STUDIES ON SEMI-SYNTHETIC 7α-FORMAMIDOGEPHALOSPORINS

III. SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF SOME 7β-[D-2-(ARYL)-2-[(4-ETHYL-2, 3-DIOXOPIPERAZIN-1-YL)-CARBONYLAMINO]ACETAMIDO]-7α-FORMAMIDO-CEPH-3-EM-4-CARBOXYLATE DERIVATIVES

Abstract

The synthesis and antibacterial activity of 7β-2-(aryl)-2-[(4-ethyl-2, 3-dioxopiperazinl-yl)carbonylamino]acetamido]-7α-formamidocephalosporins with various substituents at the C-3 position of the cephalosporin nucleus is described. Inhibition of Gram-positive and Gram-negative bacteria including β-lactamase producing strains was observed with phenyl as the aryl residue. The 3, 4-dihydroxyphenyl group further enhanced the activity against Gram-negative organisms; in this series, the 3-[(l-methyl-1H-tetrazol-5-yl)thiomethyl] and 3-[(1-carboxymethyl-1H-tetrazol-5-yl)thiomethyl] analogues (2 and 12b) exhibited exceptional activity against Gram-negative bacteria, including Pseudomonas aemginosa.