title: Cephalosporins. VI. Synthesis and structure-activity relationships of new 7 beta-[(Z)-2-alkoxyimino-2-(2-aminothiazol-4-yl)acetamido]cephalosporins with a tetraxolopyridazine at the 3-position.
abstract: The synthesis and in vitro activity of 7 beta-[(Z)-2-alkoxyimino- 2-(2-aminothiazol-4-yl) acetamido]cephalosporins with a tetrazolo[1,5-b]pyridazine at the 3-position are described. These cephalosporins showed excellent activity against Gram-negative bacteria, including beta-lactamase producing strains. The most interesting compound of the series was 7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyimino acetamido] -3-(8-carboxytetrazolo[1,5-b]pyridazin-6-yl)- thiomethyl-3-cephem-4-carboxylic acid (9, FCE 20485) because of its extraordinarily long half-life and marked in vivo activity.
mesh_terms: D002511:Cephalosporins / Q000138:chemical synthesis* / Q000633:toxicity; D006090:Gram-Negative Bacteria / Q000187:drug effects; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D011724:Pyridazines / Q000138:chemical synthesis; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship; D013777:Tetrazoles / Q000138:chemical synthesis
chemical_list: D002511:Cephalosporins; D007202:Indicators and Reagents; D011724:Pyridazines; D013777:Tetrazoles