Patent ID: 7888380

Claim:
A compound of formula I: wherein: X 1 and X 2 are independently selected from CH and N; R 1 is selected from the group consisting of a carbocyclic, a heteroaryl, and a heterocyclic, and wherein R 1 is optionally substituted with one or more substitutents independently selected from the group consisting of amido, phosphonato, phosphine, carboxyl, thiocarbonyl, sulfonyl, nitro, thiol, thioether, amine, cyano, N—(C 1-6 -alkyl)amino, N,N—(C 1-6 -alkyl) 2 amino, sulfonamide, ketone, aldehyde, ester, halogen, oxygen, haloalkyl, C 1-6 -alkyl, C 2-6 -alkenyl, C 2-6 -alkynyl, hydroxyl and C 1-6 -alkoxyl; R 2 is selected from the group consisting of hydrogen, hydroxy, nitro, amino, carboxy, carbamoyl, halo, cyano, trifluoromethyl, trifluoromethoxy, sulphamoyl, mercapto, C 1-6 -alkyl, C 2-6 -alkenyl, C 2-6 -alkynyl, C 1-6 -alkoxyl, N—(C 1-6 -alkyl)amino, N,N—(C 1-6 -alkyl) 2 amino, and sulfonyl; R 3 and R 4 are independently selected from the group consisting of hydrogen, —CH 2 OPO 3 R 5 R 6 , —CH 2 OCOR 7 , —CH 2 OCO 2 R 7 , —CH 2 OCONHR 7 , —COR 7 , wherein R 3 and R 4 are not simultaneously hydrogen; R 3 ′ is selected from the group consisting of hydrogen, heterocyclic and C 1-8 alkyl, wherein C 1-8 alkyl is optionally substituted with one or more of —CO 2 H, —CO 2 (C 1-6 )alkyl, hydroxy, C 1-6 alkoxy, amino, aminoacylamino, N—(C 1-6 -alkyl)amino, N,N—(C 1-6 alkyl) 2 amino, heterocyclic or heteroaryl; R 5 and R 6 are each selected from the group consisting of hydrogen, C 1-6 alkyl, Na, K and NH 4 and are the same unless either R 5 or R 6 is absent, hydrogen or C 1-6 alkyl, in which case the other is different, or alternatively, R 5 and R 6 together represent calcium or magnesium; R 7 is heterocyclic or C 1-6 alkyl, wherein C 1-6 alkyl is optionally substituted with one or, more of —CO 2 H, —CO 2 (C 1-6 )alkyl, amino, amino-COR 8 , carbamoyl, carbamoyl(C 1-6 )alkyl, guanidino, mercapto, thio(C 1-6 )alkyl, hydroxy, N—(C 1-6 -alkyl)amino, N,N—(C 1-6 -alkyl) 2 amino, aryl optionally substituted on aryl with one or more of C 1-4 alkyl, C 1-4 alkoxy, hydroxy, halogen, amino, aminoalkyl, nitro or cyano, heterocyclic, —(OCH 2 CH 2 ) n OCH 3 where n is 0-400, —(OCH 2 CH 2 ) n OH where n is 0-400, or —(OCH 2 CH 2 ) n OCH 2 CO 2 H where n is 0-400; and R8 is C 1-6 alkyl optionally substituted with one or more of —CO 2 H, —CO 2 (C 1-6 )alkyl, amino, aminoacylamino, carbamoyl, carbamoyl(C 1-6 )alkyl, guanidino, mercapto, thio(C 1-6 )alkyl, hydroxy, N—(C 1-6 -alkyl)amino, N,N—(C 1-6 -alkyl) 2 amino, aryl optionally substituted on aryl with one or more of C 1-4 -alkyl, C 1-4 alkoxy, hydroxy, halogen, amino, aminoalkyl, nitro or cyano, heterocyclic, —(OCH 2 CH 2 ) n OCH 3 where n is 0-400, —(OCH 2 CH 2 ) n OH where n is 0-400, or —(OCH 2 CH 2 ) n OCH 2 CO 2 H where n is 0-400; or a pharmaceutically acceptable salt thereof.