Organic Syntheses, Coll. Vol. 4, p.128 (1963); Vol. 35, p.20 (1955).
Caution! The experimental procedure involving liquid ammonia
should be conducted in a hood
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.
) of 3-chloro-2-buten-1-ol
, b.p. 58–60°/8 mm.
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.
) of 2-butyn-1-ol
, b.p. 55°/8 mm.
1.4550 (Note 3)
1,3-Dichloro-2-butene was obtained from Eastman Kodak Company
. Redistillation of the crude material did not appreciably alter the yield in the first stage of the reaction.
The checkers used an ordinary flask, well insulated, for this reaction.
Others have reported b.p. 91–93°/50 mm.
1.4635, for 3-chloro-2-buten-1-ol
, and b.p. 87–88° /100 mm.
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