DE1204218B - Process for the production of cyclohexanol - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C07c

German KL: 12 o-25

Number: 1204 218

File number: J19560IV b / 1-2 ο

Filing date: March 9, 1961

Opening day: November 4, 1965

As is known, you can cyclohexene by hydration in the presence of mineral acids such as sulfur and Phosphoric acid, in free form or applied to large-surface supports, as catalysts, in the presence from water to cyclohexanol (U.S. Pat. No. 2,504,517). It has already been described the hydration of straight-chain olefins with 2 to 4 carbon atoms on the chain to primary and carry out secondary alcohols on strongly acidic ion exchangers (USA. Patent 2 813 908). Cation exchange resins are also used in hydration. has been used by iso-olefins, the corresponding tertiary alcohols being formed (U.S. Patent 2,477,380). Cyclohexene too was already according to the method of the German patent specification 866191 with the help of acidic cation exchangers hydrated.

It has now been found that cyclohexanol can be obtained in better yield if the known reaction of cyclohexene with water is carried out over strongly acidic cation exchangers at temperatures above 100 ^° C. and under increased pressure in the presence of small amounts of nonionic emulsifiers.

Process for the production of cyclohexanol

Applicant:

Inventa A. G.

for research and patent exploitation,

Lucerne (Switzerland)

Representative:

Dr.-Ing. Dr. jur. H. Mediger, patent attorney,

Munich 9, Aggensteinstr. 13th

Named as inventor:

Dr. Alfred Flam, Chur (Switzerland);

Dr.-Ing. Kurt Kahr, Hambach (a. D. Weinstrasse)

Claimed priority:

Switzerland of March 10, 1960 (2696)

The advantage of this method over the previously known is that the proportion of higher boiling By-products in the reaction mixture is extremely low. This makes it possible to have a practically quantitative Obtain yield of cyclohexanol.

The hydration of cyclohexene is carried out in the liquid phase in pressure vessels, with expediently the emulsion of cyclohexene and water with a little emulsifier and the ion exchanger the hydration temperature and the given pressure reacts with simultaneous stirring. the Implementation can also be carried out in a tower with a stationary ion exchanger, the Emulsion of cyclohexene and water with the emulsifier, optionally with circulation on Ion exchanger is passed.

According to the process of the invention, the cyclohexene is not hydrated in one pass completely, but rather an equilibrium is established at a conversion of about 10%. By distance the cyclohexanol formed from the reaction mixture can by repeated recycling of the unreacted reaction components the cyclohexene are completely hydrated to cyclohexanol. It is important in consideration of the reaction temperature that the hydration be carried out in a completely closed System is carried out to avoid loss of cyclohexene. This can be done from the reaction mixture Mechanically water and the unreacted cyclohexene from the cyclohexanol from the organic phase Distillation are separated. The separated cyclohexene and the water can again be used for hydration can be used. In this way it is possible to make the process continuous.

The water used for hydration is advantageously in an approximately equimolecular amount to Cyclohexene used. Ethoxylated ricinoleic acid and ethylphenol glycol ether are particularly suitable as nonionic emulsifiers or alkylaryl polyether alcohols. The emulsifiers are added to the water in one concentration from about 0.1 to 1% added.

Suitable cation exchangers are e.g. B. sulf ordered and crosslinked synthetic resin cation exchangers based on polystyrene. The ones in retail are particularly suitable for this the acidic resins »Amberlite JR-120«, »Döwex50« and "Permutit RS". Abrasion-resistant and heat-resistant synthetic resin exchangers are particularly preferred.

It is necessary to use these ion exchangers in large excess to the reaction mixture if the ion exchanger is used in more than the simple volume amount, based on the reaction mixture, a.

The hydration temperature is advantageously from 105 to 13O ⁰ C. At the low temperatures give no or too low conversions. Higher temperatures are due

509 720/427

the limited heat resistance of the ion exchangers is not advantageous.

In the process according to the invention, an excess pressure is produced during the reaction, depending on the reaction temperature from to 2Xi 5 atm. a. .

