Novel Formation of 2-Arylquinolines and 1,3-Benzoxazines from 2-(1-Alkenyl)acylanilides and Active Halogens

Abstract

Abstract 2-Arylquinolines 1 were obtained in good yields by reacting iodine or NIS with 2-aminochalcones 2, which were easily synthesized by the Claisen–Schmidt reaction from 2-nitrobenzaldehyde and acetophenones. The reaction of iodine with 2-isopropenylacetanilide (3a), followed by the addition of aq. NaHCO3, afforded 4-iodomethyl-2,4-dimethyl-4H-3,1-benzoxazine (6a), of which the structure has previously been reported to be 1-acetyl-2-iodomethyl-2-methyl-1,2-dihydrobenzazete (4a) or 1-acetyl-3-iodo-3-methylindoline (5a). The reaction mechanism is discussed.