Synthesis of 2-(6-nitrobenzofuroxan-4-yl)-2H-[1,2,3]triazolo-[4,5-e][1,2,3,4]tetrazine 4,6-dioxide

At heating of 2-(2-azido-3,5-dinitrophenyl)-2H-[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine 4,6-dioxide in toluene at 110 °C, the azido group interacts mainly with the neighboring nitro group and to a lesser extent with the neighboring 1,2,3-triazole ring, resulting in 2-(6-nitrobenzofuroxan-4-yl)-2H-[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine 4,6-dioxide (2) in 68% yield, as well as 8,10-dinitro-5,11-dehydro-5H,11H-[1,2,3,4]tetrazino[5′,6′:4,5]-[1,2,3]triazolo[2,1-a][1,2,3]benzotriazole 1,3-dioxide and 8,10-dinitro-5,11-dehydro-5H,11H-[1,2,3,4]tetrazino[5′,6′:4,5][1,2,3]triazolo[2,1-a][1,2,3]benzotriazole 2,4-dioxide in 5% yields respectively. Furoxan 2 may be of interest as an energetic compound due to the combination of good thermal stability, positive estimated enthalpy of formation (ΔH°f = 1005 kJ mol−1) and optimal density.