Dinitrobenzofuroxane

The action of hydroxylamine and sodium acetate in ethanol upon picryl chloride was stated to give 4,6-dinitrobenzofuroxan, and probably some of this compound was formed, although it was later shownthat much of the original work was faulty. A report that hydroxylamine and 2,4,5-trinitrotoluene give 5-methyl-6-nitro-benzofuroxan has been found to be incorrect. Benzofuroxan has not been prepared by V-oxidation of benzofurazan, and it seems unlikely that this could be achieved, since benzofuroxan itself is oxidizable by powerful reagents to o-dinitrobenzene (Section VI, B). A report of the oxidation by nitric acid of anthraceno[l,2-c]furazan to the furoxan is incorrectlv abstracted. 

Attempts to prepare 6-hydroxybenzofuroxan by demethylation of 5-methoxybenzofuroxan, by pyrolysis of 4-azido-3-nitrophenol, and by hypochlorite oxidation of 4-amino-3-nitrophenoD failed. This rather unstable compound was finally prepared by hydrolysis of 5-acetoxybenzofuroxan its tautomeric possibilities are numerous, but from the similarity of its ultraviolet spectrum to that of 5-methoxybenzofuroxan it was considered to be largely in the hydroxy form. It is a fairly strong acid, of pK 6.76 (cf. 5-hydroxybenzo-furazan, pK 7.28). 7-Hydroxy-4,6-dinitrobenzofuroxan has been reported as arising from oxidation and nitration of dinitrosoresorcinol monooxime (tetraoxocyclohexene trioxime). ... 

Nitration of benzofuroxans (Section VII, A) and decomposition of polynitrophenyl azides, provide generally satisfactory routes to nitrobenzofuroxans. The nitro groups render the ring susceptible to nucleophilic attack (see Section VII,B). 4,6-Dinitrobenzofuroxan, 5,6-dinitrobenzofuroxan, and nitrobenzodifuroxan (34) act as acceptors in change-transfer complex formation with aromatic hydrocarbons. Nitrobenzofuroxans have not been reduced to the... 

Nucleophilic displacement of a nitro group by aniline in 5,6-dinitrobenzofuroxan has been reported. Rearrangements of 4-nitro-benzofuroxans are discussed in Section VIII. 

Benzofuroxan and 5-methylbenzofuroxan are oxidized by trifluoro-peracetic acid to o-dinitrobenzene and 3,4-dinitrotoluene, respectively. 4-Nitro- and 4,6-dinitrobenzofuroxan are unaffected by this reagent, whereas the 5-chloro and 5-methoxy compounds are destroyed.Milder reagents (performic, peracetic acids) do not oxidize benzofuroxans. ... 

Several examples of nucleophilic displacement of nitro-activated leaving groups have been recorded. 5,6-Dinitrobenzofuroxan with aniline and p-bromoandine gives the corresponding substitution product (50). Azide ion displaces chloride from both 5-chloro-4-nitro- and 4-chloro-7-nitrobenzofuroxan (51 and 52) the product from the former loses nitrogen spontaneously to give furoxanobenzo-furoxan (benzobisfuroxan, 17), which is also formed, although in poor... 

Dinitrobenzofuroxan dissolves slightly in water, giving an acid reaction, and forms a series of explosive - salts which were originally formulated as containing the anion (54). Acidification regenerates the dinitro compound. It has recently been shown that the anion is, in fact, the Meisenheimer-complex (55), on infrared, NMR, and chemical evidence, including the use of 0 and... 

H. Dinitronaphtho[l,2 cjfuroxan is also reported to form a mildly explosive salt. An anilide of 4,6-dinitrobenzofuroxan, of uncertain structure, is also known.Naphtho[I,2-c]furoxan does not form an... 

Nucleophilic reactions take place in the homocyclic ring, SwAr or AEc when it is activated by electron-withdrawing substituents. It has been described that halides can be displaced by a great number of nucleophiles via a normal and cine substitution [54,55]. Nitro containing Bfx has represented a class of neutral lO-TT-electron-defident system which exhibit an extremely high electrophilic character in many covalent nucleophihc addition and substitution processes. 4,6-Dinitrobenzofuroxan and others 4-nitro-6-substitutedbenzofuroxans (Scheme 2) have been defined as superelectrophiles and used as convenient probes to assess to the C-basicity of... 

The third study has employed 4,6-dinitrobenzofuroxan and as metabolic systems the one-electron reductants NADPHxytochrome P450 reductase and ferredoxin NADP(+) reductase and the two-electron reductants DT-diaphorase and Enterobacter cloacae nitroreductase [239]. The compound is activated either by DT-diaphorase or nitroreductase. 

Spectroscopic and kinetic investigations of the reactions between 4,6-dinitrobenzofuroxan, 4-nitrobenzofuroxan, and tertiary and secondary amines (i.e., l,4-diazabicyclo[2.2.2]octane, quinuclidine, l,8-diazabicyclo[5.4.0]undec-7-ene, and piperidine) indicate the formation of zwitterionic or anionic complexes (Equation 2). The equilibrium between zwitterionic and anionic complexes is discussed (for reaction with piperidine) on the basis of H NMR spectral data, which indicate the presence of anionic complexes arising from the zwitterionic complex by a fast proton departure. The stability and the rate of formation of title complexes are discussed and compared to similar reactions of 1,3,5-trinitrobenzene <2001J(P2)1408>. 

