. Yield: 30%; m.p. 190-192 ⁰C. t. I. c. system: CH₂CI₂ - MeOH 99:1 v/v, R_F: 0.31 , stain positive.

¹H NMR (CDCI₃): δ 1.24 (s, 3H, H-4) and 1.25 (s, 3H, H-5), 3.57 (s, 3H, H-1 ), 5.47 (s, 1 H, H- 6), 5.96 (s, 1 H₁ NH), 7.0 (m, 4H, Ar), 7.10 (m, 1 H₁ Ar), 7.15 (dd, J = 2.3, 8.8 Hz, 1 H, Ar), 7.25 (dt, J = 1.2, 6.9, 8.0 Hz₁ 1 H, Ar), 7.34 (dt, J = 1.2, 6.9, 8.2 Hz, 1 H, Ar), 7.39 (d, J = 2.6 Hz, 1 H, Ar), 7.56 (s, 1 H, triazole), 7.59 (d, J = 8.2 Hz₁ 1 H, Ar)₁ 7.68 (d, J = 6.7 Hz, 1 H, Ar), 7.69 (s, 1 H, triazole). ¹³C NMR (CDCI₃): δ 23.0 (CH₃, C-4), 23.4 (CH₃, C-5), 47.7 (C₁ C-3), 52.4

(CH₃, C-1 ), 67.6 (CH, C-6), 113.0.84 (CH), 116.9 (CH), 120.4 (CH), 123.9 (CH), 125.5 (CH), 125.6 (CH), 127.7 (CH), 128.6 (C), 129.0 (CH), 129.3 (CH), 129.6 (C), 134.5 (C), 139.8 (C)₁ 143.4 (C)₁ 176.3 (C=O₁ C-2).

Alternative method:

SOCI₂ (0.38 mL, 5.16 mmol) in anhydrous CH₃CN (10 mL) was added dropwise to a stirred solution of 1 ,2,4-triazole (0.72 g, 10.32 mmol) in anhydrous CH₃CN (10 mL) at a temperature of 10 °C. The white suspension formed was stirred for 1 h at 10⁰C. A solution of (3) (0.9 g, 2.58 mmol) in anhydrous CH₃CN (10 mL) was added to the mixture followed by activated K₂CO₃ (0.72 g, 5.16 mmol). The suspension was stirred under N₂ at room temperature for 4 days. The resulting suspension was filtered and the filtrate was evaporated in vacuo to yield a light brown oil. The oil was extracted with DCM (150 mL) and H₂O (3 x 100 mL). The organic layer was dried with MgSO₄, filtered and reduced in vacuo. The product was then purified by flash column chromatography (petroleum ether - EtOAc 90:10 v/v increasing to 10:90 v/v) followed by preparative t.l.c. (DCM - MeOH 99.5:0.5 v/v then 99:1 v/v) to give 2,2- dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-3-[1 ,2,4]triazol-1-yl-propionic acid methyl ester (11 ) as a light brown oil. Yield 0.07 g (7 %), 1. 1. c. system: petroleum ether - EtOAc 1 :1 v/v, R_F: 0.42, stain positive. ¹H NMR (CDCI₃): δ 1.25 (s, 3H₁ H-4), 1.36 (s, 3H₁ H-5), 3.53 (s, 3H, H-1 ), 5.74 (s, 1 H, NH), 7.13 (d, J= 8.0 Hz, 2H, H-3¹, H-5'), 7.20-7.23 (m, 2H, Ar), 7.33 (m, 1 H, Ar), 7.39-7.44 (m, 3H, Ar), 7.49 (s, 1 H₁ Ar), 7.68 (d, J= 8.0 Hz, 1 H, H-9"), 7.77-7.80 (m, 2H, Ar), 8.02 (s, 1 H, H-3¹"), 8.25 (s, 1 H, H-5"¹). ¹³C NMR (CDCI₃): δ 21.02 (CH₁ C-4), 24.04 (CH₁ C-5), 48.08 (C, C-3), 52.37 (CH, C-1 ), 69.23 (CH, C-6), 113.22 (CH, C-3¹, C-5¹), 116.67 (CH, C-10"), 120.50 (CH, C-6"), 123.96 (CH, C-4"), 126.62 (CH₁ C-5"), 126.86 (C, C-8"), 127.67 (CH₁ C-7", C-3¹¹¹), 128.12 (CH₁ C-9"), 129.31 (CH, C-5¹"), 129.60 (C, C-1¹), 130.56 (CH, C-2¹, C-6¹), 134.49 (C, C-3¹"), 139.73 (C, C-4¹), 143.77 (C, C-1"), 176.27 (C, C-2). HRMS (El): Calculated mass: 423.1789 (M+Na)⁺, Measured mass: 423.1786 (M+Na)⁺.

Example 5

3-lmidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid (12) 3-lmidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid methyl ester (4) (0.4 g, 1.01 mmol) in EtOH (20 mL) was saponified with KOH (0.23 g, 1.05 mmol) under reflux for 72 h. The solvent was removed under reduced pressure, H₂O (100 mL) was added and the unreacted starting materials were extracted with ether (3 X 50 mL). The aqueous layer was acidified with 1 N HCI to pH 3 and extracted with DCM (100 mL). The organic layer was dried with MgSO₄, filtered and the solvent removed under reduced pressure to give 3- imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid (12) as a brown solid. Yield 0.25 g (64 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.21 , stain positive. ¹H NMR (CDCI₃): δ 1.25 (s, 3H, H-3), 1.33 (s, 3H, H-4), 5.67 (s, 1 H₁ H-NH), 7.07 (d, J= 8.0 Hz₁ 2H₁ H-3¹, H-5¹), 7.11 (s, 1 H, H-5), 7.17 (s, 1 H₁ H-2"), 7.25 (m, 2H, H-6", H-10"), 7.32 (m, 3H, H-2¹, H-6¹, H-5"), 7.47 (s, 1 H, H-3¹"), 7.50 (s, 1 H, H-2¹"), 7.71 (d, J= 8.2 Hz, 1 H, H-4"), 7.83 (s, 1 H, H-1¹¹¹), 7.77 (m, 2H, H-7", H-9"), 8.23 (s, 1 H, H-1 ). ¹³C NMR (CDCI₃): δ 22.81 (CH, C-3), 23.05 (CH, C-4), 46.81 (C, C-2), 66.50 (CH, C-5), 109.69 (CH, C-2"), 116.24 (CH, C-10"), 116.20 (CH, C-3', C-5¹), 120.06 (CH, C-6". C-2¹"), 122.95 (CH, C-4"), 126.24 (CH, C-5", C-7"), 127.84 (CH, C-9"), 127.96 (C, C-8"), 128.27 (CH, C-3¹"), 128.43 (C, C-T)₁ 128.82 (CH, C-T"), 129.81 (CH, C-2', C-6¹), 134.30 (C, C-3"), 140.75 (C, C-4¹). 142.85 (C₁ C-1"), 176.74 (C, C-1). HRMS (El): Calculated mass: 386.1863 (M+H)⁺, Measured mass: 386.1865 (M+H)⁺. M.p. 148-150 ⁰C.

