A convenient method was developed for the synthesis of N-substituted rhodanines based on the reaction of amines, hydrazides, or acid thiohydrazides with trithiocarbonyl diglycolic acid in the presence of dicyclohexylcarbodiimide or 1,1′-carbonyldiimidazole.
oxamic acid thiohydrazides - amines - hydrazides - rhodanines - carbodiimide - 1,1′-carbonyldiimidazole