To a solution of
30 g. (0.4 mole) of anhydrous trimethylamine oxide (Note
1) in
100 ml. of dry chloroform placed in a
250-ml. three-necked, round-bottomed flask fitted with a
reflux condenser, a
stirrer, and a
dropping funnel with protection against moisture is added
48.0 g. (0.2 mole) of n-octyl iodide (Note
2) dropwise with stirring. At the beginning of the addition the flask is warmed to 40–50° on a
steam bath to initiate the reaction. The start of the reaction can be recognized by the evolution of heat, and the rate of addition can then be adjusted to maintain the temperature around 50°. Overall the addition requires about 20–30 minutes. When addition is complete, the solution is boiled under reflux for another 20 minutes. Then the solution is cooled, and
110 ml. of 2N aqueous sulfuric acid solution is added with stirring. The
chloroform layer is separated and washed successively with water,
2N aqueous sodium carbonate solution, and again with water. After the
chloroform solution has been dried over
sodium sulfate, it is concentrated under reduced pressure, and then the residue is distilled. The first distillation (Note
3) is carried out at atmospheric pressure and gives
12.0–12.5 g. of a crude oil, b.p.
155–165°. Redistillation using a
simple Vigreux column gives
10.6–11.0 g. (
41.5–43%) of a colorless oil, b.p.
69–71° (19 mm.),
n26D 1.4167.