Novel Synthesis of 2-Chloroquinolines from 2-Vinylanilines in Nitrile Solvent

2-Vinyl- or heteroaryl-substituted anilines were reacted with diphosgene in acetonitrile solution via a reactive imidoyl moiety to afford the corresponding 2-chloroquinolines. Facile syntheses of nine 2-chloroquinoline derivatives from several anilines and their postulate mechanism is described. The postulate mechanism of 2-chloroquinoline formation via imidoyl moiety as a good leaving group shows that the reaction consists of the following three steps: (1) generation of phenylisocyanate, (2) quinoline ring formation, and (3) chlorination on C2 position of quinoline.