Nitrations toluene

It has been mentioned ( 4.4.2) that nitronium tetraffuoroborate reaets with pyridine to give i-nitropyridinium tetraffuoroborate. This compound and several of its derivatives have been used to effect what is called the transfer nitration ofbenzeneandtoluene. i-Nitropyridinium tetraffuoroborate is only sparingly soluble in acetonitrile, but its homologues are quite soluble and ean be used without isolation from the solution in which they are prepared. i-Nitropyridinium tetra-fluoroborate did nitrate toluene in boiling aeetonitrile slowly, but not at 25 In eontrast, i-nitro-2-pieolinium tetraffuoroborate readily... 

The y -phenylenediamiaes are easily obtained by dinitrating, followed by catalyticaHy hydrogenating, an aromatic hydrocarbon. Thus, the toluenediamiaes are manufactured by nitrating toluene with a mixture of sulfuric acid, nitric acid, and 23% water at 330°C which first produces a mixture (60 40) of the ortho and para mononitrotoluenes. Further nitration produces the 80 20 mixture of 2,4- and 2,6-dinitrotoluene. Catalytic hydrogenation produces the commercial mixture of diamiaes which, when converted to diisocyanates, are widely used ia the production of polyurethanes (see Amines, aromatic, DIAMINOTOLUENES) (22). 

An important aspect of nitrating toluene to nitrotoluene is the very low solubility of toluene and nitroioluenes in nitrating mix Is. Therefore the nitration proceeds in a two-phase system and the rate of nitration depends greatly on dispersion, which in turn depends on keeping the two phases efficiently stirred. This is emphasized in Fig 4, which gives the yield of MNT for a 11/64/25% nitric acid/sulfuric acid/water MA and a nitration time of 30 minutes as a function of stirring speed... 

Hercules Continuous Process Kouba et al (Ref 60) describe a novel tubular nitration procedure and app by which toluene is nitrated in two stages to form trinitrotoluene. In the first stage of nitration according to this invention, toluene is partially nitrated to an average nitrogen content between about 14.5% and about 16.5%, and in the second stage of nitration partially nitrated toluene is further nitrated to form trinitrotoluene... 

The contribution of the carbon atoms from the 1- and 7- positions to TeNMe carbon were obtained by determining the specific activity of the TeNMe isolated from the nitration of toluene-1-14C and toluene-7-14 C, respectively. Similarly, by nitrating toluene-1,3,5-l4C, it was possible to determine the 3- and 5-contributions, since the contribution of the 1-position could be subtracted and the 3- and 5-positions were considered to be equivalent. Finally, the contributions of the 2-, 4- and 6-positions were determined from the nitration of toluene-2,4,6,7-14C by subtracting the contribution of the 7-position. An approximate contribution for each of these positions (2-, 4- and 6-) was obtained by considering them to be equivalent... 

Trinitrotoluene, TNT, is a well-known explosive, (a) Using the structure available on the Web site, determine the systematic name for TNT. (b) TNT is made by nitrating toluene (methylbenzene) with a... 

Nitrating toluene with HNO3/H2SO4 mixture led to a violent detonation because it was badly monitored. 

The enthalpies of formation for nitrated toluenes are listed in Table 7 and then-calculated destabilization energies are given in Table 8. One polynitrotoluene, 2,4,6-trinitrotoluene, is the well-known explosive TNT (61). 

Using acyl nitrates as nitrating agents (compare with Section 4.5.4.2) and zeolite H-ZSM-11 treated with tributylamine, Nagy et al. (1991, 1994) were able to nitrate toluene with an even more impressive percentage of the isomers obtained—ortho 2-3%, meta 1-2%, and para 95-98%. 

Army. 1985b. Carcinogenesis of nitrated toluenes and benzenes, skin and lung tumor assays in mice. Contract no. DE-AC05-840R21400. Frederick, MD U.S. Army Medical Research and Development Command, Fort Detrick. Document no. DE 85012081. 

Jaworsky nitrated toluene with better results than did Mitscherlich in 1834 (Ref 12,... 

Sulfuric acid, Acetasalicylic acid. Potassium nitrate Toluene, Sulfuric acid. Nitric acid... 

Explosive Compositions from Nitrated Toluene and Naphthalene. A soln of 30% C10H8 and 70% boluene is nitrated with. 2.5 times its wt of an equal mixt of sulfuric and nitric acids at 130° to give a product (I) mp 60° and contg 16.9%N. An expl is made by mixing... 

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. 

Expl compositions from nitrated toluene and naphthalene 6 E402... 

