Aminonitro Groups Surrounding a Fused Pyrazolotriazine Ring: A Superior Thermally Stable and Insensitive Energetic Material

Nitrogen-rich heterocyclic compounds offer promising potential backbones for constructing various high energy density compounds. Selective diazotization of 3,5-diamino-4-nitropyrazole (1) with tert-butyl nitrite followed by treatment with the sodium salt of nitroacetonitrile gives rise to a fused pyrazolotriazine ring (5) surrounded by amino and nitro groups. Compound 5, confirmed by single-crystal X-ray diffraction, has a remarkable thermal decomposition temperature of 355 °C, a high density of 1.90 g cm^-3, and low impact and friction sensitivities. The detonation performance is also superior to TATB. These advantages make 5 a promising candidate as a heat-resistant explosive.