In a
3-l. round-bottomed, short-necked flask,
1363 g. (10 moles) of anhydrous zinc chloride is dissolved in
864 cc. (10 moles) of concentrated hydrochloric acid, the flask being cooled to prevent loss of
hydrogen chloride (Note
1). To this solution is added
371 g. (5 moles) of n-butyl alcohol. The flask is attached to a
vertical, water-cooled reflux condenser (Note
2), the top of which carries a
thermometer and a
goose-neck tube connected with an efficient downward condenser. To the end of the downward condenser is attached a
1-l. Florence flask which is connected to a
250-cc. Erlenmeyer flask by a bent tube. A tube from the second receiving vessel is connected with a
gas-absorption trap (Note
3) or to a funnel inverted over
800 cc. of 10 per cent sodium hydroxide solution in a
1-l. beaker. Rubber stoppers are used throughout. Both the receiving vessels are cooled in a
large ice-salt bath.
The flask is heated by an
oil bath to 150° (bath temperature), at which temperature the solution starts to boil and
butyl chloride begins to distil. After a few moments, it is necessary to control the temperature in the reflux condenser at 75–80° by a very slow stream of water. The temperature of the oil bath is gradually raised to 155°, and one hour from the time of initial boiling practically all the
butyl chloride has distilled. If necessary, however, heating at 155° may be continued for ten to fifteen minutes longer and the temperature of the bath then raised to 160–165°, the reflux temperature not being allowed to get above 80°. The distillate is washed with 100 cc. of cold water,
50 cc. of cold concentrated sulfuric acid (in four portions), 10 cc. of water, and finally with
25 cc. of 10 per cent sodium carbonate solution. It is dried over
10 g. of calcium chloride and distilled (Note
4) and (Note
5). The fraction boiling from
75.5° to 77.5° weighs
352–361 g. (
76–78 per cent of the theoretical amount). (Note
6).