Dinitrobenzene preparation

Commercial l-chloro-2,4-dinitrobenzene prepared by the nitration of a mixture of o- and p- chloronitrobenzenes usually contains the 1,2,6-isomer. The latter differs from the 1,2,4-isomer in some of its properties. According to Borsche and Rants-cheff [24], only the 1,2,4-isomer can react with the sodium salt of acetylacetic ester, the 1,2,6-isomer remaining unchanged. 

Reactions specific to sym-trinitrobenzene Addition compounds Preparation of sym-trinitrobenzene Direct nitration of m-dinitrobenzene Preparation from a-trinitrotoluenc Preparation from picryl chloride Preparation from benzyl chloride Preparation from m-xylene Other preparatory reactions... 

The 7-deaza EHNA analog 691 was obtained by condensation of 4,6-dichloropyrimidine-5-acetaldehyde with 674 The 1,3-dideaza EHNA analog was prepared from erythro-3-amino-2-nonanol (674) by condensation with l-chloro-2,3-dinitrobenzene, prepared in turn from l-amino-2,3-dinitrobenzene, to give 692. Reduction followed by cyclization with form-amidine acetate gave 693 (88JMC390). 

CfiHgNj. Colourless crystals m.p. 63 C, b.p. 2%TC. Turns brown in air. Prepared by a one-stage reduction of m-dinitrobenzene with iron and hydrochloric acid. 

If an impure and discoloured sample of m-dinitrobenzene is used in the above preparation, add some animal charcoal to the solution immediately prior to the 20 minutes boiling the use of charcoal is to be avoided when possible, however, as it is liable to absorb an appreciable quantity of the /-nitroanilinc. 

Dinitrophenylhydrazine is a very important reagent for the identification of aldehydes and ketones (pp. 342, 346). It is readily prepared from chloro-2,4-dinitrobenzene (I). In the latter compound the chlorine is very reactive in... 

It is convenient to include under Aromatic Amines the preparation of m-nitroaniline as an example of the selective reduction of one group in a polynitro compound. When wt-dinitrobenzene is allowed to react with sodium polysulphide (or ammonium sulphide) solution, only one of the nitro groups is reduced and m-nitroanUine results. Some sulphur separates, but the main reaction is represented by ... 

An interesting application of the diazo reaction is to the preparation of the otherwise difficultly accessible o- and />-dinitrobenzenes o- or p-rutrophenyl-diazonium fluoborates react with sodium nitrite in the presence of copper powder to yield o- or p-dinitrobenzene ... 

The acids are mixed in a flask (500 c.c.), and the nitrobenzene added in portions of 5—10 c.c. at a time. Heat is evolved, and the mass becomes somewhat deeper in colour. When the nitrobenzene has been added, the flask is heated for a shoit time on the water-bath. K few drops are then potiied into a test-tube of water. The dinitrobenzene should, if the reaction is complete, separate out as a hard pale yellow cake If it is semi-sohd, the heating" must be continued. The contents of the flask are then poured, whilst warm, into a large quantity of water. The dinitrobenzene, which separates out, is filteied at the punap and well washed with water. It is then dried. The yield is nearly theoretical. A few grams should be recrystallised from spirit. The remainder may be used for the next preparation without further puiification. 

Later in the 20th century, Vompe and Stepanov delineated efficient procedures for the preparation of the so-called Zincke salts (e.g., 1) from pyridines and 2,4-dinitrochlorobenzene, involving, for example, reflux in acetone. Vompe and Lukes also noted that electron-donating substituents on the pyridinium ring of the Zincke salt retarded reaction with amines at the 2-position of the pyridinium ring, sometimes leading instead to attack at the C-1 position of the 2,4-dinitrobenzene ring, with displacement of the pyridine. 

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. 

Disubstituted quinoxalines have been prepared from 2,4-diazido-1,5-dinitrobenzene (19), which on pyrolysis is converted into 2-azido-... 

