A facile preparation of 2-amino-1,3-selenazoles by reactions of N,N-unsubstituted selenoureas with chloroacetonitrile

Reactions of N,N-unsubstituted selenoureas 1 with chloroacetonitrile 2 was investigated. When anhydrous solvent was used, the reaction gave cyanomethyl 1-piperidinoselenocarboimidate hydrochloride 3. The reaction in solvent including water yielded 2-amino-4,5-dihydro-1,3-selenazol-4-iminium chlorides 4 in moderate to high yields.