A NEW CEPHALOSPORIN. SCE-963: 7-[2-(2-AMINOTHIAZOL-4-YL)- ACETAMIDO]-3-[[[1-(2-DIMETHYLAMINOETHYL)-1H-TETRAZOL-5-YL]- THIO]METHYL]CEPH-3-EM-4-CARBOXYLIC ACID: CHEMISTRY AND STRUCTURE-ACTIVITY RELATIONSHIPS

The synthesis and the in vitro and in vivo antimicrobial activities of a series of 7-[2-(2-aminothiazol-4-yl)acetamido]cephalosporins (1) having varied 3-substituents, such as methyl, hydroxymethyl, acetoxymethyl, pyridiniomethyl and heterocyclicthiomethyls, are described. The derivatives having five membered heterocyclicthiomethyls exhibited strong inhibitory activities against Gram-negative organisms including some strains of Escherichia coli and Proteus morganii which are insensitive to cefazolin and cephaloridine. Pronounced activities were noted with 7-[2-(2-aminothiazol-4-yl)-acetamido]-3-[[[1-(2-dimethylaminoethyl)-1H-tetrazol-5-yl]thio]methyl]ceph-3-em-4-carboxylic acid (1y; SCE-963).