Patent ID: 7199239

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt or hydrolysable ester thereof, Wherein: R 1 and R 2 are independently hydrogen or C 1-3 alkyl; X represents a bond, CH 2 or O; one of R 3 and R 4 is H and the other is C 1-3 alkyl; X 1 is CH 2 , SO 2 , or CO; R 5 is —C 1-6 alkyl wherein said —C 1-6 alkyl is optionally substituted by C 1-6 alkoxy or C 1-6 alkylthio, —C 2-6 alkenyl, —C 0-6 alkyl phenyl wherein said phenyl is optionally substituted by one or more CF 3 , halogen, C 1-3 alkyl, or C 1-3 alkoxy, —COC 1-6 alkyl, or SO 2 C 1-6 alkyl; R 6 is phenyl or a 6 membered heteroaryl group containing 1, 2 or 3 N atoms wherein the phenyl or heteroaryl group is optionally substituted with 1, 2 or 3 moieties selected from the group consisting of C 1-6 alkyl, halogen, —OC 1-6 alkyl, —SO 2 C 1-3 alkyl, and phenyl optionally substituted by one or more groups selected from halogen, CF 3 , C 1-3 alkyl, OC 1-3 alkyl, acetyl, CN.