Patent ID: 7935688

Claim:
A compound represented by the following general formula (I): wherein R 1 and R 2 independently represent an optionally substituted C 1-6 alkyl group, a C 1-6 haloalkyl group, an optionally substituted C 2-6 alkenyl group, an optionally substituted C 2-6 alkynyl group or an optionally substituted C 1-6 alkoxy group, or R 1 and R 2 are taken together to form an optionally substituted C 3-8 cycloalkyl group; R 3 , R 4 , R 5 and R 6 independently represent a hydrogen atom, a halogen atom, an optionally substituted C 1-6 alkyl group, a C 1-6 haloalkyl group, an optionally substituted C 2-6 alkenyl group, an optionally substituted C 2-6 alkynyl group or an optionally substituted C 1-6 alkoxy group; R 7 , R 8 and R 9 independently represent a hydrogen atom, an optionally protected hydroxyl group, an optionally substituted amino group, an optionally substituted carboxyl group, an optionally substituted C 1-10 alkyl group or a C 1-6 haloalkyl group, or any one pair of (R 7 and R 8 ), (R 7 and R 9 ) and (R 8 and R 9 ) are taken together to form an optionally substituted C 3-10 cycloalkyl group, a carbonyl group, an optionally substituted 3- to 12-membered heterocycle or a C 3-7 lactone; X is a direct bond, methylene, ethylene, vinylene, ethynylene, —O—, —S—, —NH—, carbonyl; Y represents a phenyl group having one or two substituent or a nitrogen containing 3- to 12-membered heterocycle having one or two substituent; and the heterocycle is selected from pyrrole, oxazole, isoxazole, thiazole, isothiazole, furazan, imidazole, pyrazole, piperidine, piperazine, morpholine, thiomorpholine, pyridine, pyrazine, pyrimidine, pyridazine, indole, isoindole, indolizine, quinoline, isoquinoline, quinolizine, naphthyridine, benzimidazole, indazole, quinoxaline, quinazoline, cinnoline, phthalazine, purine, pteridine, benzoxazole and benzothiazole, wherein substituents each selected from a C 1-6 alkyl group optionally substituted with one or two hydroxyl groups, amino groups, C 1-6 alkoxycarbonyl groups and/or carboxyl groups; a C 1-6 haloalkyl group optionally substituted with one or two hydroxyl groups, amino groups, C 1-6 alkoxycarbonyl groups and/or carboxyl groups; a C 2-6 alkenyl group optionally substituted with one or two halogen atoms, amino groups, C 1-6 alkoxycarbonyl groups and/or carboxyl groups; a C 2-6 alkynyl group optionally substituted with one or two halogen atoms, amino groups, C 1-6 alkoxycarbonyl groups and/or carboxyl groups; a C 1-6 alkoxycarbonyl group; a carboxyl group; a C 1-6 alkoxy group; a cyano group; a halogen atom; a hydroxyl group; and/or a hydroxamic acid group, at least one of the substituents of Y is a C 1-6 alkyl group substituted with a carboxyl group; and a represents an integer of 0 to 3, or a pharmaceutically acceptable salt thereof.