Aromatic nitration

Nitrous acid or nitrite salts may be used to catalyze the nitration of easily nitratable aromatic hydrocarbons, eg, phenol or phenoHc ethers. It has been suggested that a nitrosonium ion (NO + ) attacks the aromatic, resulting initially in the formation of a nitro so aromatic compound (13). Oxidation of the nitro so aromatic then occurs ... 

Some investigators, however, beheve NO/ is the nitrating agent for these easily nitrated aromatics. 

The existence of the nitronium ion in sulfuric-nitric acid mixtures was demonstrated both by cryoscopic measurements and by spectroscopy. An increase in the strong acid concentration increases the rate of reaction by shifting the equilibrium of step 1 to the right. Addition of a nitrate salt has the opposite effect by suppressing the preequilibrium dissociation of nitric acid. It is possible to prepare crystalline salts of nitronium ions, such as nitronium tetrafluoroborate. Solutions of these salts in organic solvents rapidly nitrate aromatic compounds. ... 

Plastomenites. Propints, patented in Ger by Guttler in 1889—90, consisting of NC, Nitro-lignine, Nitrosugar, Nitrostarch, etc, gelatinized by the addition of nitrated aromatic compds such as benz, toluene, phenol, naphthalene, etc. Inorganic nitrates, chlorates, chromates, picrates, etc, could be added to the mixt... 

The fact that nitronium salts in which nitronium ion is known to be present (by X-ray studies) nitrate aromatic compounds shows that this ion does attack the ring. 

Multi-phase processing of nitrated aromatics is also described in [31], including both organic and aqueous phases. Side reaction take place in the organic phase, whereas all other reactions occur in the aqueous phase and are limited by organic solubility. For this reason, enabling mass transfer by large interfaces is a key to affect product selectivity. 

These compounds are not very stable and the first series members decompose at low temperatures. However, these decompositions do not represent any danger. They become dangerous in very specific operating conditions or with nitrated aromatic amides. 

Dinitrogen pentoxide (prepared by the oxidation of N204 with 03) in nitric acid is a potent nitration system. It can be used for nitrating aromatic compounds at lower temperatures than conventional system. It is also convenient for preparing explosives that are unstable in nitrating media containing sulfuric acid (Eq. 2.7).20... 

Tokiwa H, Nakagawa R, Horikawa K, et al. 1987. The nature of the mutagenicity and carcinogenicity of nitrated, aromatic compounds in the environment. Environ Health Perspect 73 191-199. 

Tokiwa, H., R. Nakagawa, K. Horikawa, and A. Ohkubo, The Nature of the Mutagenicity and Carcinogenicity of Nitrated, Aromatic Compounds in the Environment, Environ. Health Per-spect., 73, 191-199 (1987). 

Accdg to Colver (Ref 12, p 18), low-nitrated aromatic hydrocarbons, such as MN-Naphthalene, MNBz MNT started to be used in coal mining expls based on AN. This was because of their stability and insensitivity to shock to ignition... 

E) E. Saigger, GerP 636977(1936) 8c CA 31, 3280(1937) [Muzzle flash in firearms is reduced by placing at the base of the projectile one of the following salts of nitrated quinol salts (such as K Dlnitromechoxy-quinol nitrate, C7H qN306 ) or highly nitrated aromatic oompds)... 

Fluoranthene (Called 1,2-benzo-acenaphthy-len or 1,8-o-phenylen-naphthylen in Ger), C16H10(Thought to be ClaH10in early literature), mw 202.24, colorless ndls, sp gr 1.158 at 20°, nD 1.739 at 20°, bp 393°, 217°(30mm Hg), mp 109.5-110.5°, sol In benz, chlf, eth, HAc hot ale. A tetracyclic fused ring aromatic hydrocarbon, this material is found in some coal tars. It forms definite complexes with many poly nitrated aromatics (Refs 1 to 6) Refs 1) Beil 5, 685, (340, 344), [609] 2276 2) J. vonBraun E. Anton, Ber... 

