4-Nitropyrazole is a kind of low detonation velocity and high detonation pressure explosive, which has a promising future in the field of energetic materials. 4-Nitropyrazole is also used as raw material to synthesize 4-amino-3,5-dinitropyrazole, a useful intermediate for preparing trinitropyrazole. Currently, 4-nitro pyrazole is prepared by reacting with nitric acid, sulfuric acid, or nitric acid-trifluoroacetic anhydride mixtures. The reaction product contains a small amount of isomers of 4-nitropyrazole and some unknown by-products. To extend the application of 4-nitropyrazole, the crude product must be isolated and purified[1].
