Synthesis of 4‐amino‐3,5‐dinitro‐1H‐pyrazole using vicarious nucleophilic substitution of hydrogen

A novel synthesis of the title compound was achieved by direct animation using Vicarious Nucleophilic Substitution (VNS) methodology. Reaction of 1,1,1‐trimethylhydrazinium iodide with 3,5‐dinitropyrazole in DMSO produces 4‐amino‐3,5‐dinitro‐1H‐pyrazole as a 1:1 crystal solvate with DMSO. Recrystallization from water yields the monohydrated crystal. Recrystallization of the monohydrate from butyl acetate yields the compound in pure form.