Toluene, p-Nitro

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 - ... 

In contrast to the parent substance of the series, p-tolylhydroxyl amine, which is prepared by the reduction with zinc dust of p-nitro-toluene in boiling alcohol, is a quite stable compound. 

The methods of measuring the liquid phase properties were described previously [1], It was observed that heat was evolved during the preparation of all these mixtures. It should be mentioned that the electrical conductivities of the sulphuric acid-nitromethane mixtures were not constant, but were found to increase with time. Reliable data could therefore not be obtained. This is due to the fact that nitromethane reacts with sulphuric acid in dilute solutions, as has been recently discussed by Gillespie and Solomons [6]. All other properties of these mixtures were constant at 25° and measurements were restricted to this temperature. For the other four systems the viscosity, electrical conductivity and density were investigated at two temperatures 25° and 40°), because of the importance of the temperature coefficients of viscosity and electrical conductivity. The refractive indexes were measured only at 25°. The investigation of the liquid phase properties of the system with p-nitro toluene at these temperatures was possible only up to 50 mole % of p-nitrotoluene, i.e. until the solutions became saturated with respect to p-nitrotoluene. The refractive indexes of these solutions were not measured. 

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-nitro toluene 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. Recrystallise 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. 

In all discussions of the application of the rule we make reference to the principal products of the reaction substitution occurs for the most part in accordance with the rule, or with the exceptions, and small amounts of other materials arc usually formed as by-products. In the mononitration of toluene, for example, about 96 per cent of the product is a mixture of o- and p-nitro-toluene, and about 4 per cent is the m-compound. Under the influence of ortho-para orienting groups, substitution occurs in the two positions without much preference for either one, but it appears to be the case that, when nitro groups are introduced, low temperatures favor the formation of p-coinpounds. The effect... 

Haussermann 2 reduced nitrobenzene and nitrotoluenes both in alkaline and acid solution, the former with iron, the latter with platinum, electrodes. By reduction in alkaline solution, he obtained as principal product hydrazobenzene and hydrazo-toluene respectively in sulphuric-acid solution he got from nitrobenzene, as chief products, benzidine sulphate and azoxy-benzene, besides an easily changeable body which was not further determined. o-Nitrotoluene3 under like conditions gave o-tolui-dine sulphate besides small quantities of o-toluidine p-nitro-toluene yielded principally p-toluidine. 

In the presence of acetic anhydride, acetic acid, and sulfuric acid, chromic acid (chromium trioxide) converts o-nitrotoluene and p-nitro-toluene into the corresponding nitrobenzaldehyde diacetates, from which the aldehydes are obtained on hydrolysis (equation 174) [547, 548, 549. ... 

Pure products cannot be obtained by the mercuration of p-nitro-toluene with mercuric acetate at 140° C., so that the derivatives have been prepared from nitrotoluene suiphinic acids,... 

R. Fodisch, D. Honicke, Y. Xu, B. Platzer, Liquid phase hydrogenation of p-nitro-toluene in microchannel reactors, in M. Matlosz, W. Ehrfeld, J.P. Baselt (Eds.), Proceedings of the 5th International Conference on Microreaction Engineering (IMRET 5), Springer, Berlin, 2001, p. 470. 

Like radical side-chain bromination, side-chain chlorination by S02C12 and a peroxide occurs mainly on the a-carbon atom ethylbenzene gives mainly (l-chloroethyl)benzene cumol gives 90% of the a- and 10% of the /9-chloro product. Chlorine enters the jS-position of terf-butylbenzene. o- and p-Nitro-toluene cannot be converted into the corresponding benzyl chlorides by S02C12 and a peroxide.419... 

