Desilylative Nitration of C,N‐Disilylated 3‐Amino‐4‐methylfurazan.

Abstract

3,4-Bis(3-nitrofurazan-4-yl)furoxan has been synthesized by nitration of C,N-bis(trimethylsilyl) derivative of 3-amino-4-methylfurazan with nitrogen oxides.J. Heterocyclic Chem., 42, 1237Chem., 42, (2005.The reactions of 3-amino-4-methylfyrazan (1) with nitrating/nitrosating reagents have recently been shown to provide a very useful way for the amino group transformations in the preparation of nitramino-, nitro-, nitroso-, azo-, and azoxy-methylfurazans [1][2][3]. No reaction involving the methyl group of compound 1 has been described [4].In connection with our project dealing with the chemistry of 3-lithiomethyl-4-alkyl-furazans, we have been exploring the chemical reactivity of the intermediates as a versatile building block in organic synthesis [5][6][7][8]. It is the most promising technique for the functionalization of the usually resistant methyl group bridged to the furazan ring. As an extension of this study, an investigation was undertaken with the aim of realizing the activation of the methyl group in compound 1.In this paper, we describe a combination of the activation approach with the nitration/nitrosation process. Our goal is to transform both the amino and methyl group into the nitramino/nitro group and furoxan moiety, respectively.We expected that the requisite transformations of both amino and methyl groups could be accomplished via a three-step protocol involving first the lithiation of compound 1 at nitrogen and carbon atoms of these substituents with n-BuLi, followed by N,C-bis-silylation of the resulting di-lithium compound 2 with Me 3 SiCl, and finally the nitration/nitrosation of the silylated derivative 3a (Scheme 1) [9]. The sequence was expected to result in 3,4-bis(furazan-4-yl)furoxan with terminal nitro or nitramino groups, to compounds 4 or 5, respectively.

Searching for Low-Sensitivity Cast-Melt High-Energy-Density Materials: Synthesis, Characterization, and Decomposition Kinetics of 3,4-Bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole-2-oxide

“…There are two literature reports for the preparation of BNFF, both of which have drawbacks with respect to ease of synthesis and yield. Sheremetev reported a one-batch, three-step preparation of BNFF from 3-amino-4-methylfurazan in 23% yield by lithiation (RLi), followed by silylation (R 3 SiCl), and finally nitration with N 2 O 5 . Sheremetev also reported that BNFF was obtained in 50% yield by oxidation of BAFF with 96% hydrogen peroxide in trifluoroacetic acid (TFA) and methylene chloride.…”

Thermal Kinetic Performance and Thermal Safety of 3,3’‐Bis‐Oxadiazole‐5,5’‐Bis‐Methylene Dinitrate

“…Among them, 3,4-bis(3-nitrofurazan-4-yl) furoxan (DNTF) have been of practical value as a melt-cast explosive and energetic filler for propellants, performing high detonation velocity (9250 m s À 1 ), high density (1.937 g cm À 3 ), and low melting point (110°C). And the thermal stability of DNTF is quite high, 5-second delay exploding point is 308°C [15][16][17][18][19][20]. But because of its relatively high impact sensitivity and friction sensitivity, the application of DNTF is limited in explosives and propellants [21].…”

Molecular dynamics simulation of initial thermal decomposition mechanism of DNTF

“…The structures were subjected to molecular dynamics simulations for 10 ps at the temperature programmed of 300-4000 K and constant temperatures of 2000 K, 2500 K, 3000 K, 3500 K and 4000 K, respectively, to compare the thermal decomposition mechanism of DNTF at different temperature conditions. Bond length of DNTF obtained by experiment and theoretical calculation [29] Coordinate Reference /Å analyzing the evolution trend of small molecular products of DNTF decomposition under temperature programmed and constant temperature, it can be preliminarily inferred that temperature will affect the thermal decomposition rate of DNTF, but has no signi cant effect on the evolution trend of its initial thermal decomposition small molecular products. molecule at the initial stage of the reaction.…”