Compounds based on 3-amino-4-(5-methyl-1,2,4-oxadiazol-3-yl)furazan as insensitive energetic materials

Abstract

3-Amino-4-(5-methyl-1,2,4-oxadiazol-3-yl)furazan was synthesized by reacting 4-amino-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide with acetamide at a high temperature of 180 °C. N-Trinitroethylamino derivatives and energetic salts based on 3-amino-4-(5-methyl-1,2,4-oxadiazol-3-yl)furazan, which is a combination of 1,2,5- and 1,2,4-oxadizaole rings, were synthesized and fully characterized by multinuclear NMR spectroscopy, IR, and elemental analysis. And, the structures of compounds 1, 3, 4, 7, 9 were further confirmed by single crystal X-ray diffraction. The thermal stabilities of 1–12 were determined by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), indicating that the reported compounds have moderate thermal stabilities (172–246 °C, except for 3 159 °C). Compounds 1, 4–12 are insensitive towards impact (≥40.1 J) and friction (≥360 N) which were measured by standardized impact and friction tests. Detonation performance was obtained based on the calculated heats of formation and measured densities which indicated that most of these materials are superior to TNT.