Ring-opening and recyclization of 3,4-diacylfuroxans by nitrogen nucleophiles

Computational Investigation on the Structure and Performance of Novel 4,7-Dinitro-furazano-[3,4-d]-pyridazine Derivatives

“…However, the specific impulse of an energetic compound depends on its structural parameters. Keshavarz put forward a new method for calculating the specific impulse based on the structural parameters of energetic compounds, as follows, Equation 12 [44]: Isp = 2.421 − 0.0740a − 0.0036b + 0.0237c + 0.0400d − 0.1001nNH 2 , NH + 0.1466(nAr − 1) (12) where a, b, c and d are the number of carbon, hydrogen, nitrogen and oxygen atoms in C a H b N c O d , respectively, I sp is the specific impulse in N·s·g −1 and the units are ultimately converted into s, n NH 2 , NH is the number of NH 2 and NH groups, and n Ar is the number of aromatic rings in aromatic explosives. The molecular frameworks of the designed compounds are presented in Figure 2 and their structures have been optimized at B3LYP/6-311g(d,p) level.…”

“…For example, Zhou et al [8] proved that benzotrifuroxan shows excellent detonation performance and safety compared with HMX. Liu et al [9] reported the synthesis of 4H,8H-bis-furazano [3,4-b:3',4'-e]pyrazine-4,8-diylbis(methylene)dinitrate, which possess excellent energetic properties (ρ = 2.00 g·cm −3 pyridazine derivatives [10][11][12][13], such as 4,7-dimethyl-and 4,7-diphenylpyridazino [4,5-c]furoxane N,N'-dioxide, 4,7-diaminopyridazino [4,5-c]furoxan, 4,7-bis(5-methylisoxazol-3-yl)pyridazino [4,5-c]furoxan, 4,7-dimethyl-and 4,7-di(cyclopropyl)-furazan [3,4-d]pyridazine-5,6-dioxides ( Figure 1). However, the relationship between molecular structure and energetic performance for furazano- [3,4-d]-pyridazine compounds is still unclear.…”

Oximes of five-membered heterocyclic compounds with two heteroatoms. 1. Synthesis and structure (Review)

“…Diacylfuroxans 21 and hydroxylamine in pyridine rearrange to the 3-substituted 4,5-bis(hydroxyimino)-4,5-dihydroisoxazoles 22 as the main products[21][22][23]. The structure of compound 22 (R = t-Bu) was confirmed by X-ray crystallographic analysis.…”

“…For example, in the NaBH 4 /MeONa/MeOH system 4-nitro-1-phenylimidazole (118) gives the oxime 119 with a yield of 94%. The reaction of 3,4-diacylfuroxans 120 with hydrazine takes place through the intermediates 121 [22,115] and gives good yields of pyrazole dioximes 122. The reaction of 6-phenyl-1,2,4-triazine 4-oxide (123) with pyrazolones 124 gives the oximes 125 with yields of 8-35% [116].…”

Oximes of five-membered heterocyclic compounds with two heteroatoms 2. Reactions and biological activity (Review)

“…The reaction of the amidoxime 87 with ClCO 2 Et in ether leads to the formation of 1,2,4-oxadiazolone 88 [132]. It was shown that the pyrazole dioxime 89 gives the pyrazolo [3,4-c]furazan derivative 90 with a yield of 70% when heated in acetic anhydride in the presence of sodium acetate [133,134]. Several papers have been devoted to the synthesis of the imidazolopyrimidine [135,136] and pyrazolopyrimidine [137] systems from the corresponding derivatives of imidazole and pyrazole oximes.…”