Introduction of a pyrrole cycle in cephalosporine structures as approach in the search for new beta-lactame antibiotics

12 New cephalosporines containing a pyrrole cycle in the N-acyl chain have been synthesized based on N-acylation of 7-ACA or of its 3'-analogues via t he mixed anhydrides of substituted pyrrole carboxylic acids, and following two types of procedure. Confirming H-1 NMR and IR data are represented. The preliminary microbiological tests in vitro show significant antibacterial activity in some cases compared with that of cefalexin. Some common structu re-activity relationships have been observed.