Example 6

3-lmidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid ethyl ester (13)

This was prepared using Method D, wherein the alkyl bromide was bromoethane. The product was isolated by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid ethyl ester (13) as a creamy white solid. Yield 0.30 g (71 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.62, stain positive. ¹H NMR (CDCI₃): δ 1.21 (t, J= 7.0 Hz, 3H, H-1 ), 1.37 (s, 6H, H-5, H-6), 4.13 (q, J= 7.0 Hz, 2H, H-2), 5.58 (s, 1 H, H-7), 6.11 (s, 1 H, NH), 7.05-7.11 (m, 3H, H-3', H-5¹, H-2"), 7.17-7.21 (m, 2H, H-6", H-10"), 7.23-7.27 (m, 2H, H-2', H-6'), 7.31 (s, 1 H, H-3"¹), 7.34-7.36 (m, 1 H, Ar), 7.40-7.42 (m, 1 H, Ar), 7.49 (d, J= 8.2 Hz, 1 H, H-4"), 7.76- 7.78 (m, 1 H, Ar), 7.83-7.87 (m, 2H, Ar). ¹³C NMR (CDCI₃): δ 13.95 (CH, C-1 ), 23.03 (CH, C- 5), 23.56 (CH, C-6), 47.51 (C, C-4), 61.32 (C, C-2), 66.71 (CH, C-7), 112.87 (CH, C-2"), 112.95 (CH, C-10"), 116.95 (CH, C-3¹, C-5'), 120.28 (CH₁ C-6". C-2¹"), 123.84 (CH₁ C-4"), 126.44 (CH, C-5", C-7"), 127.67 (CH, C-9"), 128.68 (C₁ C-8"), 129.27 (CH, C-3"¹), 129.51 (C, C-T), 129.57 (CH, C-T"), 129.71 (CH, C-2¹, C-6¹), 134.51 (C₁ C-3"), 139.93 (C, C-4'), 143.36 (C, C-1"), 175.75 (C, C-3). HRMS (El): Calculated mass: 414.2181 (M+H)⁺, Measured mass: 414.2179 (M+H)⁺. M.p. 156-158°C Example 7

3-lmidazol- 1-yl-2, 2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid isopropyl ester (14)

This was prepared using Method D, wherein the alkyl bromide was 2-bromopropane. The product was isolated by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid isopropyl ester (14) as a creamy white solid. Yield 0.29 g (68 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.65, stain positive. ¹H NMR (CDCI₃): δ 1.1 1 (d, J= 6.8 Hz, 6H, H-1 , H- 3), 1.29 (s, 6H, H-6, H-7), 4.93 (sep, J= 6.8 Hz, 1 H, H-2), 5.54 (s, 1 H, H-8), 6.13 (s, 1 H, NH), 7.07 (d, J= 8.1 Hz, 2H, H-3¹, H-5¹), 7.17-7.21 (m, 2H, H-6", H-10"), 7.28-7.29 (m, 2H, H-2', H- 6'), 7.31 (s, 1 H₁ H-3"¹), 7.38-7.40 (m, 1 H, Ar), 7.48-7.52 (m, 2H, Ar), 7.68 (d, J= 8.2 Hz, 2H, Ar), 7.76 (d, J= 8.3 Hz, 2H, Ar). ¹³C NMR (CDCI₃): δ 21.45 (CH, C-1 , C-3), 23.10 (CH, C-6), 23.63 (CH, C-7), 47.38 (C, C-5), 67.42 (CH, C-8), 68.77 (CH, C-2), 66.73 (CH, C-6), 112.77 (CH, C-2"), 116.99 (CH, C-10"), 119.39 (CH, C-3', C-5¹), 120.37 (CH, C-6". C-2¹"), 123.85 (CH, C-4"), 126.44 (CH, C-5", C-7"), 127.60 (CH, C-9"), 128.83 (C, C-8"), 129.27 (CH, C- 3'"), 129.49 (C, C-1¹), 129.56 (CH, C-1"¹), 129.69 (CH, C-2¹, C-6'), 134.51 (C, C-3"), 139.98 (C, C-4'), 143.30 (C, C-1 "), 175.16 (C, C-4). HRMS (El): Calculated mass: 428.2338 (M+H)⁺, Measured mass: 428.2337 (M+H)⁺. M.p. 166-168 ⁰C.

Example 8

3-lmidazol- 1-yl-2, 2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid butyl ester (15)

This was prepared using Method D, wherein the alkyl bromide was 1-bromobutane. The product was isolated by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid butyl ester (15) as a yellow oil. Yield 0.30 g (67 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.65, stain positive. ¹H NMR (CDCI₃): δ 0.96 (t, J= 6.9 Hz, 3H, H-1 ), 1.18-1.28 (m, 8H, H-2, H-7, H-8), 1.46-1.49 (m, 2H, H-3), 4.12 (t, J= 6.6 Hz, 2H, H-4), 5.08 (s, 1 H, H-9), 5.93 (s, 1 H, NH), 7.15 (d, J= 8.0 Hz, 2H, H-3', H-5¹), 7.20-7.24 (m, 2H, H-6", H-10"), 7.39-7.43 (m, 3H, H-2¹, H-6^r, H-5"), 7.50 (s, 1 H, H-3¹"), 7.52 (s, 1 H, H-2¹"), 7.74 (d, J= 8.2 Hz, 2H, Ar)₁ 7.80- 7.85 (m, 3H, Ar). ¹³C NMR (CDCI₃): δ 13.81 (CH, C-1), 19.33 (CH, C-7, C-8), 20.15 (C, C-2), 32.88 (C, C-3), 47.48 (C, C-6), 66.35 (CH, C-9), 107.81 (CH₁ C-2"), 111.82 (CH₁ C-10"), 115.32 (CH₁ C-3¹, C-5¹), 120.55 (CH, C-6". C-2¹"), 122.69 (CH, C-4"), 125.19 (CH, C-5", C- 7"), 127.32 (CH, C-9"), 127.84 (C, C-8"), 128.11 (CH, C-3"¹), 128.35 (C, C-1¹), 128.86 (CH, C-1 "¹), 129.64 (CH, C-2¹, C-6¹), 135.28 (C, C-3"), 141.09 (C₁ C-4'), 143.92 (C₁ C-1"), 174.98 (C, C-5). HRMS (El): Calculated mass: 442.2489 (M+H)⁺, Measured mass: 442.2483 (M+H)⁺.

Example 9

3-lmidazol-1-yl-N-isopropyl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionamide (16)

EDC (35 mg, 0.18 mmol), 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]- propionic acid (12) (70 mg, 0.18 mmol) and HOBt (25 mg, 0.18 mmol) in DCM (10 mL) were stirred at room temperature under N₂ for 0.5 hours. lsopropylamine (0.45 mL, 0.56 mmol) was added and the reaction mixture was stirred overnight at room temperature. EtOAc (70 mL) was added and the organic layer was washed with 1 M HCI (30 mL), sat. aq. NaHCO₃ (30 mL), brine (30 mL) and H₂O (30 mL). The organic layer was dried with MgSO₄, filtered and reduced in vacuo. The residue was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 98:2 v/v) to give 3-imidazol-1-yl-N-isopropyl-2,2-dimethyl-3-[4- (naphthalen-2-ylamino)-phenyl]-propionamide (16) as a pale yellow oil. Yield 0.049 g (64 %), t. I.e. system: DCM - MeOH 97:3 v/v, R_F: 0.56, stain positive. ¹H NMR (CDCI₃): δ 1.08 (d, J= 6.6 Hz, 6H, H-1 , H-3), 1.25 (s, 3H, H-6), 1.29 (s, 3H, H-7), 4.13 (sep, J= 6.6 Hz, 1 H, H-2), 5.41 (d, J= 6.6 Hz, 1 H, CONH), 5.63 (s, 1 H, NH), 6.16 (s, 1 H, H-8), 7.05-7.10 (m, 3H, Ar),7.20-7.26 (m, 4H, Ar), 7.29-7.31 (m, 1 H, Ar), 7.42-7.45 (m, 2H, Ar), 7.65 (d, J= 8.2 Hz, 2H, Ar), 7.74 (d, J= 8.3 Hz, 2H, Ar). ¹³C NMR (CDCI₃): δ 22.39 (CH, C-1 , C-3), 22.66 (CH, C-6), 23.45 (CH, C-7), 41.72 (CH, C-2), 47.69 (C, C-5), 67.88 (CH, C-8), 112.66 (CH, C-2"), 117.05 (CH, C-10"), 119.54 (CH, C-3¹, C-5¹), 120.35 (CH, C-6". C-2¹"), 123.84 (CH, C-4"), 126.55 (CH, C-5", C-7"), 127.60 (CH, C-9"), 128.62 (C, C-8"), 129.27 (CH, C-3"¹), 129.47 (C, C-1¹), 129.81 (CH, C-1 "¹), 129.97 (CH, C-2¹, C-6¹), 134.47 (C, C-3"), 140.01 (C₁ C-4¹), 143.29 (C, C-1"), 174.27 (C, C-4). HRMS (El): Calculated mass: 427.2492 (M+H)⁺, Measured mass: 427.2492 (M+H)⁺.

