JPS6197246A - Production of arylacetic acid ester - Google Patents

Abstract

PURPOSE:In the production of the title compound, which is used as a starting material of medicines, by the reaction between a halogenated aryl compound, carbon monoxide and an alcohol, a rhodium compound is used to effect vapor- phase reaction, facilitate mixing of the starting materials and improve the reaction yield through simple operations. CONSTITUTION:In the presence of a rhodium compound as a catalyst, the vapor- phase reaction between carbon monoxide, a gaseous halogenated aryl compound and an alcohol is effected directly or in dilution with an inert gas at 100-300 deg.C to give the title compound. The rhodium compound as a catalyst is, e.g., RhCl3.3H2O; Rh(NO3)3 and preferably supported on a carrier. The carrier is preferably activated carbon and the amount of rhodium compound supported is 0.5-20wt% calculated as metallic rhodium. The amount of the alcohol and carbon monoxide used preferably is 2-100mol and 1-100mol per mole of the halogenated aryl compound, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing arylacetic acid esters. Aryl acetates, such as phenylacetate?
p-Chlorphenylacetic acid ester is used as a raw material for medicines, agricultural chemicals, fragrances, etc., and is highly used in industrial applications. The present invention relates to a method for producing these compounds from a non-rhodanated aryl compound, carbon monoxide and alcohol in the presence of a rhodium compound by gas phase catalytic reaction.

(Prior Art) A method for producing an arylacetic acid ester by reacting an I/F'-ionized aryl compound with carbon monoxide and an alcohol is conventionally known.

For example, JP-A-56-81535 discloses a method in which this reaction is carried out in the presence of an alkali metal salt of an inorganic weak acid and a cobalt carbonyl catalyst; I)) Finely powdered metal manganese, iron or nickel or alloys of these metals and (
0) A method using a catalyst consisting of three components of water-soluble sulfur compounds while keeping the reaction mixture slightly alkaline by continuously adding alkaline albencholate;
6-16134 proposes a method in which this reaction is carried out in the presence of a basic compound, a rhodium catalyst and, if necessary, an iodine-containing compound.

(Problems to be Solved by the Invention) These conventional methods of producing aryl acetate by reacting a halogenated aryl compound with carbon monoxide and alcohol have the following problems. there were.

(I) All of these methods require a large amount of basic compound to capture the halogen produced in the reaction, so gaseous carbon monoxide, liquid halogenated aryl compound, alcohol, and solid state are used. The metal halide salt after the reaction is
Complex operations such as filtration and extraction are required to separate it from the arylacetic acid ester and catalyst.

(2) In order to suppress side reactions, - of the reaction system must be adjusted to weak alkalinity. For this reason, the amount of basic compound supplied to the reaction system must be delicately adjusted.
It takes a long time for the reaction to complete.

(3) The amount of arylacetic acid ester produced per unit catalyst amount is small.

The object of the present invention is to solve the problems between these problems and provide a method for producing arylacetic esters with simpler operations and more efficiency.

(Means for Solving the Problems) The present invention is characterized in that a halogen [hyaryl compound represented by the following general formula (I), carbon monoxide and alcohol are subjected to a gas phase catalytic reaction in the presence of a rhodium compound. This is a method for producing aryl acetate.

R1-mu r -0112-x (I) (wherein R
1 is hydrogen, halogen, or a methyl group, mr is a benzene nucleus, and X is a halogen (mel).

The halogenated aryl compound used in the present invention is not particularly specified as long as it has a boiling point of 250°C or lower, but benzyl chloride, p-chlorobenzyl chloride, p-methylbenzyl chloride, benzyl bromide, benzyl chloride, etc. etc. are preferred.

Further, the alcohol is not particularly limited as long as it is an aliphatic alcohol having carbons a1 to a8, but lower alcohols such as methanol, ethanol, nf lobanol, and inzolopanol are preferable.

The carbon monoxide used does not need to be of particularly high purity;
You may use the one in which an inert gas coexists.

The rhodium compound used as a catalyst in the present invention includes a rhodium compound, an inorganic salt, or a complex compound of rhodium, such as RhC13.5H,O.

RhBr3・2H20, Rh(NO3)3, RJ(
Co) 404g.

Rh(CO)OjCP(OsHs)3)z and Rhcj
Examples include (P(C!aHs):s):s. These compounds do not need to be of high purity, such as sodium chloride,
These rhodium compounds, which may contain salts such as potassium chloride, are usually supported on an inert carrier such as activated carbon, alumina, silica diatomaceous earth, pumice, zeolide, and morechieracide, with activated carbon being particularly preferred.

