PROCEDIMIENTO DE PREPARACION DE DERIVADOS DE ACIDO 2,3-DIOXO-1-PIPERAZINOCARBOINIL-AMION -CECEFEM-4-CARBOXILICO

摘要

PURPOSE:Cephalosporins of formula I are new: [where R is amino acid residue; R<1> is H, carboxy-protecting group of salt-forming cation; n is 1-3; X is O or S; m is equal to 4-n; R<2> and R<3> are a pair of substituents such as H, halogen carboxyl and alkyl, etc. at the same carbon respectively; A is H or hydroxy; B is R<5> (R<5> is cyano, azide or an organic residue which is bonded to CH2 via O, N or S) or quat-ammonium].