Example 10

2,2-Dimethyl-3-(methyl-vinyl-amino)-3-[4-(naphthalen-2-ylamino)-phenyl]-propionamide (17) This was prepared using Method E, wherein the amine was methanolic ammonia (2M, 1 ml_, 2 mmol). The product was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 98:2 v/v) to give 2,2-dimethyl-3-(methyl-vinyl-amino)-3-[4-(naphthalen-2- ylamino)-phenyl]-propionamide (17) as a brown oil. Yield 0.14 g (71 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.47, stain positive. ¹H NMR (CDCI₃): δ 1.27 (s, 3H, H-3), 1.29 (s, 3H, H-4), 5.53 (s, 1 H, H-5), 5.59 (s, 2H₁ CONH), 5.89(s, 1 H, NH), 7.05 (d, J= 8.2 Hz, 2H, Ar), 7.17 (s, 1 H, H-3¹"), 7.19-7.25 (m, 4H, Ar), 7.28-7.30 (m, 1 H₁ Ar), 7.34-7.36 (m, 1 H, Ar)₁ 7.46 (s, 1 H, H-2"¹), 7.63 (d, J= 8.0 Hz, 1 H, Ar), 7.73 (d, J= 8.1 Hz, 2H, Ar)₁ 7.81 (s, 1 H, H-1"¹). ¹³C NMR (CDCI₃): δ 22.84 (CH, C-3), 23.84 (CH, C-4), 47.61 (C, C-2), 67.65 (CH₁ C-5), 112.85 (CH, C-2"), 116.92 (CH, C-10"), 120.42 (CH, C-3¹, C-5¹), 123.88 (CH, C-6". C-2¹"), 123.92 (CH₁ C-4"), 126.58 (CH, C-5", C-7"), 127.67 (CH₁ C-9"), 128.16 (C, C-8"), 129.27 (CH, C- 3¹"), 129.50 (C₁ C-1¹), 129.96 (CH, C-1'"), 129.98 (CH, C-2¹, C-6'), 134.50 (C, C-3"), 139.86 (C₁ C-4'), 143.46 (C, C-1"), 178.18 (C₁ C-1 ). HRMS (El): Calculated mass: 385.2028 (M+H)⁺, Measured mass: 385.2026 (M+H)⁺. Example 11

3-lmidazol-1-yl-2, 2, N-trimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionamide (18) This was prepared using Method E, wherein the amine was 33% methylamine in absolute EtOH (2 mL). The product was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 98:2 v/v) to give 3-imidazol-1-yl-2,2,N-trimethyl-3-[4-(naphthalen-2- ylamino)-phenyl]-propionamide (18) as a white brown solid. Yield 0.15 g (75 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.50, stain positive. ¹H NMR (CDCI₃): δ 1.26 (s, 3H₁ H- 4), 1.29 (s, 3H, H-5), 2.75 (d, J= 2.5 Hz₁ 3H₁ H-1 ), 5.62 (s, 1 H, H-6), 5.77 (d, J= 2.5 Hz, 1 H, CONH), 6.11 (s, 1 H, NH), 7.04 (s, 1 H₁ H-3¹"), 7.09 (d, J= 8.2 Hz₁ 1 H, Ar), 7.15 (s, 1 H, H-1¹"), 7.18-7.25 (m, 4H, Ar)₁ 7.29-7.31 (m, 1 H₁ Ar), 7.38-7.40 (m, 1 H, Ar), 7.45 (d, J= 2.6 Hz, 1 H, Ar), 7.63-7.66 (m, 2H, Ar), 7.76 (d, J= 8.1 Hz, 2H, Ar). ¹³C NMR (CDCI₃): δ 22.50 (CH, C-4), 23.47 (CH₁ C-5), 26.80 (CH₁ C-1 ), 47.87 (C, C-3), 67.95 (CH, C-6), 112.86 (CH, C-2"), 116.96 (CH, C-10"), 120.40 (CH, C-3¹, C-5¹), 123.88 (CH, C-6". C-2¹"), 123.92 (CH, C-4"), 126.56 (CH, C-5", C-7"), 127.67 (CH, C-9"), 128.52 (C₁ C-8"), 129.28 (CH, C-3¹"), 129.51 (C₁ C-1¹), 129.93 (CH, C-1¹"), 129.98 (CH, C-2¹, C-6¹), 134.50 (C, C-3"), 139.91 (C, C-4¹), 143.35 (C, C-1"), 175.97 (C₁ C-2). Anal. Calculated for C₂₅H₂₆N₄O.0.4H₂O (405.714): C 74.01%, H 6.46%, N 13.81 %. Found: C 73.68%, H 6.81 %, N 14.00%. M.p. 120-124 ⁰C.

Example 12

3-lmidazol-1-yl-2,2,N,N-tetramethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionamide (19) This was prepared using Method E, wherein the amine was dimethylamine (2M in THF, 1 mL, 2 mmol). The product was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 98:2 v/v) to give 3-imidazol-1-yl-2,2,N,N-tetramethyl-3-[4- (naphthalen-2-ylamino)-phenyl]-propionamide (19) as a brown oil. Yield 0.13 g (61 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.59, stain positive. ¹H NMR (CDCI₃): δ 1.37 (s, 3H, H-5), 1.41 (S₁ 3H, H-6), 2.95 (s, 6H, H-1 , H-2), 5.80 (s, 1 H, H-7), 6.23 (s, 1 H, NH), 7.05-7.12 (m, 4H, Ar), 7.23-7.28 (m, 3H, Ar), 7.35-7.37 (m, 1 H, Ar), 7.40-7.42 (m, 1 H, Ar), 7.45 (d, J= 2.6 Hz, 1 H, Ar), 7.66 (d, J= 7.8 Hz, 1 H, Ar), 7.69-7.74 (m, 3H, Ar). ¹³C NMR (CDCI₃): δ 24.34 (CH, C-5), 25.16 (CH, C-6), 38.75 (CH, C-1 , C-2), 47.93 (C, C-4), 68.69 (CH, C-7), 112.91 (CH, C-2"), 116.91 (CH, C-10"), 120.50 (CH₁ C-3\ C-5¹), 123.86 (CH, C-6", C-2"¹), 123.92 (CH, C-4"), 126.52 (CH₁ C-5", C-7"), 127.65 (CH, C-9"), 128.11 (C₁ C-8"), 129.24 (CH₁ C- 3'"), 129.51 (C₁ C-1¹), 129.93 (CH, C-1¹"), 129.99 (CH₁ C-2¹, C-6¹), 134.49 (C, C-3"), 139.86 (C, C-4¹), 143.67 (C, C-1"), 175.05 (C, C-3). HRMS (El): Calculated mass: 413.2336 (M+H)⁺, Measured mass: 413.2335 (M+H)⁺.

