| 摘要 |
<p>NEW MATERIAL:A cephalosporin of formulaI(R1 is methyl, ethyl), its syn isomer, and their pharmaceutically permissible acid adducts. EXAMPLE:Pivaloyloxymethyl 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamide]- 3-methoxymethyl-3-cephem-4-carboxylate. USE:Orally given remedy for microbisms: they are fairly absorbed through digestive tracts and keep the carboxylic acid-type compound in blood at high concentration. PREPARATION:The reaction of a compound of formula III with a carboxylic acid of formula IV (R<2> is amino or protected amino) or its reactive derivative affords a compound of formula V and, when R2 is protected amino group, the protecting group is removed to give the objective compound of formulaI.</p> |
