摘要 |
A cephalosporin of the formula (I): <IMAGE> (I) wherein A is a mono- or polycyclic heteroaromatic ring containing at least one nitrogen atom as a hetero atom, which may be unsubstituted or substituted; R is a phenyl group which may be unsubstituted or substituted, a thienyl group, a furyl group, a cyclohexadienyl group or a cyclohexenyl group; X is an acetoxy group, a pyridinium group which may be unsubstituted or substituted with a methyl or carbamoyl group, a group of the formula: <IMAGE> in which R1 and R2, which may be the same or different, each is a hydrogen atom or a (C1-C4)alkyl group, or a group of the formula: -S-Het in which Het is a heterocyclic ring containing 1 to 5 oxygen, nitrogen and sulfur atoms as a hetero atom, in which the heterocyclic ring system may be either polycyclic or 5- or 6-membered monocyclic and may be unsubstituted or substituted; and M is a hydrogen atom or a biologically active carboxyl-protecting group, or is an anionic charge only when X is a pyridinium group; and the pharamaceutically acceptable salts thereof, which are useful as antimicrobial agents and prepared by the reaction of a compound of the formula (II): HO-A-COOH (II) wherein A is as defined above, or a reactive derivative thereof, with a compound of the formula (III): <IMAGE> (III) wherein R, M and X are as defined above, or a derivative thereof.
|