| 摘要 |
NEW MATERIAL:A compound of formula I [A is naphthyridine ring(which may be substituted by alkyl, lower alkoxyl, etc. as well as OH); R1 is OH; R2 and R3 are H, OH, lower alkoxyl, Cl, Br, etc.; X is -OCOCH3, -S-Het (Het is thiadiazolyl, triazolyl or pyridazinyl) and a salt thereof]. EXAMPLE:7-[ D-alpha-( 4-Hydroxy-1, 5-nephthyridine-3-carboxamido )-alpha-p-hydroxyphenylacetamido]cephalosporanic acid. USE:An antimicrobial agent effective against Gram-positive and Gram-negative bacteria. PROCESS:A carboxylic acid of formula II or a reactive derivative thereof is reacted with a compound of formula III, a salt or a derivative thereof in an inert solvent, e.g. dichloromethane, at 50 deg.C or below to give the compound of formula I or a salt thereof. |
