A dry
1-l. three-necked flask fitted with a
mercury-sealed stirrer, a
calcium chloride drying tube, and a
500-ml. dropping funnel, protected by a calcium chloride drying tube, is surrounded by an ice-salt mixture at −11°. Anhydrous
methanol (130 ml.) (Note
1) and (Note
2) and
161 g. (1 mole) of β-chlorovinyl isoamyl ketone (
p. 186) are poured into the flask (Note
3). A solution of
43 g. (1.04 moles) of sodium hydroxide (97%) and
350 ml. of absolute methanol (Note
4) is added dropwise with stirring over a period of 2 hours, during which time the bath temperature is kept between −11° and −8°.
The reaction mixture is poured, with stirring, into
1 kg. of a saturated sodium chloride solution (Note
5). The mixture is extracted with four
100-ml. portions of low-boiling petroleum ether. The extracts are combined and dried over anhydrous
potassium carbonate. The liquid is decanted, the
potassium carbonate is washed with
25 ml. of low-boiling petroleum ether, and the solution is added to the main fraction. A pinch of anhydrous
potassium carbonate is added to the
petroleum ether solution, and the solution is then distilled from a
Claisen flask to give a colorless liquid; yield
151–169 g. (
80–90%); b.p.
122–125°/25 mm.; n
D25 1.4260; d
425 0.932 (Note
6).