Toluene p-sulphonyl chloride

Mix 1 0 g. of the phenol with 2 5 ml. of pyridine, add 2 g. of p-toluene-sulphonyl chloride, and heat on a water bath for 15 minutes. Pour into 25 ml. of cold water and stir until the oil solidifies. Filter, wash with cold dilute hydrochloric acid (to remove pyridine), with cold dilute sodium hydroxide solution (to remove any phenol present), and then with cold water. Recrystallise from methyl or ethyl alcohol. 

Methyl p-toluenesulphonate. This, and other alkyl esters, may be prepared in a somewhat similar manner to the n-butyl ester with good results. Use 500 g. (632 ml.) of methyl alcohol contained in a 1 litre three-necked or bolt-head flask. Add 500 g. of powdered pure p-toluene-sulphonyl chloride with mechanical stirring. Add from a separatory funnel 420 g. of 25 per cent, sodium hydroxide solution drop by drop maintain the temperature of the mixture at 23-27°. When all the alkali has been introduced, test the mixture with litmus if it is not alkaline, add more alkali until the mixture is neutral. Allow to stand for several hours the lower layer is the eater and the upper one consists of alcohol. Separate the ester, wash it with water, then with 4 per cent, sodium carbonate solution and finally with water. Dry over a little anhydrous magnesium sulphate, and distil under reduced pressure. Collect the methyl p-toluenesulphonate at 161°/10 mm. this solidifies on cooling and melts at 28°. The yield is 440 g. 

The next and only other major kinetic study was carried out by Jensen and Brown184, who used aluminium chloride as catalyst, nitrobenzene as solvent, benzene- and p-toluene-sulphonyl chlorides as sulphonylating agents and benzene, chlorobenzene, alkyl- and polyalkylbenzenes as aromatic substrates184. 

This type of reaction was originally carried out with ethyl iodide1 and has been extended to other alkyl halides,2 halogeno-carboxylic esters3 and to substituted arsine halides.4 Incidentally when p-toluene sulphonyl chloride and naphthalene-2-sulphonyl chloride were allowed to react with sodium diethyl phosphite, the corresponding disulphones were obtained in small yield.5... 

Prepare a solution of sodium hydroxide (40 g, 1 mol) in distilled water (200 mL) and cool to room temperature. Place the solution in a 2L two-necked round-bottomed flask fitted with a thermometer and add a solution of tetraethylene glycol (68 g, 60 mL, 0.35 mol) in THF (200 mL) while stirring. Put the flask in an ice bath and cool to 0 °C. Place a solution of p-toluenesulphonyl chloride (145 g, 0.76 mol) in THF (200 mL) in a pressure-equalized addition funnel and add dropwise to the stirred glycol solution over 3 h or so. Carefully monitor the temperature of the solution and keep below 5 °C throughout. Once the addition of the p-toluene-sulphonyl chloride solution is complete, continue to stir the solution for a further 1 h at below 5 °C. Pour onto a mixture of ice and water (250 g/250 mL) and continue to stir. When all the ice has melted, remove most of the THF by rotary evaporation and extract the product into dichloromethane (3 x 100 mL). Dry the dichloromethane extract over calcium chloride, filter and remove the solvent by rotary evaporation. The product, tetraethylene glycol ditosylate (3), is obtained as a colourless oil. 

Step-1. The cis-5-hydroxy-2-propyl cyclopentane on being treated with p-tosyl chloride ii.e., p-toluene sulphonyl chloride) in the presence of dry pyridine yields the corresponding cis-tosyl derivative. 

It is very important to note that the solution of 2-hexyl-2-(hydroxymethyl)-1,3-propanediol in pyridine must be added to the solution of nicotinic acid, p-toluene sulphonyl chloride in pyridine almost dropwise with frequent stirring (below 80°C). 

Trifluoroacetic anhydride is a most effective catalyst for the direct esterification of carboxylic acids by primary, secondary, and tertiary alcohols. Esterification proceeds under mild conditions via a mixed anhydride but is not successful with carboxylic acids of very low pKa and hydroxy acids when the reagent promotes lactonisation or polymerization [23, 24]. Dibasic acids may be esterified if they do not readily form cyclic anhydrides. Reagents such as trifluoromethane sulphonic anhydride [25], acetyl chloride [26], pyridine/p-toluene-sulphonyl chloride [27], sulphury chloride [28], thionyl chloride [29], and pyridine/phosphorus oxychloride [30] probably act in a similar way to trifluoracetic anhydride as reagents for direct esterification. 

Hinsberg s separation of amines. A mixture of primary, secondary and tertiary amines may be separated by treatment with p-toluene-sulphonyl chloride, which reacts with primary amines to give mono-sulphonyl derivatives soluble in alkali, and converts secondary amines to alkali-insoluble sulphonyl derivatives, but does not react with tertiary amines. 

The p-toluenesulphonate may alternatively be prepared by the Schotten-Baumann method (see below) substituting p-toluene-sulphonyl chloride for benzoyl chloride. 

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