and Iodocyclohexane could be produced through the following synthetic routes.

A. Neopentyl iodide. A 500-ml., two-necked, round-bottomed flask fitted with a reflux condenser equipped with a calcium chloride drying tube is charged with 136 g. (115 ml., 0.439 mole) of triphenyl phosphite, 35.2 g. (0.400 mole) of neopentyl alcohol, and 85 g. (37 ml., 0.60 mole) of . A thermometer of sufficient length extends into the liquid contents of the flask. The mixture is heated under gentle reflux with an electric heating mantle until the temperature of the refluxing liquid rises from its initial value of 75–80° to about 130°, and the mixture darkens and begins to fume. The time required is about 24 hours. It is necessary to adjust the heat input from the mantle from time to time as the reaction proceeds and the reflux rate diminishes.

The reaction mixture is distilled under reduced pressure through a 13-cm. Vigreux column. The fraction boiling below 65° (50 mm.) is collected and washed with 50 ml. of water, then with 50-ml. portions of cold 1 N sodium hydroxide until the washings no longer contain phenol. The product is washed again with 50 ml. of water, dried over calcium chloride and redistilled, yielding 51–60 g. (64–75%) of neopentyl iodide, b.p. 54–55° (55 mm.), n_D21 1.4882.

B. Iodocyclohexane. A 500-ml., two-necked, round-bottomed flask fitted with a reflux condenser equipped with a calcium chloride drying tube is charged with 124 g. (107 ml., 0.400 mole) of triphenyl phosphite and 85 g. (37 ml., 0.60 mole) of methyl iodide. A thermometer of sufficient length extends into the liquid contents of the flask. The mixture is heated under gentle reflux with a heating mantle until the internal temperature has risen to about 120°. At this point the mixture is dark and viscous. The flask is cooled, and 40 g. (0.40 mole) of cyclohexanol is added to the oily methyltriphenoxyphosphonium iodide. The mixture is shaken gently until homogeneous and allowed to stand overnight at room temperature. The mixture is distilled through a 13-cm. Vigreux column, yielding 62.5–63 g. (74–75%) of iodocyclohexane, b.p. 66–68° (12 mm.), n_D22 1.5475.

Notice: Methyl iodide, in high concentrations for short periods or in low concentrations for long periods, can cause serious toxic effects in the central nervous system. Accordingly, the American Conference of Governmental Industrial Hygienists2 has set five p.p.m., a level which cannot be detected by smell, as the highest average concentration in air to which workers should be exposed for long periods. The preparation and use of methyl iodide should always be performed in a well-ventilated fume hood. Since the liquid can be absorbed through the skin, care should be taken to prevent contact.