Cephalosporins IV. Synthesis and structure-activity relationships of new 7 alpha-methoxy-7 beta-vinylenethioacetamido cephalosporins.

The synthesis and in vitro activity of 7 alpha-methoxy-7 beta-vinylenethioacetamido cephalosporins with various substituents at the 3-position are described. These cephalosporins showed good activity against beta-lactamase producing Gram-negative bacteria. 7 alpha-Methoxy-7-[(Z)-beta-cyano-vinylenethioacetamido]-3-[(1-methyl-1H-tetrazol -5-yl)thiomethyl]-3-cephem-4-carboxylic acid (3) was several times more active in vitro than cefoxitin and comparable to cefmetazole.