n-Butyl p-sulfonate (CAS NO.: ), which is also known as , butyl ester, could be produced through the following synthetic routes.

In a 2-l., three-necked flask, fitted with a mechanical stirrer, a thermometer, and a 250-cc. separatory funnel, are placed 148 g. (2 moles) of n-butyl alcohol and 210 g. (1.1 moles) of pure p-toluenesulfonyl chloride. From the separatory funnel 320 cc. (1.6 moles) of 5 N sodium hydroxide is run in at a rate that does not cause the temperature of the reaction mixture to exceed 15°; the addition requires three to four hours.

Another portion of 210 g. (1.1 moles) of p-toluenesulfonyl chloride is added and then 320 cc. of 5 N sodium hydroxide solution is slowly introduced, again keeping the temperature below 15°. Stirring is continued for four hours longer, and the oily layer is separated from the water layer and any unchanged p-toluenesulfonyl chloride. Enough petroleum ether (b.p. 60–70°) or benzene is added to the oil to cause it to float on water; the solution is washed thoroughly with 50 cc. of 10 per cent sodium hydroxide and dried by standing overnight over 20 g. of anhydrous potassium carbonate. The solution is filtered, and the solvent is distilled. This is conveniently accomplished by adding the solution from a separatory funnel to a 500-cc. Claisen flask heated on a steam bath. The oily ester is then distilled under reduced pressure, and, after a forerun boiling to 170°/10 mm., the pure ester distils at 170–171°/10 mm. The yield is 250–270 g. (50–54 per cent of the theoretical amount).