| 摘要 |
<p>NEW MATERIAL:The 5-fluoronicotinic acid derivative of formula I [R<1> is H or carboxyl-protective group; R<2> is halogen, hydroxy, (amino-protected) 3- aminopyrrolidinyl, (imino-protected) piperazinyl; (substituted) alkoxy, alkylthio, arylthio, alkanesulfonyloxy or arenesulfonyloxy; X is H or F] and its salt. EXAMPLE:2-(2,4-Difluorophenylamino)-5-fluoro-6-hydroxynicotinic acid methyl ester. USE:Intermediate for 1-aryl-1,4-dihydro-4-oxonaphthyridine derivative or its salt having antibacterial activity. PREPARATION:For example, a compound of formula I wherein R<2> is OH can be produced by reacting the compound of formula II or its salt with the compound of formula III or its salt.</p> |
