7-(1,3-Dithiolan-2-imino)-.DELTA..sup.2 -cephalosporanic acid derivatives

A 7-(1,3-dithiolan-2-imino)-.DELTA..sup.2 -cephalosporanic acid derivative having the formula ##STR9## wherein R.sub.1 is selected from the group consisting of 5-methyl-1,3,4-thiadiazol-2-ylthio, 1-methyl-1,2,3,4-tetrazol-5-ylthio and 1,2,3-triazol-4-ylthio;

• R.sub.2 is selected from the group consisting of hydrogen, t-butyl, 2,2,2-trichloroethyl, benzhydryl, formyloxymethyl and alkanoyloxymethyl in which the alkanoyl group contains from 2 to 5 carbon atoms;
• R.sub.3 is selected from the group consisting of alkyl having from 1 to 4 carbon atoms, carboxymethyl, alkoxycarbonyl and (alkoxycarbonyl)methyl wherein the alkoxy group has from 1 to 4 carbon atoms, halomethyl, benzyl and substituted benzyl wherein the benzyl substituent is methoxy or halo;
• and the pharmaceutically acceptable salts thereof.