CEPHALOSPORIN DERIVATIVES

摘要

7-(2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(substituted)-iminoacetamido!-3-¢3-(quaternaryammonio)-1-propen-1-yl!-3-cephem-4-carboxylates of the formula (see formula I) in which R1 and R2 are as defined herein and (see formula II) is a quaternary ammonio group as defined herein, and salts, solvates, hydrates and esters thereof, are potent antibacterial agents. Processes for their preparation and intermediates in such processes are described.