New cephalosporins with 7-acyl groups derived from .BETA.-ketoacids. I. 7-(.BETA.-Ketoacylamino)cephalosporins.

Abstract
The synthesis and antimicrobial profile of a series of 7-(.beta.-ketoacylamino)cephalosporins bearing an acetoxymethyl or a heterocyclicthiomethyl group at the 3-position are described. Of this series, 3-[[(1-methyl-1H-tetrazol-5-yl)thio]methyl]-7-(3-oxobutyrylamino)ceph-3-em-4-carboxylic acid showed moderate antibacterial activities in in vitro and in vivo tests.