Reaction of dithiomalonic acid dianilide with substituted acetylenic ketones

The reaction of dithiomalonic acid dianilide with 1-benzoyl(2-thienyl, 2-furoyl)-2-phenylacetylenes in glacial acetic acid in the presence of equimolar amount of perchloric acid under heating (90–115°C) was used to prepare 6-anilino-2-(acylmethyl)-2-phenyl-4-(phenylimino)-4 H -1,3-dithiinium perchlorates in good yields.