Org. Synth. 1967, 47, 75
DOI: 10.15227/orgsyn.047.0075
4-HEPTANONE
Submitted by Robert Davis, Charles Granito, and Harry P. Schultz
1.
Checked by William G. Dauben and Richard J. Shavitz.
1. Procedure
A mixture of 370 ml. (4 moles) of n-butyric acid (Note 1) and 123 g. (2.2 moles) of hydrogen-reduced iron powder (Note 2) is refluxed for 5 hours in a 1-l. flask equipped with a condenser (Note 3). The apparatus is converted for downward distillation while an atmosphere of nitrogen is maintained. The nitrogen sweep is then stopped, the flask is strongly heated, and the entire distillate collected.
The crude product is washed with two 20-ml. portions of 10% sodium hydroxide solution and with one 20-ml. portion of water. The 4-heptanone is dried over 5 g. of anhydrous sodium sulfate, filtered, and distilled. The yield of 4-heptanone, b.p. 142–144°, n25D 1.4031–1.4036, is 157–171 g. (69–75%).
2. Notes
1.
n-Butyric acid, b.p. 162–164°, from Eastman Organic Chemicals was redistilled before use.
2.
Hydrogen-reduced iron powder from Fisher Scientific Company was used.
3.
Severe foaming may force brief cessations of heating during the first hour.
Boric acid (0.1 g.) somewhat diminishes the extent of foaming.
3. Discussion
The present procedure is that of Davis and Schultz.
2 4-Heptanone has also been synthesized by virtually every general method known and listed for ketones in "Chemistry of Carbon Compounds," including liquid or vapor phase decarboxylation of
n-butyric acid or its salts, oxidation of
4-heptanol, and hydration of
3-heptyne.
34. Merits of the Preparation
This method is illustrative of a general method of preparing simple ketones from normal aliphatic carboxylic acids. It is especially useful because the starting materials are easily accessible, the yields good, and the procedure very simple.
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
sodium hydroxide (1310-73-2)
iron powder (7439-89-6)
sodium sulfate (7757-82-6)
nitrogen (7727-37-9)
n-butyric acid (107-92-6)
boric acid (10043-35-3)
4-Heptanone (123-19-3)
4-heptanol (589-55-9)
3-heptyne (2586-89-2)
Copyright © 1921-, Organic Syntheses, Inc. All Rights Reserved