Toluene from -toluidine

Dissolve the substance in water and warm gently. Effervescence occurs and a dark coloured oil separates, which has the aincll of phenol. When effervescence ceases, cool and shake ii j with a little ether. Decant the ether into a dry test-tube. Evapoiate the ether and test the residue for phenol, see p. 179. 

Dissolve the substance in cold water and add it to a solution of phenol in caustic soda, drop by drop. An orange crystalline precipitate of hydvoxya/,obcn/ene is formed. Repeat, using /3 n.iphthol in place of phenol. A scarlet precipitate is obtai ned. 

Dissolve in cold water and add a fevv drops of aniline, and shake up. Diazoaminobenzene separates out as a yellow crystalline precipitate. 

Ilcato 5 gram of the dry substance on an iron tray. It decomposes with slight explosion. 

Any of the dia/o-compound which remains over should be dissolved in water and poured away. See Appendix p. 282. 

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Toluene from Toluidine.—It is often desirable to obtain tbe hydiocarbon from the base. The process of diazotisntion offers the only convenient method. The diazonium salt may be reduced by alcohol (Reaction 1, p. 162) or, as in the piesent instance, by sodium stannite. Less direct methods are the con-veision of the diazonium compound into (i) the hydrazine (see p. 174), (2) the acid and distillation with lime (p. 200), (3) the halogen derivative and reduction with sodium amalgam, 01, finally (4) the phenol and distillation with zinc dust. 

Tartaric acid, 114 Terephthalic acid, i7r Tetrabromocresol, 165 7 hiocarbamide, 128 Thiocarbanilamide, 159 Thiocarbanilide, 159 Thiourea, 128 /i-Tolyl bromide, 167 / Tolyl chloride, 165 /-Tolyl cyanide, 169 Tolyliodochloride, 169 Toluene from toluidine, 163 / Toluic acid, 170 Tribromophenol, 180 Trichloracetic acid, 99 Trimethylxanthine, 131 l rinitrophenol, 185 Triphenylguanidine, ito Triphenylmetbane, 2 4 J schugac s hydroxyl method, 223 Tube furnace, 23 Tyrosine, 133... 

Toluenesulfinic acid and its salts have been prepared by three general methods (1) The reduction of the sulfonyl chloride. The reagents which have been used for this arc sodium amalgam,1 zinc dust in alcohol or water,2 sodium sulfite,3 sodium sulfide,4 potassium hydrosulfide 5 (the thio acid being first formed) and sodium arsenite.6 (2) From toluene by the Friedel and Crafts reaction, using either sulfur dioxide and hydrogen chloride 7 or sulfuryl chloride.8 (3) From -toluidine by diazotization and... 

Toluene. from-o-Toluidine. In a 1-L flask are placed 21.4 g. (0.2 mole) of o-toluidine, 76 cc. of concentrated hydrochloric acid (sp. gr. 1 19), and 26 cc. of water. The flask is immersed in an ice-salt mixture and is fitted with an effident stirrer. While a temperature of —6° to 0° is maihtained, a solution of 14.6 g. (0.204 mole) of 97% sodium nitrite in 36 cc. of water is slowly added from a dropping fvmnel. As the reac- tion proceeds, the mixture becomes more fluid and the nitrite may be added somewhat more rapidly one-half to three-quarters of an hour is required for diazotization. 

While the direct halogenation of toluene gives a mixture of isomers that is difficult to separate into the pure isomers, the isomeric o- and /r-nitrotoluenes 6a and 6b, formed by nitration, are easy to separate from each other. Thus reduction of the single o- or /j-nitrotoluene 6 to the o- or /j-toluidine 7a or 7b respectively, followed by conversion into the corresponding diazonium salt 8 and a subsequent Sandmeyer reaction leads to the pure o- or /j-halotoluene 9. 

The hydrogenation of toluene, aniline, /r-toluidine, and 4-tert-butylaniline was examined over catalyst M1273. The reaction profile for the reactions is shown in Figure 2. From this it can be seen that the order of reactivity is aniline > toluene > /Moluidinc > 4-fer f-butylaniline. The hydrogenation products were methylcyclohexane from toluene, cyclohexylamine from aniline, 4-methyl-cyclohexylamine (4-MCYA) from /Holuidine. and 4-feri-butylcyclohexylamine (4-tBuCYA) from 4-tert-butylaniline. At 50 % conversion the cis trans ratio of 4-MCYA was 2, while tBuCYA it was 1.6. 

Similarly, benzene and hydrazoic acid in the presence of a mixture of fluorosulphonic and trifluoromethanesulphonic acid give aniline quantitatively. From toluene 100% of a mixture of o-, m- and p-toluidines is obtained and bromobenzene yields 42% o-bromoaniline and 47% p-bromoaniline, Butyl azide gives iV-butylarylamines under these conditions89. Photolysis of 1-aminoquinolinium perchlorate (76) in aromatic hydrocarbons (benzene, toluene, ethylbenzene or mesitylene) in the presence of 18-crown-6 affords arylamines, e.g. aniline and p-toluidine, by way of the nitrenium ion90 cf Reference 91. 

Biological. Under anaerobic conditions using a sewage inoculum, 3-nitrotoluene and 4-nitrotoluene both degraded to toluidine (Hallas and Alexander, 1983). Robertson et al. (1992) reported that toluene dioxygenases from Pseudomonas putida FI and Pseudomonas sp. Strain JS 150 oxidized the methyl group forming 3-nitrobenzyl alcohol. 

Nitration via diazotisation has been extensively used for the synthesis of isomeric dinitronaphthalenes. Ward and co-workers used nitration via diazotisation to prepare 3,3, 4,4 -tetranitrobiphenyl from 3,3 -dinitrobenzidine, and 3,4,5-trinitrotoluene from 3,5-dinitro-4-toluidine. Ward and Hardy " prepared 1,4,6-trinitronaphthalene from 4,7-dinitro-1-naphthylamine. Korner and Contardi used the nitrate salts of aryldiazonium compounds for the synthesis of polynitro derivatives of benzene " and toluene. " " Accordingly,... 

The method of preparation adopted is substantially that of Buchka,3 as this is the only one of practical value. fw-Nitro-toluene has been obtained by a similar process from s-nitro-2-aminotoluene 4 (obtained by nitration of acetyl-0-toluidine), but this compound is not commercially available, and gives a poor product unless carefully purified. 

Problem 19.28 Prepare (a) 2-bromo-4-hydroxytoluene from toluene, (b) 2-hydroxy-5-methylbenzaIdehyde from p-toluidine, (c) m-methoxyaniline from benzenesulfonic acid. M... 

Typical primary amines which undergo such nitrosation are m-toluidine, p-xylidine, m-anisidine, 2-amino-4-methoxytoluene, 3-amino-4-methoxy-toluene, m-aminophenol, a-naphthylamine, l-naphthylamine-2-, -6-, -7-, and -8-monosulfonic acids, and l-naphthylamine-4-monosulfonic acid (which reacts with displacement of the sulfonic acid group). The secondary amines derived from these primary amines also can be nitrosated directly (i.e., without the intermediate formation of an JV-nitroso compound which needs to be subjected to the Fischer-Hepp rearrangement). The entering nitroso group appears to substitute exclusively in the para position. 

Diaminotoluene has been prepared from 2,4-dinitro-toluene by reduction with iron and acetic acid,2 and by electrolytic reduction 3 from 4-nitro-o-toluidine by reduction with tin and hydrochloric acid 4 and from 2,4-dinitrobenzoyl chloride with tin and hydrochloric acid. ... 

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