Cephalosporins

Abstract

A compound of the formula (I): ##STR1## wherein A is a monocyclic or polycyclic heteroaromatic ring containing at least one nitrogen atom as a hetero atom, which may be unsubstituted or substituted with one or more substituents; R is a phenyl group which can be unsubstituted or substituted or a thienyl group; T is (1) a --CH.sub.2 --S--Het group, where Het is a tetrazolopyridazine ring, a triazolopyridazine ring, or a triazolopyridine ring, (2) a ##STR2## group where R.sub.1 and R.sub.2, which may be the same or different, each is a hydrogen atom or a (C.sub.1 -C.sub.4) alkyl group, (3) a --CH.sub.2 N.sub.3 group or (4) a --CH.sub.2 S--D group in which D is a group selected from the group consisting of ##STR3## where m and n each is 0 to 3: with the proviso that (a) when the HO--A-- moiety is a ##STR4## group where B represents the non-metallic atoms necessary to complete a pyridine ring, a pyrimidine ring or a pyrazole ring, each of which may be unsubstituted or substituted, then T is the --CH.sub.2 SD group wherein D is as defined above, and (b) when T is the --CH.sub.2 N.sub.3 group, then R is a substituted phenyl group and the non-toxic, pharmaceutically acceptable salts thereof, processes for preparing the same, and anti-microbial compositions containing the same.

Dependencies are inferred from the claim text.