| 摘要 |
<p>NEW MATERIAL:A compound expressed by formula I {R<1> represents H or (protected) amino; R<2> represents H, alkyl or cycloalkyl; R<3> represents (substitute) heteroring or aromatic ring; R<7> represents lower alkyl; n is 0 or 1; A<1> represents formula SA<2> [A<2> represents (substituted) heteroring] or formula X (X represents halogen or acetoxy)}. EXAMPLE:(S)-1-Benzyloxycarbonyl-2-pyrrolidinylcarbonyl-oxymethyl 7-[(Z)-2-(2- formylamino-4-thiazolyl)-2-(methoxyimino)acetamido]-3-(3-methyl-1,2,4- thiadiazol-5- yl)thiomethyl-3-cephem-4-carboxylate. USE:An antibacterial agent for oral administration. PREPARATION:A 7-amino-3-cephem-4-carboxylic acid derivative expressed by formula II [R<6> represents formula III or (protected) carboxyl] is acylated with a compound expressed by formula IV, followed by elimination of protecting groups and esterification of carboxyl groups, as necessary.</p> |
