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Org. Synth. 1930, 10, 60
DOI: 10.15227/orgsyn.010.0060
2-HEPTANOL
Submitted by Frank C. Whitmore and T. Otterbacher.
Checked by Henry Gilman and H. J. Harwood.
1. Procedure
In a 3-l. round-bottomed flask, fitted with an efficient Liebig condenser (100 by 1 cm.), 228 g. (2 moles) of methyl n-amyl ketone (Org. Syn. Coll. Vol. I, 1941, 351) is dissolved in a mixture of 600 cc. of 95 per cent alcohol and 200 cc. of water. One hundred thirty grams (5.6 gram atoms) of sodium in the form of wire is gradually added through the condenser. During the addition of the sodium the flask is cooled with running water (Note 1) so that the reaction does not become unduly violent (Note 2).
When the sodium has dissolved (Note 3), 2 l. of water is added and the mixture is cooled to 15°. The upper oily layer is then separated, washed with 50 cc. of 1:1 hydrochloric acid and then with 50 cc. of water, dried over 20 g. of anhydrous sodium sulfate, and distilled with a fractionating column (Note 4). After a small fore-run of low-boiling liquid, the pure heptanol distils at 155–157.5°. The yield is 145–150 g. (62–65 per cent of the theoretical amount).
2. Notes
1. If no cooling is used, condensation products are formed and the yield of heptanol is reduced considerably.
2. The temperature can be held conveniently below 30° by cooling with ice. Such cooling when accompanied by stirring is particularly helpful during the early addition of the sodium (either as wire or in small pieces). With cooling and stirring, very little refluxing takes place and after the addition of about 60 g. of sodium the reaction slows down to such an extent that large amounts of sodium can be added at once without danger of excessive heating.
3. The time required for addition of the sodium may be significantly decreased by the use of mechanical stirring. Although the yield is not increased appreciably by stirring, frothing is prevented and for this reason the sodium may be added more rapidly.
4. The submitters used a Young column with 20 disks 3 cm. apart. The checkers used a Glinsky three-bulbed column.
3. Discussion
2-Heptanol has been prepared by the action of n-amylmagnesium bromide on acetaldehyde,1 and by the reduction of methyl n-amyl ketone in alcoholic solution by means of sodium.2

References and Notes
  1. Henry, Rec. trav. chim. 28, 446 (1909).
  2. Thoms and Mannich, Ber. 36, 2544 (1903); Pickard and Kenyon, J. Chem. Soc. 99, 58 (1911).

Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

alcohol (64-17-5)

acetaldehyde (75-07-0)

hydrochloric acid (7647-01-0)

sodium sulfate (7757-82-6)

sodium (13966-32-0)

heptanol (111-70-6)

n-amylmagnesium bromide (693-25-4)

METHYL n-AMYL KETONE (110-43-0)

2-Heptanol (543-49-7)