Patent ID: 7351702

Claim:
A compound of formula Ia: or a pharmaceutically-acceptable salt thereof, wherein: next to R 3 represents a single or double bond; Z is oxygen or sulfur; R 1 is CH 2 Y; Y is an electronegative leaving group; R 2 is CO 2 H, CH 2 CO 2 H, or esters, amides or isosteres thereof; R 3 is hydrogen, a side chain of a natural α-amino acid, or a substituted or unsubstituted group having a molecular weight up to about 140 Daltons selected from C 1-12 aliphatic, 5-14 membered aryl, (5-14 membered aryl)-(C 1-12 -alkyl)-, 3-9 membered heterocyclyl, or (3-9 membered heterocyclyl)-(C 1-12 alkyl)-; wherein said R 3 is optionally substituted with halogen, —R, —OR, —OH, —SH, —SR, acyloxy, phenyl (Ph), —OPh, —NO 2 , —CN, —NH 2 , —NHR, —N(R) 2 , —NHCOR, —NHCONHR, —NHCON(R) 2 , —NRCOR, —NHCO 2 R, —CO 2 R, —CO 2 H, —COR, —CONHR, —CON(R) 2 , —S(O) 2 R, —SONH 2 , —S(O)R, —SO 2 NHR, —NHS(O) 2 R, ═O, ═S, ═NNHR, ═NNR 2 , ═N—OR, ═NNHCOR, ═NNHCO 2 R, ═NNHSO 2 R, or ═NR; R is C 1-6 aliphatic; R 4 is hydrogen or a C 1-6 aliphatic group that is optionally interrupted by —O—, —S—, —SO 2 —, —CO—, —NH—, or —N(C 1-4 alkyl)-, or R 3 and R 4 taken together with their intervening atoms optionally form a 3-7 membered ring having 0-2 heteroatoms selected from nitrogen, oxygen or sulfur; Ring A is carbazole.