WO2007071956A1

WO2007071956A1 - Novel benzamide derivatives

Info

Publication number: WO2007071956A1
Application number: PCT/GB2006/004744
Authority: WO
Inventors: Elaine Sophie Elizabeth Stokes
Original assignee: Astrazeneca Ab; Astrazeneca Uk Limited
Priority date: 2005-12-23
Filing date: 2006-12-19
Publication date: 2007-06-28
Also published as: GB0526351D0

Abstract

The invention concerns benzamide compounds of Formula (I) wherein W, R, X , and Q are as defined in the description. The present invention also relates to processes for the preparation of such compounds, pharmaceutical compositions containing them and their use in the manufacture of a medicament for use as an antiproliferative agent in the prevention or treatment of tumours or other proliferative conditions which are sensitive to the inhibition of histone deacetylase (HDAC).

Description

NOVEL BENZAMIDE DERIVATIVES

This invention concerns certain novel benzamide derivatives, or pharmaceutically acceptable salts thereof, which are potent inhibitors of the enzyme histone deacetylase (HDAC). The invention also relates to processes for the manufacture of these novel

5 benzamide compounds, to pharmaceutical compositions containing them and to their use in therapeutic methods, for example in the manufacture of medicaments to inhibit HDAC in a warm-blooded animal, such as man.

HDAC activity has been associated with a number of disease states, such as cancer (Marks et al, Nature Reviews, 1, 194-202, (2001)), cystic fibrosis (Li, S. et al, J. Biol. Chem.,

10 274, 7803-7815, (1999)), Huntingdons chorea (Steffan, J. S. et al, Nature, 413, 739-743, (2001)) and sickle cell anaemia (Gabbianelli, M. et al, Blood, 95, 3555-3561, (2000)). Accordingly, the invention also extends to methods of treating any of the aforementioned diseases using the benzamide compounds of the present invention, as well as to the use of these benzamide compounds in the manufacture of a medicament for the treatment of these

15 disease states.

In the eukaryotic cell, DNA is routinely compacted to prevent transcription factor accessibility. When the cell is activated this compacted DNA is made available to DNA- binding proteins, thereby allowing the induction of gene transcription (Beato, M., J. Med. Chem., 74, 711-724 (1996); Wolffe, A. P., Nature, 387, 16-17 (1997)). Nuclear DNA

20 associates with nuclear proteins known as histones to form a complex called chromatin. The core histones, termed H2A, H2B, H3 and H4, are surrounded by 146 base pairs of DNA to form the fundamental unit of chromatin, and which is known as the nucleosome. The N- terminal tails of the core histones contain lysine residues that are sites for post-transcriptional acetylation. Acetylation of the terminal amino group on the lysine side chain neutralizes the

25 potential of the side chain to form a positive charge, and is thought to impact on chromatin structure. . ^**

Histone Deacetylases (HDACs) are zinc-containing enzymes which catalyse the removal of acetyl groups from the ε-amino termini of lysine residues clustered near the amino terminus of nucleosomal histones. HDACs may be divided into two classes, the first (HDAC 30 1, 2, 3 and 8) represented by yeast Rpd3-like proteins, and the second (HDAC 4, 5, 6, 7, 9 and 10) represented by yeast Hdal-like proteins. The reversible process of acetylation is known to be important in transcriptional regulation and cell-cycle progression. In addition, HDAC deregulation has been associated with several cancers and HDAC inhibitors, such as Trichostatin A (a natural product isolated from Streptomyces hygroscopicus), have been shown to exhibit significant cell growth inhibition and anti-tumour effects (Meinke, P. T., Current Medicinal Chemistry, 8, 211-235 (2001)). Yoshida et α/, (Exper. Cell Res., 177, 122- 131 (1988)) teach that Trichostatin A causes the arrest of rat fibroblasts at the Gl and G2 phases of the cell cycle, thereby implicating the role of HDAC in the regulation of the cell cycle. Furthermore, Trichostatin A has been shown to induce terminal differentiation, inhibit cell growth, and prevent the formation of tumours in mice (Finnin et ah, Nature, 401, 188-193 (1999)). It is known from International Patent Publication Numbers WO 03/087057 and

WO 03/092686, that certain benzamide derivatives are inhibitors of HDAC. One particular compound disclosed in WO 03/087057 is N-(2-aminophenyl)-4-pyridin-2-yl-benzamide.

However, there is no specific disclosure in either of these documents of benzamide derivatives, which possess a further substituted-pyridin-2-yl ring moiety at the 4-position of the benzamide ring. We have now found that certain benzamide derivatives possessing a substituted 3-methylpyridin-2-yl group in the 4-position of the benzamide ring are potent inhibitors of the HDAC enzyme.

According to the present invention there is provided a compound of formula (I):

(I) wherein

W is methyl or ethyl; R is hydrogen or (l-4C)alkyl;

X is -[CR^aR^b]_n- where each R^a and R^b group present is independently selected from hydrogen or (l-2C)alkyl and integer n is 1, 2 or 3;

Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, pyridyl, imidazolyl, triazolyl and isoxazolyl, and wherein Q is optionally substituted by 1 to 4 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino; or a pharmaceutically acceptable salt thereof.

According to a further aspect of the present invention there is provided a compound of formula (I):

(D wherein

W is methyl or ethyl;

R is hydrogen or (l-4C)alkyl;

Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, pyridyl, imidazolyl, and triazolyl, and wherein Q is optionally substituted by 1 to 4 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (1- 2C)alkoxy, halo, cyano, hydroxy, or amino; or a pharmaceutically acceptable salt thereof.

It is to be understood that, insofar as certain of the compounds of Formula (I) defined above may exist in optically active or racemic forms by virtue of one or more asymmetric carbon atoms, the invention includes in its definition any such optically active or racemic form which possesses the above-mentioned activity. The synthesis of optically active forms may be carried out by standard techniques of organic chemistry well known in the art, for example by synthesis from optically active starting materials or by resolution of a racemic form. Similarly, the above-mentioned activity may be evaluated using the standard laboratory techniques referred to hereinafter.

It is to be understood that certain compounds of Formula (I) defined above may exhibit the phenomenon of tautomerism. In particular, tautomerism may affect any heterocyclic groups that bear 1 or 2 oxo substituents. It is to be understood that the present invention includes in its definition any such tautomeric form, or a mixture thereof, which possesses the above-mentioned activity and is not to be limited merely to any one tautomeric form utilised within the formulae drawings or named in the Examples.

It is to be understood that certain compounds of Formula I above may exist in unsolvated forms as well as solvated forms, such as, for example, hydrated forms. It is to be understood that the present invention encompasses all such solvated forms that possess antiproliferative activity.

It is also to be understood that certain compounds of the Formula I may exhibit polymorphism, and that the present invention encompasses all such forms which possess antiproliferative activity.

Where optional substituents are selected from "one or more" substituent groups it is to be understood that this definition includes all substituents being chosen from one of the specified groups or the substituents being chosen from two or more of the specified groups.

In this specification the generic term "(l-4C)alkyl" includes both straight-chain and branched-chain alkyl groups such as propyl, /sopropyl and tert-butyl, and also (3-

4C)cycloalkyl groups such as cyclopropyl and cyclobutyl, and also a cyclopropylmethyl group. However, references to individual alkyl groups such as "propyl" are specific for the straight- chain version only, and references to individual branched-chain alkyl groups such as "ώøpropyl" are specific for the branched-chain version only. A suitable value for R when it is (l-4C)alkyl is methyl, ethyl, propyl, wopropyl, tert- butyl, and cyclopropyl.

Particular examples of the group Q-X- include 3,4-dimethoxybenzyl, 4- methoxybenzyl, 3-methoxybenzyl, 2-methoxybenzyl, (5-methyl-2-furyl)methyl, [6- (trifluoromethyl)pyridin-3-yl]methyl, (5-methyl-lH-pyrazol-3-yl)propyl, (1,5-dimethyl-lH- pyrazol-3-yl)methyl, (tetrahydrofuran-2-yl)methyl, (tetrahydro-2H-pyran-4-yl)methyl, and (3,5-dimethyl-lH-pyrazol-4-yl)ethyl. A further example is (5-methylisoxazol-3-yl)methyl.

Particular novel compounds of the invention include, for example, benzamide derivatives of the Formula (I), or pharmaceutically-acceptable salts thereof, wherein, unless otherwise stated, each of W, R, X, and Q has any of the meanings defined hereinbefore or in paragraphs (1) to (22) hereinafter:-

(1) W is methyl; (2) R is hydrogen or methyl;

(3) R is methyl;

(4) R is hydrogen;

(5) X is -[CR^aR^b]_n- where each R^a and R^b group present is independently selected from hydrogen or methyl and integer n is 1, 2 or 3;

(6) X is -[CR^aR^b]_n- where each R^a and R^b group is hydrogen and integer n is 1, 2 or 3;

(7) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino;

(8) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, and (l-2C)alkoxy; (9) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, furyl, pyrazolyl, and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino;

(10) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, furyl, pyrazolyl, and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl and (l-2C)alkoxy;

(11) Q is selected from:

(i) a phenyl ring, which is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino;

(ii) or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, and pyridyl, which is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino; (12) Q is selected from:

(i) a phenyl ring, which is optionally substituted by 1 to 3 (l-2C)alkoxy groups;

(ii) or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, and pyridyl, and wherein said heterocyclic ring is optionally substituted by 1 to 3 (l-2C)alkyl or trifluoromethyl groups;

(13) Q is selected from:

(i) a phenyl ring, which is optionally substituted by 1 or 2 (l-2C)alkoxy groups; (ii) or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, and pyridyl and wherein said heterocyclic ring is optionally substituted by 1 or 2 (l-2C)alkyl or trifluoromethyl groups;

(14) Q is selected from 2-methoxyphenyl, 3- methoxyphenyl, 4-methoxyphenyl, 3,4- dimethoxyphenyl, 5-methyl-2-furyl, 6-(trifluoromethyl)pyridin-3-yl, 5-methyl-lH- pyrazol-3-yl, l,5-dimethyl-lH-pyrazol-3-yl, tetrahydrofuran-2-yl, tetrahydro-2H- pyran-4-yl, and 3,5-dimethyl-lH-pyrazol-4-yl.

