Patent ID: 7576091

Claim:
A compound of formula 1, or a pharmaceutically acceptable salt thereof, wherein: X is S; “a” is a single bond; or “a” is a double bond and one of R 3 and R 4 , and one of R 5 and R 6 are absent; R 1 is H; or is selected from an alkyl group, a cycloalkyl group, a heteroaryl group, an aralkyl group, CO-alkyl, SO 2 -alkyl, CO 2 R 13 and an aryl group, each of which optionally contains one or more heteroatoms, and is optionally substituted with one or more groups selected from R 8 and R 9 ; R 2 is H, R 8 , or an alkyl group optionally substituted with one or more R 8 groups; R 3 , R 4 , R 5 , and R 6 are each independently selected from H, R 8 , an alkyl group and an alkenyl group, wherein said alkyl and alkenyl groups are optionally substituted with one or more R 8 groups; or R 3 and R 4 , and/or R 5 and R 6 together represent ═O; R 7 is H, R 8 , NH(CH 2 ) n R 9 , CO(CH 2 ) n R 9 , NHCO(CH 2 ) n R 9 , O(CH 2 ) n R 9 , or an alkyl or phenyl group, each of which is optionally substituted with one or more groups selected from R 8 and R 9 ; R 8 is OR 10 , NR 10 R 11 , halogen, CF 3 , NO 2 , COR 10 , CN, COOR 10 , CONR 10 R 11 , SO 2 R 10 or SO 2 NR 10 R 11 ; R 9 is a saturated or unsaturated 5- or 6-membered cyclic group optionally containing one or more heteroatoms selected from N, O and S, and optionally substituted with one or more R 8 groups; R 10 , R 11 , R 12 and R 13 are each independently H or a hydrocarbyl group; and n is 0, 1, 2 or 3.