Toluene p-sulphonamide

Toluene-p-sulphonamide can be similarly converted into the dimethyl-amide, but the methylation now occurs in two definite stages. First the sulphonamide dissolves in the sodium hydroxide to form the mono-sodium salt (see p. 252), which then reacts with the dimethyl sulphate to give the mono-... 

Dissolve log. of powdered toluene-p-sulphonamide in 6o ml. of 10% aqueous sodium hydroxide (2 5 mols.) diluted with 50 ml. of water to moderate the reaction. Then, using the same precautions as in the previous preparation, add 127 ml. (17 g., 2 3 mols.) of dimethyl sulphate and shake the mixture vigorously. The crystalline dimethylamide rapidly separates from the warm... 

Dichloramine-T. Dilute 80 ml, of freshly prepared 2N sodium hypochlorite soluticMi (preparation, p. 525) with 80 ml. of w ter, and then add with stirring 5 g. of finely powdered toluene-p-sulphonamide, a clear solution being rapidly obtained. Cool in ice-water, and then add about 50 ml. of a mixture of equal volumes of glacial acetic acid and water slowly with stirring until precipitation is complete the dichloro-amide separates at first as a fine emulsion, which rapidly forms brittle colourless crystals. Filter off the latter at the pump, wash well with... 

Choice of solvent for recrystallisation Obtain small samples (about 0.5 g) of the following compounds from the storeroom (i) salicylic acid (ii) acetanilide (iii) m-dinitrobenzene (iv) naphthalene and (v) toluene-p-sulphonamide. Use the following solvents distilled water, industrial spirit, rectified spirit, acetone, toluene, glacial acetic acid and hexane. 

The strong characteristic i.r. absorption of the S02 (or SO) group exhibited by all these compounds is clearly apparent in the spectrum of toluene-p-sulphonamide (Fig. 3.40). In addition, the absorption arising from the presence of the OH, Cl, NH2 or OR groups is usually easily assigned. The confirmation of aromatic substitution patterns by inspection of the p.m.r. spectra is described in the preparative examples below, wherein the fragmentation patterns observable in the m.s. are also discussed. 

When toluene-p-sulphonamide is dissolved in excess calcium hypochlorite solution and then acidified with acetic acid, the /V,/V-dichloro derivative [(6) dichloramine-T] separates rapidly. When this is heated with sodium hydroxide solution the sodium salt of the N-monochloro derivative [(7) chloramine-T)] is formed and crystallises out on cooling at a suitable concentration (Expt 6.43). 

Toluene-p-sulphonamide. Grind together 10 g (0.0525 mol) of toluene-p-sulphonyl chloride (Expt 6.41) and 20g of ammonium carbonate in a mortar until a fine uniform powder is obtained. Heat the mixture in an evaporating dish on a water bath for 1-2 hours and stir the mixture frequently with a glass rod. Allow to cool and extract with a little cold water to remove the excess of ammonium salts. Recrystallise the crude toluene-p-sulphonamide from boiling water (200-250ml), and dry the colourless crystals at 100 °C. The yield of pure product, m.p. 138 °C, is 7.9 g (88%). 

Dichloramine-T(jV,jV-dichlorotoluene-p-sulphonamide). Prepare about 200 ml of a saturated solution of calcium hypochlorite by grinding a fresh sample of bleaching powder with water and filtering with slight suction. Dissolve 5 g (0.029 mol) of toluene-p-sulphonamide in as small a volume of the calcium hypochlorite solution as possible (about 150 ml) and filter the solution if necessary. Cool in ice, and add about 50 ml of a mixture of equal volumes of glacial acetic acid and water slowly and with stirring until precipitation is complete. The dichloramine-T separates out first as a fine emulsion, which... 

Photo-substitution of benzene by the imidazolinone (294 R = Cl) yields the diphenyl compound (294 R = Ph). ATV -Diacetylimidazolin-2-one gives the Diels-Alder adduct (295) with cyclopentadiene, and the photoadduct (296) with ethylene.Treatment of 7V7V -dimethylimidazoline-2-thione with bromine and toluene-p-sulphonamide leads to the thione-5-imide (297). The thione-thiol tautomerism of the nitroxides (298)= 299) has been studied by e.s.r. spectroscopy... 

Tamaru et a 1. The products (125) are produced in good yields from the alkenyl toluene-p-sulphonamides (124) and under mild conditions. In a related procedure, Pd1 -catalysed cyclization of the allenic amine derivatives (126) in the presence of carbon monoxide and... 

The sulphonylation method may be used for the S3mtheses of dichloramine-T and chloramine-T starting from toluene-p-sulphonamide and dichloramine-T respectively. 

Step II. Preparation of Dichloramine-T from toluene-p-sulphonamide. 

Toluene-p-sulphonyl chloride either on heating with ammonium carbonate or liquid ammonia replaces the chloro group with an amino moiety to result the formation of toluene-p-sulphonamide and a mole of HCl gets eliminated. 

Procedure. In actual practice, there are two different procedures that are used for the S3mthesis of toluene-p-sulphonamide as given below ... 

Method-II. An alternate equally effective and feasible method for the preparation of toluene-p-sulphonamide is as stated below ... 

Filter the crude product and reciystallize the toluene-p-sulphonamide from boiling water (add 0.5 g of decolourizing carbon, if required). The 3rield of pure product (mp 137.5-138°C) is nearly to that of theoretical 3ueld (4.89 g). 

Toluene-p-sulphonamide = 171.15 g 5 g of Toluene-p-sulphonyl chloride shall 3ueld... 

Hence, Theoretical yield of Toluene-p-sulphonamide = 4.89 g Reported Practical yield = 4.1 g... 

Add to the above solution 5 g of finely powdered toluene-p-sulphonamide with constant stirring so as to obtain a rapid clear solution. 

Toluene-p-sulphonamide must be pulverised to fine powder before it is used in the reaction to get better 3neld. 

Method-I. From Dichloramine-T, and Method-II. Direct from Toluene-p-Sulphonamide. 

The interaction between toluene-p-sulphonamide with freshly prepared sodium hypochlorite solution (2 M) in the presence of 10% NaOH solution results into the formation of chloramine-T, and a mole of H2O gets eliminated. 

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