(15) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (1- 2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino;

(16) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (1- 2C)alkyl, trifluoromethyl, and (l-2C)alkoxy; (17) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (1- 2C)alkoxy, halo, cyano, hydroxy, or amino;

(18) Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl and (l-2C)alkoxy;

(19) Q is selected from:

(ii) or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, which is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino;

(20) Q is selected from:

(ii) or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and wherein said heterocyclic ring is optionally substituted by 1 to 3 (l-2C)alkyl or trifluoromethyl groups;

(21) Q is selected from:

(i) a phenyl ring, which is optionally substituted by 1 or 2 (l-2C)alkoxy groups; (ii) or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl and wherein said heterocyclic ring is optionally substituted by 1 or 2 (l-2C)alkyl or trifluoromethyl groups;

(22) Q is selected from 2-methoxyphenyl, 3- methoxyphenyl, 4-methoxyphenyl, 3,4- dimethoxyphenyl, 5-methyl-2-furyl, 6-(trifluoromethyl)pyridin-3-yl, 5-methyl-lH- pyrazol-3-yl, l,5-dimethyl-lH-pyrazol-3-yl, tetrahydrofuran-2-yl, tetrahydro-2H- pyran-4-yl, 3,5-dimethyl-lH-pyrazol-4-yl, and 5-methylisoxazol-3-yl.

Suitably, W is methyl.

Suitably, R is hydrogen, methyl or ethyl, particularly hydrogen or methyl, and most particularly hydrogen. Suitably, each R^a and R^b group present is hydrogen (such that X is therefore selected from -CH₂-, -CH₂-CH₂-, and -CH₂-CH₂-CH₂-).

Suitably, Q is phenyl ring or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and most particularly tetrahydrofuranyl, furyl, pyrazolyl, and pyridyl. Suitably, Q is optionally substituted by 1 to 3 substituents groups, and more particularly 1 or 2 substituent groups, independently selected from halo, hydroxy, cyano, (l-2C)alkyl, trifluoromethyl, and (l-2C)alkoxy. In a particular group of compounds of the invention, Q is optionally substituted by 1 to 3 (l-2C)alkyl, trifluoromethyl or (l-2C)alkoxy groups (and especially 1 or 2 (l-2C)alkyl, trifluoromethyl or (l-2C)alkoxy groups).

In particular compounds of the invention Q is a tetrahydrofuran-2-yl ring.

In particular compounds of the invention Q is a tetrahydropyran-4-yl ring.

In particular compounds of the invention Q is a 2-furyl ring.

In particular compounds of the invention Q is a pyrazol-3-yl or a pyrazol-4-yl ring. In particular compounds of the invention Q is a pyrid-3-yl ring.

In particular compounds of the invention Q is an isoxazolyl ring.

When Q is a heterocyclic ring, it is suitably a carbon-linked heterocyclic ring.

A particular group of compounds of the invention have the general formula IA shown below

(IA) wherein Q and X have any one of the definitions set out hereinbefore.

In compounds of formula IA above, X is particularly as defined in any one of paragraphs (5) and (6) above. In compounds of formula IA above, Q is particularly as defined in any one of paragraphs (7) to (22) above. Particular novel compounds of the invention include any one of the following:

N-(2-aminophenyl)-4-(5-{[(2-methoxybenzyl)amino]methyl}-3-methylpyridin-2- yl)benzamide;

N-(2-aminophenyl)-4-(5-{ [(3-methoxybenzyl)anτino]niethyl}-3-rnethylpyridin-2- yl)benzamide; iV-(2-aminophenyl)-4-(5- { [(4-methoxybenzyl)amino]methyl } -3-methylpyridin-2- yl)benzamide;

N-(2-aminophenyl)-4-(5-{ [(3,4-dirnethoxybenzyl)amino]methyl}-3-methylpyridin-2- yl)benzamide; N-(2-aminophenyl)-4-[3-methyl-5-({ [(5-methyl-2-furyl)methyl] amino }methyl)pyridin-2- yl]benzamide;

N-(2-aminophenyl)-4-{3-methyl-5-[({[6-(trifluoromethyl)pyridin-3- yljmethyl } amino)methyl]pyridin-2-yl }benzamide;

N-(2-aminophenyl)-4-[3-methyl-5-({ [3-(5-methyl-lH-pyrazol-3- yl)propyl] amino } methyl)pyridin-2-yl]benzamide ;

N-(2-aminophenyl)-4-[5-({[(l,5-dimethyl-lH-pyrazol-3-yl)methyl]amino}methyl)-3- methylpyridin-2-yl]benzamide; iV-(2-aminophenyl)-4-(3-methyl-5-{[(tetrahydrofuran-2-ylmethyl)amino]methyl}pyridin-2- yl)benzamide; iV-(2-aminophenyl)-4-(3-methyl-5-{ [(tetrahydro-2H-pyran-4-ylmethyl)amino]methyl }pyridin- 2-yl)benzamide;

N-(2-aminophenyl)-4-[5-({[2-(3,5-dimethyl-lH-pyrazol-4-yl)ethyl]amino}methyl)-3- methylpyridin-2-yl]benzamide; and

N-(2-aminophenyl)-4-[3-methyl-5-({[(5-methylisoxazol-3-yl)methyl]amino}methyl)pyridin-2- yl]benzamide.

A suitable pharmaceutically-acceptable salt of a compound of the Formula (I) is, for example, an acid-addition salt of a compound of the Formula (I), for example an acid-addition salt with an inorganic or organic acid such as hydrochloric, hydrobromic, sulphuric, trifluoroacetic, citric or maleic acid; or, for example, a salt of a compound of the Formula (I) which is sufficiently acidic, for example an alkali or alkaline όarth metal salt such as a calcium or magnesium salt, or an ammonium salt. A further suitable pharmaceutically acceptable salt of a compound of the Formula (I) is, for example, a salt formed within the human or animal body after administration of a compound of the Formula (I). The compounds of the invention may be administered in the form of a pro-drug that is a compound that is broken down in the human or animal body to release a compound of the invention. A pro-drug may be used to alter the physical properties and/or the pharmacokinetic properties of a compound of the invention. A pro-drug can be formed when the compound of the invention contains a suitable group or substituent to which a property-modifying group can be attached. Examples of pro-drugs include in vivo cleavable ester derivatives that may be formed at a carboxy group or a hydroxy group in a compound of the Formula (I) and in vivo cleavable amide derivatives that may be formed at a carboxy group or an amino group in a compound of the Formula (I).

Accordingly, the present invention includes those compounds of the Formula (I) as defined hereinbefore when made available by organic synthesis and when made available within the human or animal body by way of cleavage of a pro-drug thereof. Accordingly, the present invention includes those compounds of the Formula (I) that are produced by organic synthetic means and also such compounds that are produced in the human or animal body by way of metabolism of a precursor compound, that is a compound of the Formula (I) may be a synthetically-produced compound or a metabolically-produced compound.

A suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) is one that is based on reasonable medical judgement as being suitable for administration to the human or animal body without undesirable pharmacological activities and without undue toxicity. Various forms of pro-drug have been described, for example in the following documents :- a) Methods in Enzvmology, Vol. 42, p. 309-396, edited by K. Widder, et al. (Academic Press, 1985); b) Design of Pro-drugs, edited by H. Bundgaard, (Elsevier, 1985); c) A Textbook of Drug Design and Development, edited by Krogsgaard-Larsen and H. Bundgaard, Chapter 5 "Design and Application of Pro-drugs", by H. Bundgaard p. 113-191 (1991); d) H. Bundgaard, Advanced Drug Delivery Reviews, 8, 1-38 (1992); e) H. Bundgaard, et ah, Journal of Pharmaceutical Sciences, 77, 285 (1988); f) N. Kakeya, et ah, Chem. Pharm. Bull., 32, 692 (1984); g) T. Higuchi and V. Stella, "Pro-Drugs as Novel Delivery Systems", A.C.S. Symposium Series, Volume 14; and h) E. Roche (editor), "Bioreversible Carriers in Drug Design", Pergamon Press, 1987. A suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) that possesses a carboxy group is, for example, an in vivo cleavable ester thereof. An in vivo cleavable ester of a compound of the Formula (I) containing a carboxy group is, for example, a pharmaceutically-acceptable ester, which is cleaved in the human or animal body to produce the parent acid. Suitable pharmaceutically-acceptable esters for carboxy include (l-6C)alkyl esters such as methyl, ethyl and tert-butyl, (l-6C)alkoxymethyl esters such as methoxymethyl esters, (l-6C)alkanoyloxymethyl esters such as pivaloyloxymethyl esters, 3-phthalidyl esters, (3-8C)cycloalkylcarbonyloxy-(l-6C)alkyl esters such as cyclopentylcarbonyloxymethyl and 1- cyclohexylcarbonyloxyethyl esters, 2-oxo-l,3-dioxolenylmethyl esters such as 5-methyl-2- oxo-l,3-dioxolen-4-ylmethyl esters and (l-6C)alkoxycarbonyloxy-(l-6C)alkyl esters such as methoxycarbonyloxymethyl and 1-methoxycarbonyloxyethyl esters.

A suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) that possesses a hydroxy group is, for example, an in vivo cleavable ester or ether thereof. An in vivo cleavable ester or ether of a compound of the Formula (I) containing a hydroxy group is, for example, a pharmaceutically-acceptable ester or ether, which is cleaved in the human or animal body to produce the parent hydroxy compound. Suitable pharmaceutically-acceptable ester forming groups for a hydroxy group include inorganic esters such as phosphate esters (including phosphoramidic cyclic esters). Further suitable pharmaceutically-acceptable ester forming groups for a hydroxy group include (l-lOC)alkanoyl groups such as acetyl, benzoyl, phenylacetyl and substituted benzoyl and phenylacetyl groups, (l-lOC)alkoxycarbonyl groups such as ethoxycarbonyl, N,N-[di-(l-4C)alkyl]carbamoyl, 2-dialkylaminoacetyl and 2-carboxyacetyl groups. Examples of ring substituents on the phenylacetyl and benzoyl groups include aminomethyl, iV-alkylaminomethyl, iV,iV-dialkylaminomethyl, morpholinomethyl, piperazin-1-ylmethyl and 4-(l-4C)alkylpiperazin-l-ylmethyl. Suitable pharmaceutically-acceptable ether forming groups for a hydroxy group include α-acyloxyalkyl groups such as acetoxymethyl and pivaloyloxymethyl groups. A suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) that possesses an amino group is, for example, an in vivo cleavable amide derivative thereof. Suitable pharmaceutically-acceptable amides from an amino group include, for example an amide formed with (l-lOC)alkanoyl groups such as an acetyl, benzoyl, phenylacetyl and substituted benzoyl and phenylacetyl groups. Examples of ring substituents on the phenylacetyl and benzoyl groups include aminomethyl, iV-alkylaminomethyl, N,iV-dialkylaminomethyl, morpholinomethyl, piperazin-1-ylmethyl and 4-(l-4C)alkylpiperazin-l-ylmethyl.

