| 摘要 |
Novel cephalosporins of the formula <IMAGE> in which R1 represents methyl or methylsulphonyl and R2 represents 2-methyl-1,3,4-thiadiazol-5-yl or 1-methyl-1,2,3,4-tetrazol-5-yl and which, with respect to the centre of chirality C*, can be present in the two possible configurations R and S and as mixtures of the diastereomers resulting therefrom, and their non-toxic, pharmaceutically tolerable salts are prepared. These compounds are obtained by reacting an appropriate cephalosporin compound which has the acetoxymethyl radical in the 3-position with 2-methyl-5-mercapto-1,3,4-thiadiazole or 1-methyl-5-mercapto- 1,2,3,4-tetrazole in water or in solvents at a pH of 2-9 and at a temperature of 20-100 DEG C. Resulting cephalosporins are optionally converted into the free acids or into non-toxic, pharmaceutically tolerable salts. The novel cephalosporins are used as medicaments, in particular as antibacterial agents. |
