Patent ID: 7825124

Claim:
A compound of formula I wherein R a is H; C 1-4 alkyl; or C 1-4 alkyl substituted by OH, NH 2 , NHC 1-4 alkyl or N(C 1-4 alkyl) 2 ; R b is H or C 1-4 alkyl; R is a radical of formula (e) or (f) wherein each of R 11 and R 14 is OH; SH; a heterocyclic residue; NR 16 R 17 wherein each of R 16 and R 17 , independently, is H or C 1-4 alkyl; or R 16 and R 17 form together with the nitrogen atom to which they are bound a heterocyclic residue; or a radical of formula α —X—R c —Y (α) wherein X is a direct bond, O, S or NR 18 wherein R 18 is H or C 1-4 alkyl, R c is C 1-4 alkylene or C 1-4 alkylene wherein one CH 2 is replaced by CR x R y wherein one of R x and R y is H and the other is CH 3 , each of R x and R y is CH 3 or R x and R y form together —CH 2 —CH 2 —, and Y is bound to the terminal carbon atom and is selected from OH, a heterocyclic residue and —NR 19 R 20 wherein each of R 19 and R 20 independently is H, C 3-6 cycloalkyl, C 3-6 cycloalkyl-C 1-4 alkyl, aryl-C 1-4 alkyl or C 1-4 alkyl optionally substituted on the terminal carbon atom by OH, or R 19 and R 20 form together with the nitrogen atom to which they are bound a heterocyclic residue; each of R 12 , R 13 , R 15 and R′ 15 , independently, is H, halogen, C 1-4 alkyl, CF 3 , OH, SH, NH 2 , C 1-4 alkoxy, C 1-4 alkylthio, NHC 1-4 alkyl, N(C 1-4 alkyl) 2 or CN; either E is —N═ and G is —CH═ or E is —CH═ and G is —N═; and ring A is optionally substituted, or a salt thereof.