Efficient Synthesis of a Superior Heat-Resistant Energetic Material Based on Fused Pyrazolotriazine Ring

Fused-ring energetic materials are considered to be promising energetic materials. However, their practical applications are usually hindered due to the tedious synthetic routes. In this work, 4-amino-3,8-dinitropyrazolo[5,1- c ][1,2,4]triazin-7-ol ( 4 ) was easily prepared within three straightforward steps starting from commercially available ethyl cyanoglyoxylate 2-oxime ( 1 ). Compound 4 is a promising heat-resistant explosive, with remarkable thermal stability (decomposition temperature 332 °C) and thermal sensitivity (burst point 380 °C at 5 s). In addition, it demonstrates high density (1.88 g cm –3 ), good detonation velocity (8538 m s –1 ), and low impact and friction sensitivities ( IS > 40 J; FS > 360 N). Optimized conditions for the synthesis of 4 have also been investigated, and a scale of 10 g could be prepared over one-batch reaction using the modified synthetic path with a high overall yield (46%). The advanced performance and scalable production of 4 make it a bright prospect for industrial production.