Cephalosporins having a ureido acyl side chain are disclosed in U.S. Pat. Nos. 3,673,183; 3,708,479; 3,833,568; and 3,860,591. Cephalosporins substituted in the 3-position with -CH.sub.2 -S-hetero groups and in the 7-position with ##STR3## GROUPS ARE DISCLOSED AS POSSESSING ANTI-BACTERIAL ACTIVITY IN U.S. Pat. Nos. 3,641,021; 3,759,904; 3,813,388; 3,878,204; 3,796,801 (method of treating Enterobacter infections), etc. Also disclosed as useful intermediates are cephalosporins substituted in the 3-position with -CH.sub.2 -S-hetero groups and in the 7-position with a ##STR4## U.S. Pat. No. 3,819,621.
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