Reactions with N‐Acylimino‐dithiocarbonic‐acid‐diesters.Reactions of N‐acylimino‐dithiocarbonic‐acid‐S,S‐diesters 1 with nucleophilic com‐pounds present new possibilities to synthesize heterocycles. With amines1areacts by mono‐ and disubstitution, respectively, of methylthio‐groups to isothioureas2and guanidines3, with 1,2‐bi‐nucleophilic arenes to benzoheterocycles4, with aliphatic diamines to imidazolidines5, pyrimidines6, diazepines7and the hexamethylene‐diamine‐derivatives8. 1areacts also with hydrazines to 1,2,4‐triazoles9and with hydrazides to the thiosemicarbazones10or 1,3,4‐oxadiazoles11. Heterocyclisations of1with guanidines, thiourea, salts of thiourea and amidines give the 1,3,5‐triazines12, 14, 15and16. N‐benzoyl‐dithiocarbonic‐acid‐methylester ‐amid reacts with CH‐acidic compounds to thiazoles17. The structures of the final products are determ