The in vivo effects of a compound of the Formula (I) may be exerted in part by one or more metabolites that are formed within the human or animal body after administration of a compound of the Formula (I). As stated hereinbefore, the in vivo effects of a compound of the Formula (I) may also be exerted by way of metabolism of a precursor compound (a pro-drug).

Preparation of Compounds of Formula I Another aspect of the present invention provides a process for preparing a compound of formula (I) or a pharmaceutically acceptable salt thereof (wherein Q, X, R and W are as hereinbefore defined), said process comprising the steps of:

(a) the reaction of a compound of the formula (A)

(A) wherein Z is a reactive group, with a compound of the formula (B)

wherein

R⁵⁰ is a group of formula Q-X-N(R)-CH₂- as hereinbefore defined or a precursor thereof,

W is as hereinbefore defined, M is a metal,

L is a ligand, and integer n' is O to 3; and wherein if R⁵⁰ is a precursor for the group Q-X-N(R)-CH₂-, then said process thereafter comprises a step of converting the compound formed by the reaction of a compound of the formula (A) with a compound of the formula (B) to a compound of formula (I) (by converting the precursor into the appropriate Q-X-N(R)-CH₂- group); or

(b) The reaction of a compound of the formula (C)

(C) wherein M, L and integer n' are as defined above, with a compound of the formula (D)

(D) wherein R⁵⁰, W and Z are as defined herein; and wherein if R⁵⁰ is a precursor for the group Q-X-N(R)-CH₂-, then said process thereafter comprises a step of converting the compound formed by the reaction of a compound of the formula (C) with a compound of the formula (D) to a compound of formula (I) (by converting the precursor into the appropriate Q-X-N(R)-CH₂- group); or

(c) the reaction, under suitable amide coupling conditions or in the presence of a suitable amide coupling reagent, in particular 4-(4,6-dimethoxy-l,3,5-triazinyl-2-yl)-4- methylmorpholinium chloride, of a compound of the formula (E)

(E) with a compound of the formula (F)

(F) wherein R⁵⁰ and W are as defined herein, and wherein if R⁵⁰ is a precursor for the group Q-X-N(R)-CH₂-, then said process thereafter comprises a step of converting the compound formed by the reaction of a compound of the formula (E) with a compound of the formula (F) to a compound of formula (I) (by converting the precursor into the appropriate Q-X-N(R)-CH₂- group); and thereafter, if necessary: i) converting a compound of the formula (I) into another compound of the formula (I); and/or ii) removing any protecting groups.

A suitable base for process (a), (b) or (c) above is, for example, an organic amine base such as, for example, pyridine, 2,6-lutidine, collidine, 4-dimethylaminopyridine, triethylamine, morpholine, N-methylmorpholine or diazabicyclo[5.4.0]undec-7-ene, or, for example, an alkali or alkaline earth metal carbonate or hydroxide, for example sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide or potassium hydroxide, or, for example, an alkali metal hydride, for example sodium hydride, or an alkaline metal hydrogencarbonate such as sodium hydrogencarbonate, or a metal alkoxide such as sodium ethoxide.

A suitable reactive group Z is, for example, a halo or a sulphonyloxy group, for example a chloro, bromo, iodo, methanesulphonyloxy, trifluoromethanesulphonyloxy or toluene-4-sulphonyloxy group.

The reactions are conveniently carried out in the presence of a suitable inert solvent or diluent, for example an alkanol or ester such as methanol, ethanol, isopropanol or ethyl acetate, a halogenated solvent such as methylene chloride, chloroform or carbon tetrachloride, an ether such as tetrahydrofuran, 1,2-dimethoxyethane or 1,4-dioxan, an aromatic solvent such as toluene, or a dipolar aprotic solvent such as N,N-dimethylformamide, N,N- dimethylacetamide, N-methylpyrrolidin-2-one or dimethylsulphoxide. The reactions are conveniently carried out at a temperature in the range, for example, 10 to 250°C, preferably in the range 40 to 80°C.

Metal M may be any metal that is known in the literature to form organometallic compounds that undergo catalytic cross coupling reactions. Examples of suitable metals include boron, tin, zinc, magnesium. A suitable value for n' is dependent on the metal M, but is usually in the range 0-3.

Suitable values for the ligand L, when present, include, for example, a hydroxy, a halo, (l-4C)alkoxy or (l-6C)alkyl ligand, for example a hydroxy, bromo, chloro, fluoro, iodo, methoxy, ethoxy, propoxy, isopropoxy, butoxy, methyl, ethyl, propyl, isopropyl or butyl ligand or, where n is 2 and M is boron, the two ligands present may be linked such that, together with the boron atom to which they are attached, they form a ring.

Suitably, the group ML_n- is a group of the formula -BL L , where B is boron and L and L² are as defined for ligand L above. In particular, the ligands L¹ and L² may be linked such that, together with the boron atom to which they are attached, they form a ring. For example, L¹ and L² together may define an oxy-(2-4C)alkylene-oxy group, for example an oxyethyleneoxy, a -O-C(CH₃)₂C(CH₃)₂-O- group or an oxypropyleneoxy group such that, together with the boron atom to which they are attached, they form a cyclic boronic acid ester group.

A suitable catalyst for process (a) or (b) includes, for example, a metallic catalyst such as a ρalladium(O), palladium(II), nickel(O) or nickel(II) catalyst, for example tetrakis(triphenylphosphine)palladium(0), palladium(II) chloride, palladium(II) bromide, bis(triphenylphosphine)palladium(π) chloride, tetrakis(triphenylphosphine)nickel(0), nickel(II) chloride, nickel(II) bromide, bis(triphenylphosphine)nickel(II) chloride or dichloro[l-l'-bis(diphenylphosphino)ferrocene]palladium(II). In addition, a free radical initiator may conveniently be added, for example an azo compound such as azo(bisisobutyronitrile). The direct product of reacting A and B in process (a), C and D in process (b) and E and F in processes (c) can shown as a compound of the formula II shown below

(ID wherein R⁵⁰ is a group of formula Q-X-N(R)-CH₂- as hereinbefore defined (thereby making a compound of formula I as defined herein), or R ⁵⁰ is a precursor of the Q-X-N(R)-CH₂- group (which is subsequently reacted to form a compound of formula I in processes (a), (b) and (c) above).

Where R⁵⁰ is a suitable precursor group for a Q-X-N(R)-CH₂- group, then said precursor group may be converted into the appropriate Q-X-N(R)-CH₂- group using standard chemical techniques that are well known to those skilled in the art.

Examples of suitable R⁵⁰ precursor groups include hydroxy or alcohol-containing groups (e.g. -CH₂OH), aldehyde-containing groups (e.g. -CHO), carboxylic acid-containing groups (e.g. -(CH₂)_O-3-COOH) ester containing groups (e.g. -(CH₂)o_-3-COOR , where R is (l-4C)alkyl), activated ester containing groups (e.g. -(CH₂)o_-3-COOR^y, where R^y is a group such as, for example, pentafluorophenyl), amide containing groups (e.g. -CONH₂), acyl halide containing groups (e.g -(CH₂)_O-3-C(O)X¹, where X¹ is a halogen such as, for example, chloride) or a group -CH₂-Z where Z is a reactive group as hereinbefore defined.

A person skilled in the art will appreciate how to select the most appropriate precursor group for conversion into the desired Q-X-N(R)-CH₂- group. For example, if R⁵⁰ is a precursor group selected from -COOH, an acyl chloride

(-C(O)Cl), an ester (-COOR²) or an activated ester (-COOR^y) as hereinbefore defined, then such a group can be readily converted into the appropriate Q-X-N(R)-CH₂- group in a process whereby compound of formula II above (in which the aniline may be protected) is reacted with a compound of formula Q-X-N(R)H in a suitable solvent and in the presence of a suitable base; and thereafter, if necessary, removing any protecting groups that are present.

Where R is -COOH, the reaction is conveniently carried out in the presence of a suitable coupling agent. Examples of suitable coupling agents include HATU (0-(7- azabenzotriazol-l-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate), EDCI (l-(3- dimethylaminopropyl)-3-ethylcarbodiimide), DCCI (l,3-dicyclohexylcarbodiimide), DMTMM (4-(4,6-dimethoxy-l,3,5-triazinyl-2-yl)-4-methylmorpholinium chloride), PYBOP (benzotriazole-1-yl-oxy-trispyrrolidinonophosphonium hexafluorophosphate) or CDI(I₅I' - carbonyldiimidazole). A suitable base for this conversion (i.e. the conversion of a compound in which R⁵⁰ is -COOH precursor group to a compound of formula I) is an organic amine base such as DIPEA (N,N-diisopropylethylamine), triethylamine or N-methylmorpholine. The reaction can be carried out in solvents such as dichloromethane or DMF (N,N- dimethylf ormamide) .

If R⁵⁰ is -COOH, it may also be desirable to initially convert it into a more reactive group, such as an acyl chloride or an activated ester, prior to the reaction with the compound of formula Q-X-N(R)H. For example, the -COOH R⁵⁰ group can be converted into a more reactive -C(O)Cl R⁵⁰ group by reacting it with a suitable chlorinating agent such as, for example, thionyl chloride or oxalyl chloride. Alternatively, the -COOH R⁵⁰ group can be converted into an activated ester group (such as, for example, a pentafluorophenoxy ester by reacting the -COOH R⁵⁰ group with pentafluorophenol in the presence of a suitable coupling reagent, such as those previously defined herein, for example, HATU, EDCI, or DCCI, and in the presence of a suitable organic base such as DIPEA, triethylamine or N-methyl morpholine in dichloromethane). If R⁵⁰ is a precursor group selected from an acyl chloride or an activated ester as hereinbefore defined, the reaction may be carried out in the presence of a suitable organic base in a solvent such as dichloromethane. If R⁵⁰ is an ester precursor group (other than an activated ester) as herein before defined, then the reaction could be carried out in a solvent, such as an alcohol, without a base present.

