STUDIES ON CEPHALOSPORIN ANTIBIOTICS: IV. SYNTHESIS, ANTIBACTERIAL ACTIVITY AND ORAL ABSORPTION OF NEW 3-(2-SUBSTITUTED-VINYLTHIO)-7β-[(Z)-2-(2-AMINOTHIAZOL-4-YL)-2-(CARBOXYMETHOXYIMINO)ACETAMIDO]CEPHALOSPORINS

A series of new 7β-[(Z)-2-(2-aminothiazol-4-yl)-2-(carboxymethoxyimino)acetamido]cephalosporins (1) having various substituted-vinylthio groups at the C-3 position of the cephem nucleus was synthesized and evaluated for antibacterial activity and oral absorption in rats in comparison with cefixime. Of these, the cephalosporins (1a and 1c) with a lower alkoxycarbonylvinylthio group (Z-form) at the C-3 position showed a potent antibacterial activity against Gram-negative bacteria, improved activity against Staphylococcus aureus as well as good oral absorption in rats. The structure-activity relationships of 1 are also presented.