Patent ID: 8796272

Claim:
A compound of formula [I] or a pharmaceutically acceptable salt thereof: wherein R 1 and R 1′ are the same or different, and each represent a hydrogen atom, a halogen atom, a C 1-6 alkoxy group, a haloC 1-6 alkyl group, a cyano group, a heteroaryl group (which may be substituted by a C 1-6 alkyl group), a C 1-6 alkyl group, a C 3-6 cycloalkyl group, a C 1-6 alkylamino group, or the formula CONR 7 R 8 (R 7 and R 8 are the same or different, and each represent a hydrogen atom or a C 1-6 alkyl group), R 2 represents a hydrogen atom or a C 1-6 alkyl group, R 3 represents a phenyl group (which may be substituted by 1 to 3 substituents selected from halogen atoms, cyano groups, C 1-6 alkyl groups, C 1-6 alkoxy groups, C 1-6 alkylamino groups, C 1-6 alkylsulfonyl groups, haloC 1-6 alkyl groups, haloC 1-6 alkoxy groups, haloC 1-6 alkylsulfanyl groups, phenyl groups, phenoxy groups, heteroaryl groups (which may be substituted by a C 1-6 alkyl group), and the formula —SO 2 NR 9 R 10 (R 9 and R 10 are the same or different, and each represent a hydrogen atom or a C 1-6 alkyl group)) or a heteroaryl group or a bicyclic heteroaryl group (the each heteroaryl group may be substituted by 1 to 3 substituents selected from halogen atoms, C 1-6 alkyl groups, C 3-6 cycloalkyl groups, C 1-6 alkoxy groups, cyano groups, C 1-6 alkanoyl groups, and haloC 1-6 alkyl groups), R 4 represents a C 1-6 alkyl group (which may be substituted by 1 to 3 halogen atoms, a C 1-6 alkoxy group, a C 3-6 cycloalkyl group, or a phenyl group), a C 3-6 cycloalkyl group, or a phenyl group, R 5 and R 6 are the same or different, and each represent a hydrogen atom or a C 1-6 alkyl group, and A 1 , A 2 , A 3 , and A 4 are the same or different, and each represent the formula CH or a nitrogen atom, provided that one or two of A 1 , A 2 , A 3 , and A 4 represent a nitrogen atom.