An initial fractional distillation under vacuum produces a distillate of nearly pure o-nitrotoluene. Its low content of a few per cent of p-nitro-toluene may be removed by recrystallization. After the fraction containing the o-nitrotoluene has been removed, a higher boiling fraction containing most of the m-isomer is recycled to build up its amount for vacuum fractionations to jdeld finally pure m-nitrotoluene. The still residue is cooled and crystallized to obtain pure p-nitrotoluene. The vacuum distillation under 12 mm pressure is run at about 96°C for the first fraction and at 97-107°C for the higher fraction. 

The type of the electrochemical cell (divided or undivided) can influence the EOI values especially for the treatment of benzene derivatives containing a -NO2 substituent. A typical example is the electrochemical treatment of p-Nitro Toluene Sulfonic acid (p-NTS) low EOI values (- 0,1) were obtained in the divided cell contrary to the undivided cell where high EOI values (0,5) were obtained. The increase of EOI values in the undivided cell is due to the cathodic reduction of -NOg group to -NH2 group, this transformation promotes the electrochemical oxidation as the substituent constant (a) for -NH2 has negative value (favouring the electrophilic attack on the benzene ring) contrary to the -NO2 substituent which has positive value (see 4 i). 

I is generally known tliai 2.4-dinitrotoluene is formed by nitration of o-and p-nitrotoluene and 2.6-dinitro isomer by nitration of o-niirotoluene. It was accepted that 2.3-. 3.4- and 3.6-isorners are produced from m-nitrotoluenc. Nevertheless it was firmly established that the nitration of o- and p-nitrotoluene can also produce a small proportion (below 0.5%) of 2,3 and 3,4-dinitrotoluene respectively (33 J. Also small proportions of other isomeric dinitrotoluenes, such as 2.3-. 2.5- and 3.4- was proved from o- and p-nitrololuenc respectively (34j. Ilii and co-workers (39] have found that the nitration of pure o- and p-nitro-toluene at —10°C with a nitrating mixture containing SO3 yielded only 0.17 dinitro- and trinitroproducts deriving from m-nitrotoluene. 

Of particular interest are ipso-additions - of an electrophile, since the respective a-complexes are in most cases unfavourable from the thermodynamic point of view. Therefore, one must be careful to draw conclusions on the initial ratio of isomeric a-complexes from the ratio of isomeric reaction products. Thus, the nitration of 4-isopropyltoluene (p-cymene) by nitronium tetrafluoroborate in sulpholane at 25 C gives 2-nitro- and 3-nitro-4-isopropyltoluenes as well as p-nitro-toluene with the yields 85.2, 5.3 and 9.5 %, respectively Accordingly the reactivity ratio of the 2- and 3-positions of p-cymene in the nitration is 16 1. However, in the nitration of p-cymene by acetylnitrate in acetic anhydride at 0 °C among the above reaction products (with 41.8 and 10% yields, respectively) there is a considerable amount (41%) of cis- and trans-isomers of l-nitro-4-acetoxy-l-methyl-4-isopropylcyclohexa-2,5-diene This may be due to the capture of the acetate-... 

The nitro-groups are completely reduced to amido-groups and a hydroxyl-group is taken up, always in a para-position to one of the amido-groups. As in the case of o-nitro-toluene sometimes also a sulpho-group is taken up. p-nitro-tolnene on electrolysis behaves differently. Here the final product has the composition C H N,0, and its formation is as follows p-Amido-benzyl alcohol is formed from p-tolyl-hydroxylamine (an intermediate product in the reduction of p-nitro-toluene) by molecular rearrangement,... 

The behavior of p-nitro-toluene is different, since in this case, the p-position being occupied by the nitro-group, an analogous reaction with formaldehyde is impossible. 

While p-nitro-toluene is converted in an alkaline solution smoothly into azo-toluene and in an acid solution into p-toluidene, nearly equal quantities of two different products are obtained in the presence of formaldehyde, viz. ... 

The Gesellschaft f. Chem. Industrie of Basel prepare orange dyes by using as cathode fluid an alkaline solution of the yellow condensation products of p-nitro-toluene-sulphonic acid,... 

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