Acidic nitration

Electrophilic nitrations of aliphatic nitriles, carboxylic acids,carboxylic esters, ° and /3-diketones have been reported. The nitration of 2-alkyl-substituted indane-l,3-diones with nitric acid, followed by alkaline hydrolysis, is a standard laboratory route to primary nitroalkanes.  

Treatment of some carboxylic acids with nitric acid is a route to em-dinitroalkanes, as in the case of tyo-butyric acid (103), which undergoes nitration-decarboxylation on treatment with 

The half esters of malonic acid (105) yield Q ,Q -dinitroesters (106) on nitration-decarboxylation with nitric acid, although yields are often poor. Treatment of these Q ,Q -dinitroesters with hydrazine hydrate or alkali metal hydroxides yields the corresponding m-dinitroalkanes.  

A potential industrial route to potassium dinitromethane (18) involves treatment of methyl malonate (107) with red fuming nitric acid to give methyl Q ,Q -dinitroacetate (108), followed by hydrolysis-decarboxylation with aqueous potassium hydroxide. Dinitromethane is a precursor to 2,2-dinitroethanol and 2,2-dinitro-1,3-propanediol, both of which are useful in addition and esterification reactions for the production of energetic oligomers and plasticizers. 

Trinitroacetonitrile (110), a precursor to dinitroacetonitrile and its derivatives, can be synthesized from the nitration of cyanoacetic acid (109) with a solution of sulfur dioxide and absolute nitric acid in carbon tetrachloride.This method is particularly attractive because the trinitroacetonitrile can be kept as a solution in carbon tetrachloride without isolation trinitroacetonitrile is hazardous to handle and its vapours are both toxic and lachrymatory. 

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If phenol is heated with more concentrated nitric add (in the presence of sulphuric acid), nitration occurs ultimately at the para and at both the ortho positions, giving picric acid or 2,4,6-trinitrophenol. To prepare picric acid, however, it is more convenient first to heat the phenol with sulphuric acid, whereby a mixture of 0- and p-phenol sulphonic acids is readily obtained. If this mixture is now heated with concentrated nitric acid, nitration occurs at the... 

Picric acid, the 2 4 6-trinitro derivative of phenol, cannot be prepared in good yield by the action of nitric acid upon phenol since much of the latter is destroyed by oxidation and resinous products are also formed. It is more convenient to heat the phenol with concentrated sulphuric acid whereby a mixture of o- and p-phenolsulphonic acids is obtained upon treatment of the mixture with concentrated nitric acid, nitration occurs at the two positicsis mela to the —SOjH group in each compound, and finally, since sulphonation is reversible, the acid groups are replaced by a third iiitro group yielding picric acid in both cases ... 

To solve some of the environmental problems of mixed-acid nitration, we were able to replaee sulfuric acid with solid superacid catalysts. This allowed us to develop a novel, clean, azeotropic nitration of aromatics with nitric acid over solid perfluorinated sulfonic acid catalysts (Nafion-H). The water formed is continuously azeotroped off by an excess of aromatics, thus preventing dilution of acid. Because the disposal of spent acids of nitration represents a serious environmental problem, the use of solid aeid eatalysts is a significant improvement. 

The influence of added species upon the rates and kinetic forms of nitration in organic solvents were of the greatest importance in elucidating details of the processes involved, particularly of the steps leading to the nitronium ion. These influences will first be described, and then in the following section explained. The species to be considered are sulphuric acid, nitrate ions, urea and water. The effect of nitrous acid is considered later ( 4.3). 

Nitration in the presence of strong acids or Lewis acids Solutions of dinitrogen pentoxide in sulphuric acid nitrate 1,3-dimethyl-benzene-4,6-disulphonic acid twice as fast as a solution of the same molar concentration of nitric acid. This is consistent with Raman spectroscopic and cryoscopic data, which establish the following ionisation ... 

The catalysis was very strong, for in the absence of nitrous acid nitration was very slow. The rate of the catalysed reaction increased steeply with the concentration of nitric acid, but not as steeply as the zeroth-order rate of nitration, for at high acidities the general nitronium ion mechanism of nitration intervened. 

