Patent ID: 7659304

Claim:
A compound represented by the following formula (I) or a salt thereof: wherein X represents a halogen atom; R 1 represents a hydrogen atom, substituted or unsubstituted C 1-6 alkyl group, substituted or unsubstituted C 2-6 alkenyl group, substituted or unsubstituted C 2-6 alkynyl group, substituted or unsubstituted aromatic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted acyl group, substituted or unsubstituted arylsulfonyl group, substituted or unsubstituted C 1-6 alkylsulfonyl group, substituted or unsubstituted C 2-7 alkoxycarbonyl group, or hydroxyl group; R 2 represents a C 1-21 alkyl group which is optionally substituted by one or more substituents selected from an aromatic group, an acyl group, a hydroxyl group, a carboxy group, and C 1-6 alkoxy group; R 3 , R 5 , and R 6 are the same or different and represent a hydrogen atom or halogen atom; R 4 represents a hydrogen atom or substituted or unsubstituted C 1-6 alkyl group; and R 7 represents a hydrogen atom or substituted or unsubstituted C 1-21 hydrocarbon group.