An unusual reduction of azido group accompanied by ring closure to 1,2,3-triazole 3-oxide

Resumo

The reaction of 2-[(2-azidophenyl)hydrazono]-2-(tert-butyl-NNO-azoxy)-N′-hydr oxyethanimidamide with sodium acetate in DMF aff ords 2-(2-aminophenyl)-5-(tert-butyl-NNO-azoxy)-2H-1,2,3-triazol-4-amine 3-oxide rather than the anticipated 2-(2-azidophenyl)-5- (tert-butyl-NNO-azoxy)-2H-1,2,3-triazol-4-amine. The formation of this product can be explained by intramolecular reduction of azido to amino group and cyclization of an inter mediate vicinal (azo)nitrosoethylene into a triazole 3-oxide ring. The structure of aminotriazole 3-oxide 10 was confirmed by X-ray diff raction and NMR spectroscopy.