2.3- Dinitrotoluene

4- Dinitrotoluene is reduced to yield diaminotoluene to make TDI, which reacts with polyols to prepare TDHerminated prepolymers for polyurethane elastomer applications. 

GFS Chemicals King Tang Chemical (China) Nanjing King-Pharm (China) Hangzhou Meite Chemicals (China) 

Diphenylamine reacts with acetone to produce acetone diphenylamine condensation product antioxidant for rubber. 

Diphenylamine reacts with diisobutylene to synthesize octylated diphenylamine antioxidant for rubber. 

Diphenylamine is a very important feedstock in the production of 6PPD antiozonant. Nonrubber Uses 

The dinitrotoluenes [CH3C6H3(N02)2] are manufactured by the nitration of toluene that gives a mixture containing 65 to 80% of the 2,4-dinitro derivative and 20 to 35% of the 2,6-dinitro compound. 

If the pure 2,4-compound is required, mononitration of toluene followed by separation of pure p-nitrotoluene from the ortho isomer, and then further nitration of p-nitrotoluene gives the pure 2,4-dinitro isomer. 

Nearly all the dinitrotoluenes are hydrogenated to diamines, which are converted into diisocyanates to give toluene diisocyanate, a monomer for polyurethane. A small amount of the dinitrotoluenes is further nitrated to the explosive 2,4,6-trinitrotoluene (TNT). 

Diphenyl ether (diphenyl oxide) is obtained as a by-product in the manufacture of phenol from chlorobenzene and caustic soda. 

Diphenyl ether is used in the soap and perfume industries because of its great stability and strong geranium-type odor. 

Place 18 g. (12 ml.) of fuming nitric acid, sp. gr. 1 5, and 30 g. (16-5 ml.) of concentrated sulphuric acid and a few fragments of broken glass in a 250 or 500 ml. round-bottomed flask. Add gradually, in small portions, 14 g. of p-nitrotoluene do not allow the temperature to rise above 50 and cool the flask, if necessary, by immersion in cold water. Place a small funnel in the mouth of the flask and heat on a water bath at 90-95° for 30 minutes. Allow to cool almost to the laboratory temperature and pour the reaction mixture slowly into about 500 ml. of ice water containing a few small pieces of ice. Filter the crude dinitrotoluene through a Buchner funnel at the pump, wash it thoroughly with cold water, and drain as completely as possible. RecrystalUse from the minimum volume of hot methyl alcohol (flask, reflux condenser, and water bath experimental details as in Section IV,12). The yield of pure 2 4-dinitrotoluene, m.p. 71°, is 12 -5 g. 

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Further nitration of the 2- and 4- isomers yields 2,4-dinitrotoluene, yellow crystals, m.p. 71 "C. This material is reduced to 2,4-di-aminotoluene and treated with phosgene to give 2,4-diisocyanatotoluene, a precursor of polyurethanes. 

Toluene, Proceed as for Benzene but use 0-5 ml. of toluene and a mixture of 3 ml. of concentrated sulphuric acid and 2 ml. of fuming nitric acid. Gently warm the mixture over a free flame for 1-2 minutes, cool, and pour into 20 ml. of ice water. Recrystalhse the product from dilute alcohol. 2 4-Dinitrotoluene, m.p. 71°, is obtained. 

Nitrotoluene is similarly converted largely into 2 4-dinitrotoluene ... 

Formic acid is a good reducing agent in the presence of Pd on carbon as a catalyst. Aromatic nitro compounds are reduced to aniline with formic acid[100]. Selective reduction of one nitro group in 2,4-dinitrotoluene (112) with triethylammonium formate is possible[101]. o-Nitroacetophenone (113) is first reduced to o-aminoacetophenone, then to o-ethylaniline when an excess of formate is used[102]. Ammonium and potassium formate are also used for the reduction of aliphatic and aromatic nitro compounds. Pd on carbon is a good catalyst[103,104]. NaBH4 is also used for the Pd-catalyzed reduction of nitro compounds 105]. However, the ,/)-unsaturated nitroalkene 114 is partially reduced to the oxime 115 with ammonium formate[106]... 

Attempts have been made to develop methods for the production of aromatic isocyanates without the use of phosgene. None of these processes is currently in commercial use. Processes based on the reaction of carbon monoxide with aromatic nitro compounds have been examined extensively (23,27,76). The reductive carbonylation of 2,4-dinitrotoluene [121 -14-2] to toluene 2,4-diaLkylcarbamates is reported to occur in high yield at reaction temperatures of 140—180°C under 6900 kPa (1000 psi) of carbon monoxide. The resultant carbamate product distribution is noted to be a strong function of the alcohol used. Mitsui-Toatsu and Arco have disclosed a two-step reductive carbonylation process based on a cost effective selenium catalyst (22,23). 