The applications of 1,2,5-oxadiazole iV-oxide and benzo[c][l,2,5]oxadiazole iV-oxide derivatives as compounds which have herbicidal activity are known. For example, the most active compound, butylcarbamoylbenzoL] 1,2,5-oxadiazole iV-oxide, displayed herbicidal activity at concentrations as low as 24 gha-1 <2000JFA2995>. The preparation of 5,7-disubstituted 4,6-dinitrobenzofuroxane derivatives (2-chlorophenylamino, 2,5-dichlorophenyl-amino, 2-hydroxyphenylamino, or 4-bromophenylamino), which are useful as agricultural arachnicides and bactericides, was described <2005RUP2255935>. 

Dinitrobenzofuroxan ist praktisch unloslich in Wasser, Alkohol und Benzin, gut loslich in aromatischen Kohlenwasserstoffen und sieden-dem Eisessig. 

Von gewissem Interesse sind das Kalium- und Bariumsalz, welche thermisch sehr stabil und schwache - Initialexplosivstoffe sind. Das Kalium-Dinitrobenzofuroxan (KDNBF) liegt in der Schlag- und Reib-empfindlichkeit zwischen dem - Knallquecksilber und dem - Bleiazid und ist hauptsachlich in den USA Bestandteil einiger Zundpillensatze. 

Thorough thermodynamic and kinetic investigation of solvolysis of 4,6-dinitrotetrazolo[l,5- ]pyridine 11 in water and methanol has been carried out <2003OBC2764>. It has been shown that in water the anionic rr-complex 12 is formed exclusively, whereas addition of methanol results in partial formation of the neutral carbinolamine-type adduct 13 at low pH (Scheme 4). All these results indicate that 11 is an even more powerful electrophile than dinitrobenzofuroxane. 

It should also be mentioned that NO2 is the electron-attracting substituent which is most commonly used to stabilize Meisenheimer-type complexes. See, for example, recent studies of the reaction of 1,3,5-trinitrobenzene and phenoxide ions215, and the reactions of 4,6-dinitrobenzofuroxan with 5-substituted indoles216. See also the appropriate chapter in each year of the Series Organic Reaction Mechanisms1 1. 

The photometric determination of mixtures of aniline, p-nitroaniline and o-nitroaniline was described. Distribution coefficients and separation efficiency of these compounds by LLE in various solvents were compared517. Substituted nitroanilines such as 2-chloro-4-nitroaniline and 2,4-dinitroaniline are intermediates in the manufacture of the dye D C Red No. 36 and were identified as impurities by RP-LC518. A spectrophotometric method was developed for the determination of aniline and m-nitroaniline in a mixture of aniline and nitroaniline isomers by derivatization with 5,7-dichloro-4,6-dinitrobenzofuroxan (244). The relative error of the determination is <5%519. See also Section IV.D.3.b for similar derivatives. 

Picryl chloride (87) reacts with hydroxylamine hydrochloride to yield 2,4,6-trinitroaniline (53) (picramide) and not the expected At-hydroxy-2,4,6-trinitroaniline. In contrast, the same reaction in the presence of sodium ethoxide is reported to yield 4,6-dinitrobenzofuroxan (94) via substitution of the halogen by hydroxylamine, followed by an internal redox reaction between the hydroxyamino group and one of the adjacent o-nitro groups. ... 

Some nitro derivatives of benzofurazan have been investigated for their explosive properties. 4-Amino-5,7-dinitrobenzofurazan (56) has been prepared by a number of routes including (1) the thermally induced cyclodehydration of l,3-diamino-2,4,6-trinitrobenzene (55), (2) the nitration of 4-amino-7-nitrobenzofurazan and (3) the reduction of 4-amino-5,7-dinitrobenzofuroxan with triphenylphoshine. The isomeric 5-amino-4,7-dinitrobenzofurazan (57) has been prepared along similar routes. ... 

Dinitrobenzofuroxan (DNBF) (68) has been prepared from the nitration of benzofuroxan (69) with mixed acid," and by treating picryl chloride (67) with sodium azide and heating the resulting picryl azide (70) in an inert solvent." " ... 

Diamino-4,6-dinitrobenzofuroxan (DADNBF) (82), an impact insensitive high performance explosive (VOD 8050 m/s, d = 1.91 g/cm ), has been prepared in four steps from l,3,5-trichloro-2,4-dinitrobenzene (78), ° and also by treating the Meisenheimer complex (83) with excess hydroxylamine hydrochloride in aqueous base. DADNBF has also been synthesized in five steps starting from 2-nitroaniline. ... 

W. P. Norris, 7-amino-4,6-dinitrobenzofuroxan, an Insensitive High Explosive , NWC TP 6522 (1984), Naval Weapons Center, China Lake, CA. 

C. Boren, W. Naixing and O. Yuxiang, Synthesis of /V,/V -Bis-(2,4-dinitrobenzofuroxan)-l,3,5-trinitro-2,6-diaminobenzene , in Proc. 17th International Pyrotechnics Seminar (Combined with 2nd Beijing International Symposium on Pyrotechnics and Explosives), Beijing Institute Technical Press, Beijing, China, 235 (1991). 

Nitration at the 4-position occurs readily and further reaction gives the 4,6-dinitro derivatives. 5-Substituted analogues react similarly, 5-chlorobenzofuroxan affording the 4-nitro-5-chloro compound and subsequently 5-chloro-4,6-dinitrobenzofuroxan <84H(22)27i>. In such cases the isolated product may be the 7-substituted-4,6-dinitro compound due to rearrangement of the first-formed derivative (see Section 4.05.5.1.4). 

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