Patent ID: 8163767

Claim:
A compound represented by formula (Ia): wherein R 1 is hydrogen, or lower alkyl or aryl, each of which may be substituted with one or more substituent(s); X is a bond, NH or O; R 4 is cycloalkyl, heterocycloalkyl, lower alkyl, aryl, or heteroaryl, each of which may be substituted with one or more substituent(s); M is —(CH 2 ) n —, wherein n is an integer of 0 to 4; R 5 is hydrogen or lower alkyl; R 6 is hydrogen or lower alkyl which may be substituted with one or more substituent(s); Y is N or CR 7 , wherein —R 7 is hydrogen, nitro, cyano, amino, acyl or lower alkyl optionally substituted with one substituent selected from the group consisting of heterocycloalkyl and heteroaryl, each of which may be substituted, or a pharmaceutically acceptable salt thereof.