In a
3-l. three-necked round-bottomed flask fitted with a
reflux condenser and a
mercury-sealed stirrer,
250 g. (2 moles) of 1,3-dichloro-2-butene (Note
1) and
1.25 l. of 10% sodium carbonate are heated at reflux temperature for 3 hours. The
3-chloro-2-buten-1-ol is extracted with three
300-ml. portions of ether, which are then dried over anhydrous
magnesium sulfate. The
ether is removed by distillation through a
20-cm. Fenske column, and the residue is distilled from a
250-ml. Claisen flask, yielding
134 g. (
63%) of
3-chloro-2-buten-1-ol, b.p.
58–60°/8 mm.,
n20D 1.4670.
A solution of
sodium amide in liquid ammonia is prepared according to the procedure described on
p. 763 using a
4-l. Dewar flask equipped with a plastic cover (Note
2) and a
mechanical stirrer. Anhydrous
liquid ammonia (3 l.) is introduced through a small hole in the plastic cover, and
1.5 g. of hydrated ferric nitrate is added followed by
65 g. (2.8 g. atoms) of clean, freshly cut sodium. The mixture is stirred until all the
sodium is converted into
sodium amide, after which
134 g. (1.26 moles) of 3-chloro-2-buten-1-ol is added over a period of 30 minutes. The mixture is stirred overnight, then
148 g. (2.8 moles) of solid ammonium chloride is added in portions at a rate that permits control of the exothermic reaction. The mixture is transferred to a metal bucket (5-l., preferably of stainless steel) and allowed to stand overnight in the hood while the
ammonia evaporates. The residue is extracted thoroughly with five
250-ml. portions of ether, which is removed by distillation through a 20-cm. Fenske column. Distillation of the residue yields
66–75 g. (
75–85%) of
2-butyn-1-ol, b.p.
55°/8 mm.,
n20D 1.4550 (Note
3).