2096-20-0Relevant academic research and scientific papers
The Pyridazine Scaffold as a Building Block for Energetic Materials: Synthesis, Characterization, and Properties
Gospodinov, Ivan,Singer, Johannes,Klap?tke, Thomas M.,Stierstorfer, J?rg
, p. 1247 - 1254 (2019/11/16)
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.
Energetic Functionalization of the Pyridazine Scaffold: Synthesis and Characterization of 3,5-Diamino-4,6-dinitropyridazine-1-Oxide
Gospodinov, Ivan,Klap?tke, Thomas M.,Stierstorfer, J?rg
, p. 1004 - 1010 (2018/03/06)
The synthesis of 3,5-diamino-4,6-dinitropyridazine-1-oxide (8) is reported. It is prepared in a six-step synthetic procedure starting from acyclic compounds, and shows good properties (detonation velocity DC–J = 8486 m s–1, detonation pressure pC–J = 302 kbar), and sensitivity toward mechanical stimuli. Compound 8 and its precursor (7, 3,5-dimethoxy-4,6-dinitropyridazine-1-oxide) were characterized by means of multinuclear (1H, 13C, 14N, 15N) NMR spectroscopy, mass spectrometry, vibrational spectroscopy (IR and Raman), elemental analysis and differential thermal analysis (DTA) measurements. Compounds 4, 5, 6, 7, 8 and 9 were also characterized by low-temperature single-crystal X-ray diffraction. The heats of formation for 7 and 8 were calculated using the atomization method based on CBS-4M enthalpies. Using the experimentally determined (X-ray) densities and the calculated standard molar enthalpies of formation, several detonation parameters such as the detonation pressure, energy and velocity were predicted by using the EXPLO5 code (V6.03). The sensitivities of 3,5-dimethoxy-4,6-dinitropyridazine-1-oxide (7) and 3,5-diamino-4,6-dinitropyridazine-1-oxide (8) toward impact, friction and electrical discharge were tested according to BAM standards. In addition, the shock reactivity of 8 was measured by applying the small-scale shock reactivity test, showing similar values to HNS, PYX and TKX-55.
A large scale synthesis of 3-chloro-5-methoxypyridazine
Bryant,Kunng,South
, p. 1473 - 1476 (2007/10/03)
A large scale synthesis of 3-chloro-5-methoxypyridazine was developed (18 moles) that relies on the protection of the pyridazinone nitrogen of 4,5-dichloro-3(2H)-pyridazinone as the tetrahydropyranyl derivative 2. The 5-chloro position of the protected pyridazinone was selectively displaced with methoxide to give 3 followed by catalytic hydrogenation of the 4-chloro group to give 4. Removal of the protecting group with acid followed by phosphorous oxychloride treatment gave the target compound 6 in good yield. This route is superior to the previously described synthesis of this compound.
