The chemistry of trityl isoselenocyanate revisited: A preparative and structural investigation

The reaction of trityl chloride with KSeCN gives trityl isoselenocyanate which was structurally characterised by X-ray diffraction. Trityl isoselenocyanate reacts with hydrazine to give trityl selenosemicarbazide and with primary amines to give selenourea derivatives. However, with secondary amines mixtures of selenoureas and substitution products are formed. Trityl selenosemicarbazide undergoes a condensation reaction with salicylaldehyde to give the corresponding trityl selenosemicarbazone. In the case of 2-pyridinecarboxaldehyde, the analogous selenosemicarbazone cannot be isolated, instead a small quantity of the diselenide was isolated from the reaction mixture. The compounds prepared here were fully characterised spectroscopically and several also by X-ray diffraction.