On the Reaction of Thiochroman-4-one and 3-(Hydroxymethylene)thiochroman-4-one With N-Chlorosuccinimide

Abstract

Treatment of 3-(hydroxymethy1ene)thiochroman-4-one (4) with N-chlorosuccinimide afforded efficient routes to 3-chlorothiochroman-4-one (5), 3-chlorothiochromone (6) and 2,3-dichlorothiochromone (7). Contrary to an earlier report, 3-formylthiochromone was not obtained from this reaction. The products obtained are rationalized in terms of C-chlorination, in contrast to the action of N-chlorosuccinimide on thiochroman-4one (1), for which S-chlorination is postulated.