Example 13

a) 3-Hydroxy-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2, 2-dimethyl-propionic acid methyl ester (20)

To 6-methoxy-2-naphthylboronic acid (1.81 g, 8.96 mmol), 3-(4-aminophenyl)-3-hydroxy-2,2- dimethylpropionic acid methyl ester (2) (1.0 g, 4.48 mmol), anhydrous Cu(OAc)₂ (1.22 g, 6.72 mmol), pyridine (0.7 ml_, 8.96 mmol) and activated 4 A molecular sieves (250 mg) under an atmosphere of air was added DCM (20 ml_) and the reaction mixture was stirred at ambient temperature for 2 days. The product was isolated by direct flash column chromatography of the crude reaction mixture (petroleum ether - EtOAc 70:30 v/v) to give 3- hydroxy-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2, 2-dimethyl-propionic acid methyl ester (20) as a yellowish brown solid. Yield: 1.3 g (77%), t.l.c. system: petroleum ether - EtOAc 2:1 v/v, R_F: 0.62, stain positive. ¹H NMR (CDCI₃): δ 1.15 (s, 3H, H-4), 1.21 (s, 3H, H- 5), 3.10 (s, 1 H, OH), 3.75 (s, 3H, H-1 ), 3.96 (s, 3H₁ OCH₃), 4.89 (s, 1 H, H-6), 5.94 (s, 1 H, NH), 7.08 (d, J= 7.6 Hz, 2H₁ H-3¹, H-5'), 7.16 (d, J= 7.7 Hz, 2H, H-2¹, H-6¹), 7.26-7.32 (m, 3H, H-5", H-7", H-10"), 7.41 (s, 1 H, H-2"), 7.61 (d, J= 8.2 Hz₁ 1 H, H-4"), 7.69 (d, J= 8.3 Hz, 1 H, H-9"). ¹³C NMR (CDCI₃): δ 19.12 (CH, C-4), 23.09 (CH₁ C-5), 47.88 (C₁ C-3), 52.09 (CH, C- 1 ), 55.45 (CH, OCH₃), 78.55 (CH, C-6), 106.04 (CH, C-7"), 113.65 (CH, C-2"), 116.40 (CH, C-3¹, C-5', C-10"), 119.12 (CH, C-4"), 121.20 (CH, C-5"), 127.92 (CH, C-9"), 128.70 (CH₁ C- 2¹, C-6'), 129.86 (C, C-8"), 130.36 (C, C-T), 132.10 (C, C-3"), 138.59 (C, C-4¹), 143.35 (C, C- 1"), 156.35 (CH, C-6"), 178.32 (C, C-2). Anal. Calculated for C₂₃H₂₅NO₄ (379.434): C 72.80%, H 6.64%, N 3.69%. Found: C 72.58%, H 6.53%, N 3.72%. M.p. 84-86 ⁰C.

b) 3-lmidazol- 1-yl-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2, 2-dimethyl-propionic acid methyl ester (21)

To a solution of 3-hydroxy-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2, 2-dimethyl- propionic acid methyl ester (20) (0.4 g, 1.15 mmol) in anhydrous CH₃CN (20 mL) was added imidazole (0.24 g, 3.45 mmol) and CDI (0.28 g, 1.73 mmol). The mixture was then heated under reflux overnight. The reaction mixture was filtered and the precipitate was washed with H₂O (10 mL) and hot CH₃CN (10 mL) to give 3-imidazol-1-yl-3-[4-(6-methoxy-naphthalen-2- ylamino)-phenyl]-2, 2-dimethyl-propionic acid methyl ester (21) as a white solid. Yield 0.33 g (68 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.64, stain positive. ¹H NMR (DMSO-d₆): δ 1.22 (s, 6H, H-4, H-5), 3.57 (s, 3H, H-1 ), 3.89 (s, 3H, OCH₃), 5.60 (s, 1 H, H-6), 6.85 (s, 1 H, Ar), 7.15-7.20 (m, 3H, Ar), 7.20 (s, 1 H, H-3"¹), 7.24 (d, J= 7.8 Hz, 1 H, Ar), 7.29 (d, J= 7.7 Hz, 2H, H-2¹, H-6¹), 7.41 (s, 1 H, H-2"'), 7.45 (s, 1 H, H-1"¹), 7.61 (d, J= 8.2 Hz, 1 H, H-4"), 7.69 (d, J= 8.3 Hz, 1 H, H-9"), 7.82 (s, 1 H₁ H-2"), 8.33 (s, 1 H, NH) . ¹³C NMR (DMSO-d₆): δ 22.69 (CH₁ C-4), 22.91 (CH, C-5), 47.35 (C₁ C-3), 51.91 (CH₁ C-1 ), 55.06 (CH₁ OCH₃), 66.75 (CH, C-6), 106.08 (CH, C-7"), 111.59 (CH, C-2"), 112.59 (CH, C-2¹"), 115.37 (CH, C-3¹, C-5¹, C- 10"), 118.60 (CH, C-4"), 119.73 (CH, C-3¹¹¹), 120.94 (CH, C-5"), 127.25 (CH, C-1¹"), 127.67 (C, C-8"), 127.86 (CH, C-9"), 128.08 (CH, C-2¹, C-6¹), 129.45 (C, C-1¹), 129.78 (C₁ C-3"), 138.53 (C, C-4'), 143.65 (C, C-1"), 155.54 (C₁ C-6"), 175.32 (C, C-2). Anal. Calculated for C₂₆H₂₇N₃O₃ (429.502): C 72.71 %, H 6.34%, N 9.78%. Found: C 72.87%, H 6.25%, N 9.67%. M.p. 220-222⁰C.

Example 14

3-[4-(6-Hydroxy-naphthalen-2-ylamino)-phenyl]-3-imidazol-1-yl-2, 2-dimethyl-propionic acid methyl ester (22)

3-lmidazol-1-yl-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2, 2-dimethyl-propionic acid methyl ester (21 ) (0.1 g, 0.23 mmol) and n-Bu₄NI (0.11 g, 0.3 mmol) were stirred in dry DCM (10 mL) at -78°C under N₂. A solution of BCI₃ (0.6 ml_, 1 M in DCM₁ 2.5 mmol) was added over 2 minutes. After 5 minutes the reaction solution was allowed to warm to 20°C and was stirred for 1 hour. The reaction solution was quenched with ice and H₂O, stirred for 30 minutes, diluted with sat. aq. NaHCO₃ solution and extracted with DCM (50 mL). The organic layer was dried with MgSO₄, filtered and reduced in vacuo. The residue was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 95:5 v/v) to give 3-[4-(6- hydroxy-naphthalen-2-ylamino)-phenyl]-3-imidazol-1-yl-2,2-dimethyl-propionic acid methyl ester (22) as a yellow oil. Yield 0.047 g (49 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.59, stain positive. ¹H NMR (CDCI₃): δ 1.27 (s, 3H, H-4), 1.30 (s, 3H, H-5), 3.65 (s, 3H, H- 1), 5.57 (S₁ 1 H, H-6), 6.01 (s, 1 H, NH), 7.04 (d, J= 7.8 Hz, 2H, Ar), 7.11 (s, 1 H₁ H-3"¹), 7.18- 7.22 (m, 2H, Ar), 7.26 (d, J= 7.6 Hz, 1 H, Ar), 7.33 (d, J= 7.5 Hz₁ 2H, H-2¹, H-6'), 7.41 (s, 1 H, H-2'"), 7.50 (d, J= 8.0 Hz, 1 H, H-4"), 7.62 (s, 1 H, H-1"'), 7.69 (d, J= 8.2 Hz, 1 H, H-9"), 7.73 (s, 1 H, H-2"), 7.91 (S₁ 1 H₁ OH). ¹³C NMR (CDCI₃): δ 22.67 (CH₁ C-4), 22.93 (CH₁ C-5), 47.35 (C, C-3), 51.84 (CH, C-1), 66.88 (CH, C-6), 104.88 (CH, C-7"), 110.87 (CH, C-2"), 112.44 (CH, C-2"¹), 116.06 (CH, C-3¹, C-5¹, C-10"), 118.62 (CH, C-4"), 119.71 (CH, C-3"¹), 121.22 (CH, C-5"), 127.15 (CH, C-1"¹), 127.68 (C, C-8"), 128.01 (CH, C-9"), 128.09 (CH, C-2¹, C-6¹), 129.44 (C, C-1 '), 130.15 (C, C-3"), 136.13 (C, C-4¹), 141.28 (C₁ C-1"), 148.91 (C, C-6"), 175.55 (C, C-2). HRMS (El): Calculated mass: 416.1969 (M+H)⁺, Measured mass: 416.1970 (M+H)⁺.

