The Preparation of Allyl Iodide[1]
Reported methods for the preparation of allyl iodide involve the reaction of allyl alcohol or glycerol with either hydriodic acid or phosphorus and iodine[2]. We find that preparative quantities of allyl iodide may be obtained very conveniently by the action of sodium iodide on allyl chloride in acetone. This preparation is based on a reaction investigated kinetically by Conant, Kirner and Hussey[3].
A mixture made of 0.6 mole (45.9g) of allyl chloride, 0.75 mole (113g) of sodium iodide, and 100ml of acetone was warmed on the steam-bath for three hours and then poured into 500ml of water. The organic layer was separated, washed with both a dilute sodium bisulfite solution and with water, dried over sodium sulfate, and distilled. The yield of allyl iodide (bp 101-102°C) was 63.1g (62.6%). When the reflux time was increased to twenty-four hours and 200ml of acetone was used as solvent, the yield was increased to 76.7%.
References:
[1] JACS 70, 2818 (1938).
[2] JACS 61, 226 (1929); JACS 38, 1076 (1916); JACS 36, 1005 (1914); Ann., 116, 156 (1870).
[3] JACS 47, 488 (1925).
