Patent ID: 7368444

Claim:
A compound represented by formula (I-a): wherein R 2 represents (1) C1-8 alkyl or (2) a halogen atom; R 3 represents (1) ring B or (2) a C1-8 alkyl which is substituted by 1-5 group(s) selected from ring B or CONR 6 R 7 ; R 4 represents (1) a hydrogen atom or (2) C1-8 alkyl group; n=0 or 1; ring B represents C5-8 monocyclic carbocyclic ring which may be substituted by 1-2 group(s) selected from (1) C1-8 alkyl, (2) OR 5 , or (3) a halogen atom; R 5 represents (1) a hydrogen atom or (2) C1-8 alkyl; R 6 and R 7 each independently represents (1) a hydrogen atom or (2) -D 1 -D 2 , wherein D 1 represents a single bond and D 2 represents (a) C1-8 alkyl which may be substituted by ring C or (b) ring C; ring C represents benzene or cyclopropane which may be substituted by 1-2 group(s) selected from C1-8 alkyl or a halogen atom, or a pharmaceutically acceptable salt thereof.