Example 15

3-lmidazol-1-yl-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl)-2,2-dimethyl-propan-1-ol (23)

A solution of 3-imidazol-1-yl-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2,2-dimethyl- propionic acid methyl ester (21 ) (0.1 g, 0.23 mmol) in dry THF (10 mL) under N₂ was cooled to 0^cC. LiAIH₄ (1.2 mL, 1 M in THF, 1.2 mmol) was added dropwise via syringe. The reaction mixture was stirred at 0⁰C for 1 hour, then at room temperature overnight. The reaction was quenched by the addition of EtOAc (70 mL). The organic layer was washed with H₂O (50 mL) dried with MgSO₄, filtered and reduced in vacuo. The residue was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol- 1-yl-3-[4-(6-methoxy-naphthalen-2-ylamino)-phenyl]-2,2-dimethyl-propan-1-ol (23) as a brown oil. Yield 0.073 g (79 %), 1. 1. c. system: DCM - MeOH 97:3 v/v, R_F: 0.60, stain positive. ¹H NMR (CDCI₃): δ 1.07 (s, 3H, H-3), 1.71 (s, 3H, H-4), 2.48 (s, 1 H, H-OH), 3.26 (d, J= 8.0 Hz, 1 H₁ H-1 ), 3.30 (d, J= 8.0 Hz, 1 H, H-1 ), 3.91 (s, 3H, H-OCH₃), 5.38 (S₁ 1 H, H- 5), 5.91 (s, 1 H₁ H-NH)₁ 7.03 (d, J= 7.8 Hz, 2H, Ar), 7.11 (m, 3H, Ar), 7.20-7.24 (m, 2H, Ar)₁ 7.33 (d, J= 7.7 Hz₁ 2H₁ Ar), 7.42 (d, J= 2.8 Hz₁ 1 H, 7"), 7.57 (d, J= 8.1 Hz, 1 H₁ 4"), 7.69 (d, J= 8.2 Hz, 1H₁ H-9"), 7.73 (s, 1 H, H-2"). ¹³C NMR (CDCI₃): δ 21.53 (CH₁ C-3), 22.43 (CH₁ C- 4), 40.76 (C₁ C-2), 55.34 (CH₁ C-OCH₃), 69.07 (C₁ C-1 ), 106.04 (CH, C-7"), 118.59 (CH, C- 2"), 114.54 (CH, C-2¹"), 116.34 (CH, C-3¹, C-5¹, C-10"), 119.39 (CH, C-4"), 121.47 (CH, C- 3"¹), 121.94 (CH, C-5"), 127.98 (CH₁ C-1¹"), 128.15 (C, C-8"), 128.95 (CH, C-9"), 129.78 (CH₁ C-2¹, C-6'), 130.17 (C, C-1¹), 160.63 (C, C-3"), 137.99 (C, C-4¹), 143.80 (C, C-1"), 156.53 (C, C-6"). HRMS (El): Calculated mass: 402.2176 (M+H)\ Measured mass: 402.2176 (M+H)⁺.

Example 16

a) 3-Hydroxy-2,2-dimethyl-3-[4-(naphthalen-1-ylamino)-phenyl]-propionic acid methyl ester (24)

To 1-naphthylboronic acid (0.79 g, 4.6 mmol), 3-(4-aminophenyl)-3-hydroxy-2,2- dimethylpropionic acid methyl ester (2) (0.51 g, 2.3 mmol), anhydrous Cu(OAc)₂ (0.63 g, 3.45 mmol), pyridine (0.37 ml_, 4.6 mmol) and activated 4 A molecular sieves (250 mg) under an atmosphere of air was added DCM (15 ml_) and the reaction mixture stirred at ambient temperature for 2 days. The product was isolated by direct flash column chromatography of the crude reaction mixture (petroleum ether - EtOAc 70:30 v/v) to give 3- hydroxy-2,2-dimethyl-3-[4-(naphthalen-1-ylamino)-phenyl]-propionic acid methyl ester (24) as a yellowish brown oil. Yield: 0.34 g (42%), t.l.c. system: petroleum ether - EtOAc 2:1 v/v, R_F: 0.59, stain positive. ¹H NMR (CDCI₃): δ 1.11 (s, 3H₁ H-4), 1.19 (s, 3H, H-5), 2.96 (s, 1 H, OH)₁ 3.77 (s, 3H, H-1 ), 4.88 (s, 1 H, H-6), 5.97 (s, 1 H, NH), 6.93 (d, J= 8.2 Hz, 2H, H-3¹, H- 5¹), 7.20 (d, J= 8.1 Hz, 2H, H-2', H-6¹), 7.34-7.37 (m, 2H, H-3", H-4"), 7.46-7.49 (m, 2H, H-7", H-8"), 7.57 (d, J= 8.2 Hz, 1 H, H-2"), 7.86 (d, J= 8.3 Hz, 1 H, H-6"), 8.05 (d, J= 8.2 Hz, 1 H, H- 9"). ¹³C NMR (CDCI₃): δ 19.12 (CH, C-4), 23.09 (CH, C-5), 47.87 (C, C-3), 52.06 (CH, C-1), 78.57 (CH, C-6), 116.06 (CH, C-2"), 116.51 (CH₁ C-3', C-5'), 121.77 (CH, C-4"), 123.12 (CH, C-9"), 125.71 (CH, C-8"), 125.99 (CH, C-7"), 126.14 (CH₁ C-3"), 127.73 (CH, C-6"), 127.80 (C, C-10"), 128.66 (CH, C-2¹, C-6'), 131.90 (C, C-1¹), 134.72 (C, C-5"), 138.60 (C₁ C-4¹), 144.42 (C₁ C-1"), 178.29 (C, C-2). HRMS (El): Calculated mass: 350.1751 (M+H)⁺, Measured mass: 350.1748 (M+H)⁺.

b) 3-lmidazol- 1-yl-2, 2-dimethyl-3-[4-(naphthalen-1-ylamino)-phenyl]-propionic acid methyl ester (25)

To a solution of 3-hydroxy-2,2-dimethyl-3-[4-(naphthalen-1-ylamino)-phenyl]-propionic acid methyl ester (24) (0.2 g, 0.57 mmol) in anhydrous CH₃CN (20 mL) was added imidazole (0.12 g, 1.71 mmol) and CDI (0.14 g, 0.86 mmol). The mixture was then heated under reflux overnight. The reaction mixture was allowed to cool and then extracted with EtOAc (150 mL) and H₂O (3 x 100 mL). The organic layer was dried with MgSO₄, filtered and reduced in vacuo. The product was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-1-ylamino)- phenylj-propionic acid methyl ester (25) as a pale yellow oil. Yield 0.12 g (52 %), 1. 1. c. system: DCM - MeOH 97:3 v/v, R_F: 0.61 , stain positive. ¹H NMR (CDCI₃): δ 1.32 (s, 6H₁ H-4, H-5), 3.65 (S, 3H, H-1 ), 5.51 (s, 1 H, H-6), 6.11 (s, 1 H₁ H-NH), 6.89 (d, J= 8.0 Hz₁ 2H, H-3¹, H- 5¹), 7.03 (s, 1 H, H-3¹"), 7.09 (s, 1 H, H-2"¹), 7.14 (d, J= 8.1 Hz, 2H₁ H-2¹, H-6¹), 7.39-7.42 (m, 2H, H-2", H-3"), 7.46-7.50 (m, 2H, H-4", H-7"), 7.59-7.62 (m, 2H, H-8", H-1¹"), 7.88 (d, J= 8.0 Hz, 1 H, H-6"), 8.12 (d, J= 8.2 Hz, 1 H₁ H-9"). ¹³C NMR (CDCI₃): δ 22.92 (CH, C-4), 23.42 (CH₁ C-5), 47.72 (C, C-3), 52.37 (CH, C-1 ), 67.57 (CH, C-6), 116.13 (CH, C-2"), 117.56 (CH, C-3¹, C-5¹), 121.97 (CH, C-4"), 123.96 (CH, C-9"), 125.89 (CH₁ C-2¹"), 125.94 (CH, C-8"), 126.23 (CH, C-7"), 127.59 (CH, C-3¹"), 128.33 (CH, C-3", C-6"), 128.56 (C, C-10"), 128.95 (C, C-1'), 129.90 (CH, C-2', C-6', C-1¹"), 134.74 (C₁ C-5"), 137.85 (C, C-4¹), 145.34 (C₁ C-1"), 176.28 (C, C-2). Anal. Calculated for C₂₅H₂₅N₃O₂.0.2H₂O (403.095): C 74.49%, H 6.25%, N 10.42%. Found: C 74.36%, H 6.31 %, N 10.43%. Example 17

