7α-methoxycephalosporins and pharmaceutical composition comprising the same

Claim 1

A 7α-methoxycephalosporin or salt thereof, said 7α-methoxycephalosporin being represented by the formula: ##STR41## wherein R' represents a hydrogen atom or a carboxyl-protecting group; R 2 represents a substituted or unsubstituted lower alkoxy, lower alkylthio, C 1-10 acyloxy, carbamoyloxy or heterocyclic thio group in which the thio linkage is attached to a carbon atom of a 5 or 6 membered aromatic heterocyclic ring composed of carbon and at least one hetero atom selected from oxygen, sulfur and nitrogen, the heterocyclic moiety of said heterocyclic thio group being composed of said aromatic heterocyclic ring or of said aromatic heterocyclic ring fused to a benzene ring or being triazolopyridyl, purinyl, or pyridine-1-oxide-2-yl, the substituent of the substituted group being selected from a halogen, lower alkyl, phenyl, C 2-5 alkenyl, hydroxyl, lower alkoxy, lower alkylthio, nitro, cyano, lower alkylamino, di-lower alkylamino, C 1-10 acylamino, C 1-10 acyl, C 1-10 acyloxy, C 1-10 acyl-lower alkyl, carboxyl, carbamoyl, amino-lower alkyl, N-lower alkylamino-lower alkyl, N,N-di-lower alkyl-amino-lower alkyl, hydroxy-lower alkyl, hydroxyimino-lower alkyl, lower alkoxy-lower alkyl, carboxy-lower alkyl, sulfo-lower alkyl, sulfo, sulfamoyl-lower alkyl, sulfamoyl, carbamoyl-lower alkyl, carbamoyl-C 2-5 alkenyl, and N-hydroxycarbamoyl-lower alkyl; R 3 represents a lower alkyl group; n is 0, 1 or 2; A represents a hydrogen atom or a straight- or branched-chain C 1-14 alkyl group which is unsubstituted or substituted with a halogen, lower alkoxy, cyano, nitro, carboxyl, lower alkoxycarbonyl, hydroxyl, lower alkylthio or C 1-10 acyl group; and B represents a straight- or branched-chain C 1-14 alkyl group which is unsubstituted or substituted with a halogen, hydroxyl, protected hydroxyl, C 1-10 acyl, mercapto, lower alkylthio, nitro, amino, protected amino, imino, protected imino or carboxyl group.