Likewise, if R⁵⁰ in the compound of formula II above is a precursor group having the formula -CH₂-Z, wherein Z is a reactive group as hereinbefore defined, it can be conveniently converted into a desired Q-X-N(R)-CH₂- group to form a compound of formula I by reacting the compound of formula II (wherein the aniline may be protected) with a compound of the formula Q-X-N(R)H; and thereafter, if necessary, removing any protecting groups.

A suitable base for this process is, for example, an organic amine base such as, for example, pyridine, 2,6-lutidine, collidine, 4-dimethylaminopyridine, triethylamine, morpholine, N-methylmorpholine or diazabicyclo[5.4.0]undec-7-ene, or, for example, an alkali or alkaline earth metal carbonate or hydroxide, for example sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide or potassium hydroxide, or, for example, an alkali metal hydride, for example sodium hydride, or an alkaline earth metal hydrogencarbonate such as sodium hydrogencarbonate, or a metal alkoxide such as sodium ethoxide.

Alternatively, if R⁵⁰ in the compound of formula II above is a -CHO (formyl) precursor group, it may be conveniently converted into a desired Q-X-N(R)-CH₂- group to form a compound of formula I by reacting the compound of formula II (wherein the aniline may be protected) with a compound of the formula Q-X-N(R)H in the presence of a suitable reducing agent and a suitable acid; and thereafter, if necessary, removing any protecting groups. A suitable reducing agent for this process includes, for example, an inorganic borohydride salt such as, sodium borohydride, sodium triacetoxyborohydride or sodium cyanoborohydride. A suitable acid for this process includes a Bronsted acid such as, for example formic acid, acetic acid, trifluoroacetic acid, hydrochloric acid, sulphuric acid, pαratoluene sulfonic acid or camphor sulfonic acid; or a Lewis acid of formula MX_Z, wherein M is a metal, X is a reactive group as hereindefined and z is in the range of 1-6 and the value of z will depend on the metal M. Typical examples of suitable Lewis acids include boron trifluoride, scandium(m) trifluoromethanesulfonate, tin(VI) chloride, titanium(IV) isopropoxide or zinc(II) chloride.

Another aspect of the present invention provides a particular process for preparing a compound of formula II above in which R⁵⁰ is -CHO (formyl), said process comprising the steps of: i) the reaction of a compound of the formula (J), wherein L and integer n' are as hereinbefore defined,

(J)

with a suitable formylating agent, to produce a compound of the formula (K).

(K)

ii) the reaction, in the presence of a suitable base, of a compound the formula (K), made in step (i) above, with a compound of formula (C) as defined above; and thereafter, if necessary, removing any protecting groups.

A suitable choice of formylating agent for step (i) includes, for example, carbon monoxide, N-formylmorpholine, N-formylpiperidine and N,N dimethylformamide.

A suitable choice of base and catalyst for step (ii) are as hereinbefore defined for processes (a) and (b). A further aspect of the present invention provides a particular process for preparing a compound of formula π in which R⁵⁰ is a -COOH (carboxy) precursor group, said process comprising the steps of: i) the reaction of a compound of the formula (J), wherein M, L and integer n are as hereinbefore defined,

(J) with a suitable electrophilic reagent, to produce a compound of the formula (L).

ii) the reaction, in the presence of a suitable base and suitable catalyst, of a compound the formula (L), made in step (i) above, with a compound of formula (C) as defined above; and thereafter, if necessary, removing any protecting groups.

Metal M may be any metal known in the literature to form nucleophilic organometallic compounds. Examples of suitable metals include lithium and magnesium. A suitable choice of electrophilic reagent for (step (i) includes, for example, carbon dioxide. A suitable choice of base and catalyst step (ii) are as hereinbefore defined for processes (a) and (b). A further aspect of the present invention provides a particular process for preparing an intermediate of compound (F) above wherein W is -C₂H₅ (ethyl), said process comprising the steps of : i) the reaction of a compound of formula (S), wherein X is a reactive group as hereinbefore defined,

with a compound of formula (T),wherein as outlined above the carboxylate group may be suitably protected and M, L & integer n' are as hereinbefore defined,

(T)

to produce the compound (U)

(U)

ii) The conversion of a compound of formula (U) into a compound of formula (F) wherein W is C₂H₅- (ethyl), using techniques well known to one skilled in the chemical art. An example of such a conversion includes, for example, the reaction of a compound (U), in the presence of a suitable base, for example sodium tert-butoxide, with methyltriphenyl phosphonium iodide, followed by hydrogenation over a catalyst such as palladium-on-carbon.

A suitable choice of base and catalyst for process (k) (step (i)) are as hereinbefore defined for processes (a) and (b).

M, L and n' are as previously defined herein.

It will be appreciated that it may be necessary/desirable to protect the carboxylate group. A suitable protecting group for this group is, for example, an esterifying group as hereinbefore defined, such as for example a methyl ester (-CO2Me). It will be appreciated by a person skilled in the art that it may be necessary/desirable to protect any sensitive groups in the compounds in some of the processes/ reactions mentioned herein. The instances where protection is necessary or desirable, and suitable methods for providing such protection are known to those skilled in the art. Conventional protecting groups may be used in accordance with standard practice (for illustration see T.W. Green & P.G.M. Wuts, Protective Groups in Organic Synthesis, 3^rd edition, John Wiley and Sons, 1999). Thus, if reactants include groups such as amino, carboxy or hydroxy it may be desirable to protect the group in some of the reactions mentioned herein.

Any protecting groups utilised in the processes described herein may in general be chosen from any of the groups described in the literature or known to the skilled chemist as appropriate for the protection of the group in question and may be introduced by conventional methods. Protecting groups may be removed by any convenient method as described in the literature or known to the skilled chemist as appropriate for the removal of the protecting group in question, such methods being chosen so as to effect removal of the protecting group with minimum disturbance of groups elsewhere in the molecule. Specific examples of protecting groups are given below for the sake of convenience, in which "lower", as in, for example, lower alkyl, signifies that the group to which it is applied preferably has 1-4 carbon atoms. It will be understood that these examples are not exhaustive. Where specific examples of methods for the removal of protecting groups are given below these are similarly not exhaustive. The use of protecting groups and methods of deprotection not specifically mentioned is of course within the scope of the invention.

A suitable protecting group for an amino or alkylamino group is, for example, an acyl group, for example an alkanoyl group such as acetyl, an alkoxycarbonyl group, for example a methoxycarbonyl, ethoxycarbonyl or t-butoxycarbonyl group, an arylmethoxycarbonyl group, for example benzyloxycarbonyl, or an aroyl group, for example benzoyl. The deprotection conditions for the above protecting groups necessarily vary with the choice of protecting group. Thus, for example, an acyl group such as an alkanoyl or alkoxycarbonyl group or an aroyl group may be removed for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an acyl group such as a t-butoxycarbonyl group may be removed, for example, by treatment with a suitable acid as hydrochloric, sulphuric or phosphoric acid or trifluoroacetic acid and an arylmethoxycarbonyl group such as a benzyloxycarbonyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon, or by treatment with a Lewis acid for example boron tris(trifluoroacetate). A suitable alternative protecting group for a primary amino group is, for example, a phthaloyl group which may be removed by treatment with an alkylamine, for example dimethylaminopropylamine, or with hydrazine. A suitable protecting group for a hydroxy group is, for example, an acyl group, for example an alkanoyl group such as acetyl, an aroyl group, for example benzoyl, or an arylmethyl group, for example benzyl. The deprotection conditions for the above protecting groups will necessarily vary with the choice of protecting group. Thus, for example, an acyl group such as an alkanoyl or an aroyl group may be removed, for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an arylmethyl group such as a benzyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon.

A suitable protecting group for a carboxy group is, for example, an esterifying group, for example a methyl or an ethyl group which may be removed, for example, by hydrolysis with a base such as sodium hydroxide, or for example a tert-butyl group which may be removed, for example, by treatment with an acid, for example an organic acid such as trifluoroacetic acid, or for example a benzyl group which may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon.

The protecting groups may be removed at any convenient stage in the synthesis using conventional techniques well known in the chemical art. It will be appreciated that certain of the various ring substituents in the compounds of the present invention may be introduced by standard aromatic substitution reactions or generated by conventional functional group modifications either prior to or immediately following the processes mentioned above, and as such are included in the process aspect of the invention. Such reactions and modifications include, for example, introduction of a substituent by means of an aromatic substitution reaction, reduction of substituents, reductive amination of substituents, alkylation of substituents and oxidation of substituents. The reagents and reaction conditions for such procedures are well known in the chemical art. Particular examples of aromatic substitution reactions include the introduction of a nitro group using concentrated nitric acid, the introduction of an acyl group using, for example, an acyl halide and Lewis acid (such as aluminium trichloride) under Friedel Crafts conditions; the introduction of an alkyl group using an alkyl halide and Lewis acid (such as aluminium trichloride) under Friedel Crafts conditions; and the introduction of a halo group. Particular examples of modifications include the reduction of a nitro group to an amino group by for example, catalytic hydrogenation with a nickel catalyst or treatment with iron in the presence of hydrochloric acid with heating; oxidation of alkylthio to alkylsulphinyl or alkylsulphonyl.

Biological Assays

The following assays can be used to measure the effects of the compounds of the present invention as HDAC inhibitors, as inhibitors in vitro of recombinant human HDACl produced in Hi5 insect cells, and as inducers in vitro & in vivo of Histone H3 acetylation in whole cells and tumours. They also assess the ability of such compounds to inhibit proliferation of human tumour cells.

(a) In Vitro Enzyme Assay of recombinant HDACl

HDAC inhibitors were screened against recombinant human HDACl produced in Hi5 insect cells. The enzyme was cloned with a FLAG tag at the C-terminal of the gene and affinity purified using Anti-FLAG M2 agarose from SIGMA (A2220).

