CEPHALOSPORINS. III

7-(O-AMINOMETHYLPHENYLACETAMIDO)CEPHALOSPORANIC ACIDS WITH BICYCLIC HETEROAROMATICS IN THE C-3 SIDE CHAIN

Abstract

Bicyclic heteroaromatic thiols with a bridge-head nitrogen atom were used for nucleophilic substitution of 7-ACA at the C-3 acetoxy function followed by N-acylation of the 7-amino group with o-aminomethylphenylacetic acid to afford a series of new cephalosporins (24) with potent antibacterial activity against gram-positive and gram-negative organisms. The most active member of this series was 7-(o-aminomethylphenylacetamido)-3-(tetrazolo-[4, 5-b]pyridazin-6-ylthiomethyl)-3-cephem-4-carboxylic acid (BB-S 226) (24e) with antibacterial
activity superior to cephalothin and cefazolin.