Reactions of acyl azides with secondary amines in the presence of copper(ii) acetate

The nucleophilic substitution of the azide group in acyl azides for secondary amines in the presence of copper(ii) acetate was studied. The formation of the corresponding amides and copper(ii) azide in the course of the reaction was observed. The shift of the absorption band of stretching vibrations of the azide group was observed in the IR spectra of the reaction products, which could be explained by the intermediate formation of a complex of acyl azide with the amine complex of copper(ii) acetate and by its decomposition to form copper(ii) azide and the corresponding amide. A blue-green color of the solution characteristic of copper(ii) acetate changed in the course of the reaction to the brown color of a solution of copper(ii) azide.