The deacetylase assays were carried out in a 50 μl reaction. HDACl (75 ng of enzyme) diluted in 15μl of reaction buffer (25 mM TrisHCl (pH 8), 137 mM NaCl, 2.7 mM KCl, 1 mM MgCl₂) was mixed with either buffer alone (10 μϊ) or buffer containing compound (10 μl) for 30 minutes at ambient temperature. 25 μM acetylated histone H4 peptide (KI 174 Biomol) diluted in 25μl of buffer was then added to the reaction and incubated for one hour at ambient temperature. The reaction was stopped by addition of an equal volume (50 μl) Fluor de Lys developer (Biomol) containing Trichostatin A at 2 μM. The reaction was allowed to develop for 30 minutes at ambient temperature and then fluorescence measured at an excitation wavelength of 360 nM and an emission wavelength of 465 nM. IC₅₀ values for HDAC enzyme inhibitors were determined by performing dose response curves with individual compounds and determining the concentration of inhibitor producing fifty percent decrease in the maximal signal (diluent control).

(b) In Vitro Assay of inhibition of proliferation in whole cells

Inhibition of proliferation in whole cells was assayed using the Promega cell titer 96 aqueous proliferation assay (Promega #G5421). HCTl 16 cells were seeded in 96 well plates at 1x10 cells/well, and allowed to adhere overnight. They were treated with inhibitors for 72 hours. 20 ju-1 of the tetrazolium dye MTS was added to each well and the plates were reincubated for 3 hours. Absorbance was then measured on a 96 well plate reader at 490 nM. The IC₅₀ values for HDAC inhibitors were determined by performing dose response curves with individual compounds and determining the concentration of inhibitor producing fifty percent decrease in maximal signal (diluent control).

(c) In Vitro Enzyme Assay of Histone Deacetylase activity in whole cells

Histone H3 acetylation in whole cells was measured using immunohistochemistry and analysis using the Cellomics arrayscan. A549 or HCTl 16 cells were seeded in 96 well plates at 1x10 cells/well, and allowed to adhere overnight. They were treated with inhibitors for 24 hours and then fixed in 1.8% formaldehyde in tris buffered saline (TBS) for one hour. Cells were permeabilized with ice-cold methanol for 5 minutes, rinsed in TBS and then blocked in TBS 3% low-fat dried milk for 90 minutes. Cells were then incubated with polyclonal antibodies specific for the acetylated histone H3 (Upstate #06-599) diluted 1 in 500 in TBS 3% milk for one hour. Cells were rinsed three times in TBS and then incubated with fluorescein conjugated secondary antibodies (Molecular Probes #A11008) & Hoechst 333542 (1 μg/ml) (Molecular Probes #H3570) in TBS plus 1% Bovine serum albumin (Sigma #B6917) for one hour. Unbound antibody was removed by three rinses with TBS and after the final rinse 100 μl of TBS was added to the cells and the plates sealed and analysed using the Cellomics arrayscan. EC_5O values for HDAC inhibitors were determined by performing dose response curves with individual compounds and then determining the concentration of inhibitor producing fifty percent of the maximal signal (reference compound control - Trichostatin A (Sigma)).

Although the pharmacological properties of the compounds of the formula (I) vary with structural change as expected, in general activity possessed by compounds of the Formula I, may be demonstrated at the following concentrations or doses in one or more of the above tests (a)-(b):-

Test (a):- IC₅₀ in the range, for example, < 0.060/zM; Test (b):- IC₅₀ in the range, for example, < 0.75μM.

The following table discloses various biological data for a representative selection of compounds of the present invention. Comparative test data is also provided for N-(2- aminophenyl)-4-pyridin-2-ylbenzamide (Comparator) .

According to a further aspect of the invention there is provided a pharmaceutical composition which comprises a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore in association with a pharmaceutically-acceptable diluent or carrier.

The composition may be in a form suitable for oral administration, for example as a tablet or capsule, for parenteral injection (including intravenous, subcutaneous, intramuscular, intravascular or infusion) as a sterile solution, suspension or emulsion, for topical administration as an ointment or cream or for rectal administration as a suppository.

In general the above compositions may be prepared in a conventional manner using conventional excipients. The compound of formula (I) will normally be administered to a warm-blooded animal at a unit dose within the range 5-5000 mg/m² body area of the animal, i.e. approximately 0.1-100 mg/kg, and this normally provides a therapeutically-effective dose. A unit dose form such as a tablet or capsule will usually contain, for example 1-250 mg of active ingredient. Preferably a daily dose in the range of 1-50 mg/kg is employed. However the daily dose will necessarily be varied depending upon the host treated, the particular route of administration, and the severity of the illness being treated. Accordingly the optimum dosage may be determined by the practitioner who is treating any particular patient.

We have found that the compounds defined in the present invention, or a pharmaceutically acceptable salt thereof, are effective cell cycle inhibitors (anti-cell proliferation agents), which property is believed to arise from their HDAC inhibitory properties. We also believe that the compounds of the present invention may be involved in the inhibition of angiogenesis, activation of apoptosis and differentiation. Accordingly the compounds of the present invention are expected to be useful in the treatment of diseases or medical conditions mediated alone or in part by HDAC enzymes, i.e. the compounds may be used to produce a HDAC inhibitory effect in a warm-blooded animal in need of such treatment. Thus, the compounds of the present invention provide a method for treating the proliferation of malignant cells characterised by inhibition of HDAC enzymes, i.e. the compounds may be used to produce an anti-proliferative effect mediated alone or in part by the inhibition of HDACs.

According to one aspect of the present invention there is provided a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore for use in a method of treatment of the human or animal body by therapy.

Thus according to a further aspect of the invention there is provided a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore for use as a medicament.

According to a further aspect of the invention there is provided the use of a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore in the manufacture of a medicament for use in the production of a HDAC inhibitory effect in a warm-blooded animal such as man. According to a further feature of this aspect of the invention there is provided a method for producing a HDAC inhibitory effect in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore.

According to a further aspect of the invention there is provided the use of a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore in the manufacture of a medicament for use in the production of a cell cycle inhibitory (anti-cell-proliferation) effect in a warm-blooded animal such as man. According to a further feature of this aspect of the invention there is provided a method for producing a cell cycle inhibitory (anti-cell-proliferation) effect in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore. According to an additional feature of this aspect of the invention there is provided a method of treating cancer in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore.

According to a further feature of the invention there is provided a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore in the manufacture of a medicament for use in the treatment of cancer.

According to an additional feature of this aspect of the invention there is provided a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, or a pharmaceutically acceptable salt thereof, as defined hereinbefore, for use in the treatment of cancer.

In a further aspect of the present invention there is provided the use of a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore, in the manufacture of a medicament for use in lung cancer, colorectal cancer, breast cancer, prostate cancer, lymphoma and/or leukaemia. In a further aspect of the present invention there is provided a method of treating lung cancer, colorectal cancer, breast cancer, prostate cancer, lymphoma or leukaemia, in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore.

Cancers that are amenable to treatment with the present invention include oesophageal cancer, myeloma, hepatocellular, pancreatic and cervical cancer, Ewings tumour, neuroblastoma, kaposis sarcoma, ovarian cancer, breast cancer, colorectal cancer, prostate cancer, bladder cancer, melanoma, lung cancer [including non small cell lung cancer (NSCLC) and small cell lung cancer (SCLC)], gastric cancer, head and neck cancer, brain cancer, renal cancer, lymphoma and leukaemia.

There is further provided is a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore, for use in a method of treating inflammatory diseases, autoimmune diseases and allergic/atopic diseases. In particular a compound of the formula (I), or a pharmaceutically acceptable salt thereof, as defined hereinbefore, is provided for use in a method of treating inflammation of the joint (especially rheumatoid arthritis, osteoarthritis and gout), inflammation of the gastrointestinal tract (especially inflammatory bowel disease, ulcerative colitis and gastritis), inflammation of the skin (especially psoriasis, eczema, dermatitis), multiple sclerosis, atherosclerosis, spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis, arthritis connected to ulcerative colitis), AIDS-related neuropathies, systemic lupus erythematosus, asthma, chronic obstructive lung diseases, bronchitis, pleuritis, adult respiratory distress syndrome, sepsis, and acute and chronic hepatitis (either viral, bacterial or toxic).

Further provided is a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore, for use as a medicament in the treatment of inflammatory diseases, autoimmune diseases and allergic/atopic diseases in a warm-blooded animal such as man.

In particular a compound of the formula (I), or a pharmaceutically acceptable salt or pro-drug thereof, as defined hereinbefore, is provided for use as a medicament in the treatment of inflammation of the joint (especially rheumatoid arthritis, osteoarthritis and gout), inflammation of the gastro-intestinal tract (especially inflammatory bowel disease, ulcerative colitis and gastritis), inflammation of the skin (especially psoriasis, eczema, dermatitis), multiple sclerosis, atherosclerosis, spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis, arthritis connected to ulcerative colitis), AIDS-related neuropathies, systemic lupus erythematosus, asthma, chronic obstructive lung diseases, bronchitis, pleuritis, adult respiratory distress syndrome, sepsis, and acute and chronic hepatitis (either viral, bacterial or toxic).

Further provided is the use of a compound of the formula (I), or a pharmaceutically acceptable salt thereof, as defined hereinbefore, in the manufacture of a medicament for use in the treatment of inflammatory diseases, autoimmune diseases and allergic/atopic diseases in a warm-blooded animal such as man.

