The Pyridazine Scaffold as a Building Block for Energetic Materials: Synthesis, Characterization, and Properties

In the present studies, the synthesis of new energetic materials based on the pyridazine scaffold and their characterization is the main subject. For this purpose, desired 3,5‐dimethoxy‐4,6‐dinitropyridazine‐1‐oxide (7) was synthesized in the first instance. The persubstituted pyridazine precursor laid the groundwork for further preparative modification. The targeted functionalization through the regioselective introduction of various smaller amine nucleophiles such as methylamine or 2‐aminoethanol gave several new energetic materials. Among them are 3,5‐bis(methylamino)‐4,6‐dinitropyridazine‐1‐oxide (8), 3,5‐bis(methylnitramino)‐4,6‐dinitropyridazine‐1‐oxide (9), 3,5‐bis(dimethylamino)‐4,6‐dinitropyridazine‐1‐oxide (10), and 3,5‐bis((2‐hydroxyethyl)amino)‐4,6‐dinitropyridazine‐1‐oxide (11). With the aim of increasing the detonation performance, compound 8 was additionally nitrated and 3,5‐bis(methylnitramino)‐4,6‐dinitropyridazine‐1‐oxide (9) was obtained. These new energetic materials were characterized and identified by multinuclear NMR (1H, 13C, 14N, 15N) and IR spectroscopy, elemental analysis and mass spectrometry. In addition, their sensitivities toward impact, friction and electrostatic discharge were thoroughly examined. Furthermore, obtained single‐crystals of the substances were characterized by low‐temperature single‐crystal X‐ray diffraction.