AN IMPROVED SYNTHESIS OF 2,2-DISUBSTITUTED-1,2-DIHYDROQUINOLINES AND THEIR CONVERSION TO 3-CHLORO-2,2-DISUBSTITUTED-TETRAHYDROQUINOLINES

N-(1,1-disubstitutedpropargyl)anilines can be cyclised to 2,2-disubsti tuted-12-dihydroquinolines by refluxing them in toluene containing cup rous chloride. Electron donating groups in the para position of the ri ng enhance the reaction rare and electron withdrawing groups markedly decrease the rare. The derived N-acetyldihydroquinolines can be cis di chlorinated and selectively monodechlorinated at the benzylic position to produce 3-chlorotetrahydroquinolines.