Hexamethylene chlorohydrin (CAS NO.: ), which is also known as , 6-chloro-, could be produced through the following synthetic routes.

The apparatus shown in Fig. 14 is constructed from a 1-l. distilling flask (A) and a 500-ml. distilling flask (B) the side arm of which has been replaced by 10-mm. Pyrex tubing sealed at an upward angle to the side arm of the larger flask (A). Charred cork stoppers are used, and a hydrogen chloride trap2 is connected to the water-cooled reflux condenser. The bent side arm (C) is insulated by a wrapping of cloth. Reaction flask A is charged with 105 g. (0.89 mole) of hexamethyleneglycol,3 785 ml. (9.5 moles) of concentrated hydrochloric acid, 130 ml. of water, and 55 ml. of toluene. In flask B are put 350 ml. toluene and a few boiling chips. The apparatus is assembled, and the flasks are heated in oil baths. The bath covering about two-thirds of flask A is kept at 95°; the one surrounding most of flask B is kept between 160° and 165°. As the reaction proceeds and the products are removed by the continuous flow of toluene through the mixture, the organic-aqueous interface in A falls steadily. After 9 hours the heating baths and condensers are removed, and water is added to A to force the upper layer of toluene into B. The aqueous solution is siphoned out of A, and then the toluene extract in B is poured into a dropping funnel inserted through a stopper in the neck of a 500-ml. Claisen flask. Some of the extract is run into the flask, and most of the toluene is removed by distillation at atmospheric pressure while the remainder of the solution is slowly run into the flask. To remove the last of the solvent, the pressure is lowered to 65 mm. while the bath temperature is kept at 100°.

                        Fig. 14.

The material obtained from two such runs is combined and fractionated through a Fenske-Whitmore column4 packed with glass helices. Distillation is carried out at a pressure of 8–12 mm., with a reflux ratio of 5:1. After a fore-run of 5–15 g., about 45 g. (16%) of hexamethylene dichloride distils at 80–84°/9 mm., n²⁰D 1.4585–1.4565. An intermediate fraction of 10–20 g. distils at 84–100° /9 mm., and then 108–122 g. (45–50%) of hexamethylene chlorohydrin boiling at 100–104° /9 mm., n²⁰D 1.4551–1.4557, is collected. If several runs are made the residues may be distilled from a Claisen flask and the distillate combined with the intermediate fractions for refractionation. In this way the average yield may be raised to 50–55%.