Trinitrotoluene , reactions

Cohen and Dakin, (10) investigating more thoroughly the reaction discovered by Tiemann, to which reference is made above, identified the product from the reaction of ammonia and hydrogen sulphide on trinitrotoluene as dinitrotolylhydroxylamine. Dini-trotoluene also reacts similarly with this reagent. The trinitrotoluene reaction takes place thus ... 

Physical (including thermochemical and explosive) properties Chemical properties of 2,4,6-trinitrotoluene Reaction with sodium sulphite Oxidation of 2,4,6-trinitrotoluene Reduction of 2,4,6-trinitrotoluene Melhylation of 2,4,6-trinitrotoluene... 

Organic Reactions. Nitric acid is used extensively ia iadustry to nitrate aHphatic and aromatic compounds (21). In many iastances nitration requires the use of sulfuric acid as a dehydrating agent or catalyst the extent of nitration achieved depends on the concentration of nitric and sulfuric acids used. This is of iadustrial importance ia the manufacture of nitrobenzene and dinitrotoluene, which are iatermediates ia the manufacture of polyurethanes. Trinitrotoluene (TNT) is an explosive. Various isomers of mononitrotoluene are used to make optical brighteners, herbicides (qv), and iasecticides. Such nitrations are generally attributed to the presence of the nitronium ion, NO2, the concentration of which iacreases with acid strength (see Nitration). 

They claim that in substantially all of the prior art processes, the operation is really a modified batch process in that high hold-up vessel-type nitrators are employed. Moreover, extensive circulation, recirculation, and a relatively long residence time of the reaction mixt in the nitrating zone are characteristics of a majority of the previously proposed methods, and such features are inherently undesirable because they favor degradative side reactions, which occur at all stages of the nitration of toluene to trinitrotoluene, and particularly in the final stage. ... 

A typical chem manufg operation is the production of trinitrotoluene — TNT, the dominant mil expl. It involves the manuf of huge quantities of nitric and sulfuric acids, from sulfur and ammonia, in chem plants exactly similar to those which make nitric and sulfuric acids in the civilian economy. Mixed nitric and sulfuric acid is then combined with liq toluene in a series of reaction kettles... 

The enthalpy ol formation of trinitrotoluene (TNT) is —67 kj-mol", and the density of TNT is 1.65 g-cm-3. In principle, it could be used as a rocker fuel, with the gases resulting from its decomposition streaming out of the rocket to give the required thrust. In practice, of course, it would be extremely dangerous as a fuel because it is sensitive to shock. Explore its potential as a rocket fuel by calculating its enthalpy density (enthalpy released per liter) for the reaction... 

As a simpler example of a complex reaction, consider (abstractly, not experimentally) the nitration of toluene to give trinitrotoluene ... 

This reaction cannot be elementary. We can hardly expect three nitric acid molecules to react at all three toluene sites (these are the ortho and para sites meta substitution is not favored) in a glorious, four-body collision. Thus, the fourth-order rate expression 01 = kab is implausible. Instead, the mechanism of the TNT reaction involves at least seven steps (two reactions leading to ortho- or /mra-nitrotoluene, three reactions leading to 2,4- or 2,6-dinitrotoluene, and two reactions leading to 2,4,6-trinitrotoluene). Each step would require only a two-body collision, could be elementary, and could be governed by a second-order rate equation. Chapter 2 shows how the component balance equations can be solved for multiple reactions so that an assumed mechanism can be tested experimentally. For the toluene nitration, even the set of seven series and parallel reactions may not constitute an adequate mechanism since an experimental study found the reaction to be 1.3 order in toluene and 1.2 order in nitric acid for an overall order of 2.5 rather than the expected value of 2. 

C04-0139. Compounds that undergo explosions typically produce large quantities of hot gases from much smaller volumes of highly reactive solids or liquids. Balance the reaction for the decomposition of trinitrotoluene (TNT), a violent explosive C7 H5 N3 Og(/) N2(g) + C02(g) + H2 0(g) + C(,3 )... 

Vorbeck C, H Lenke, P Fischer, JC Spain, H-J Knackmuss (1998) Initial reductive reactions in aerobic microbial metabolism of 2,4,6-trinitrotoluene. Appl Environ Microbiol 64 246-252. 

