The question of 1,2- or 1,4-addition of organolithium compounds to quinolines

Abstract

The reactions of quinoline and 4-methylquinoline with organolithium reagents lead to the corresponding 2-sub-stituted 1,2-dihydro-1-lithioquinolines (IV), which upon hydrolysis provide the 2-substituted quinolines (V). Addition of ethyl chloroformate to the reaction mixture prior to hydrolysis gives the ethyl 1,2-dihydroquinoline-1-carboxylates (VI) and not the 1,4-dihydroquinoline analogues (III) as was recently postulated.