Overcoming the inertness of the C -NH 2 bond in heterocyclic amines remains a fundamental challenge in synthetic chemistry. Here, we report the first direct hydrazine substitution of a heterocyclic amine, 3,5-diamino-4-nitropyrazole (DANP), yielding both di- (1a) and monohydrazine (2a) substitution products. Orbital-weighted dual descriptor analysis, together with X-ray crystallography, reveals the electronic asymmetry responsible for selective C –NH 2 activation and identifies a resonance-assisted pathway that facilitating the second substitution. The pyrazole-hydrazine product 2a enables concise access to a thermally stable fused-ring energetic scaffold (3, T d = 305 o C) and its N -aminated energetic derivatives (4 and 5), providing a new strategy for constructing high-performance energetic materials. A safe and efficient hydrazine substitution of pyrazole amine for the synthesis of advanced pyrazole-based energetic materials. (1) A direct hydrazination strategy has been developed for the synthesis of hydrazine-substituted pyrazole derivatives. (2) Synthetic utility is demonstrated by transforming product 2a into a heat-resistant fused-ring energetic material 3 , as well as aminated isomers 4 and 5. (3) The zwitterionic nature of 4 endows a distinct advantage in enhancing the acid resistance of energetic materials.
Tang et al. (Wed,) studied this question.