Patent ID: 8846943

Claim:
A compound of formula (I): wherein R 1 represents a C 1 -C 6 alkyl group or a C 7 -C 12 aralkyl group, R 2 represents a group selected from the group consisting of a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group and a C 7 -C 12 aralkyl group, R 3 represents a C 1 -C 6 alkyl group, R 4 and R 5 which are the same or different represent a group selected from the group consisting of a hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, C 1 -C 6 alkoxy group and a cyano group, and n represents an integer of 1 to 6.