For o- nitrotoluene

Flash photolysis revealed intermediates for o-nitrotoluene and its nitroderivatives. The... 

In order to slow down the overall reaction we added acetic anhydride as a diluent, thereby giving the zeolite a better chance to exert an influence over the reaction. Indeed, this led to a slower reaction and zeolite HP then exerted a greater influence over both the rate and selectivity. The yield after 2 h at -10 °C in the absence of the zeolite was only 16 % and the 2 3 ratio was the usual 2 1, but with the zeolite present the yield increased to 99 % and the ratio to 17 1. p-Nitrotoluene could also be nitrated with the optimised system used for o-nitrotoluene, but the reaction was much slower. Therefore, for direct dinitration of toluene it would be necessary to minimise the amount of the diluent used. 

Analytical and Test Methods. o-Nitrotoluene can be analyzed for purity and isomer content by infrared spectroscopy with an accuracy of about 1%. -Nitrotoluene content can be estimated by the decomposition of the isomeric toluene diazonium chlorides because the ortho and meta isomers decompose more readily than the para isomer. A colorimetric method for determining the content of the various isomers is based on the color which forms when the mononitrotoluenes are dissolved in sulfuric acid (45). From the absorption of the sulfuric acid solution at 436 and 305 nm, the ortho and para isomer content can be deterrnined, and the meta isomer can be obtained by difference. However, this and other colorimetric methods are subject to possible interferences from other aromatic nitro compounds. A titrimetric method, based on the reduction of the nitro group with titanium(III) sulfate or chloride, can be used to determine mononitrotoluenes (32). Chromatographic methods, eg, gas chromatography or high pressure Hquid chromatography, are well suited for the deterrnination of mononitrotoluenes as well as its individual isomers. Freezing points are used commonly as indicators of purity of the various isomers. 

Batch syntheses comparable to those used for MDA produce 3,3 -dimethy1methy1enedi(cyclohexylamine) marketed under the trade name Laromia C-260. The starting aromatic diamiae, 3,3 -dimethy1methy1enediani1ine [838-88-0] is prepared from o-toluidine [95-53-4] condensation with formaldehyde. Similarly 3,3 -dimethyldicyclohexylaniiae [24066-10-2] may be produced (38) from o-toHdine [119-93-7] derived from o-nitrotoluene [88-72-2]. The resultant isomer mixtures are dependent on reduction conditions as ia MDA hydrogeaatioa. 

C-Methylation products, o-nitrotoluene and p-nitrotoluene, were obtained when nitrobenzene was treated with dimethylsulfoxonium methylide (I)." The ratio for the ortho and para-methylation products was about 10-15 1 for the aromatic nucleophilic substitution reaction. The reaction appeared to proceed via the single-electron transfer (SET) mechanism according to ESR studies. 

In 1971, Batcho and Leimgruber introduced a new method for the synthesis of indoles. For example, condensation of o-nitrotoluene (5) with N,N-dimethylformamide dimethyl acetal (6) (DMFDMA) was followed by reduction of the rrans-P-dimethylamino-2-nitrostyrene (7) which resulted to provide the indole (8). ... 

This method has been applied to a large-scale preparation of 6-bromoindole, which reacts with various arylboronic acids via the Suzuki reaction to afford 6-aryhndoles fEq. 10.50. 6-Bromo-5-methoxyindole for use in the synthesis of marine bromoindole " and 5-amino-7-ethoxycarbonyhndole for use in synthesis of l//-pyrrolo[3,2-g quina2ohne ring system fEq. 10.51 " have been prepared from the appropriate o-nitrotoluene. 

Morrison and Migdalof (Ref 14) irradiated o-nitrotoluene and p-nitrotoluene with a Pyrex-filtered mercury lamp using D20 and p-dioxane as solvents. C-D bonds formed with o-nitrotoluene, with no C-D formation for p-nitro-toluene - ... 

Ethyl o-nitrophenylpyruvate and o-nitrophenylpyruvic acid 14-21 have been prepared by condensation of o-nitrotoluene with diethyl oxalate in the presence of potassium ethoxide,4 14 sodium ethoxide,16-20 or sodium methoxide.21 Sodium ethoxide is less reactive, however, and cannot be substituted successfully for potassium ethoxide in the present procedure, as it gives a very poor yield and poor quality of precipitated sodium salt. With sodium ethoxide the reaction does not appear to go to completion even under the conditions of refluxing ethanol usually employed,16-21 which are considerably more severe than the room temperature conditions employed with potassium ethoxide in the present procedure. o-Nitrophenylpyruvic add has also been prepared by hydrochloric acid hydrolysis of o-nitro-a-acetamino-dnnamic azlactone.4... 

