JPH0748315A - Production of halogenated benzoyl halide - Google Patents

Abstract

PURPOSE:To produce a high-purity o-, m-or p-halogenated benzoyl halide in high yield industrially and inexpensively. CONSTITUTION:An o-, m- or p-phthaloyl halide of formula I (X is halogen) is heated in the presence of a metal catalyst to produce an o-, m- or p- halogenated benzoyl halide of formula II.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to an improved process for the preparation of halogenated benzoyl halides.

[0002]

2. Description of the Related Art m-Chlorobenzoyl chloride, which has been used as a raw material for various industrial chemicals, is conventionally synthesized by reacting m-chlorotoluene with chlorine under light irradiation to synthesize m-chlorobenzotrichloride. Method of synthesizing by hydrolyzing in the presence of iron chloride, oxidizing m-chlorotoluene,
A method of synthesizing m-chlorobenzoic acid and chlorinating it to produce m-chlorobenzoyl chloride, a method of reacting benzoyl chloride with chlorine in the presence of iron chloride (US Pat. No. 3,816,526), m-chloro Known is a method of reacting benzotrichloride with sulfur dioxide in the presence of antimony chloride (US Pat. No. 3,806,545).

[0003]

In the conventional method for producing m-chlorobenzoyl chloride, the method (1) has a drawback that the production cost is high because the starting material m-chlorotoluene used is expensive, and the method (1) and (2). Has a drawback that it is difficult to produce high-purity m-chlorobenzoyl chloride because isomers are mixed in the course of the reaction, and the method causes environmental pollution because sulfur dioxide is discharged. However, it is difficult to inexpensively and easily produce m-chlorobenzoyl chloride.

[0004]

In order to solve the above problems, the inventors of the present invention have made various studies and as a result, when phthaloyl halide, which can be easily manufactured at low cost, is heated in the presence of various metal catalysts, decarbonylation occurs. It was found that halogenated benzoyl halide can be produced with high purity and high yield, and the present invention was completed. Accordingly, the present invention comprises a method for producing a halogenated benzoyl halide (2), which comprises heating the phthaloyl halide (1) in the presence of a metal catalyst, as shown in the reaction scheme below.

[0005]

[Chemical 3] In the above formula, X represents a halogen atom such as chlorine, bromine or iodine. The two halogenated carbonyl groups (-COX) in the formula (1) and the bonding position of the halogenated carbonyl group (-COX) and the halogen (X) in the formula (2) are any of o-, m- and p-. But it's okay. When o-, m- or p-phthaloyl halide is used as the starting compound (1), the corresponding o-, m-, p
A halogenated benzoyl halide is obtained. The starting compound, o-, m- or p-phthaloyl halide (1), can be easily produced by halogenating o-, m- or p-phthalic acid according to a conventional method.

As the metal catalyst used in the production method of the present invention, a noble metal catalyst such as palladium, rhodium or ruthenium supported on aluminum oxide, barium sulfate or carbon is used. The amount of the noble metal to be supported is 1 to 10%, preferably 3 to 5% (weight). The amount of the metal catalyst used in the reaction is 0.01 to 1.0%, preferably 0.02 to 0.5% (weight) with respect to the phthalic acid halide. The heating temperature depends on the activity of the catalyst used, but it is required to be 200 ° C. or higher, preferably 24
It is 0 to 300 ° C. Heating is preferably performed using a high boiling organic heat medium such as triphenyl type or alkylnaphthalene type. Although the heating time depends on the heating temperature and the activity of the catalyst, about 4 to 30 hours is suitable. If the reaction proceeds excessively, dihalogenated benzene is produced, so it is desirable to control the reaction temperature and the reaction time within the above range. After completion of the reaction, the produced halogenated benzoyl halide is collected from the reaction mixture and purified according to a conventional method. Industrially, a method is preferred in which the produced halogenated benzoyl halide is distilled out of the reaction system, and on the other hand, phthalic acid halide is replenished to continuously advance the reaction. The product halogenated benzoyl halide (2) is used as a raw material for various industrial chemicals.

