Org. Synth. 1955, 35, 20
DOI: 10.15227/orgsyn.035.0020
2-BUTYN-1-OL
Submitted by P. J. Ashworth, G. H. Mansfield, and M. C. Whiting
1.
Checked by John C. Sheehan, George Buchi, and Walfred S. Saari.
1. Procedure
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. (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).
2. Notes
1.
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.
2.
The checkers used an ordinary flask, well insulated, for this reaction.
3.
Others have reported b.p.
91–93°/50 mm.,
n25D 1.4630;
2 b.p.
160.5°,
n25D 1.4635;
3 b.p.
160–161°,
n25D 1.4635, for
3-chloro-2-buten-1-ol, and b.p.
87–88° /100 mm.,
n25D 1.4520;
2 b.p.
140–141°,
n25D 1.4517
4 for
2-butyn-1-ol.
3. Discussion
2-Butyn-1-ol has been prepared as above for the first stage
2,3,4 but using aqueous
sodium hydroxide2 and alcoholic
potassium hydroxide4 for the second stage. The reaction between
propynylmagnesium bromide and
formaldehyde also has been employed.
5,6,7
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
ammonia (7664-41-7)
ether (60-29-7)
ammonium chloride (12125-02-9)
sodium hydroxide (1310-73-2)
formaldehyde (50-00-0)
sodium carbonate (497-19-8)
potassium hydroxide (1310-58-3)
sodium (13966-32-0)
magnesium sulfate (7487-88-9)
sodium amide (7782-92-5)
ferric nitrate
2-Butyn-1-ol (764-01-2)
1,3-dichloro-2-butene
3-Chloro-2-buten-1-ol (40605-42-3)
propynylmagnesium bromide
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