One way in which the step of the reaction in which the proton is lost might be slowed down, and perhaps made kinetically important (with i), would be to carry out nitration at high acidities. Nitration of pentadeuteronitrobenzene in 97-4% sulphuric acid failed to reveal such an effect. In fact, nitrations under a variety of conditions fail to show a kinetic isotope effect. 

Control of NO emissions from nitric acid and nitration operations is usually achieved by NO2 reduction to N2 and water using natural gas in a catalytic decomposer (123—126) (see Exhaust control, industrial). NO from nitric acid/nitration operations is also controlled by absorption in water to regenerate nitric acid. Modeling of such absorbers and the complexities of the NO —HNO —H2O system have been discussed (127). Other novel control methods have also been investigated (128—129). Vehicular emission control is treated elsewhere (see Exhaust control, automotive). 

Other Glycol Nitrates. Other Hquid nitrates have been used as explosive plasticizers for nitroceUulose (Table 8). These may be made by mixed-acid nitration using procedures similar to those used for nitroglycerin. 

In the last few years several modifications to the traditional mixed acid nitration procedure have been reported. An adiabatic nitration process was developed for the production of nitrobenzene (9). This method eliminated the need to remove the heat of reaction by excessive cooling. The excess heat can be used in the sulfuric acid reconcentration step. An additional advantage of this method is the reduction in reaction times to 0.5—7.5 minutes. 

Dinitration of toluene results in the formation of a number of isomeric products, and with a typical sulfuric—nitric acid nitrating mixture the following mixture ofisomers is obtained 75 wt % 2,4-dinitrotoluene [121-14-2] 19 wt % 2,6-dinitrotoluene [606-20-2], 2.5 wt % 3,4-dinitrotoluene [610-39-9], 1 wt %... 

By contrast, HLW from LWR fuel reprocessing is stored ia cooled, well-agitated, stainless steel tanks as an acidic nitrate solution having relatively few sohds. Modem PUREX flow sheets minimise the addition of extraneous salts, and as a result the HLW is essentially a fission-product nitrate solution. Dissolver soHds are centrifuged from the feed stream and are stored separately. Thus the HLW has a low risk of compromising tank integrity and has a favorable composition for solidification and disposal (11). 

In some processes the reactant bases are too weak to be protonated significantly except in the presence of very strong acids such as fuming sulfuric acid or a mixture of concentrated sulfuric and nitric acids, ie, mixed acid. Nitration of toluene, for example, requires such solutions two Hquid phases are present in the reactor. 

Nitrochlorobenzene from chlorobenzene and nitric acid Nitration... 

Manufacture of pure products, such as sulfuric acid, nitric acid, nitrates, phosphates, adipic acid, and so on... 

Separation of Am(III) and Cm(III) from aqueous acidic nitrate media by CCC using two different extraction systems have been studied ... 

MIXED ACID (NITRATING ACID) see ACID MIXTURES, NITRATING ... 

Kobalto-. cobaltous, cobalto-, cobalt(II). -chlorid, n. cobaltous chloride, cobalt(II) chloride, -cyanwasserstoff, m., -cyanwasser-stoffs ure, /. cobaltocyanic acid, -nitrat, n. cobaltous nitrate, cobalt(II) nitrate, -oxyd, n. cobaltous oxide, cobalt (II) oxide, -salz, n. cobaltous salt, cobalt(IJ) salt, -sulfat, n. cobaltous sulfate, cobalt(II) sulfate, -sulfid, n. cobaltous sulfide, cobalt (II) sulfide, -verbindung, /. cobaltous compound. cobalt(II) compound. 

Salpeter-luft,/. nitrogen (old name), -messer, m. nitrometer, -milchsiure, /. lactic acid nitrate, -papier, n. niter paper, nitrous paper, -plantage, /. saltpeter plantation, -probe, /. saltpeter test, nitrate test saltpeter sample. 

Salpeter-sauresalz. n. salt of nitric acid, nitrate, -schaum, m. wall saltpeter (calcium nitrate efflorescence). 

Copper alloys Ammonia/amines Nitric acid/nitrate fumes... 

