Patent ID: 7517898

Claim:
A compound of formula I or a pharmaceutically acceptable salt thereof: wherein Z is selected from O═ and S═; R 1 is selected from R 5 R 6 N—C 1-6 alkyl, R 5 O—C 1-6 alkyl, R 5 C(═O)N(—R 6 )—C 1-6 alkyl, R 5 R 6 NS(═O) 2 —C 1-6 alkyl, R 5 CS(═O) 2 N(—R 6 )—C 1-6 alkyl, R 5 R 6 NC(═O)N(—R 7 )—C 1-6 alkyl, R 5 R 6 NS(═O) 2 N(R 7 )—C 1-6 alkyl, C 6-10 aryl-C 1-6 alkyl, C 6-10 aryl-C(═O)—C 1-6 alkyl, C 3-10 cycloalkyl-C 1-6 alkyl, C 4-8 cycloalkenyl-C 1-6 alkyl, C 3-6 heterocyclyl-C 1-6 alkyl, C 3-6 heterocyclyl-C(═O)—C 1-6 alkyl, C 1-10 hydrocarbylamino, R 5 R 6 N—, R 5 O—, R 5 C(═O)N(—R 6 )—, R 5 R 6 NS(═O) 2 —, R 5 CS(═O) 2 N(—R 6 )—, R 5 R 6 NC(═O)N(—R 7 )—, R 5 R 6 NS(═O) 2 N(R 7 )—, C 6-10 aryl-C 6-10 aryl-C(═O)—, C 3-10 cycloalkyl, C 4-8 cycloalkenyl, C 3-6 heterocyclyl and C 3-6 heterocyclyl-C(═O)—; wherein said C 6-10 aryl-C 1-6 alkyl, C 6-10 aryl-C(═O)—C 1-6 alkyl, C 3-10 cycloalkyl-C 1-6 alkyl, C 4-8 cycloalkenyl-C 1-6 alkyl, C 3-6 heterocyclyl-C 1-6 alkyl, C 3-6 heterocyclyl-C(═O)—C 1-6 alkyl, C 1-10 hydrocarbylamino, C 6-10 aryl, C 6-10 aryl-C(═O)—, C 3-10 cycloalkyl, C 4-8 cycloalkenyl, C 3-6 heterocyclyl or C 3-6 heterocyclyl-C(═O)— used in defining R 1 is optionally substituted by one or more groups selected from carboxy, halogen, cyano, nitro, methoxy, ethoxy, methyl, ethyl, hydroxy and —NR 5 R 6 ; R 2 is selected from the group consisting of C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 3-8 cycloalkyl, C 3-8 cycloalkyl-C 1-6 alkyl, C 4-8 cycloalkenyl-C 1-6 alkyl, C 3-6 heterocycloalkyl-C 1-6 alkyl, C 4-8 cycloalkenyl, R 5 R 6 N—, C 3-5 heteroaryl, C 6-10 aryl and C 3-6 heterocycloalkyl, wherein said C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 3-8 cycloalkyl, C 3-8 cycloalkyl-C 1-6 alkyl, C 4-8 cycloalkenyl-C 1-6 alkyl, C 3-6 heterocycloalkyl-C 1-6 alkyl, C 4-8 cycloalkenyl, C 3-5 heteroaryl, C 6-10 aryl or C 3-6 heterocycloalkyl used in defining R 2 is optionally substituted by one or more groups selected from halogen, cyano, nitro, methoxy, ethoxy, methyl, ethyl, hydroxy, and —NR 5 R 6 ; wherein R 5, R 6 and R 7 are independently selected from —H, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, and a divalent C 1-6 group that together with another divalent R 5 , R 6 or R 7 forms a portion of a ring; and R 3 and R 4 are independently selected from —OH, R 8 and —O—R 8 , wherein R 8 is independently selected from C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, and a divalent C 1-6 group that together with another divalent R 8 forms a portion of a ring, wherein R 3 and R 4 are not —H at the same time, and wherein said C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, or divalent C 1-6 group in defining R 8 is optionally substituted by one or more groups selected from carboxy, halogen, cyano, nitro, methoxy, ethoxy, hydroxy, carboxy and —NR 5 R 6 ; or R 3 and R 4 together with the nitrogen connected thereto form a portion of a 5- or 6-membered ring, wherein said ring is optionally substituted by one or more groups selected from carboxy, halogen, cyano, nitro, methoxy, ethoxy, hydroxy, carboxy and —NR 5 R 6 .