In this case, the amount of the rhodium compound supported is 0.5 to 20% by weight relative to the carrier in terms of rhodium metal, and the amount is rectified. For example, refer to the reference example below.

The reaction of the present invention is carried out by using -carbon oxide, a gaseous I-lodenated aryl compound, and an alcohol as they are or by diluting them with an inert gas and introducing them in a gas phase onto a rhodium catalyst. The reactor used is a conventional fixed bed reactor used for gas phase reactions.

The reaction in the present invention is carried out at 100 to 300°C! It is preferable to carry out the process under normal pressure, but it can also be carried out under increased pressure.

The amount of alcohol and carbon oxide used as raw materials is 2 to 100, respectively, per 1 m01 of the halogenated aryl compound.
mol and 1-100! A range of 1101 is preferred.

The contact time of the raw material with the catalyst layer is preferably in the range of 0.2 to 10 seconds.

After the reaction, the reactant discharged from the reaction tube is cooled and condensed according to a conventional method, followed by distillation to obtain an arylacetic acid ester.

〔Example〕

Next, the present invention will be specifically explained using reference examples and examples.

Reference example catalyst: fA Rhcj3.3H2o 11 m” methanol 1004
Activated carbon ioIIe was dissolved in this solution and immersed in it. Methanol was then evaporated by air drying. Next, this activated carbon was packed into a reaction tube, and carbon monoxide was added to the reaction tube at a rate of Qj 3 per hour at 200°C.
After introducing at mob speed for 1 hour, it was used for the reaction.

Example 1 A catalyst in which RhCj3.5iIgOI & was adsorbed on spherical activated carbon ICIK was packed into a heat-resistant glass reaction tube with an inner diameter of 25 mm and a height of 600 mm, and then heated to 250'C for monoxide. Carbon was introduced at a rate of Q, 13 mol per hour for 1 hour.

Next, carbon monoxide, benzyl chloride, and methanol each at a rate of 0.20 per hour! ! 101.0.04! mol, 0
．． The mixture was evaporated through a preheater maintained at 220° C. at a rate of 40 mobs and introduced into the exhaust reaction tube. Reaction temperature 250℃
, the reaction was carried out under normal pressure.

Analysis of the reaction product by fcif chromatography revealed that methyl phenylacetate was 5. Omol/XF-
It was produced at the same rate as the catalyst/Ar, and methyl chloride and benzyl methyl ether were also produced as by-products. 7 after the start of the reaction
The total amount of methyl phenylacetate produced up to 2 hours was 560
! ! 101/'pg-b with catalyst.

Example 2 The same procedure as Example 1 was carried out except that methanol was changed to ethanol. As a result of analyzing the reaction product by chromatography, ethyl phenylacetate was found to be 4.8 mo1/9
-Produced at the same rate as catalyst/Ar, and other by-products were ethyl chloride and benzyl ethyl ether. The amount of ethyl phenylacetate produced up to 72 hours after the start of the reaction was 345
mol/K9-6 with catalyst.

Example 3 The same procedure as Example 1 was carried out except that benzyl chloride was changed to p-chlorobenzyl chloride. As a result of chromatographic analysis of the reaction product, methyl p-chlorophenylacetate was found to be 4. It was produced at the same rate as Omob/Yuichi's catalyst/Ar, and methyl chloride and p-chloropentyl methyl ether were also produced as by-products. p up to 72 hours after the start of the reaction
-The total amount of methyl chlorophenylacetate produced was 288 mo
b/'Q-catalyst.

(Effects of the Invention) As explained above, since the present invention does not require a basic compound in a gas phase reaction, it is easy to mix raw materials and obtain a product, and it is possible to easily control the reaction system. without needing,
In addition, it is an excellent method that has high catalytic efficiency and is easy to implement with simple operations.

Patent Applicant Denki Kagaku Kogyo Co., Ltd. Procedural Amendment November 13, 1980 1 Case Description 1982 Patent Application No. 218510 2 Title of Invention Process for Producing Aryl Acetate Ester 3 Amendment Relationship of Patent Applicant Address: 1-4-1-4, Yurakucho, Chiyoda-ku, Tokyo, Subject of Amendment: Column 5 of Detailed Description of the Invention in Book JI, Contents of Amendment (I) tfI, page 8, line 1, line 1 ~Delete "methyl chloride and" in line 2 and line 18.

Claims (1)

[Scope of Claims] A method for producing an arylacetic acid ester, which comprises subjecting a halogenated aryl compound represented by the following general formula (I), carbon monoxide, and alcohol to a gas phase contact reaction in the presence of a rhodium compound. R_1-Ar-CH_2-X(I) (wherein R_1 is hydrogen, halogen, or methyl group, Ar is a benzene nucleus, and X is a halogen).