As stated above the size of the dose required for the therapeutic or prophylactic treatment of a particular cell-proliferation disease will necessarily be varied depending on the host treated, the route of administration and the severity of the illness being treated. A unit dose in the range, for example, 1-100 mg/kg, preferably 1-50 mg/kg is envisaged. The HDAC inhibitory activity defined hereinbefore may be applied as a sole therapy or may involve, in addition to a compound of the invention, one or more other substances and/or treatments. Such conjoint treatment may be achieved by way of the simultaneous, sequential or separate administration of the individual components of the treatment. In the field of medical oncology it is normal practice to use a combination of different forms of treatment to treat each patient with cancer. In medical oncology the other component(s) of such conjoint treatment in addition to the cell cycle inhibitory treatment defined hereinbefore may be: surgery, radiotherapy or chemotherapy. Such chemotherapy may include one or more of the following categories of anti-tumour agents:

(i) antiproliferative/antineoplastic drugs and combinations thereof, as used in medical oncology, such as alkylating agents (for example cis-platin, carboplatin, cyclophosphamide, nitrogen mustard, melphalan, chlorambucil, busulphan and nitrosoureas); antimetabolites (for example antifolates such as fluoropyrimidines like 5-fluorouracil and tegafur, raltitrexed, methotrexate, cytosine arabinoside and hydroxyurea; antitumour antibiotics (for example anthracyclines like adriamycin, bleomycin, doxorubicin, daunomycin, epirubicin, idarubicin, mitomycin-C, dactinomycin and mithramycin); antimitotic agents (for example vinca alkaloids like vincristine, vinblastine, vindesine and vinorelbine and taxoids like taxol and taxotere); and topoisomerase inhibitors (for example epipodophyllotoxins like etoposide and teniposide, amsacrine, topotecan and camptothecin);

(ii) cytostatic agents such as antioestrogens (for example tamoxifen, toremifene, raloxifene, droloxifene and iodoxyfene), oestrogen receptor down regulators (for example fulvestrant), antiandrogens (for example bicalutamide, flutamide, nilutamide and cyproterone acetate), LHRH antagonists or LHRH agonists (for example goserelin, leuprorelin and buserelin), progestogens (for example megestrol acetate), aromatase inhibitors (for example as anastrozole, letrozole, vorazole and exemestane) and inhibitors of 5α-reductase such as finasteride; (iii) Agents which inhibit cancer cell invasion (for example metalloproteinase inhibitors like marimastat and inhibitors of urokinase plasminogen activator receptor function);

(iv) inhibitors of growth factor function, for example such inhibitors include growth factor antibodies, growth factor receptor antibodies (for example the anti-erbb2 antibody trastuzumab [Herceptin™] and the anti-erbbl antibody cetuximab [C225]) , farnesyl transferase inhibitors, MEK inhibitors, tyrosine kinase inhibitors and serine/threonine kinase inhibitors, for example inhibitors of the epidermal growth factor family (for example EGFR family tyrosine kinase inhibitors such as N-(3-chloro-4-fluorophenyl)-7-methoxy-6-(3- morpholinopropoxy)quinazolin-4-amine (gefitinib, AZD1839), JV-(3-ethynylphenyl)-6,7- bis(2-methoxyethoxy)quinazolin-4-amine (erlotinib, OSI-774) and 6-acrylamido-iV-(3-chloro- 4-fluorophenyl)-7-(3-morpholinopropoxy)quinazolin-4-amine (CI 1033)), for example inhibitors of the platelet-derived growth factor family and for example inhibitors of the hepatocyte growth factor family;

(v) antiangiogenic agents such as those which inhibit the effects of vascular endothelial growth factor, (for example the anti-vascular endothelial cell growth factor antibody bevacizumab [Avastin™], compounds such as those disclosed in International Patent Applications WO 97/22596, WO 97/30035, WO 97/32856 and WO 98/13354) and compounds that work by other mechanisms (for example linomide, inhibitors of integrin αvβ3 function and angiostatin); (vi) vascular damaging agents such as Combretastatin A4 and compounds disclosed in International Patent Applications WO 99/02166, WO00/40529, WO 00/41669, WO01/92224, WO02/04434 and WO02/08213;

(vii) antisense therapies, for example those which are directed to the targets listed above, such as ISIS 2503, an anti-ras antisense;

(viii) gene therapy approaches, including for example approaches to replace aberrant genes such as aberrant p53 or aberrant BRCAl or BRC A2, GDEPT (gene-directed enzyme pro-drug therapy) approaches such as those using cytosine deaminase, thymidine kinase or a bacterial nitroreductase enzyme and approaches to increase patient tolerance to chemotherapy or radiotherapy such as multi-drug resistance gene therapy;

(ix) immunotherapy approaches, including for example ex- vivo and in- vivo approaches to increase the immunogenicity of patient tumour cells, such as transfection with cytokines such as interleukin 2, interleukin 4 or granulocyte-macrophage colony stimulating factor, approaches to decrease T-cell anergy, approaches using transfected immune cells such as cytokine-transfected dendritic cells, approaches using cytokine-transfected tumour cell lines and approaches using anti-idiotypic antibodies;

(x) Cell cycle inhibitors including for example CDK inhibitiors (eg flavopiridol) and other inhibitors of cell cycle checkpoints (eg checkpoint kinase); inhibitors of aurora kinase and other kinases involved in mitosis and cytokinesis regulation (eg mitotic kinesins); and other histone deacetylase inhibitors; and

(xi) differentiation agents (for example retinoic acid and vitamin D).

According to this aspect of the invention there is provided a pharmaceutical composition comprising a compound of the formula (I) as defined hereinbefore and an additional anti-tumour substance as defined hereinbefore for the conjoint treatment of cancer. In addition to their use in therapeutic medicine, the compounds of formula (I) and their pharmaceutically acceptable salts thereof, are also useful as pharmacological tools in the development and standardisation of in vitro and in vivo test systems for the evaluation of the effects of inhibitors of cell cycle activity in laboratory animals such as cats, dogs, rabbits, monkeys, rats and mice, as part of the search for new therapeutic agents. The invention will now be illustrated in the following Examples in which, generally: (i) operations were carried out at ambient temperature, i.e. in the range 17 to 25°C and under an atmosphere of an inert gas such as argon unless otherwise stated;

(ii) evaporations were carried out by rotary evaporation in vacuo and work-up procedures were carried out after removal of residual solids by filtration; (iii) column chromatography (by the flash procedure) and medium pressure liquid chromatography (MPLC) were performed on Merck Kieselgel silica (Art. 9385) or Merck Lichroprep RP-18 (Art. 9303) reversed-phase silica obtained from E. Merck, Darmstadt, Germany or using proprietory pre-packed normal phase silica cartridges, for example Redisep(TM) disposable chromatography cartridges obtained from Presearch Ltd., Hitchin, UK, or high pressure liquid chromatography (HPLC) was performed on Cl 8 reverse phase silica, for example on a Dynamax C-18 6θA preparative reversed-phase column;

(iv) yields, where present, are not necessarily the maximum attainable;

(v) in general, the structures of the end-products of the Formula (I) were confirmed by nuclear magnetic resonance (NMR) and/or mass spectral techniques; fast-atom bombardment (FAB) mass spectral data were obtained using a Platform spectrometer and, where appropriate, either positive ion data or negative ion data were collected; NMR chemical shift values were measured on the delta scale [proton magnetic resonance spectra were determined using a Jeol JNM EX 400 spectrometer operating at a field strength of 400 MHz, Varian Gemini 2000 spectrometer operating at a field strength of 300MHz or a Bruker AM300 spectrometer operating at a field strength of 300MHz;

(vi) intermediates were not generally fully characterised and purity was assessed by thin layer chromatographic, HPLC, infra-red (IR) and/or NMR analysis;

(vii) melting points are uncorrected and were determined using a Mettler SP62 automatic melting point apparatus or an oil-bath apparatus; melting points for the end-products of the formula (I) were determined after crystallisation from a conventional organic solvent such as ethanol, methanol, acetone, ether or hexane, alone or in admixture;

(viii) the following abbreviations have been used, where necessary and appropriate:- DMF N,N-dimethylformamide

DCM dichloromethane DME 1,2-dimethoxyethane DMSO dimethylsulphoxide

THF tetrahydrofuran

HATU O-(7-Azabenzotriazol-l-yl)-N,N,N',N'- tetramethyluronium hexafluorophosphate

EDCI l-(3-Dimethylaminopropyl)-3-ethylcarbodiimide

DCCI 1 ,3-Dicyclohexylcarbodiimide

PYBOP Benzotriazole-1-yl-oxy-trispyrrolidinonophosphonium hexafluorophosphate

DEAD Diethyl azodicarboxylate

DIAD Diisopropyl azodicarboxylate

DTAD Di-tert-butyl azodicarboxylate

DIPEA N,N-Diisopropylethylamine

MeOH Methanol

TFA Trifluoroacetic acid

Example 1

Preparation of iV-(2-aminophenyl)-4-(5-{ r(2-methoxybenzyl)amino1methyl }-3-methylpyridin- 2-yl)benzamide

tert-Butyl (2-{ [4-(5-formylpyridin-2-yl)benzoyl] amino }phenyl)carbamate (0.20 g,

0.4634 mmol; prepared as described in Method 2 below) and (2-methoxybenzyl)amine (0.7 mmol) was dissolved in dichloromethane (5 ml). Titanium (IV) zsøpropoxide (0.28 ml, 0.9 mmol) was added and the mixture stirred at ambient temperature for 2 hours. Sodium borohydride (70 mg, 1.85 mmol) and methanol (0.6 ml) was added and the mixture stirred for a further hour. Water (4 ml) and an aqueous sodium bicarbonate solution (2 ml) was added and stirred for 10 minutes. The product was extracted with dichloromethane (3 x 10 ml) and the organic extracts concentrated to give a residue. The residue was purified using chromatography eluting with 10% methanol in ethyl acetate then concentration of the relevant fractions gave product as a gum. The gum was dissolved in dichloromethane (5 ml), trifluoroacetic acid (1 ml) added and the solution then stirred at ambient temperature for 2 hours. The resultant solution was absorbed onto an SCX-2 column washed with methanol (3 column volumes) and the product eluted with a 2M solution of ammonia in methanol (3 column volumes) which after concentration gave the product as a gum. This was triturated with diethyl ether (3 ml) to give the product as a solid (84 mg, 40%).

NMR Spectrum: (DMSO-d₆); 2.37 (s, 3H), 3.81 (m, 7H), 4.92 (s, 2H), 6.62 (m, IH), 6.80 (m, IH), 6.98 (m, 3H), 7.23 (m, 2H), 7.39 (m, IH), 7.71 (m, 3H), 8.08 (d, 2H), 8.49 (s, IH), 9.72 (s, IH). Mass Spectrum: M+H⁺453.

Examples 2 to 8

Using a method similar to that used in Example 1 above, the appropriate amine was reacted with tert-butyl (2-{ [4-(5-formylpyridin-2-yl)benzoyl]amino}phenyl)carbamate (see Method 2) to give the compounds shown in Table 1 below.