a) 3-[4-(2-Ethoxy-naphthalen-1-ylamino)-phenyl]-3-hydroxy-2, 2-dimethyl-propionic acid methyl ester (26) To 2-ethoxy-1-naphthylboronic acid (1.94 g, 8.96 mmol), 3-(4-aminophenyl)-3-hydroxy-2,2- dimethylpropionic acid methyl ester (2) (1.0 g, 4.48 mmol), anhydrous Cu(OAc)₂ (1.22 g, 6.72 mmol), pyridine (0.7 ml_, 8.96 mmol) and activated 4 A molecular sieves (250 mg) under an atmosphere of air was added DCM (20 ml_) and the reaction stirred at ambient temperature for 2 days. The product was isolated by direct flash column chromatography of the crude reaction mixture (petroleum ether - EtOAc 70:30 v/v) to give 3-[4-(2-ethoxy- naphthalen-1-ylamino)-phenyl]-3-hydroxy-2, 2-dimethyl-propionic acid methyl ester (26) as a brown oil. Yield: 0.07 g (4%), t.l.c. system: petroleum ether - EtOAc 2:1 v/v, R_F: 0.63, stain positive. ¹H NMR (CDCI₃): δ 1.11 (s, 3H, H-4), 1.18 (s, 3H, H-5), 1.41 (t, J= 7.6 Hz, 3H, H- 2'"), 2.88 (s, 1 H, OH), 3.71 (s, 3H₁ H-1), 4.14 (q, J= 7.7 Hz, 2H, H-1¹"), 4.75 (s, 1 H, H-6), 5.94 (s, 1 H, NH), 6.63 (d, J= 8.0 Hz, 2H, H-3¹, H-5'), 7.10 (d, J= 8.1 Hz, 2H, H-2\ H-6¹), 7.33- 7.38 (m, 3H, Ar), 7.71 (d, J= 8.3 Hz, 1 H, Ar), 7.80-7.83 (m, 2H, H-6", H-9"). ¹³C NMR (CDCI₃): δ 15.13 (CH, C-2'"), 19.09 (CH₁ C-4), 23.07 (CH, C-5), 47.87 (C, C-3), 52.09 (CH, C-1 ), 65.29 (C, C-1"¹), 78.68 (CH, C-6), 114.84 (CH, C-3', C-5'), 115.13 (CH₁ C-3"), 122.94 (CH, C-9"), 123.79 (CH, C-4"), 123.83 (C, C-1", C-10"), 125.01 (CH, C-7"), 125.76 (CH, C- 8"), 127.72 (CH, C-6"), 128.59 (CH, C-2¹, C-6¹), 129.52 (C, C-5"), 130.56 (C, C-1¹), 146.76 (C, C-4'), 149.88 (C, C-2"), 178.30 (C, C-2).

b) 3-[4-(2-Ethoxy-naphthalen-1-ylamino)-phenyl]-3-imidazol- 1-yl-2, 2-dimethyl-propionic acid methyl ester (27) To a solution of 3-[4-(2-ethoxy-naphthalen-1-ylamino)-phenyl]-3-hydroxy-2, 2-dimethyl- propionic acid methyl ester (26) (0.2 g, 0.57 mmol) in anhydrous CH₃CN (20 mL) was added imidazole (0.12 g, 1.71 mmol) and CDI (0.14 g, 0.86 mmol). The mixture was then heated under reflux overnight. The reaction mixture was allowed to cool and then extracted with EtOAc (150 mL) and H₂O (3 x 100 ml_). The organic layer was dried with MgSO₄, filtered and reduced in vacuo. The product was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-[4-(2-ethoxy-naphthalen-1-ylamino)-phenyl]-3- imidazol-1-yl-2,2-dimethyl-propionic acid methyl ester (27) as a brown oil. Yield 0.096 g (38 %), t. I. c. system: DCM - MeOH 97:3 v/v, R_F: 0.64, stain positive. ¹H NMR (CDCI₃): δ 1.21 (S, 3H, H-4), 1.25 (s, 3H, H-5), 1.36 (t, J= 7.6 Hz, 3H, H-2¹"), 3.66 (s, 3H, H-1), 4.16 (q, J= 7.5 Hz, 2H, H-1¹"), 5.51 (s, 1 H, H-6), 5.96 (s, 1 H, NH), 6.62 (d, J= 7.8 Hz, 2H, H-3¹, H-5¹), 7.03 (d, J= 8.0 Hz, 2H, H-2¹, H-6¹), 7.08 (d, J= 2.2 Hz, 1 H, Ar), 7.32-7.38 (m, 4H, Ar), 7.72 (d, J= 8.2 Hz, 1 H₁ Ar), 7.81-7.86 (m, 3H, H-6", H-9", H-1 "¹). ¹³C NMR (CDCI₃): δ 15.10 (CH, C- 2"¹¹), 22.59 (CH, C-4), 23.81 (CH, C-5), 47.67 (C, C-3), 52.42 (CH, C-1 ), 65.13 (C, C-1¹¹"), 68.29 (CH, C-6), 114.90 (CH, C-3¹, C-5¹), 115.09 (CH, C-3"), 123.44 (CH, C-9", C-2"¹), 123.90 (CH, C-4"), 124.03 (C, C-1 ", C-10"), 125.76 (CH, C-7", C-3¹"), 126.27 (CH, C-8"), 126.36 (CH, C-6"), 129.31 (CH, C-2¹, C-6', C-1¹"), 129.42 (C, C-5"), 130.68 (C, C-1¹), 147.47 (C, C-4¹), 150.24 (C, C-2"), 176.17 (C, C-2). HRMS (El): Calculated mass: 444.2282(M+H)\ Measured mass: 444.2280 (M+H)⁺.

Example 18

3-lmidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid benzyl ester (28)

This was prepared using Method D, wherein the alkyl bromide was benzyl bromide. The product was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid benzyl ester (28) as a yellow oil. Yield 0.27 g (57 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.65, stain positive. ¹H NMR (CDCI₃): δ 1.25 (s, 6H, H-3, H-4), 5.06 (s, 2H, H-6), 5.55 (S, 1 H, H-1 ), 5.94 (s, 1 H, NH), 7.08 (d, J= 8.0 Hz, 2H₁ H-3¹, H-5¹), 7.15 (d, J= 7.8 Hz, 2H, Ar), 7.21 (m, 4H, Ar)₁ 7.32-7.39 (m, 5H, Ar), 7.45-7.49 (m, 3H, Ar), 7.66 (d, J= 8.1 Hz, 1 H, Ar), 7.69-7.72 (m, 2H₁ Ar). ¹³C NMR (CDCI₃): δ 22.25 (CH₁ C-3, C-4), 47.75 (C, C-2), 65.52 (CH, C-1), 72.54 (C, C-6), 66.73 (CH, C-6), 106.81 (CH, C-2"), 111.46 (CH, C-10"), 115.30 (CH, C-3¹, C-5¹), 120.92 (CH, C-6". C-2¹"), 122.63 (CH, C-4"), 126.22 (CH, C-5", C- 7"), 127.35 (CH, C-8, C-10, C-12, C-9"), 127.96 (C, C-8"), 128.13 (CH, C-3¹"), 128.28 (C, C- 1¹), 128.77 (CH, C-1¹"), 129.13 (CH, C-9, C-11), 129.69 (CH, C-2¹, C-6¹), 134.28 (C, C-3"), 140.59 (C, C-4¹), 141.29 (C, C-7), 142.82 (C, C-1"), 175.18 (C, C-5). HRMS (El): Calculated mass: 476.2319 (M+H)⁺, Measured mass: 476.2323 (M+H)⁺.

