ABSOLUTE-CONFIGURATION OF OPTICAL ISOMERS OF OBENZOYLAMINO)-3-[2(1H)-QUINOLINON-4-YL]-PROPIONIC ACID (REBAMIPIDE)

The absolute configuration of enantiomers of robenzoylamino)-3-[2(1H)- quinolinon-4-yl]propionic acid [(+/-)-1, rebamipide] was assigned. The key intermediate, (S)-quinoline derivative [(S)-3], was prepared by p alladium-catalyzed coupling reaction of 4-iodoquinoline with organozin c compound. This quinolinylalanine derivative was also synthesized fro m alpha-amino acid derivative of 2(1H)-quinolinone [(+)-4], which was able to convert into optically active rebamipide. Therefore the absolu te configuration of (+)- and (-)-rebamipide was found to be R and S, r espectively.