Synthesis of propyl thiocyanate

Preparation of propyl thiocyanate ((propylsulfanyl)carbonitrile; propylthiocyanate)

Preparation of propyl thiocyanate ((propylsulfanyl)carbonitrile; propylthiocyanate)

A 1-liter three-necked flask is fitted with an air-tight stirrer, a reflux condenser, and a 250 ml separatory funnel. 133 grams of potassium thiocyanate and 310 ml of  95% ethanol are placed in the flask. The mixture is stirred vigorously and heated to boiling. From the separatory funnel, 113.5 ml (154 g) of n-propyl bromide are dropwise added during the course of 15-20 minutes. The mixture is refluxed, with vigorous stirring, for 5 hours, then cooled to room temperature. The solution is filtered in order to remove the precipitated potassium bromide and washed with 75 ml of 95% ethanol. The alcohol is removed by evaporation and the residue is treated with water, the upper layer of n-propyl thiocyanate is separated. The aqueous layer is extracted with ether, the extracts are combined, dried with anhydrous sodium or magnesium sulfate, and ether is removed by evaporation. The residue is distilled through an efficient fractionating column. A little ether, ethyl alcohol and water pass over first (to 110° C); the temperature then rises rapidly to 164-165° C and the remainder distils constantly at 165° C. The yield of n-propyl thiocyanate is 93 g.

A text book of practical organic chemistry, by A. I. Vogel, 305-306, 1974

Related Syntheses:

Synthesis of butyl thiocyanate Synthesis of N-amyl-thiocyanate Synthesis of N-octyl-thiocyanate Synthesis of cyclohexyl thiocyanate Synthesis of N-nonyl thiocyanate