Monothioxamides unsubstituted at the thioamidic nitrogen atom were obtained by the reaction of NS-morpholino-NO-R-thioxamides with ammonia. Carbamoyl-containing 5-phenylcarbamoyl-1,2,4-dithiazoles, 6-phenylcarbamoyl-5,6-dihydro-[1,2,4,5]-dithiadiazin-3-one, and 5-phenylcarbamoyl-2-oxy-1,3,4-thiadiazole were synthesized by the reaction of monothioxamides or thiohydrazides of oxamic acids with chlorocarbonylsulfenyl chloride.