CS239022B1 - Process for the preparation of phase transfer catalysts for the production of alkyl aryl ethers - Google Patents

Abstract

Method for preparing phase transfer catalysts, particularly suitable for the production of alkylaryl ethers. These catalysts are quaternary ammonium compounds of the general formula R - Ν+ζΟΗ^^Χ-, where X~ represents an anion, halide, in particular chloride, alkyl sulfate, benzene or p-toluene sulfonate, R is alkyl or aralkyl with a number of carbon atoms 1-7.

Description

The invention relates to a process for the preparation of phase transfer catalysts, particularly suitable for the production of alkylarylethers. These catalysts are quaternary ammonium compounds of the general formula R - Ν ⁺ (OΗ) ~ ~, where x ”represents an amide halide, in particular chloride, alkyl sulphate, benzene or p-toluenesulphonate,

R is alkyl or aryl having a carbon number of 1 to 7,

The quaternary ammonium salts produced hitherto have substituents on the quaternary nitrogen atom having a carbon number greater than 10. These compounds are supplied in the form of an anhydrous or aqueous solution. is expensive for consumers, aqueous solutions have the disadvantage of producing alkylarylethers in that they increase consumption and reduce the concentration of alkali hydroxide solution used in the synthesis.

These disadvantages are eliminated by a method of manufacturing the phase-transfer catalysts for the production of alkyl aryl ethers of general formula R - N ⁺ (CH3) ₃ X- by reaction of trimethylamine with an alkylating agent RX in an equimolar ratio at a reaction temperature of 15-120 ° C, _from whose principle consists in that the reaction is carried out in an alcohol medium R ' OH, wherein R ' is alkyl C1-C6 optionally substituted by R < 0 >

The prepared catalyst is in the form of an alcoholic solution, which is the reaction component in the production of the corresponding alkylarylethers. The concentration of the obtained catalyst, alkyltrimethylammonium compound, R - N (CH ₃ ) ₃ ⁺ X "is adjusted to the required concentration by the addition of alcohol before use and the solution is used for the preparation

239.022 of R * -O-aryl alkyl aryl ether. The preparation of the catalyst in the form of an alcoholic solution is fast and low energy consumption, since the concentration, filtration and drying of the product are eliminated. The potential risk of corrosion of the evaporator, handling of dry powder material, which usually accompanies the recovery of the dry catalyst, is eliminated. Another advantage is that the course of the reaction in the production of alkylarylethers using the catalyst thus prepared is not hampered by the presence of water, which is the case when using catalysts in the form of aqueous solutions. Alcoholic catalyst solutions in which the alcohol used is an alkoxylating agent are readily metered.

In order to further elucidate the invention, the following examples are provided:

Example 1

632 parts by weight of benzyl chloride are dissolved in 930 parts by weight of ethyl alcohol with stirring, and 296 parts by weight of trimethylamine are added in one hour. The reaction mixture is heated to 80 DEG C. for 2 hours and stirred at this temperature for 3 hours. After cooling, the obtained alcoholic solution of benzyltrimethylammonium chloride, suitable for the preparation of alkylarylethers, is poured into barrels.

Example 2

Analogously to Example 1, the reaction was carried out except that 684 parts by weight of isobutyl bromide was used in place of benzyl chloride to obtain an alcoholic solution of isobutyltrimethylammonium bromide suitable for the preparation of alkylarylethers.

Example 3

The reaction was carried out analogously to Example 1 except that 630 parts by weight of dimethyl sulphate were used instead of benzyl chloride. An alcoholic solution of tetramethylammonium methosulfate, suitable for the preparation of alkyl aryl ethers, is obtained.

- 3 Example 4

239 022

632 pbw of benzyl chloride are dissolved in 930 pbw of methanol, with stirring, and 296 pbw of trimethylamine are allowed in one hour. The reaction mixture is heated to reflux for 2 hours and after 5 hours the reaction is complete. A methanolic solution of benzyltrimethylammonium chloride, suitable for the preparation of methylarylethers, is obtained.

EXAMPLE 5 Analogously to Example 1, benzyltrimethylammonium chloride is prepared except 2-methoxyethanol is used instead of ethyl alcohol. A solution of benzyltrimethylammonium chloride suitable for use in the preparation of 2-methoxyethylarylethers is obtained.

Example 6

296 parts by weight of trimethylamine are dissolved in 930 parts by weight of ethyl alcohol with stirring, and 632 parts by weight of benzyl chloride are admitted within 1 hour. The procedure of Example 1 is followed.

Claims (1)

A method for preparing a phase-transfer catalysts of the general formula R - ΙΓ (CH ^) ^ ^»where the anion is halide, alkyl sulfate to C ?, or? Benzensulfonanový toluensulfonanový and R is alkyl or aryl and 0 ≤ Ογ by reaction of trimethylamine with an alkylating agent RX, in equimolar ratio at a reaction temperature of 15 ° C to 120 ° C, characterized in that the reaction is carried out in an alcohol medium R * OH, where R * is alkyl to C 1, optionally substituted by R ² * O, where R ** is alkyl C 1 to C 6.