| 摘要 |
Readily hydrolysable esters of cephalosporin derivatives of the general formula <IMAGE> in which R<1> represents hydrogen, methyl or carboxyl-lower alkyl, X represents sulphur, oxygen or one of the groups -SO- and -SO2-, Y represents the group -CH= or nitrogen, Z represents sulphur or selenium and R<2> represents lower alkyl which is optionally substituted by carboxyl, hydroxyl, readily hydrolysable acyloxy or dimethylamino, with the exception of (6R,7R)-7-[2-(2-amino-4-thiazolyl)-2- methoxyimino-acetamido]-3-[[(5-carboxy-2-methyl-2H-1,2,4-triazol-3- yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, and acid addition salts of these esters and hydrates of these esters or acid addition salts, processes for their preparation and intermediates for this purpose, and pharmaceutical compositions containing them. The products are antibiotically active, in particular bactericidally active. |
