Abstract
Reactions of imines with trichloroacetylating agents rely upon their structural differences. 3, 3-Dichloro-2-azetidinone formation was effected by the reaction of α-arylsubstituted N-benzylideneamines similarly to that of N-benzylideneamines. The imines, of which imino carbons are bound to alkyls possessing at least one hydrogen at C1 of the alkyls, however, reacted with trichloroacetic anhydride and trichloroacetyl chloride to give β-trichloroacetylated enamines. In the reaction with trifluoroacetic anhydride in place of trichloroacetic anhydride N-trifluoroacetylenamines were obtained instead, but the products easily undergo N→C migration on heating in xylene to give β-trifluoroacetylated enamines. Acid-catalyzed quinoline ring-closures of the β-trihaloacetylated enamines obtained above are also described.
