Through the separatory funnel are introduced 1.6 l. of water,
500 cc. of c. p. acetone, and
372 cc. of glacial acetic acid. The stirrer is started and the temperature of the
water bath is raised to 70–80°, so that the mixture in the flask is at about 65° (Note
2). Then
354 cc. (7.3 moles) of bromine is carefully added through the separatory funnel. The addition, which requires one to two hours, is so regulated as to prevent the accumulation of unreacted
bromine (Note
3). As a rule the solution is decolorized in about twenty minutes after the
bromine has been added. When the solution is decolorized, it is diluted with 800 cc. of cold water, cooled to 10°, made neutral to
Congo red with about
1 kg. of solid anhydrous sodium carbonate, and the oil which separates is collected in a separatory funnel and dried with
80 g. of anhydrous calcium chloride. After drying, the oil is fractionated and the fraction boiling at
38–48°/13 mm. is collected. The yield is
470–480 g. (
50–51 per cent of the theoretical amount). It may be used without further purification for the preparation of
acetol (p. 5); but, if a purer product is desired, the above product is refractionated and the fraction boiling at
40–42°/13 mm. is collected. The yield is
400–410 g. (
43–44 per cent of the theoretical amount).