Synthesis and nitration of N,N´-bis(3-R-furoxan-4-yl)methylenediamines

Abstract

A Mannich reaction of 4 amino 3 R furoxans with paraformaldehyde in 10% aqueous H 2 SO 4 led to the high yields of N,N´ bis(3 R furoxan 4 yl)methylenediamines, whose struc ture (using R = Me as an example) was confirmed by X ray diffraction study. The N,N´ bis (3 R furoxan 4 yl)methylenediamines obtained were nitrated to N,N´ dinitro N,N´ bis (3 R furoxan 4 yl)methylenediamines upon the action of 100% HNO 3 in acetic or trifluoro acetic anhydride.Key words: 4 amino 3 R furoxans, paraformaldehyde, hydroxymethylation, the Mannich reaction, 4 hydroxymethylamino 3 R furoxans, N,N´ bis(3 R furoxan 4 yl)methylenedi amines, N nitration, N,N´ dinitro N,N´ bis(3 R furoxan 4 yl)methylenediamines.Derivatives of methylenebisamines are widely used in synthetic organic chemistry, for example, as aminometh ylating agents, 1 while methylenedinitramine fragments are a part of high energy compounds, in particular, hexogene and octogene. The most common and convenient method for the synthesis of methylenediamine derivatives is con densation of 2 moles of amines with 1 mole of formalde hyde by the Mannich reaction. Conditions for this reac tion vary within a wide range and depend, in particular, on the basicity of amines used. 2 This approach was used for the synthesis of derivatives of various heterocyclic amines and their N,N´ dinitro derivatives, including those derived from aminofurazans, i.e., N,N´ bis(furazanyl)methylene diamines and N,N´ dinitro N,N´ bis(furazanyl)methyl enediamines. 3-7Though, compounds derived from N,N´ bis(furoxan yl)methylenedinitramines can be of interest for the prepa ration of potentially high energy compounds, 8 the Man nich bases from aminofuroxans and their further transfor mations are not described in the literature by now, which is due, by all accounts, to the fact that aminofuroxans with suitable substituents at the second C atom are not easily available. 3 Aminofuroxans, except their 4 aryl deriva tives, 9 are virtually unavailable. However, in the last years new fairly convenient methods for the preparation of func tionally substituted 4 aminofuroxans were developed, 10-12 that allowed one to start an extensive study of their re activity.The present work is devoted to the study of behavior of isomeric 4 and 3 aminofuroxans in the Mannich reac tion with formaldehyde in order to obtain N,N´ bis(fur oxanyl)methylenediamines and their nitration to N,N´ di nitro derivatives. The study was started from 4 amino 3 R furoxans 1a-f with substituents of different types at the C(3) atom of the ring (Scheme 1). Initially, in the synthe sis of target N,N´ bis(3 R furoxan 4 yl)methylenedi Scheme 1 R = Me (a), Ph (b), Ac (c), COOMe (d), CONH 2 (e), CON 3 (f)

Prospective Symbiosis of Green Chemistry and Energetic Materials

“…At hree-component version of the Mannich reaction, in which aminofuroxans, formaldehyde, and TNM were used as starting compounds and the [Bmpyrr] [OTf] served as the solvent, afforded the same condensation products in acceptabley ields. [99] (2,2,2-Trinitroethylnitroamino)furazans (TNENAF) were obtained from the correspondinga minofurazans by as imilar condensation/nitration reactions equence in the IL mediuma nd their physicochemical and energetic characteristics were determined (Scheme 10). [99] (2,2,2-Trinitroethylnitroamino)furazans (TNENAF) were obtained from the correspondinga minofurazans by as imilar condensation/nitration reactions equence in the IL mediuma nd their physicochemical and energetic characteristics were determined (Scheme 10).…”

“…Thus prepared TNEAFO were converted to (2,2,2-trinitroethylnitroamino)furoxans (TNENAFO) under the action of the HNO 3 /TFAAn itrating system in [Bmpyrr][OTf]. [99] (2,2,2-Trinitroethylnitroamino)furazans (TNENAF) were obtained from the correspondinga minofurazans by as imilar condensation/nitration reactions equence in the IL mediuma nd their physicochemical and energetic characteristics were determined (Scheme 10). [100] Acyl chlorides reacted smoothly with TNE in the imidazolium ILs with perhaloborate, phosphate, or aluminate anionst o afford the corresponding trinitroethyle sters in 74-95 %y ield at ambient temperature, which is as ignificant improvement to knownm ethods in which hazardoush eatingi sn eeded.…”

Enhanced Energetic Performance via the Combination of Furoxan and Oxa-[5,5]bicyclic Structures

“…However, the relatively high sensitivity and poor thermal stability remain constraints on its applications. Common energetic compounds containing furoxan include structures that multiple furoxans directly connect or through the NHCH 2 NH, N=N (O) bridge connection [11][12][13]. Another kind of structure is mainly based on the combination of the furoxan ring and five-membered heterocycles, such as furoxan connected with isoxazole [14], 1,2,4-oxadiazole [15,16], 1,3,4-oxadiazole [17,18], 1,2,5-oxadiazole [19,20], 1,2,4-triazole [21,22], tetrazole [23,24], etc.…”