Synthesis of 7 beta-(4-oxo-3,4-dihydrothieno[2,3-d] pyrimidyl-2-thioacetamido)cephalosporanic acid derivatives.

Synthesis of new cephalosporins possessing thieno [2,3-d]pyrimidine is described in the present paper. Potassium salts of 2-thio-4-oxo-3,4-dihydrothieno [2,3-d]pyrimidines, which gave then 2-carboxymethylmercapto-4-oxo-3,4-dihydrothieno [2,3-d]pyrimidines, were prepared from 2-amino-3-carbethoxythiophene derivatives. These compounds were allowed to react with 7-aminocephalosporamic acid (ACA) benzhydryl esters or with 7 beta-chloroacetamidocephalosporanic acid derivatives to obtain new cephalosporins. Antibacterial activities of these new cephalosporins are summarized in the present paper as well.