Semisynthetic .BETA.-lactam antibiotics. IX. Synthesis and antibacterial activity of 7-(2-(2-aminothiazol-4-yl)-2-sulfoacetamido)cephalosporanic acid and its derivatives.

Novel 2-(2-aminothiazol-4-yl)-2-sulfoacetyl cephalosporins (10a-c) were synthesized by two routes : A, acylation of 7-aminocephalosporanic acid (8a) or its analogs (8b, c) with an active derivative of 2-(2-aminothiazol-4-yl)-2-sulfoacetic acid, and B, side chain sulfonation of γ-chloroacetoacetyl cephalosporins (13a, b) with SO3-dioxane and subsequent thiazole ring formation by treatment with thiourea. The cephalosporin with 4-carbamoylpyridiniomethyl at the 3-position (10c) showed a potent antipseudomonal activity but had poor activity against other gram-negative bacteria, while the cephalosporin with 1-methyltetrazol-5-ylthiomethyl at the 3-position (10b) showed a broad spectrum but caused no inhibition of Pseudomonas aeruginosa.