Patent ID: 8889727

Claim:
A compound represented by the following formula (I), wherein: R 1 represents a hydrogen atom, a C 1-6 alkyl or a trifluoromethyl group; R 2 represents a hydrogen atom, a C 1-6 alkyl, a halogen, a —COO(C 1-6 alkyl) or a —(CH 2 ) 1-3 COOR group, wherein R represents a hydrogen atom or a C 1-6 alkyl; R 3 represents a hydrogen atom, a C 1-6 alkyl, an amino, a trifluoromethyl group or an —OR group, R represents a hydrogen atom or a C 1-6 alkyl; R 4 represents a hydroxyl group; R 5 represents a hydrogen atom, a C 1-6 alkyl, a hydroxyl group or a halogen; R 6 represents a C 1-6 alkyl, a trifluoromethyl group, a halogen, an amino group, a —NR a R b group, a nitro group, a hydroxy C 1-6 alkyl, a —CONR a R b group, a —COO(C 1-6 alkyl), a —COOH, a —(CH 2 ) 1-3 COOR group, or an —OR a group, wherein R represents a hydrogen atom or a C 1-6 alkyl, and R a and R b are the same or different from each other and represent a hydrogen atom, a C 1-6 alkyl or a C 1-6 acyl; R 7 represents a hydrogen atom, a C 1-6 alkyl, an —OR group, wherein R represents a hydrogen atom or a C 1-6 alkyl; and R 8 represents a hydrogen atom, a C 1-6 alkyl, a hydroxyl group, an amino group or a nitro group, with the proviso that when R 1 is a hydrogen atom, R 3 is not a hydrogen atom, and the compound wherein R 1 is tert-butyl group, R 3 is an amino group, R 4 is a hydroxyl group and R 6 is a methyl group is excluded, or a salt thereof