Synthesis and structure-activity relationships of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]cephalosporin derivatives. IV. Synthesis of 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetic acid derivatives and related compounds.

In an effort to improve the antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-cephalosporins by introducing a methoxyimino group into the 7-acyl side chain, geometrically isomeric 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetic acids and their derivatives were selectively synthesized. Structurally related acid derivatives were also synthesized. A facile and practical synthesis of an important starting material, 2-(2-chloroacetamidothiazol-4-yl)-(Z)-2-methoxyiminoacetic acid, for the preparation of SCE-1365 which is now under extensive clinical trial was achieved.