Example 19

3-lmidazol-1-yl-2, 2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid pentyl ester (29) This was prepared using Method D, wherein the alkyl bromide was 1-bromopentane. The product was purified by flash column chromatography (DCM - MeOH 100:0 v/v increasing to 97:3 v/v) to give 3-imidazol-1-yl-2,2-dimethyl-3-[4-(naphthalen-2-ylamino)-phenyl]-propionic acid pentyl ester (29) as a yellow oil. Yield 0.32 g (69 %), t.l.c. system: DCM - MeOH 97:3 v/v, R_F: 0.65, stain positive. ¹H NMR (CDCI₃): δ 0.95 (t, J= 6.8 Hz, 3H, H-1 ), 1.20-1.31 (m, 1 OH, H-2, H-3, H-8, H-9), 1.50-1.54 (m, 2H, H-4), 4.08 (t, J= 6.5 Hz, 2H, H-5), 5.55 (s, 1 H, H- 10), 6.01 (s, 1 H, NH)₁ 7.16-7.22 (m, 4H, H-3', H-5¹, H-6", H-10"), 7.30-7.35 (m, 3H, H-2¹, H- 6", H-5"), 7.42 (m, 1 H, Ar), 7.46-7.49 (m, 2H, Ar), 7.72-7.75 (m, 2H, Ar), 7.80-7.83 (m, 2H, Ar). ¹³C NMR (CDCI₃): δ 13.93 (CH, C-1), 22.23 (C, C-2), 23.21 (CH, C-7), 23.43 (CH, C-8), 27.98 (C₁ C-3), 28.07 (C, C-4), 47.58 (C, C-7), 65.51 (C, C-5), 67.48 (CH, C-10), 112.96 (CH, C-2"), 116.94 (CH, C-10"), 120.36 (CH, C-3¹, C-5¹), 123.90 (CH, C-6". C-2¹"), 126.56 (CH, C-4"), 127.67 (CH, C-5", C-7"), 128.78 (CH, C-9"), 129.29 (C, C-8"), 129.54 (CH, C- 3'"), 129.68 (C, C-1¹), 129.86 (CH, C-1"¹), 130.09 (CH, C-2¹, C-6¹), 134.50 (C, C-3"), 139.86 (C, C-4¹), 143.32 (C, C-1"), 175.81 (C, C-6). HRMS (El): Calculated mass: 456.2632 (M+H)⁺, Measured mass: 456.2637 (M+H)⁺.

Biological assays

Materials and Methods

Biochemical studies - Inhibitory potency and selectivity

A commercial assay carried out by lnpharmatica was used to determine the selectivity of compounds for inhibition of CYPs and compared to the IC₅₀ value of the compound for CYP26. Cellular CYP26 inhibition assays

(a) MCF-7 cell assay (antiproliferative assay)

In order to assess the inhibitory action of the compounds against metabolism of retinoic acid by CYP26, the following MCF-7 cell assay was used to determine IC₅O values.

MCF-7 cells were seeded in 12-well cell culture plates (Comings Inc. New York, USA) at 2.5 x 10⁵ cells per well in a total volume of 1.5ml_. Cells were allowed to adhere to the well for 24 hours. After 24 hours, the medium from each well was removed, washed once with Phosphate Buffer Saline (PBS) and replaced by fresh medium plus 10 μL inhibitor/solvent (acetonitrile) and 10μL of ATRA (to give final concentration of 1x 10^'7M ATRA and 0.1 μCi [11 ,12-³H] a\\-trans retinoic acid). The plates were foil wrapped and incubated at 37°C for 9 hours. Each treatment was performed in duplicate. The incubation was stopped by addition of 1 % acetic acid (100μl_/well), the medium was removed into separate glass tubes. Distilled water (200μL) was added to each well and the cells scraped off and he contents added to the appropriate glass tube. This procedure was repeated with a further 400μL water but without scraping. Ethyl acetate containing 0.05% (w/v) butylated hydroxyanisole (2x 2ml_) was added to each tube. After vortexing for 15 seconds, the tubes were spun down at 3000rpm for 15 minutes. The organic layer was then evaporated using a Christ centrifuge connected to a vacuum pump and a multitrap at -80⁰C.

Metabolites were measured in terms of percentage activity relative to the total radioactivity (i.e. metabolite peak plus retinoic acid peak). Using a control with ethanol instead of inhibitor, these results were expressed as "percentage inhibition relative to control" = 100-[(% metabolites with inhibitor/% metabolites control)x100]. IC₅₀ values were determined using a range of concentrations in ethanol and determined graphically from a plot of log₁₀ [inhibitor concentration] vs % inhibition.

The IC₅₀ values calculated, and shown in the results section below, are the average (+/- 5%) of two experiments.

(b) SH-SY5Y cell assay (anti-proliferative assay)

In order to compare the anti-proliferative effect of ATRA or 13cisRA in combination with either compound 4 or R116010, the following SH-SY5Y cell assay was used to determine IC₅₀ values. SH-SY5Y cells were seeded in 96-well plates at a density of 1000 cells well^"1 and allowed to attach overnight. ATRA (0.01 μM), 13cisRA (0.1 μM), compound 4 or R116010 (1 μM) were added alone or in combination and cell growth determined after 6 days using the SRB assay as described previously (Skehan P, 1990 J Natl Cancer Inst 82, 1107-1112). Briefly, cells were fixed with 10% trichloroacetic acid (TCA) and stained with 0.4% sulphorhodamine B (SRB) in 1% acetic acid for 30 min. Protein-bound dye was extracted with 10 mM Tris (unbuffered) and absorption measured at 570 nM. Potentiation factors were calculated (% cell growth inhibition in presence of RA+lnhibitor / RA alone) from ≥ 3 independent experiments.

(c) mRNA induction assay (SH-SY5Y neuroblastoma cells)

The induction of CYP26B1 mRNA was used to evaluate the ability of compounds to enhance the biological effects of ATRA. CYP26B1 mRNA was chosen as it is a more responsive marker than CYP26A1.

Cell line: SH-SY5Y neuroblastoma cells where cultured at 37°C in RPMI 1640 medium containing foetal calf serum (10%) and l-glutamine (2nM) in a humidified atmosphere of 5% CO₂ in air.

Cell treatment: The cells were treated with R116010 (R: 1 μM), or compound 4 (1 μM), alone or in combination for 1 or 6 days. ATRA was dissolved in dimethyl sulfoxide and added to the culture medium as described by Armstrong et al [add full ref].

Real-time PCR: RNA was reverse-transcribed from random hexamer primers and real-time PCR performed on 20ng cDNA using TaqMan Gene Expression products for human CYP26B1 in combination with the TaqMan Universal PCR master mix (Applied Biosystems, Warrington, UK) on a GeneAmp 5700 Sequence Detection System as described previously for CYP26A1. Appropriate controls for non-specific amplification and contamination were included and β-actin was measured simultaneously using the endogenous control assay provided by Applied Biosystems as an internal standard. The thermocycling program consisted of one cycle at 50⁰C for 2min followed by 95°C for 10 min and 40 cycles at 95°C (15s) and 60⁰C (1 min). The comparative C₁ method (2 ^ΔΔCt) was used for relative quantification of gene expression. The values derived from 2 experiments are expressed as expression relative to cells treated with 0.01 μM ATRA at the 1-day time point, and normalised to β-actin expression.