TNT is the abbreviation of the aromatic nitrated aromatic compound 2,4,6-trinitrotoluene. It is a pale-yellow crystalline solid that was first synthesized in 1863 by the German chemist Joseph Wilbrand (1811—1894), but it was not immediately used as an explosive. TNT is made by nitrating toluene using nitric acid, sulfuric acid, and oleum (a mixture of sulfuric acid and S03). Nitration of toluene occurs in stages, with the nitro units added sequentially in a stepwise process as the reaction proceeds. The last nitro unit is accomplished by using oleum (SO, dissolved in sulfuric acid). After nitration, unused acids are recycled, and the product is washed with sodium sulfite and water to remove impurities. 

Some nitramines may be prepared without treating amines with nitric acid. The classical example is the so-called E-method of cyclonite preparation in which a nitramine is formed by dehydration of a mixture of paraformaldehyde and ammonium nitrate, i.e. without using either amine or nitric acid (this will be discussed more fully on p. 109). When a nitramine is required with a non-nitrated aromatic ring which readily undergoes nitration with nitric acid, Bamberger s method [45], involving the oxidation of diazo compounds (13), may be applied. 

T. Urbanski and Rabek-Gawronska [11] found that cyclonite dissolves in molten, highly-nitrated aromatic hydrocarbons, substituted urea derivatives, and camphor to form eutectics of the composition given in Table 18. It is almost insoluble in molten diphenylamine. 

The molecular composition of picric acid was established in the early ninteenth century when it was the only highly-nitrated aromatic compound then known. It was evident that its oxygen content was insufficient for complete combustion (to C02 and H20). This was considered to be an adequate foundation for the erroneous theory that, because of its insufficient oxygen content, the substance has no explosive properties. It was believed that explosive properties are achieved only by mixing picric acid with oxidizing agents such as chlorates, or sodium or potassium nitrates. 

Name Nitroglycerine and nitroglycol with collodion cotton Am- monium nitrate Sodium nitrate Aromatic nitro compounds Wood- meal Dye... 

Diphenylamine is not used for stabilizing powders containing nitroglycerine since it hydrolyses this ester. Diphenylamine also causes the decomposition of higher nitrated aromatic compounds and therefore should not be used in powders containing such compounds. 

CA 71, 23401m (1969) [Aqueous expl compns of d 1.0—1.5 contg no selfexplosive or metallic sensitizers, yet capable of reliable detonability at low temps, comprise 40—75% inorg oxidizer (such as a nitrate or perchlorate of NH4, Na, K, Mg, etc or their mixts), 2—40% partially nitrated aromatic sensitizers (such as MNT, DNT, PhN02, DNB, MNX, DNX, or their blends), 1—30% of a C1.4 lower aliphatic monoamide sensitizer dispersant (such as HCONMe2, AcNMe2, propionamide, or acrylamide),... 

The solution of the problem was more closely approached by the use of highly nitrated aromatic hydrocarbons, especially the low-melting eutectic mixts of the isomers of di- and tri-nitrotoluenes (such as l,TNT oil" or "drip oil which dissolve readily in NG even at low temps and desensitize it much less than the mono-nitro compds. However, these compds did not produce dynamites which were absolutely non-freezing at the lowest winter temps reached in some countries such as in Canada or Siberia... 

The term nitrate is also used when HNOa combines directly with an organic molecule without replacing any H, as in aniline nitrate Many nitrated aromatic and aromatic-aliphatic derivs have been prepd and theoretically many more can be prepd. Numerous compds of these types, already prepd are expl, bur relatively few possess a combination of props which make them acceptable for use as military or industrial expls The individual nitrated compds are described in this work under what may be considered their parent compds eg TNT under toluene, PA (2,4,6-trinitrophenol) under phenol, etc... 

When two or more different primary plosophores are present in a single molecule, the compd is called hybrid (eg nitrate aliphatic nitro, nitrate aromatic nitro, nitramine aromatic nitro). It was established that hybrids are as powerful (or more) as pure types, although they tend to exhibit somewhat greater variability. This property of hybrids is of importance, because it extends enormously the synthetic possibilities for expls... 

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