Patent ID: 8420694

Claim:
A compound represented by the formula (I′): wherein R 1 is a hydrogen atom, a halogen atom or a lower alkyl group; R 2 is a halogen atom, a lower alkyl group optionally having halogen atom(s) or a lower alkoxy group optionally having halogen atom(s); R 4 is a hydrogen atom or a halogen atom; R 5 and R 6 are each a hydrogen atom; R 7 is a lower alkyl group optionally having substituent(s) selected from a hydroxy group, a lower alkoxy group and a C 3-6 cycloalkyl group, or an aralkyl group optionally having substituent(s) selected from a halogen atom and a cyano group; R 8 is a hydrogen atom, a lower alkyl group or a C 3-6 cycloalkyl group; and R 10 and R 11 are the same or different and each is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkenyl group, an aralkyl group, or a lower alkyl group substituted by a hydroxyl group (in this case, R 10 and R 11 optionally form cyclopropane together with the adjacent carbon atom).