Lead tetraacetate oxidation of 1- and 2-amino-5-phenyl[1,2,3]triazolo[4,5-d][1,2,3]triazoles; synthesis of a fused 1,2,3,4-tetrazine

Abstract

N-Amination of 5-phenyl-1,5-dihydro[1,2,3]triazolo[4,5-d][1,2,3]triazole with O-(mesitylsulphonyl)hydroxylamine afforded 1-amino and 2-amino derivatives. The oxidation of the 1-amino derivative with lead tetraacetate gave 2-phenyl[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine, whereas that of the 2-amino derivative resulted in the formation of 1,3-dicyano-2-phenyltriazenimide. The tetrazine was decomposed in solvent to form 2-phenyl-5-cyano-2H-1,2,3,4-tetrazole and 2-phenyl-2H-1,2,3-triazole. The degradation mechanism is also reported.