Cephalosporins, process for their preparation and pharmaceutical compositions containing them.

摘要

A compound of the general formula: wherein R<0> is hydrogen, a nitrogen-containing heterocyclic group, an acyl group or an amino-protective group; Z is S S->O, O or CH2; R<4> is hydrogen, a methoxy or formamido; R<1><3> is hydrogen, methyl, hydroxyl or halogen; and A is an option. ally substituted condensed cyclic cationic group consisting of the same or different two 5- or 6-membered nitrogen containing heterocyclic rings sharing a C-N bond with each other,, or a salt or ester thereof. @, and a process for preparing the same and a pharmaceutical composition thereof are disclosed.