Clostridium bifermentans reduced 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene, and a metabolite was formed by reaction of one of the amino groups with methylglyoxal (Lewis et al. 1996). 

The Sundberg indole synthesis using aromatic azides as precursors of nitrenes has been used in synthesis of various indoles. Some kinds of aryl azides are readily prepared by SNAr reaction of aromatic nitro compounds with an azide ion. For example, 2,4,6-trinitrotoluene (TNT) can be converted into 2-aryl-4,6-dinitroindole, as shown in Eq. 10.60.83... 

Nitration of toluene by mixture of nitric and sulfuric acids produces an explosive material known as TNT (trinitrotoluene). The overall reaction can be shown as... 

In the study of the reaction of 2,4,6-trinitrotoluene with base (NaOMe, under first-order conditions), kinetic and equilibrium data for reaction in methanol-DMSO have been obtained. Since it has been found that plots of logarithms of rate and equilibrium constants versus the mole fraction of DMSO are linear, the value in pure methanol have been extrapolated (Kp = 12.4 lmol-1)213. 

It has been known for a long time that polynitroaromatic compounds produce colored products in contact with aUcafis [1]. These color reactions have been extensively used for the identification of nitroaromatic explosives. In the Janowski reaction [7], a solution of the polynitroaromatic compound (di- or trinitroaromatic) in acetone is treated with concentrated aqueous KOH solution. 1,3,5-Trinitrobenzene (TNB) and 2,4,6-trinitrotoluene (TNT), treated with 30% aqueous KOH, produced violet-red and red colors, respectively. Many variations of the Janowski reaction were reported, using KOH or NaOH in aqueous or ethanoHc solutions as reagents, and dissolving the explosives in acetone, ethanol or acetone-ethanol mixture [3,8]. The reaction was used both for spot tests and for spraying TLC plates [9]. 

Two other derivatives of toluene are the important explosive trinitrotoluene (TNT) and the polyurethane monomer toluene diisocyanate (TDI). TNT requires complete nitration of toluene. TDI is derived from a mixture of dinitrotoluenes (usually 80% o,p and 20% o,o) by reduction to the diamine and reaction with phosgene to the diisocyanate. TDI is made into flexible foam polyurethanes for cushioning in furniture (35%), transportation (25%), carpet underlay (20%), and bedding (10%). A small amount is used in polyurethane coatings, rigid foams, and elastomers. 

Nitration reactions are mostly substitution type, forming a wide variety of products including nitrobenzene, nitrotoluenes, nitroglycerine, nitrocellulose, trinitrotoluene, nitrophenols and nitroparaffins, many of which are known chemical explosives. Some examples are ... 

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. 

Ref 6) and Clift Fedoroff (Ref 7) described prepn of MeTetryl from beta- and gamma-Trinitrotoluene isomers always present as impurities on the surface of crysts of etude aipha-TNT. The jS and y isomers can be removed by washing the crysts of crude a TNT with 8% aqueous Na sulfite soln (called Sellite). This converts the isomers into water-soluble dinitrotoluene sulfonates. Then, on their treatment with me thy famine the following reaction takes place ... 

Nowadays, nitration of toluene is a continuous process, where toluene enters the reactor at one end and trinitrotoluene is produced at the other end. The nitrating acid flows in the opposite direction to the toluene and is topped up as required at various points. Stirring of the reactants plays an important part in the reaction since it speeds up the nitration process and helps to increase the yield. 

Crude TNT contains isomers and nitrated phenolic compounds resulting from side reactions. The usual method of purification is to treat crude TNT with 4% sodium sulfite solution at pH 8-9, which converts the unsymmetrical trinitro compounds to sulfonic acid derivatives. These by-products are then removed by washing with an alkaline solution. Pure TNT is then washed with hot water, flaked and packed. It is important to remove the waste acid and unsymmetrical trinitrotoluenes together with any by-products of nitration as they will degrade the TNT, reduce its shelf life, increase its sensitivity and reduce its compatibility with metals and other materials. Trace amounts of unsymmetrical trinitrotoluenes and by-products will also lower the melting point of TNT. TNT can be further recrystallized from organic solvents or 62% nitric acid. 

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