CEPHALOSPORINE DERIVATIVE, ITS PRODUCTION AND ANTIBACTERIAL PHARMACEUTICAL COMPOSITION CONTAINING SAID DERIVATIVE

摘要

An antibacterial cephalosporin derivative of the formula I:- …… in which X is S, O, CH2 or SO; R2 is hydrogen, methoxy or formylamino; R3 is carboxy or a biodegradable ester thereof; R1 represents a variety of groups known in the cephalosporin art and R4 represents a group NR42R43 wherein R42 is hydrogen, lower alkyl or benzyl and R43 is one of a group of neutral heterocyclic species defined in the specification. Pharmaceutical compositions, manufacturing processes and intermediates are also described.