Preparation mononitrotoluenes

The sepMation of the production unit of mononitrotoluene from the next stages of nitration is desirable so as to provide the mononitration unit with a unit for removing m-nitrotoluene by distillation. A mixture of o and p- nitrotoluene or o- nitrotoluene alone is then used for further nitration. In the latter case p- nitrotoluene is utilized for the preparation of dyes (from p- toluidine, derivatives of stilbene, etc.) and pharmaceuticals (p- aminobenzoic acid.)... 

During World War II a method of preparing mixtures of nitro compounds (e.g. TNT and TNX, or TNT and tetryl, see Vol. IV) was developed by the Germans. It consisted in the nitration of the corresponding lower nitrated compounds, namely a mixture of mononitrotoluenes plus mononitroxylenes was nitrated in two stages to form trinitro compounds. In this way a product containing 20% of TNX and 80% of TNT was obtained. 

The history of the discovery and preparation of mononitrotoluene runs parallel with that of toluene, since it was by the preparation of the former that tol-... 

Beilstein and Kuhlberg prepared two dinitrotol-uenes, but give the melting-point of but one of the two. This was the same as that of Deville. The work of Beilstein and Kuhlberg seems to have been mostly on the mononitro-compounds of toluene, and the acidic and basic compounds of mononitrotoluene. 

Upon reduction, the mononitrotoluenes act differently, according to the metal used in the reduction. It iron be used with hydrochloric acid, the corresponding toluidin is produced, the reaction being analogous to the preparation of aniline. If zinc and hydrochloric acid is employed, a chlortolmdin is produced. 

Preparation. The alpha dinitrotoluene is obtained usually by the nitration of mononitrotoluene. It may also be prepared by eliminating the amiao group from nitrotoluidin, first diazotizmg, then forming the hydrochloride and saponifying. 

According to Neogi and Adhicary (17) omega mononitrotoluene is readily prepared by the action of mercurous nitrate or benzyl chloride. Heim (18) concludes from a series of researches, that pure phenylnitro-methane is not subject to spontaneous decomposition, but a small amount of impurities may cause such action. Korwalloff (19) has determined that this substance, on reduction, yields the corresponding aldehyde and oxime. 

Benzene, methyinitro- EINECS 215-311-9 HSDB 6301 Methylnitrotjenzene MNT Mononitrotoluene Nitrophenylmethane Nitrotoluene Nitrotoluene (all isomers) Nltrotoluenes Nitrotoluidines (mono) NItrotoluol UN2660. Mixture of 0, m and p-isomers. Used as intermediates in the preparation of trinitrotoluene. 

Treatment of the mixed mononitrotoluenes depends upon the end use intended for them. When the MNT is to be used in the preparation of DNT or TNT, it is normally not given any treatment but is transferred immediately to the next nitration-process steps after its separation from spent acid. Some European procedures for the manufacture of TNT include... 

Mizuta, M. Separation and utilization of o- and p-nitrotoluene from the mononitrotoluenes prepared from the gasoline fraction of Syukkoko crude oil. in. Preparation of safranine and magenta total... 

TNT (7.3) is produced by the nitration of toluene with mixed nitric and sulfuric acids in several steps. Toluene is hrst nitrated to mononitrotoluene and then dinitrotoluene and hnally crude trinitrotoluene. The trinitration step needs a high concentration of mixed acids with free SO3 groups. A summary for the preparation of trinitrotoluenes from toluene is presented in Reaction 7.3. 

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