A linear relationship between Chapman-Jouguet pressure and density was confirmed for Cyclotol and Octol (Ref 28). Despite the near-equal performance of RDX and HMX at equal densities there appears to be no economical way of making the density of RDX equal to the cast density of HMX. Dinitrobenzene (DNB) has been evaluated as an economical or emergency substitute for TNT but charges prepared with DNB gave somewhat poorer performance than... 

VII. Preparation. There are two industrial methods of manufg PA 1) nitration of Phenol 2) nitration of dinitrophenol prepd by hydrolysis of chloro dinitrobenzene... 

The complexes precipitate immediately on mixing 1 1 complexes (n = 1) are prepared from arenes such as benzene, biphenyl, naphthalene, acenaphthalene, fluorene, phenanthrene, anthracene and m-dinitrobenzene. These complexes contain a complex Hg(I) cation with the arene v coordinated to one Hg as in III ... 

SNAr reactions also provide an important strategy for the preparation of various kinds of diaryl ethers. p-Dinitrobenzene reacts with even sterically hindered phenols to give the corre-... 

The SNAr reaction followed by intramolecular cyclization provides a useful method for the preparation of heterocyclic compounds, as summarized in Ref. 1. Reaction of 1-fluoronitroben-zene or 1,2-dinitrobenzene with guanidine in hot THF followed by treatment with t-BuOK gives 3-amino-1,2,4-benzotriazene 1-oxide in good yield (Eq. 9.11).19... 

Preparation of 4,5,6,7-tetrabromobenzotriazole and its tetrachloro analog by direct bromination or chlorination of benzotriazole is described in Section 5.01.7. However, other tetra-substituted benzotriazoles have to be constmcted from a suitably substituted benzene ring. Thus, treatment of pentamethylbenzene 1293 with fuming nitric acid in concentrated sulfuric acid provides 3,4,5,6-tetramethyl-l,2-dinitrobenzene 1294 in 66% yield. Using routine procedures, derivative 1294 is reduced with SnCl2 in aqueous HC1, and the obtained diamine 1295 is subsequently treated with NaNOz (in aq. HC1) to provide 4,5,6,7-tetramcthyl-l //-benzotriazole 1296 (Scheme 216) <2004BMC2617>. 

Dinitrobenzene was prepared from mononitrobenzene by addition of three equivalents of nitric acid. After 20 minutes the mono was half used up and the o-, m- and p- forms of the dinitrobenzene were present in the proportions 6.4, 93.5 and 0.1. Find the second order specific rates of the three reactions. 

Olah and Lin reported obtaining pure TNB (2) in 50 % yield from the nitration of m-dinitrobenzene (32) with nitronium tetrafluoroborate in fluorosulfuric acid at 150 °C higher yields of TNB can be obtained by reducing reaction time but the product then contains some unreacted m-dinitrobenzene. A solution of dinitrogen pentoxide in sulfuric acid at 160 °C is also reported to effect the conversion of m-dinitrobenzene to TNB. TNB is rarely prepared via these routes and is best obtained from TNT via an indirect route (Section 4.9). 

A,A -Bis(3-aminopicryl)-l,2-ethanediamine (108) (m.p. 275 °C) is prepared from the reaction of ethylenediamine with two equivalents of 3-chloro-2,4,6-trinitroaniline. " The same chemists reported 3,3 -diamino-2,2 4,4, 6,6 -hexanitrodiphenylamine (109), a heat resistant explosive (m.p. 232-237 °C) prepared from the reaction of l,3-dichloro-4,6-dinitrobenzene with 3-chloroaniline followed by mixed acid nitration and subsequent chloro group displacement with ammonia. The potassium salt of 3,3 -diamino-2,2, 4,4, 6,6 -hexanitrodiphenylamine shows very high thermal stability. " ... 

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. ... 

This statement was prepared to give you information about 1,3-dinitrobenzene (1,3-DNB) and... 

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