PROCESS FOR PREPARING CEPHEM DERIVATIVES

摘要

Cephem intermediates (I; A,B, = H, amino substitution product; R = H, thiol substitution product; Hal = halogen ; X = hydroxy, carboxy protecting group; dotted line between A and R mean that the substitution product can be bonded to form the 2 rings of azetidinothiazolin when R and B are H and A is carboxylacyl; Y = hydroxy, piperidino, morpholino, C2-20 disubstituted amino group) were prepd. by treating compd. II with halogenation agents such as halogen molecular and N-haloamide.