Assembling Nitroamino and Amino Groups on a Pyrazolyl-1,3,4-Oxadiazole Framework for the Construction of High-Performance and Insensitive Energetic Materials

Abstract The introduction of nitroamino groups onto a nitrogen-rich heterocyclic skeleton is an efficient method for constructing high-performance energetic compounds. In this work, the nitroamino-functionalized compound 4-(5-amino-1,3,4-oxadiazol-2-yl)-N,N′-dinitro-1H-pyrazole-3,5-diamine was synthesized in yields of up to 83%. In addition, its energetic salts were also prepared. All these compounds were characterized by NMR and IR spectroscopy and, in two cases, by single-crystal X-ray diffraction. In addition, the difference in the reactivities of the three amino groups on the pyrazolyloxadiazole system was analyzed by an average local ionization energy analysis. The hydrazinium salt of the diamine exhibits promising detonation properties and good molecular stability, suggesting it has good application potential. Compared with previous works, this strategy gives an improved isolated yield and provides a promising method for the construction of nitroamino-functionalized 1,3,4-oxadiazole derivatives.