In Ref 8 are discussed the effects of acid concns on the formn of mono- and polynitro compds by the mixed acid nitration of naphthalene. Other studies on the coml prodn of 1-MNN are in Refs 16, 20,29 30... 

Sources of thermochemical data for such calculations are Vol 7, H38 Lff Heat Effects — Data for Common Explosives NBS Circular 500 (Ref 39a) Cox Pilcher (Ref 89) and the studies of Rhodes Nelson (Ref 24b) and McKinley Brown (Ref 28a) on mixed acids As an example of such a calculation we will compute the heat evolution and temp rise occurring during the mixed acid nitration of glycerol to NG. We will assume that a typical 50/50 nitric acid/sulfuric acid MA is used and that the MA/glycerol ratio is 5/1. Further assumptions are that all the glycerol is converted to NG, and that the heats of soln of NG in die. spent acid, and of spent acid in the NG, are negligibly small (cf discussion of these effects by the writer in Ref 51). The net reaction is then ... 

A recent investigation (Ref 90) of the 2-stage mixed acid nitration of tetranitroethane (TNE) to hexanitroe thane revealed that the ntiration was first-order in N02+, TNE and base" (either H20 or HSO4 ). The reaction was claimed to proceed via simultaneous attack of N02+ on the C, and of base on the H of the TNE... 

Oxybenzoic Acid, Nitrated Leed Salt (Lead 2,4,6-Trinitro-3-Oxybenzoate, Trinitrometa-oxybenzoate in Fr). H. Ficheroulle and A. Kovache (Ref) prepd and characterized this material... 

The general mechanism of nitrating alcohols to form nitrate esters is described under Nitration in this Vol. Several specific remarks about PETN are contained in that article. The industrial nitration of PE differs from most nitrate esters in that it employs coned nitric acid rather than mixed acid. Nevertheless nitration via the nitronium ion mechanism, which is the preferred mechanism in mixed acid nitrations, is also feasible in coned nitric acid. However, Eremenko and co-workers claim that the nitrating agent in PE nitrations, in mixed acid, is unionized nitric acid (Refs 39 76). The present writer does not find Eremenko s arguments to be very convincing. In any case, commercial production of PETN employs nitric acid and not the mixed acids of Eremenko s studies... 

Red Water — which can be almost black at times - also contains dissolved TNT however, it is not an incidental stream like Pink Water it is a major by-product stream from TNT manuf. The mixed-acid nitration of toluene yields not only 2,4,6-trinitrotoluene, the desired product, but also a host of other isomers and by-products amounting to approx 4.5% of the total yield and it is necessary to remove them from the product. They are removed by extraction with a Na sulfite—Na carbonate soln which sulfonates and dissolves them the extract is called Red Water. Red Water is a very complex and somewhat variable mixt containing 15% or so of sulfonated or sellited nitrobodies and a number of inorganic salts. Typical components are w, NajSOj—NaS04, NaN02— NaNOj, sulfonated or... 

N-chlorosuccinimide, reaction+PhOH, 92 chrysene, bromination of, 405 —, hydrogen exchange with, 258 —, nitration of, 39 cinnamic acid, nitration of, 39 cinnanyl p-totyl ethers, Ciaisen rearrangement of, 472... 

Alcohols form esters from inorganic acids as shown above. Like all esterifications, these reactions are reversible that is, in the presence of water and the right conditions, they revert to the original alcohol and acid. Nitrate esters are mainly used as explosives, but some have found use as diesel fuel additives. Note the difference between a nitrate ester such as ethyl nitrate (C2H5ONO2) and an organic nitro compound such as nitroethane (C2H5NO2). 

Xiao F, Yoo B, Ryan MA, Lee KH, Myung NV (2006) Electrodeposition of PbTe thin films from acidic nitrate baths. Electrochim Acta 52 1101-1107... 

The crude mixture of 4- and 5-nitroindanes produced by mixed acid nitration of indane following a literature method [1] is hazardous to purify by distillation. The warm residue from distillation of 15 mmol at 80°C/1.3 mbar exploded on admission of air, and a 1.3 mol batch exploded as distillation began under the same conditions. Removal of higher-boiling poly-nitrated material before distillation is recommended. 

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