Table 1

Example 9

Preparation of N-(2-aminophenyl)-4-(3-methyl-5-{ F(tetrahydrofuran-2- ylmethyl)aminolmethyl|pyridin-2-yl)benzamide

The tert-butyl [2-({4-[5~(hydroxymethyl)-3-methyrpyridin-2- yl]benzoyl}amino)phenyl]carbamate.(See Method 1 below 200 mg, 0.46 mmol) was stirred in tetrahydrofuran (5 ml) and diώøpropylethylamine (0.24 ml, 1.38 mmol) added and the solution cooled with an ice bath. Methanesulphonylchloride (0.05 ml, 0.61 mmol) was added, the solution stirred for 30 minutes and then warmed to ambient temperature. Tetrahydrofurfurylamine (0.7 ml, 6.9 mmol) in tetrahydrofuran (2 ml) was added drop wise and the solution stirred for 18 hours. The mixture was evaporated and the residue purified by chromatography on silica eluting with methanol in ethylacetate (10%). Evaporation gave the product as a yellow gum which was dissolved in dichloromethane (6 ml) and trifluoroacetic acid (1.2 ml) added then stirred at ambient temperature for 2 hours. The reaction mixture was loaded onto an SCX-2 column and the column washed with methanol (x 2) and then the product eluted with ammoniacal methanol (2M). Evaporation of the eluants gave the product as a gum. This was triturated with ether/isohexane to give the title compound as a solid (145 mg, 75%).

NMR Spectrum: (DMSO-d₆) 6 1.55 (m, IH), 1.80 (m, 2H), 1.92 (m, IH), 2.37 (s, 3H), 2.60 (d, 2H), 3.62 (m, IH), 3.75 (m, IH), 3.80 (s, 2H), 3.91 (m, IH), 4.92 (s, 2H), 6.62 (m, IH), 6.80 (m, IH), 6.99 (m, IH), 7.21 (m, IH), 7.68 (m, 3H), 8.07 (d, 2H), 8.46 (s, IH), 9.72 (s, IH); Mass Spectrum: M+H⁺417.

Example 10

Preparation of iV-(2-aminophenyl)-4-r5-(| [2-(3,5-dimethyl-lH-pyrazol-4- yl)ethyllamino}methyl)-3-methylpyridin-2-vHbenzamide

The tert-butyl (2-{ [4-(5-formyl-3-methylpyridin-2-yl)benzoyl]amino}phenyl) carbamate

(259 mg, 0.60 mmol; prepared as described in Method 2 below) and 2-(3,5-dimethyl-lH- pyrazol-4-yl)ethylamine (83.3 mg, 0.60mmol) were stirred together in DCM (5 ml) at ambient temperature. Acetic acid (34 μl, 0.60mmol) was added and the mixture stirred for 1 hour. Sodium triacetoxyborohydride (178 mg, 0.84 mmol) was added and the mixture stirred at ambient temperature for 48 hours. The reaction mixture was loaded onto an SCX-2 column and the column washed with methanol (x 2) and the product eluted with ammoniacal methanol (2M). Evaporation of the solvent gave the product as a gum which was purified further by flash chromatography on silica eluting with 25 % ethylacetate/wohexane concentration gave product as a foam. The foam was stirred and dissolved in dichloromethane (2.0 ml), trifluoroacetic acid (0.5 ml) was added and the mixture stirred for 3 hours. The solution was loaded onto an SCX-2 column. The column was washed with methanol (x 2) and the product eluted with ammoniacal methanol (2M) which after concentration gave product as a gum. This was triturated with diethyl ether to give the title compound as a solid (57 mg, 21 %).

NMR Spectrum: ¹H NMR (400.132 MHz, DMSO) δ 2.13 (s, 6H), 2.41 (s, 3H), 2.68 (m, 2H), 2.99 (m, 2H), 4.28 (s, 2H), 4.93 (bs, 2H), 6.63 (m, IH), 6.81 (d, IH), 7.00 (m, IH), 7.21 (d, IH), 7.71 (d, 2H), 7.89 (s, IH), 8.10 (d, 2H), 8.63 (s, IH), 9.07 (bs, IH), 9.75 (s, IH), 12.04 (s, IH); Mass Spectrum: M+H* 455.

Example 11

Preparation of N-(2-aminophenyl)-4-(3-methyl-5-( F(tetrahydro-2H-pyran-4- ylmethvDaminol methyl } pyridin-2- vDbenzamide

To a solution of tørt-butyl (2-{[4-(3-methyl-5-{[(tetrahydro-2H-pyran-4- ylmethyl)amino]methyl}pyridin-2-yl)benzoyl]amino}phenyl)carbamate (450 mg, 0.84mmol, see Method 4) in methanol (2 ml) was added hydrogen chloride in dioxane (4.0M, 8 ml, 32mmol). The mixture was stirred at ambient temperature for 16 hours, resulting in the precipitation of a white solid. The mixture was concentrated in vacuo then re-dissolved in methanol (3 ml) and loaded onto a 20 g SCX-2 column. The column was washed with methanol, then the product eluted with 2N NΗ3-MeOΗ. This was concentrated to yield a yellow oil. Ethyl acetate (20 ml) was added and the solution concentrated in vacuo to yield the title compound as a yellow solid (330 mg, 90%).

NMR Spectrum: (DMSO-d₆); 1.16 (m, 2H), 1.64 (m, 3H), 2.35 (s, 3H), 2.43 (d, 2H), 3.27 (s, 2H), 3.75 (s, 2H), 3.84 (m, 2H), 4.91 (s, 2H), 6.61 (t, IH), 6.78 (d, IH), 6.97 (t, IH), 7.20 (d, IH), 7.67 (m, 3H), 8.06 (d, 2H), 8.45 (s, IH), 9.71 (s, IH),. Mass Spectrum: M+H⁺431. Example 12

N-(2-aminophenyl)-4-r3-methyl-5-rr(5-methyl-l,2-oxazol-3-vDmethylamino1methyl1pyridin- 2-vHbenzamide (or Af-(2-aminophenyl)~4~r3-methyl-5-({ r(5-methylisoxazol-3- vDmethyll amino ) methvPpyridin-2-vπbenzamide)

To a stirred solution of tert-butyl N-[2-[[4-[3-methyl-5-[[(5-methyll,2-oxazol-3- yl)methylamino]methyl]pyridin-2-yl]benzoyl]amino]phenyl]carbamate ( 96 mg, 0.18 mmol) in dichloromethane (5 ml) was added trifluoroacetic acid (1 ml). The reaction mixture was allowed to stir at ambient temperature for 2 hours before being poured directly onto a pre- equilibrated (with methanol) SCX-2 cartridge (5 g). The cartridge was washed with methanol, before the products were eluted with a 2M solution of ammonia in methanol. The ammoniacal eluant was evaporated to dryness to afford the title compound (63 mg, 81%); NMR Spectrum: (DMSO-dβ) δ 2.37 (s, 3H), 2.41 (s, 3H), 3.82 (m, 4H), 4.92 (s, 2H), 6.29 (s, IH), 6.62 (m, IH), 6.80 (m, IH), 6.99 (m, IH), 7.21 (m, IH), 7.68 (d, 2H), 7.73 (m, IH), 8.08 (d, 2H), 8.48 (m, IH), 9.72 (s, IH) Mass Spectrum: M+H⁺ 428

Methods Method 1

Preparation of tert-butyl r2-((4-r5-(hydroxymethyl)-3-methylpyridin-2- yllbenzoyl }amino)phenyllcarbamate

tert-Butyl (2-{ [4-(5-formyl-3-methylpyridin-2-yl)benzoyl]amino}phenyl)carbamate (2 g, 4.64 mmol, see Method 2 below) was stirred and suspended in methanol (100 ml) then sodium borohydride (350 mg, 9.28 mmol) added in portions and the solution stirred for 2 hours at ambient temperature. The solution was concentrated under reduced pressure and the residue partitioned between saturated sodium bicarbonate solution (100 ml) and dichloromethane. This was extracted with dichloromethane, the combined organic extracts were washed with brine and dried over magnesium sulphate. The solid was filtered and the solution concentrated under reduced pressure to give the title compound (2.04 g, 100 %); NMR Spectrum: (DMSO-d₆) 1.46 (s, 9H), 2.37 (s, 3H), 4.58 (d, 2H), 5.32 (t, IH), 7.20 (m, 2H), 7.58 (m, 2H), 7.68 (s, IH), 7.72 (d, 2H), 8.05 (d, 2H), 8.47 (s, IH), 8.69 (s, IH), 9.90 (s, IH); Mass Spectrum: M+H⁺434.

Method 2

Preparation of tert-butyl (2-ir4-(5-formyl-3-methylpyridin-2-yl)benzoyllamino|phenyl) carbamate

N-(2-t-Butoxycarbonylaminophenyl)-4-(4,4,5 ,5-tetramethyl- 1 ,3 ,2,-dioxaborolan-2-yl) benzamide (7.69 g, 17.55 mmol - prepared as described in Method 13, page 60, of International patent publication number WO 03/087057), was added to a stirred solution of 6- bromo-5-methylnicotinaldehyde (3.51 g, 17.55 mmol, see Method 3 below) in dimethoxyethane (100 ml) at ambient temperature under a nitrogen atmosphere. l,rBis(diphenylphosphino)ferrocenedichloropalladium(π) (0.72 g, 0.88 mmol) was added followed by saturated aqueous sodium bicarbonate solution (50 ml) and the mixture heated at 60 C for 2 hours. The reaction mixture was concentrated under reduced pressure and the residue partitioned between dichloromethane and water. The dichloromethane layer was washed with saturated aqueous sodium bicarbonate solution and brine, then dried over magnesium sulphate, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography, eluting with 40 % ethyl acetate in zsøhexane, to give the title compound (5.93 g, 75 %); NMR Spectrum: (DMSO-d₆) 1.46 (s, 9H), 2.47 (s, 3H), 7.20 (m, 2H), 7.58 (m, 2H), 7.80 (d, 2H), 8.09 (d, 2H), 8.23 (s, IH), 8.70 (s, IH), 9.04 (s, IH), 9.94 (s, IH), 10.17 (s, IH); Mass Spectrum: MH-H⁺ 432.

