The reaction of l-aryl-3-(dimethylamino)-2-propen-l-ones (enaminones) and l-aryl-3- (dimethylamino)-2-propene-1-thiones (thioenaminones) with hydroxylamine-0-sulfonic acid gave, respectively, isoxmoles in 76-84% yields and isothiazoles in 60-65% yields. The reaction of enaminones with phosphorus oxychloride, followed by treatment with sodium perchlorate and reaction with sodium sulfide, gave thioenaminones in 4&73% yields.