Fig. 134.—Phase diagram for poly-(N,N -sebacoyl piperazine) with each of the diluents m-cresol (A), o-nitrotoluene ( ), and diphenyl ether O crystallization, O liquid-liquid separation). (Flory, Mandelkern, and Hall. )...

However, this catalyst is not effective for less reactive aromatics such as o-nitrotoluene. In such cases, hafnium(IV) and zirconium(IV) triflates are excellent catalysts (10 mol%) for mononitration of less reactive aromatics. The catalysts are readily recycled from the aqueous phase and reused (Eqs. 2.3 and 2.4).12... 

The Batcho indole synthesis involves the conversion of an o-nitrotoluene to a (3-dialkyl-amino-o-nitrostyrene with dimethylformamide acetal, followed by reductive cyclization to indoles. This provides a useful strategy for synthesis of substituted indoles (Eq. 10.49).63... 

Diethyl oxalate, condensation with o-nitrotoluene, 43, 40 for synthesis of triethyl oxalylsucci-nate, 44, 67... 

The 60 still base was a 45.5 m3 horizontal, cylindrical, mild steel tank 7.9 m long and 2.7 m diameter. The still was used to separate a mixture of the isomers of mononitrotoluene (MNT), two of which (o-nitrotoluene and m-nitrotoluene) are liquids at room temperature and third (p-nitrotoluene) a solid. Other byproducts were also present, principally dinitrotoluene and nitrocresols. It is well known in the industry that these nitro compounds can be explosive in the presence of strong alkali or strong acid, but in addition explosions can be triggered if they are heated to high temperatures or held at moderate temperatures for a long period. 

Vanadium(V) oxytrinitrate [VO(N03)3] has been established as a powerful but moisture-sensitive reagent which nitrates a range of substituted aromatic compounds in good yield in dichloromethane at room temperature. The hydrated triflates Hf(OTf)4 and Zr(OTf)4 are excellent recyclable catalysts for the mononitration of o-nitrotoluene with 1 equiv. of concentrated nitric acid. ... 

Administered by oral gavage to rats for 6 months, all three isomers produced splenic lesions. The meta and para isomers produced testicular atrophy, whereas o/t/ o-nitrotoluene caused renal lesions. ... 

Wirz and coworkers also studied photorelease from o-nitrotoluene derivative 89 (Scheme 46). The authors proposed a mechanism of photorelease from these compounds that is similar to that proposed for 83. The authors demonstrated that the reaction medium, including solvent, pH, and buffer concentration, affects the rate of release (Scheme 45). For example, in methanol (pH up to 8), the rate of release from... 

Similarly with the raising of the b.p. in violet or reddish-violet soln. of iodine in benzophenone, carbon disulphide, ethyl chloride, chloroform, carbon tetrachloride, ethylene chloride or benzene or in brown soln. of ethyl alcohol, methyl alcohol, thymol, ethyl ether, methylal, or acetone. The values for the last three solvents were rather low, presumably because of the chemical action of solute on solvent. High values with benzene are attributed to the formation of a solid soln. of solvent and solid. Confirmatory results were found by J. Hertz with naphthalene, and by E. Beckmann and P. Wantig with pyridine. The results by I. von Ostromisslensky (o-nitrotoluene), by G. Kriiss and E. Thiele (glacial acetic acid), and by H. Gautier and G. Charpy indicate polymerization, but they are not considered to be reliable. 

The heats of sublimation of mon-, di and trinitro aromatics are listed in Table 6. Consider the nitrobenzenes for which the specific heats of sublimation are 0.117, 0.115 and 0.109Kcal/g for the mono-, di- and trinitro derivatives, respectively. In this grouping, the specific heats of sublimation are essentially constant. This is not the case for the nitrotoluenes, for which the corresponding heats of sublimation are 0.138, 0.129 and 0.113Kcal/g. For the nitro-anilines these values are 0.151 and 0.122Kcal/g for o-MNA and 2,4,6-TNA, respectively... 

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