Method 3

Preparation of 6-bromo-5-methvmicotmaldehvde

2,5-Dibromo-3-picoline (5.1 g, 20.30 mmol) in tetrahydrofuran (25 ml) was added dropwise to a 2M solution of isopropylmagnesium chloride (10.7 ml, 21.3 mmol) in tetrahydrofuran at 0 ⁰C. The solution was stirred for 2 hours at 0 ⁰C and then for 1 hour at ambient temperature. A solution of 4-formylmorpholine (2.1 ml, 20.3 mmol) in tetrahydrofuran (25 ml) was added dropwise and the solution stirred at ambient temperature for 1 hour. The solution was poured into water and extracted with ethyl acetate. The combined organic extracts were washed with brine, dried over magnesium sulphate, filtered and the solution concentrated under reduced pressure. The residue was purified by flash chromatography, eluting with 10 % ethyl acetate in isohexane, to give the title compound (3.0 g, 74 %); NMR Spectrum: (DMSO-d₆) 2.44 (s, 3H), 8.19 (s, IH), 8.73 (s, IH), 10.09 (s, IH).

Method 4

fert-butyl (2-1 r4-(3-methyl-5-{ r(tetrahvdro-2H-pyran-4-ylmethyl)aminolmethyllpyridin-2- vDbenzoyll amino }phenyl)carbamate

Titanium (IV) iso-propoxide (1.04 grm, 3.66mmol) was added to a stirred solution of tert- butyl (2-{[4-(5-formyl-3-methyl pyridin-2-yl) benzoyl]amino}phenyl)carbamate (500 mg, 1.22mmol, see Method 2) and 4-(aminomethyl)tetrahydropyran (280mgs, 2.44mmol) in dichloromethane (20 ml) at ambient temperature. The mixture was stirred for two hours. Sodium borohydride (230 mg) was added followed by methanol (4 ml) and the mixture was stirred for a further 18hrs. Water (10 ml) and dichloromethane were added, the mixture stirred for 10 minutes and then filtered. The filter was washed with more dichloromethane (20ml) and the organic phase dried and evaporated to dryness. The residue was purified by chromatography on a silica column eluting with methanol/ethyl acetate (1 :4) to give a white solid (530 mg, 82%).

NMR Spectrum: (DMSO-d₆); 1.15 (m, 2Η), 1.44 (s, 9H), 1.65 (m, 3H), 2.35 (s, 3H), 2.40 (d, 2H), 3.28 (m, 3H), 3.73 (s, 2H), 3.83 (m, 2H), 7.20 (m, 2H), 7.55 (m, 2H), 7.70 (s, 2H), 7.73 (s, IH), 8.03 (d, 2H), 8.44 (s, IH), 8.69 (br s., IH), 9.88 (s, IH),. Mass Spectrum: M-HH⁺ SSl. Method 5

te^butyl N-r2-rr4-r3-methyl-5-rr(5-methyll,2-oxazol-3-yl')methylaniino1methyl1pyridin-2- yllbenzoyliaminolphenyllcarbamate

To a stirred solution of tert-butyl N-[2-[[4-(5-formyl-3-methyl-pyridin-2- yl)benzoyl]amino]phenyl]carbamate (200 mg, 0.46mmol, see Method 2) and (5-methyl-3- isoxazolyl)methylamine (80.3 mg, 0.72mmol), in dichloromethane (5 ml), was added titanium (IV) isopropoxide (0.28 ml, 0.93mmol) and a further aliquot of dichloromethane (1 ml). The reaction mixture was left to stir for 2 hours. Sodium borohydride (70 mg, 1.85mmol) was then added, followed by methanol (0.6 ml) and the reaction left to stir for a further 1 hour. The reaction mixture was then partitioned between dichloromethane and a dilute aqueous solution of sodium bicarbonate (saturated aqueous sodium bicarbonate solution diluted 1:2 v/v with water). The mixture was stirred for 10 minutes before filtration under gravity through a coarse filter cup. The organic phase was then separated, washed with water (100 ml) and evaporated to dryness. The residue was purified by flash chromatography on silica, eluting with 10% (v/v) methanol in ethyl acetate. Product containing fractions were evaporated to dryness to afford the title compound (96 mg, 39%); Mass Spectrum: M+H^"1" 528

Claims

1. A compound of formula (I):

(D wherein

W is methyl or ethyl;

R is hydrogen or (l-4C)alkyl; X is ~[CR^aR^b]_n- where each R^a and R^b group present is independently selected from hydrogen or (l-2C)alkyl and integer n is 1, 2 or 3;

2. A compound according to claim 1, wherein W is methyl.

3. A compound according to claims 1 or 2, wherein R is hydrogen or methyl.

4. A compound according to claim 3, wherein R is hydrogen.

5. A compound according to any one of claims 1 to 4, wherein X is -[CR a Rτ>b ]i_n- where each R^a and R^b group is hydrogen and integer n is 1, 2 or 3.

6. A compound according to any one of claims 1 to 5, wherein Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, (l-2C)alkoxy, halo, cyano, hydroxy, or amino.

7. A compound according to any one of claims 1 to 5, wherein Q is phenyl or a heterocyclic ring selected from tetrahydrofuranyl, tetrahydropyranyl, furyl, pyrazolyl, isoxazolyl and pyridyl, and wherein Q is optionally substituted by 1 to 3 substituents groups independently selected from (l-2C)alkyl, trifluoromethyl, and (l-2C)alkoxy.

8. A compound according to any one of claims 1 to 5, wherein Q is selected from 2- methoxyphenyl, 3- methoxyphenyl, 4-methoxyphenyl, 3,4-dimethoxyphenyl, 5-methyl-2- furyl, 6-(trifluoromethyl)pyridin-3-yl, 5-methyl-lH-pyrazol-3-yl, l,5-dimethyl-lH-pyrazol-3- yl, tetrahydrofuran-2-yl, tetrahydro-2H-pyran-4-yl, 3,5-dimethyl-lH-pyrazol-4-yl, and 5- methylisoxazol-3-yl.

9. A compound which is selected from any one of the following:

N-(2-aminophenyl)-4-(5- { [(2-methoxybenzyl)amino]methyl } -3-methylpyridin-2- yl)benzamide; iV-(2-aminophenyl)-4-(5- { [(3-methoxybenzyl)amino]methyl } -3-methylpyridin-2- yl)benzamide;

N-(2-aminophenyl)-4-(5-{[(4-methoxybenzyl)amino]methyl}-3-methylpyridin-2- yl)benzamide; N-(2-aminophenyl)-4-(5-{ [(3,4-dimethoxybenzyl)amino]methyl }-3-methylpyridin-2- yl)benzamide;

N-(2-aminophenyl)-4-[3-methyl-5-({[(5-methyl-2-furyl)methyl]amino}methyl)pyridin-2- yljbenzamide; N-(2-aminophenyl)-4-{ 3-methyl-5-[({ [6-(trifluoromethyl)pyridin-3- yl]methyl } amino)methyl]pyridin-2-yl }benzamide;

N-(2-aminophenyl)-4-[3-methyl-5-({[3-(5-methyl-lH-pyrazol-3- yl)propyl]amino}methyl)pyridin-2-yl]benzamide;

5 N-(2-aminophenyl)-4-[5-({[(l,5-dimethyl-lH-pyrazol-3-yl)methyl]amino}methyl)-3- methylpyridin-2-yl]benzamide;

N-(2-aminophenyl)-4-(3-methyl-5- { [(tetrahydrofuran-2-ylmethyl)amino]methyl }pyridin-2- yl)benzamide;

N-(2-aminophenyl)-4-(3-methyl-5- { [(tetrahydro-2H-pyran-4-ylmethyl)amino]methyl }pyridin- 10 2-yl)benzamide;

15

10. A pharmaceutical composition which comprises a compound as claimed in any one of claims 1 to 9, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically-acceptable diluent or carrier.

20 11. A compound as claimed in any one of claims 1 to 9 for use as a medicament.

12. The use of a compound as claimed in any one of claims 1 to 9, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for use in the production of a HD AC inhibitory effect in a warm-blooded animal such as man.

25

13. A method for producing a HDAC inhibitory effect in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound as claimed in any one of claims 1 to 9, or a pharmaceutically acceptable salt thereof.

14. The use of a compound as claimed in any one of claims 1 to 9, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for use in the treatment of cancer in a warm-blooded animal such as man.

15. A method of treating cancer in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound as claimed in any one of claims 1 to 9, or a pharmaceutically acceptable salt thereof.

10 16. A process for preparing a compound of formula (I) according to anyone of claims 1 to 9, or a pharmaceutically acceptable salt thereof, said process comprising the steps of:

(a) the reaction of a compound of the formula (A)

15 (A) wherein Z is a reactive group, with a compound of the formula (B)

20 wherein

R ,so is a group of formula Q-X-N(R)-CH₂- as defined in claim 1 or a precursor thereof, W is as defined in claim 1, M is a metal, L is a ligand, and integer n' is 0 to 3; and wherein if R⁵⁰ is a precursor for the group Q-X-N(R)-CH₂-, then said process thereafter comprises a step of converting the compound formed by the reaction of a compound of the formula (A) with a compound of the formula (B) to a compound of formula (I) (by converting the precursor into the appropriate Q-X-N(R)-CH₂- group); or

(b) The reaction of a compound of the formula (C)

(D) wherein R⁵⁰, W and Z are as defined above; and wherein if R⁵⁰ is a precursor for the group Q-X-N(R)-CH₂-, then said process thereafter comprises a step of converting the compound formed by the reaction of a compound of the formula (C) with a compound of the formula (D) to a compound of formula (I) (by converting the precursor into the appropriate Q-X-N(R)-CH₂- group); or

(c) the reaction, under suitable amide coupling conditions or in the presence of a suitable amide coupling reagent, in particular 4-(4,6-dimethoxy- 1 ,3 ,5-triazinyl-2-yl)-4- methylmorpholinium chloride, of a compound of the formula (E)

(E) with a compound of the formula (F)

(F) wherein R >50 and W are as defined above, and wherein if R⁵⁰ is a precursor for the group Q-X-N(R)-CH₂-, then said process thereafter comprises a step of converting the compound formed by the reaction of a compound of the formula (E) with a compound of the formula (F) to a compound of formula (I) (by converting the precursor into the appropriate Q-X-N(R)-CH₂- group); and thereafter, if necessary: i) converting a compound of the formula (I) into another compound of the formula (I); and/or ii) removing any protecting groups.