The parts given in the following examples are parts by weight.

example 1

In an autoclave equipped with a stirrer, 200 parts of cyclohexene with 45 parts of water to which 0.6 parts of ethoxylated ricinoleic acid are added as an emulsifier, activated with 400 parts of cation exchanger "Amberlite JR-120" with vigorous mixing at 120 ⁰ C for 10 hours Brought reaction. This results in a pressure of 4 ätü. After the reaction mixture has cooled and left to stand, the separated water is separated off and the organic phase is separated by distillation. The cyclohexene is distilled under normal pressure, the cyclohexanol at 30 mm Hg pressure. Additional anol is obtained from the aqueous phase by extraction with ether or methylene chloride. In this way, 29.3 parts of cyclohexanol are obtained.

Example-2

In a Atoklav equipped with a stirrer, 200 parts of cyclohexene with 45 parts of water to which 0.6 parts of ethoxylated ricinoleic acid are added as an emulsifier, activated with 400 parts of cation exchanger "Dowex brought 50" under vigorous mixing at 120 ⁰ ClO hours for reaction. This results in a pressure of 4 atm. After the reaction mixture has cooled and left to stand, the separated water is separated off and the organic phase is worked up by distillation. The cyclohexene is distilled under normal pressure, the cyclohexanol at 30 mm Hg pressure. Additional cyclohexanol is obtained from the aqueous phase by extraction. In this way, 31.0 parts of cyclohexanol are obtained *

Example 3

In an autoclave equipped with a stirrer, 200 parts of cyclohexene are reacted with 45 parts of water, to which 0.6 part of ethoxylated ricinoleic acid has been added as an emulsifier, with 400 parts of activated cation exchanger “Permutit RS” with vigorous mixing at 110 ^° C. for 10 hours . This results in a pressure of 4 atm. After the reaction mixture has cooled and left to stand, the separated water is separated off and the organic phase is split up by distillation. The cyclohexene is distilled under normal pressure, the cyclohexanol at a pressure of 30 mm Hg. Additional cyclohexanol is obtained from the aqueous phase by extraction. In this way, 28.1 parts of cyclohexanol are obtained.

Example 4

Cyclohexene, water and emulsifier are put into a mixing vessel in one apparatus. The emulsion formed with stirring is then pumped through an externally heated (120 ° C.) pressure reaction vessel filled with the ion exchanger. It is then let down in a distillation still of a distillation column. From the top of the column over at 70 ⁰ C azeotropically boiling cyclohexene-water mixture (with 10 weight percent water) over condenser, pump and heating is returned into the pressure reaction vessel. The cyclohexanol can be obtained in a simple extractive or distillative manner from the sump, which is mainly composed of cyclohexanol and water.

The advantageous results that can be achieved using the above procedure are shown in the following test report: ¹

Test report
■ Experiment a)

200 parts of cyclohexene, 45 parts of water, to which 0.6 part of ethoxylated ricinole oil was added as an emulsifier, were placed in an autoclave, and the mixture was allowed to react with 400 parts of activated cation from ₇ exchanger "Amberlite IR-120" at 120 ° C. for 10 hours. After the reaction mixture had cooled, the water was separated off and the organic phase was separated by distillation. Extra cyclohexanol was obtained from the aqueous phase by extraction with ether. A total of 30.1 parts of cyclohexanol were recovered.

The conversion of cyclohexene was 12.4%.

Experiment b)

The procedure was as in experiment a), but with 0.6 parts of "Emuisogen ELN" (ethylphenol polyglycol ether) as Emulsifier.

A total of 31.5 parts of cyclohexanol were recovered; Cyclohexene conversion 12.9%

Experiment c)

The procedure was as in experiment a), but omitting the addition of emulsifier.

16.4 parts of cyclohexanol were obtained; Cyclohexene conversion 6.7%.

Claims (2)

Patent claims: 1. A process for the preparation of cyclohexanol by hydrating cyclohexene in the presence of acidic cation exchangers at temperatures above 100 ^° C. at elevated pressure, characterized in that the hydration is also carried out in the presence of small amounts of nonionic emulsifiers. 2. The method according to claim 1, characterized in that the emulsifiers in one Amount of 0.1 to 1 percent by volume, based on the water, used. Considered publications:
German Patent No. 866191;
U.S. Patent Nos. 2,813,908, 2,504,517. 509 720/427 10.65 © Bundesdruckerei Berlin