If pure isomers are required, the ortho and meta compounds can be prepared by indirect methods. o-Nitrotoluene can be obtained by treating 2,4-dinitrotoluene with ammonium sulfide followed by diazotization and boiling with ethanol. / -Nitrotoluene can be prepared from -toluidine by acetylation, nitration deacetylation, diazotization, and boiling with ethanol. A fairly pure -nitrotoluene, which has been isolated from the isomeric mixture, can be purified further by repeated crystallization. 

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 %... 

Dinitrotoluene crystallizes in yellow needles from carbon disulfide and is soluble in a number of organic solvents. It is only slightly soluble in water, 0.03 g/100 g of water at 22°C. Its physical properties are Hsted in Table 13. 

Dinitrotoluene can be prepared by the nitration of -nitrotoluene with yields of ca 96% or it can be obtained from the direct nitration of toluene. 

Dinitrotoluene is oxidized to 2,4-dinitrobenzoic acid [610-30-0] by potassium permanganate or chromic acid, and is reduced to 2,4-diaminotoluene by iron and acetic acid. It is reduced partially by zinc chloride and hydrochloric acid to 2-amino-4-nitrotoluene [99-55-8] and by ammonium sulfide to 4-amino-2-nitrotoluene [119-32-4],... 

The nitration step produces two isomers, 2,4-dinitrotoluene and 2,6-dinitrotoluene, the former predorninating. Mixtures of the two isomers are frequendy used, but if single isomers are desired, particulady the 2,4-dinitrotoluene, nitration is stopped at the mono stage and pure i ra-nitrotoluene is obtained by crysta11i2ation. Subsequent nitration of this material yields only 2,4-dinitrotoluene for conversion to the diisocyanate. 

Methyl groups in the 2-, 4- or 6-position of pyrimidine are active in the sense of that in 2,4-dinitrotoluene in the 5-position, a methyl group resembles that of toluene itself. 

Dinitrotoluene [121-14-2] M 182.1, m 70.5-71.0 . Crystd from acetone, isopropanol or MeOH. Dried under vacuum over H2SO4. Purified by zone melting. Could be EXPLOSIVE when dry. 

The TDI mixtures are produced by a series of reactions starting from toluene. The first stage is the nitration of the toluene to yield 2-nitrotoluene and 4-nitrotoluene in roughly equal proportions. These can be further nitrated, the 4-isomer yielding only 2,4-dinitrotoluene and 2-nitrotoluene both the 2,4- and the 2,6-dinitro compound Figure 27.1). 

If toluene is dinitrated without separation a mixture of about 80% 2,4-dinitrotoluene and 20% 2,6-dinitrotoluene is obtained. Nitration of separated 2-nitrotoluene will yield a mixture of approximately 65% of the 2,4- and 35% of... 

Trinitrotoluene (TNT) is made by nitration of toluene. Display electrostatic potential maps for toluene, 4-nitrotoluene (the first nitration product) and 2,4-dinitrotoluene (the second nitration product). Are the second and third nitration steps likely to be easier or more difficult than the initial nitration of toluene Explain. 

Figure 15.14 Separation of explosives exnacted from water by using SPE-SFE-GC at several SEE trapping temperatures, peak identification is as follows NG, nitroglycerin 2,6-DNT, 2,6-dinitrotoluene 2,4-DNT, 2,4-dinitrotoluene TNT, triniti otoluene IS, 1,3-tiichloroben-zene. Adapted Journal of High Resolution Chromatography, 16, G. C. Slack et al., Coupled solid phase extraction supercritical fluid extraction-on-line gas cliromatography of explosives from water , pp. 473-478, 1993, with permission from Wiley-VCH.

PETN with 80% m-dinitrobenzene 82.4 10% PETN with 90% 2,4-dinitrotoluene 67.3 13% PETN with 87% Oi-trinitrotoluene 76.1 30% PETN with 70% Tetryl 111.3... 

Dinitrotoluene is a highly toxic material, and is readily absorbed thru intact skin. Vapors are absorbed thru the respiratory tract. It produces a marked increase in metabolism and temp, profuse sweating, collapse and death. It can also cause dermatitis, cataracts, wt loss, granulocytopenia, polyneuropathy, and exfoliative dermatitis (Ref 10)... 

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