In a 2-l. three-necked flask, fitted with a dropping funnel, mercury-sealed stirrer, and condenser, is placed 625 g. (3.2 moles) of n-butyl sulfite (p. 112). The condenser is connected to a gas absorption trap, and 217 g. (131 cc., 1.6 moles) of sulfuryl chloride (Note 1) is added over a period of thirty minutes, with rapid stirring and cooling with tap water. The dropping funnel is then replaced by a thermometer dipping into the liquid, and the flask is heated slowly, with stirring, until the refluxing of the butyl chloride becomes vigorous (about 100–110°). Sulfur dioxide is evolved copiously during this time. The condenser is replaced with a 40-cm. Vigreux column and downward condenser; the temperature is gradually raised to 130–135° and kept there until no more sulfur dioxide or butyl chloride distils. The heating and distillation require about two hours. The residue of crude n-butyl sulfate is cooled to room temperature, and 100 cc. of saturated sodium carbonate solution is added. The mixture is stirred for about ten minutes, poured into a separatory funnel, and let stand for thirty minutes to allow the layers to separate. The upper layer is dried with calcium chloride, at least overnight, and then allowed to stand over 15 g. of anhydrous sodium or potassium carbonate for a day, with occasional shaking. The product is filtered into a 500-cc. modified Claisen flask with a 25-cm. fractionating side arm, and distilled from an oil bath. The first distillation gives 250–280 g. (74–83 per cent of the calculated amount) of n-butyl sulfate, b.p. 110–114°/4 mm., which has a sharp odor. Redistillation gives a pure material with a slight ester odor, boiling at 109–111° at 4 mm., with only a small mechanical loss (Note 2).