Org. Synth. 1945, 25, 22
DOI: 10.15227/orgsyn.025.0022
2-CHLOROCYCLOHEXANONE
[Cyclohexanone, 2-chloro-]
Submitted by M. S. Newman, M. D. Farbman, and H. Hipsher.
Checked by C. S. Hamilton and C. W. Whitehead.
1. Procedure
In a 3-l. three-necked round-bottomed flask, fitted with a gas inlet tube reaching almost to the bottom, a sealed mechanical stirrer (Note 1), and a gas outlet tube connected to a mercury valve (Note 2), are placed 294 g. (3 moles) of cyclohexanone (Note 3) and 900 ml. of water. After the reaction vessel has been swept out with chlorine, the gas outlet tube is connected to the mercury valve, the flask is cooled in an ice bath, the stirrer is started, and 215 g. (slightly more than 3 moles) of chlorine is bubbled in as rapidly as the gas is absorbed (about 45 minutes) (Note 4).
The heavier chlorocyclohexanone layer is separated and combined with three 150-ml. ether extracts of the aqueous phase, and washed with 150 ml. of water and then with 200 ml. of saturated sodium chloride solution. After filtration (gravity) through anhydrous sodium sulfate the ether is removed and the residue vacuum-distilled in a modified Claisen flask. The fraction (300–340 g.) boiling below 100° at 10 mm. (Note 5) is collected (Note 6). This material is then fractionated carefully under reduced pressure by means of a 42-in. modified Vigreux column (heated) with a total-condensation variable take-off head (Note 7). The yield of 2-chlorocyclohexanone boiling at 90–91°/14–15 mm. is 240–265 g. (61–66%) (Note 8) and (Note 9).
2. Notes
1.
A large propeller-type stirrer is satisfactory. The blades should be pitched to drive the liquid upwards, and the propeller should be located just below the surface of the liquid to provide splashing. The checkers used a
glycerol-lubricated rubber-tube seal.
12.
The
mercury valve consists of a tube dipping about 0.5 in. into some
mercury in a vented test tube. This allows the reaction to be carried out under a slight pressure of
chlorine. The checkers found a water valve to be more satisfactory. The outlet tube was made to dip about 7 in. into water in a vented glass tube. A
trap (
125-ml. suction flask) was placed between the water valve and the reaction flask to prevent water from being sucked into the reaction mixture.
3.
The checkers used Eastman's
cyclohexanone boiling at
154–156°. The submitters report that the practical grade gives just as good yields.
4.
Careful control of the temperature is unnecessary as approximately the same results are obtained when the temperature is allowed to rise to about 50° or is kept below 20°. However, at the lower temperature a greater amount of
cyclohexanone is recovered.
5.
Or below 110°/13 mm., or 92°/4 mm.
6.
This preliminary purification is advisable before careful fractionation.
7.
The head used was similar to that described by Turk and Matuszak
2 except for the stopcock, which was of the variety described by Newman.
38.
This material shows a long flat at 23.2° cor. in a time-temperature cooling curve. It can be stored in a
refrigerator in
paraffin-covered stoppered bottles for long periods of time without discoloration.
9.
About
15–40 g. (
5–13%) of
cyclohexanone, b.p.
52°/14–15 mm., is recovered.
3. Discussion
2-Chlorocyclohexanone can be prepared by chlorinating
cyclohexanone in
glacial acetic acid as the solvent,
4 by passing
chlorine into a mixture of
cyclohexanone5 or
cyclohexanol6 and water in the presence of powdered
calcium carbonate, by the electrochemical chlorination of
cyclohexanone in
hydrochloric acid,
7 by the action of
monochlorourea in
acetic acid on the ketone,
8 by the oxidation of
2-chlorocyclohexanol,
9 and by the chlorination of the sodio derivative of
cyclohexanone with
ethyl hypochlorite.
10
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
hydrochloric acid (7647-01-0)
acetic acid (64-19-7)
ether (60-29-7)
Cyclohexanol (108-93-0)
Cyclohexanone (108-94-1)
sodium chloride (7647-14-5)
sodium sulfate (7757-82-6)
mercury (7439-97-6)
calcium carbonate (471-34-1)
chlorine (7782-50-5)
2-Chlorocyclohexanol (1561-86-0)
2-Chlorocyclohexanone,
Cyclohexanone, 2-chloro-,
chlorocyclohexanone (822-87-7)
monochlorourea
ethyl hypochlorite (624-85-1)
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