Org. Synth. 1930, 10, 62
DOI: 10.15227/orgsyn.010.0062
[Dodecyl alcohol]
Submitted by S. G. Ford and C. S. Marvel.
Checked by Frank C. Whitmore and D. J. Loder.
1. Procedure
The central neck of a 5-l. three-necked round-bottomed flask is fitted with a stopper carrying a mercury-sealed mechanical stirrer. One of the side necks is connected by means of a short piece of heavy rubber tubing to a large reflux condenser about 2 m. long, with an inner tube 2.5 cm. in diameter (Note 1). The third neck is fitted with a separatory funnel.
In the flask are placed 70 g. (3 moles) of sodium and 200 cc. of dry toluene (Note 2). The flask is heated in an oil bath until the sodium is melted. The stirrer is then started; when the sodium is finely divided, the oil bath is removed and the mixture allowed to cool. Stirring must be continued during the cooling in order to keep the sodium finely divided.
When the mixture has cooled to about 60°, there are added from the separatory funnel, first, a solution of 114 g. (0.5 mole) of ethyl laurate (Note 3) in 150 cc. of absolute alcohol (Note 4), then 500 cc. more of alcohol, as rapidly as is possible (Note 5) without loss of material through the condenser. The time required for the addition of the ester solution and the alcohol is less than five minutes, usually two or three minutes. When the reaction has subsided, the flask is heated on a steam bath until the sodium is completely dissolved (Note 6). The mixture is then steam-distilled to remove the toluene and ethyl alcohol. The contents of the flask are transferred to a separatory funnel while still hot and washed three times with 200-cc. portions of hot water to remove the sodium laurate (Note 7). The lauryl alcohol is extracted with ether from the cooled mixture and the washings. The combined ether extracts are washed with water, sodium carbonate solution, and again with water, and dried over anhydrous magnesium sulfate. The ether is evaporated and the lauryl alcohol distilled under diminished pressure. The yield is 60–70 g. (65–75 per cent of the theoretical amount) of a product boiling at 143–146°/18 mm. or 198–200°/135 mm. (Note 8).
2. Notes
1. The reaction is very vigorous and, unless the condenser has a wide bore, finely divided sodium may be forced out the top and bad fires may result. The inner tube of the condenser may advantageously be made of brass or copper.
2. The toluene is dried by distillation; the first 10 per cent is discarded and the remainder is stored over sodium until used.
3. The ethyl laurate used was prepared by the alcoholysis of cocoanut oil and fractionation of the resulting esters. The material boiled at 127–132°/5 mm. See Org. Syn. 20, 69, and Organic Chemical Reagents III, Univ. Illinois Bull. 19 (6) 62 (1921).
4. The grade of absolute alcohol used in the reduction is very important. Alcohol dried with magnesium methoxide (Org. Syn. Coll. Vol. I, 1941, 249) was used in this preparation. Alcohol dried over lime gives very low yields.
5. The best yields are obtained when the reductions are carried out rapidly. If the reaction seems to be about to get out of control, the stirrer is stopped and the mixture is cooled with an ice pack.
6. When several reductions are being made, time is saved by transferring the mixture at this point to another flask, thus having the original apparatus ready for another reduction.
7. Unless the sodium laurate is carefully removed, it causes trouble some emulsions.
8. Ethyl undecylenate has been reduced to undecylenyl alcohol (b.p. 123–125°/6 mm.) in 70 per cent yields; ethyl myristate to myristyl alcohol (b.p. 170–173°/20 mm.; m.p. 39–39.5°) in 70–80 per cent yields; ethyl palmitate to cetyl alcohol (b.p. 178–182°/12 mm.; m.p. 48.5–49.5°) in 70–78 per cent yields by this same procedure.
3. Discussion
Lauryl alcohol has been prepared by the reduction of the aldehyde;1 by the reduction of esters of lauric acid with sodium and absolute alcohol2 or with sodium, liquid ammonia and absolute alcohol,3 or catalytically;4 and by the reduction of lauramide with sodium and amyl alcohol.5 The method in the above procedure is essentially that described by Levene and Allen.2
This preparation is referenced from:

References and Notes
  1. Krafft, Ber. 16, 1718 (1883); Sivkov and Novikova, J. Applied Chem. (U.S.S.R.) 13, 1272 (1940) [C. A. 35, 2110 (1941)].
  2. Bouveault and Blanc, Bull. soc. chim. (3) 31, 674 (1904); Ger. pat. 164,294 [Frdl. 8, 1260 (1905–07)]; Levene and Allen, J. Biol. Chem. 27, 443 (1916); Marvel and Tanenbaum, J. Am. Chem. Soc. 44, 2649 (1922); Adams and Marvel, Org. Chem. Reagents IV, Univ. Illinois Bull. 20 (8) 54 (1922).
  3. Chablay, Compt. rend. 156, 1021 (1913); Ann. chim. (9) 8, 215 (1917).
  4. Adkins and Folkers, J. Am. Chem. Soc. 53, 1095 (1931); Böhme A.-G., Brit. pat. 356,606 [C. A. 26, 5573 (1932)].
  5. Scheuble and Loebl, Monatsh. 25, 348 (1904).

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

ethyl alcohol,
alcohol (64-17-5)

ammonia (7664-41-7)

ether (60-29-7)

sodium carbonate (497-19-8)

Lauryl alcohol,
dodecyl alcohol (112-53-8)

copper (7440-50-8)

toluene (108-88-3)

sodium (13966-32-0)

magnesium methoxide

amyl alcohol (71-41-0)

magnesium sulfate (7487-88-9)

Cetyl alcohol (36653-82-4)

ethyl laurate (106-33-2)

sodium laurate (629-25-4)

Ethyl undecylenate

Undecylenyl alcohol

ethyl myristate (124-06-1)

Myristyl alcohol (112-72-1)

ethyl palmitate (628-97-7)

esters of lauric acid (143-07-7)

lauramide (1120-16-7)