These results show that by using the LMD technique it is possible to nitrate even less reactive molecules such as PNT with a high degree of conversion, under mild conditions and with high selectivities. It is noteworthy that this system nitrates toluene quantitatively. The reason why performances are not as good with MNT (mononitrotoluenes), probably lies in the fact that theire exists a competitive adsorption between HNOj and MNT ont the surface of the dessicant. 

Laszlo and co-workers[11,25-271 developed a reagent known as claycop, which is Cu(NC>3)2 supported on acidic montmorillonite clay, that selectively nitrates toluene using nitric acid, and acetic anhydride as water trapping reagent (Menke conditions). The reaction conditions required to obtain high selectivity of the para-isomer... 

The influence of the nitration temperature on the orientation of a nitro group is in certain cases rather marked When nitrating toluene with a mixture of nitric and sulphuric acids at -5°C, Pictet [56] observed that more para-isomer was obtained than at the temperature of 0°C. 

Kirk Mid Brandt [25] nitrated toluene with a mixture of nitric and sulphuric acids both by the usual method and by the simultaneous use of the electrolytic method Mid found that with the latter technique higher yields could be obtained. AtMiasiu Mid Belcot [26,27] treated aromatic hydrocarbons with a much dilute nitric acid (at a concentration insufficient for nitration) and, due to the electrolysis, which they carried out simultaneously, they succeeded in obtaining nitration in the anode area, hi studying the reaction they observed particularly vigorous oxidation processes. 

Goddard and co-workers [108-111] found that nitryl chloride in various solvents at room temperature and below (-10°C) chlorinates, rather than nitrates, toluene, m- and p- xylene, and mesitylene, though not benzene. 

Davis [127,128] and later Blechta and Patek [129] found that as a result of nitrating toluene in the presence of mercuric nitrate, besides nitrotoluenes, trinitro-m- cresol and p- nitrobenzoic acid could also be obtained. The authors explained the mechanism of the reaction by assuming the formation of toluene and the mercury salt complex to be the first stage. On decomposition of the complex by the action of nitric acid, the activated hydrocarbon thus formed was nitrated. 

Noelting and Forel [11] found that the content of p- nitrotoluene increased gradually with increase in the HN03 content of the nitrating acid. Thus, when nitrating toluene with a mixture of nitric and sulphuric acids, the authors obtained 60% of the p- isomer but if nitric acid alone was used, 66% of p- nitrotoluene was obtained,... 

Recently, as the disposal of large volumes of toxic waste waters from the purification of TNT by sulphitation has. become a problem (p. 390), new ways are being sought for the manufacture of TNT free from the unsymmetrical isomers. Apart from the possibility, mentioned above, of the utilization of nitrotoluene obtained by nitrating toluene with a mixture of acetic anhydride and nitric acid, factories TNT are now tending to separate nitrotoluene isomers by methods similar to those applied in the manufacture of dyestuffs intermediates. 

The aqueous layer is sepMated Mid the oil washed with water until alkali free when tested with phenolphthalein. The oil is steamed to remove un-nitrated toluene Mid aliphatic compounds. Distillation is continued until the oil coming over sinks in water. The distillate is collected and fractionated once or twice a yeM. It contains ca. 20% of nitrotoluenes. 

At Griesheim a continuous method of nitrating toluene to nitrotoluenes was also used. The nitration unit consisted of two nitrators connected by their bottom outlets, fed with mixed acid of the same composition as in the batch process. 

Kovache and Thibon also found that similar inflammable metal products were formed by lower nitrated toluene derivatives, e.g. p- nitrotoluene and 2,4-dinitroto-luene, and also by trinitrobenzene. Nitrobenzene and trinitroxylene did not react... 

Detoluation. Another characteristic feature of this method was the extraction of higher nitrated toluene derivatives, dissolved in the spent acids. The latter were conveyed to denitration and distillation (concentration) only after the nitro compounds present in them had been extracted with nitrotoluene, an operation which was called detoluation . Primarily it consisted in stirring the spent acids, heated to 75-80°C with a quantity of crude MNT, amounting to one quarter of the acid volume. A slight amount of nitrotoluene became nitrated due to the presence of the unreacted HN03 in the spent acid. 

During World War II a continuous process for nitrating toluene to TNT developed by J. Meissner [19] and patented in 1941 was introduced at the Schlebusch factory in Germany. The nitration unit consisted of 5 nitrators and 4 separators, as shown in the schematic diagram in Fig. 86. Both the nitrators and the separators... 

---