Results Biochemical studies - Inhibitory potency and selectivity

Cellular CYP26 inhibition assays

(a) MCF-7 cell assay (antiproliferative assay)

R116010 has an IC₅₀ value in the same assay of about 10 nM.

(b) SH-SY5Y cell assay (anti-proliferative assay)

(c) mRNA induction assay (SH-SY5Y neuroblastoma cells)

Compound 4 shows a 3-fold greater efficacy at 6 days compared to R116010.

CYP26 microsomal metabolism of all-fraπs-retinoic acid assay

This method is based on the method disclosed in Han, I. S. & Choi, J. H., Journal of Clinical

Endocrinology and Metabolism, 81 , 2069-2075 (1996).

Induction of CYP26 expression

MCF-7 breast cancer cells were grown in the presence of 1 μM all-frans-retinoic acid (ATRA) for 24 hours to induce expression of CYP26. The cells were harvested by treatment with trypsin/EDTA, followed by being centrifuged at 4°C, for 5 minutes at 1500 rpm. The resulting pellet was washed twice with PBS and centrifuged as before. The cell pellet was then stored in the freezer (-20⁰C) until microsome extraction.

Preparation of microsomes

The following procedures were all performed on ice. The cell pellets were defrosted on ice and re-suspended in homogenisation buffer (10 mM Tris (pH 7.4); 1 mM EDTA; 0.5 M sucrose; 1 mM PMSF; 0.1 μg/ml leupeptin; 0.04 U/ml aprotinin). The cells were homogenised in a Dounce homogeniser (10 strokes), and the homogenate was diluted with an equal volume of Tris/EDTA. The diluted homogenate laid over V. (original) volume homogenisation buffer in ultra-centrifuge tubes, and then centrifuged at 4°C for 10 minutes at approximately 13 500 rpm. The supernatant was re-spun as above. The supernatant was then spun at 4°C for 60 minutes at 100 000g. The small resultant "ghost" pellet was re- suspended in storage buffer, homogenised, aliquotted and stored at -80⁰C until use. The storage buffer was identical to homogenisation buffer except the sucrose molarity reduced to 0.25 M. ³H ATRA metabolism microsome assay

The assay buffer comprised: 50 mM Tris (pH 7.4), 150 mM KCI, 10 mM MgCI₂, and 0.02 %^w/v BSA. The reaction components were: 50 μg microsomal protein (defrosted on ice), +/- inhibitor solution (diluted in assay buffer), 10 nM ATRA (diluted in assay buffer), 0.1 μCi ³H ATRA (10 μl in ethanol), 2 mM NADPH (20 μl in 0.01 M NaOH), assay buffer to give total volume of 200 μl.

Microsomal protein and assay buffer were aliquotted into small amber eppendorf tubes, flick mixed and centrifuged briefly. The test compound, ATRA and ³H ATRA were added and flick mixed. The eppendorfs were incubated in a water bath at 37⁰C for 10 minutes with shaking (75 shakes/min). NADPH was added, flick mixed and centrifuged briefly. The tubes were then incubated in a water bath at 37°C for 60 minutes with shaking. The reaction was quenched with 200 μl ice-cold acetonitrile, and the eppendorfs centrifuged at 4⁰C for 5 minutes at 18 000g. 200 μl supernatant was then transferred to HPLC vials for analysis, and the HPLC sample chamber maintained at 4°C.

HPLC analysis of metabolites

100 μl of the sample was injected into the HPLC system fitted with a radiochemical detector

(= 0.025 μCi ³H ATRA). The activity of the metabolite peaks was measured by manual integration of peaks. The following calculations were used to determine the inhibition:

%metabolites in uninhibited samples = 100 x (activity of metabolite peaks/total activity of injection)

% inhibition = 100 - [100 x (activity of all metabolites/ average %metabolites in uninhibited reactions)]

Claims

1. A compound of formula (I):

wherein

X is selected from O, S, NH or CH₂;

R^d and R^p are optional naphthyl group substituents;

R^Het is imidazolyl, triazolyl or pyridyl; and

R^c is Ci-₄ alkyl substituted by a group selected from: hydroxy, amino, amido, carboxy, C_1-7 alkyl ester, C₅-₇ aryl-Ci.₂ alkyl ester, sulfonamino, sulfinamino, hydroxamino and tetrazolyl.

2. A compound according to claim 1 , wherein the compound is of formula Ia:

Ia

3. A compound according to claim 1 , wherein the compound is of formula ib:

4. A compound according to any one of claims 1 to 3, wherein X is O.

5. A compound according to any one of claims 1 to 3, wherein X is NH.

6. A compound according to any one of claims 1 to 3, wherein X is CH₂.

7. A compound according to any one of claims 1 to 6, wherein the optional naphthyl group substituents are selected from: Ci_-7 alkyl, C_3-2O heterocyclyl, C_5-20 aryl, halo, hydroxy, ether, nitro, cyano, acyl, ester, amido, amino, acylamido, ureido, acyloxy, thiol, thioether, sulfoxide, sulfonyl, thioamido and sulfonamino.

8. A compound according to claim 7, wherein the optional naphthyl group substituents are selected from: Ci_-4 alkyl, C_5-6 aryl, halo, hydroxy, C_1-4 alkyl ether, C_1-4 alkyl acyl, Ci_-4 alkyl ester, amino, C_1-4 alkylamino and diC_1-4 alkylamino.

9. A compound according to any one of claims 1 to 8, wherein there are one, two or three R^p groups on the proximal naphthyl ring.

10. A compound according to any one of claims 1 to 9, wherein there are one, two, three or four R^d groups on the distal naphthyl ring.

11. A compound according to any one of claims 1 to 10, wherein R^Het is imidazolyl

12. A compound according to any one of claims 1 to 10, wherein R^Het is triazolyl.

13. A compound according to any one of claims 1 to 10, wherein R^Het is pyridyl.

14. A compound according to any one of claims 1 to 13, wherein the substituent for R^c is selected from amino, amido, carboxy, sulfonamino, sulfinimido, hydroxamino and tetrazolyl.

15. A compound according to claim 14, wherein the substituent for R^c is selected from carboxy, amido and sulfonamino.

16. A compound according to claim 14, wherein the substituent for R^c is selected from carboxy, Ci_-7 alkyl esters, C_5-7 aryl-C_1-2 alkyl esters and amido.

17. A compound according to any one of claims 1 to 16, wherein R^c is methyl.

18. A compound according to any one of claims 1 to 16, wherein R^c is ethyl.

19. A compound according to any one of claims 1 to 16, wherein R^c is propyl.

20. A composition comprising a compound according to any one of claims 1 to 19 and a pharmaceutically acceptable carrier or diluent.

21. A compound according to any one of claims 1 to 19 or a composition according to claim 20 for use in a method of therapy.

22. The use of a compound according to any one of claims 1 to 19 or a composition according to claim 20 in the preparation of a medicament for treating diseases which are ameliorated by the inhibition of CYP26 mediated retinoic acid metabolism.

23. The use according to claim 22, wherein the disease ameliorated by the inhibition of CYP26 mediated retinoic acid metabolism is selected from:

(a) cancer;

(b) a dermatological disorder;

(c) late onset Alzheimer's disease (LOAD).

24. The use of a compound according to any one of claims 1 to 19 or a composition according to claim 20 in combination with RA in the preparation of a medicament for treating diseases which are ameliorated by the administration of RA.

25. The use according to claim 24, wherein the disease ameliorated by the administration of RA is selected from:

(a) cancer;

(b) a dermatological disorder;

(c) late onset Alzheimer's disease (LOAD).