To-Nitrotoluene

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... 

Kogelbauer, A., Vassena, D., Prins, R. and Armor, J.N. Solid acids as substitutes for sulfuric acid in the liquid phase nitration of toluene to nitrotoluene and dinitrotoluene, Catal. Today, 2000, 55, 151-160. 

A few workers have investigated recently the problem of the influence of stirring on the rate of nitration and the yield of the reaction. McKinly and White [7] reported that the rate of nitration of toluene to nitrotoluene increased by 3% only when the stirring speed was increased from 1327 to 2004 r.p.m. 

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. 

Dr. Wilson, in the same article to which reference is made above, makes this statement concerning nitrotoluene The changing of toluene to nitrotoluene is carried out without difficulty in the usual manner. The boiling-point of nitrotoluene lies between 220 and 225° C. This body boils without decomposition. The last statement of Dr. Wilson, concerning the ability of nitrotoluene to be distilled without decomposition, confirmed experiments carried out by Glenard and Boudalt. This question was a much mooted one at this time, since other chenoists had proved to their entire satisfaction that nitrotoluene could not be distilled without undergoing decomposition. Comment-... 

In concentrated sulfuric acid / -nitrotoluene is reported to give 4-amino-2 -methyl-5 -nitrodiphenylmethane (XXI) [113,126], which has been verified [127]. Gattermann and Koppert [126] suggested that the primarily formed / -tolylhydroxylamine rearranged into /7-aminobenzyl alcohol (XXII), which then attacked unreduced /7-nitrotoluene. It seems more likely that the intermediate is a carbocation (XXIII), which on addition of water would form XXII, and on addition to / -nitrotoluene would give XXI ... 

HUMAN TOXICITY DATA material is moderately toxic to humans between one ounce and one pint may be fatal toxic on ingestion, inhalation, or by absorption through skin individuals with anemia, pulmonary, or cardiovascular diseases may show more susceptibility to nitrotoluene poisoning. 

The EI-MS of a,a,a-trideutero-orf/to-nitrotoluene does not have a significant fragment ion at mIz = 120 but does have a peak at mIz = 122. Show the fragmentation process that explains these observations. 

White crystals, m.p. 90-9 rC. Prepared fromp-nitrotoluene by way of p-aminobenzoic acid. It is used as a local anaesthetic on mucous surfaces internally and by injection, and is taken internally to relieve gastric pain. 

Oxidation of a side chain by alkaline permanganate. Aromatic hydrocarbons containing side chains may be oxidised to the corresponding acids the results are generally satisfactory for compounds with one side chain e.g., toluene or ethylbenzene -> benzoic acid nitrotoluene -> nitrobenzoic acid) or with two side chains e.g., o-xylene -> phthalic acid). 

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. 

Equip a I litre three-necked flask with a mechanical stirrer and a thermometer, and immerse the flask in a bath of ice and salt. Place 306 g. (283 ml.) of acetic anhydride, 300 g. (285 ml.) of glacial acetic acid and 25 g. of p-nitrotoluene in the flask, and add slowly, with stirring, 42 5 ml. of concentrated sulphuric acid. When the temperature has fallen to 5°, introduce 50 g. of A.R. chromic anhydride in small portions at such a rate that the temperature does not rise above 10° continue the stirring for 10 minutes after all the chromium trioxide has been added. Pour the contents of the flask into a 3 litre beaker two-thirds filled with crushed ice and almost fill the beaker with cold water. Filter the solid at the pump and wash it with cold water until the washings are colourless. Suspend the product in 250 ml. of cold 2 per cent, sodium carbonate solution and stir mechanically for 10-15 minutes filter (1), wash with cold water, and finally with 10 ml. of alcohol. Dry in a vacuum desiccator the yield of crude p-nitrobenzal diacetate is 26 g. (2),... 

That the rate profiles are close to parallel shows that the variations in rates reflect the changing concentration of nitronium ions, rather than idiosyncrasies in the behaviour of the activity coefficients of the aromatic compounds. The acidity-dependences of the activity coefficients of / -nitrotoluene, o- and -chloronitrobenzene (fig. 2.2, 2.3.2), are fairly shallow in concentrations up to about 75 %, and seem to be parallel. In more concentrated solutions the coefficients change more rapidly and it... 

The reduction of o-nitrophenyl acetic acids or esters leads to cyclization to oxindoles. Several routes to o-nitrophenylacetic acid derivatives arc available, including nitroarylation of carbanions with o-nitroaryl halides[2l,22] or trif-late[23] and acylation of o-nitrotoluenes with diethyl oxalate followed by oxidation of the resulting 3-(u-nitrophenyl)pyruvate[24 26]. 

Diethyl oxalate (29.2 g, 0.20mol) and 4-bromo-2-nitrotoluene (21.6 g, O.lOmol) were added to a cooled solution of sodium cthoxide prepared from sodium (4.6 g, 0.20 mol) and ethanol (90 ml). The mixture was stirred overnight and then refluxed for 10 min. Water (30 ml) was added and the solution refluxed for 2h to effect hydrolysis of the pyruvate ester. The solution was cooled and concentrated in vacuo. The precipitate was washed with ether and dried. The salt was dissolved in water (300 ml) and acidified with cone. HCl. The precipitate was collected, washed with water, dried and recrystallizcd from hexane-EtOAc to give 15.2 g of product. 

Reductive Gyclizations. The Batcho-Leimgmber protocol involves condensation of an o-nitrotoluene with a dimethylformamide acetal to form a P-( nitrophenyl)enamine (27). A reducing agent then affects the reductive cycli2ation to an indole. 

Mixtures of HNO, H2SO4, and SO also result in high concentrations of NO/, and toluene can be readily nitrated at —40 to — 10°C as a result (6). At these low temperatures, the formation of the meta-isomer of mononitrotoluene (MNT) is greatiy reduced. Such a reduction is highly desired in the production both of dinitrotoluenes (DNTs) employed to produce intermediates for polyurethane production and of trinitrotoluene (TNT), which is a high explosive. > -MNT results in the production of undesired DNT and TNT isomers (see Nitrobenzene and nitrotoluenes). 

The methyl group of -nitrotoluene is activated by the para nitro group. -Nitrotoluene is oxidized to -nitrobenzoic acid [62-23-7] by potassium hexacyanoferrate(III) in alkaline solution, potassium permanganate, or potassium dichromate. -Nitrotoluene is converted to -nitrobenzaldehyde... 

The separation of the isomers is carried out by a combination of fractional distillation and crystallization. In a fractional vacuum distillation step, the distillate, obtained at a head temperature of 96—97°C at 1.6 kPa (12 mm Hg), is fairly pure o-nitrotoluene and can be purified further by crystallization. The meta isomer is distilled from a mixture of m- and -nitrotoluene and can be purified further by additional distillation and crystallization steps. The bottoms product from the distillation steps is cooled in a crystallizer to obtain nitrotoluene. 

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