Cephalosporin antibiotics. Synthesis and antimicrobial activity of 7.BETA.-(2-(5-amino-1,2,4-thiadiazol-3-yl)-2-oxyiminoacetamido)cephalosporin derivatives.

Cephalosporins with a 7 beta-[2-(5-amino-1,2,4-thiadiazol-3-yl) -2-oxyiminoacetamido] side chain were synthesized and their in vitro inhibitory potency was established. The compounds exhibit a strong antibacterial activity against various Gram-positive and Gram-negative bacteria. The antimicrobial activity is related to the oxime-substituent R1 and the C-3 substituent R2. Selected amino-1,2,4-thiadiazolyl-cephems 1 show a prolonged half-life in mice.