Patent ID: 8338461

Claim:
A compound represented by the formula (I): wherein R 1 is a monocyclic nitrogen-containing heterocyclic group optionally condensed with a benzene ring or a heterocycle, the monocyclic nitrogen-containing heterocyclic group optionally condensed with a benzene ring or a heterocycle optionally has substituent(s), R 2 is an optionally substituted C 6-14 aryl group, an optionally substituted thienyl group or an optionally substituted pyridyl group, R 3 and R 4 are each a hydrogen atom, or one of R 3 and R 4 is a hydrogen atom and the other is an optionally substituted lower alkyl group, an acyl group, a halogen atom, a cyano group or a nitro group, and R 5 is an alkyl group, or a salt thereof.