Patent ID: 7977327

Claim:
A compound of formula (I): wherein R 1 represents a hydrogen atom, a C 1 -C 6 alkyl group, or a substituted carbonyl group derived from an amino acid, a dipeptide, or a tripeptide; R 2 represents a hydrogen atom or a C 1 -C 6 alkyl group, and, when either one or each of R 1 and R 2 is an alkyl group, the alkyl group may be substituted with a group selected from the group consisting of a hydroxyl group, an amino group, a halogen atom, a C 1 -C 6 alkylthio group, and a C 1 -C 6 alkoxy group; R 3 represents a C 2 -C 6 alkyl group, a C 2 -C 6 alkenyl group, or a C 3 -C 6 cycloalkyl group; R 4 and R 5 each independently represents a hydrogen atom or a C 1 -C 6 alkyl group; R 6 represents a C 3 -C 6 halogenocycloalkyl group; R 7 represents a hydrogen atom, a phenyl group, an acetoxymethyl group, a pivaloyloxymethyl group, an ethoxycarbonyl group, a choline group, a dimethylaminoethyl group, a 5-indanyl group, a phthalidyl group, a 5-alkyl-2-oxo-1,3-dioxol-4-ylmethyl group, a 3-acetoxy-2-oxobutyl group, a C 1 -C 6 alkyl group, a C 2 -C 7 alkoxymethyl group, or a phenylalkyl group formed of a C 1 -C 6 alkylene group and a phenyl group; X 1 represents a hydrogen atom or a halogen atom; and A represents a nitrogen atom or a partial structure represented by the following formula (II): wherein X 2 represents a C 1 -C 6 alkyl group or a C 1 -C 6 alkoxy group; a salt, or a hydrate thereof.