Studies on orally active cephalosporins. II. Synthesis and structure-activity relations of new [(E) or (Z) 3-substituted carbamoyloxy]-1-propenyl cephalosporins.

In an effort to find a new oral cephalosporin with well-balanced antibacterial spectrum, good oral absorbability and long plasma half-life, a series of oxyimino aminothiazolyl 3-[(E)- or (Z)-N-substituted carbamoyloxy]propenyl cephems was synthesized and evaluated for antibacterial activity and oral absorbability. The substituents of the carbamoyloxy group affected their in vitro activity and bioavailability after oral administration of their pivaloyloxymethyl esters at the C-4 position. The compound possessing an N,N-dimethylcarbamoyloxy moiety at the C-3 position showed good oral absorption and well-balanced antibacterial activity. In this report, the structure-activity relationships and the structure-oral absorbability relationships of 3-(N-substituted carbamoyloxy)-propenyl cephems are described.