| abstract |
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 <IMAGE> in which R<1> and R<2> are as defined herein and <IMAGE> 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. |