Patent ID: 8252929

Claim:
A compound of formula: wherein A is Y is chosen from O and S; R 1 is —NHR 8 ; R 2 and R 2a are both hydrogen or taken together R 2 and R 2a are ═O; R 3 is chosen from hydrogen, lower alkyl, alkenyl, aryl, heterocyclyl, benzyl and hydroxyalkyl; R 4 is chosen from hydrogen, hydroxy, amino, lower alkoxy, C 1 -C 20 alkyl and C 1 -C 20 alkyl substituted with hydroxy or carbonyl; R 5 is lower alkyl; R 6 is lower alkyl; R 7 is chosen from hydrogen and hydroxy; or together R 4 , R 5 , R 6 and R 7 may form from one to three rings, said rings having optional additional substitution; and R 8 is hydrogen.