The present invention will be described below with reference to examples. Example 1 203.0 g of isophthaloyl chloride and 0.4 g of 5%
Palladium / alumina was placed in a 3-neck flask containing 300 ml and heated under reflux at 260 ° C. for 20 hours. The composition of the thus obtained reaction mixture was found to be 86.7% m-chlorobenzoyl chloride, 10.4% isophthaloyl chloride and 3.3% m-dichlorobenzene from the area ratio of the gas chromatography. The reaction product is distilled and 145.
25 g (yield 83%) of m-chlorobenzoyl chloride (area ratio by gas chromatography; 98.3%) was obtained.

Example 2 303.0 g of 203.0 g of isophthaloyl chloride and 0.5 g of a catalyst containing 3% palladium on barium sulfate were used.
Transfer to a 3-necked flask containing 0 ml for 16.5 hours 240 ~
The mixture was heated to reflux at 260 ° C. The composition of the thus obtained reaction mixture was found to be 78.0% m-chlorobenzoyl chloride, 16.5% isophthaloyl chloride and 3.5% m-dichlorobenzene from the area ratio of gas chromatography. The reaction product was distilled to give 131.3 g (yield 75
%) M-chlorobenzoyl chloride (area ratio by gas chromatography; 98.0%).

Example 3 203.0 g of isophthaloyl chloride and 0.6 g of a catalyst containing 3% rhodium on alumina were placed in a 3-neck flask containing 300 ml, and 16.5 hours, 240 to 260.
Heated to reflux at ° C. The composition of the reaction mixture thus obtained was found to be 75.6% m-chlorobenzoyl chloride and 1 part isophthaloyl chloride based on the area ratio of gas chromatography.
It was 8.5% and m-dichlorobenzene 4.8%. The reaction product was distilled to give 122.5% (yield 70%) m.
-Chlorobenzoyl chloride (area ratio by gas chromatography; 97.5%) was obtained.

Example 4 300 ml of 0.53.0 g of a catalyst in which 20% of isophthaloyl chloride and 3% of ruthenium are supported on alumina.
In a 3-necked flask containing 1 240 hours 240-26
The mixture was heated to reflux at 0 ° C. The composition of the thus obtained reaction mixture was found to be 65.6 g of m-chlorobenzoyl chloride, 29.5% of isophthaloyl chloride and 3.8% of m-dichlorobenzene from the area ratio of gas chromatography. The reaction product was distilled to obtain 110.3 g (yield 63%) of m-chlorobenzoyl chloride (area ratio by gas chromatography: 97.9%).

Example 5 Stirrer, thermometer, isobaric dropping funnel filler (outer diameter 3 mm,
20 in a 300 ml 4-necked flask equipped with a fractionating tube filled with a cylindrical biscuit chip with an inner diameter of 1 mm and a length of 5.3 mm.
Take 0 g of isophthaloyl chloride and 0.5 g of 5% palladium / alumina and heat to 260 ° C. After heating under reflux for 5 hours, the fraction distilled at 250 to 260 ° C. was distilled, while the reaction was allowed to proceed while gradually supplementing isophthaloyl chloride. It took 53 hours to replenish 2,500 g of isophthaloyl chloride,
86 g of distillate was obtained. This distillate was rectified and
6.7 g (yield 89.2%) of m-chlorobenzoyl chloride (area ratio by gas chromatography: 99.6)
%) Was obtained.

Example 6 203.0 g of isophthaloyl chloride and 0.05 g of a catalyst containing 5% palladium on alumina were added to 300 m of the catalyst.
The mixture was placed in a 3-necked flask containing l and heated to reflux at 250 ° C. for 10 hours. The composition of the reaction mixture obtained here was determined by the area ratio of gas chromatography to be 70.1% m-chlorobenzoyl chloride, 20.5% isophthaloyl chloride, and m.
-Dichlorobenzene 5.9%. The reaction product was distilled to obtain 110.3 g (yield 63%) of m-chlorobenzoyl chloride (area ratio by gas chromatography: 98.7%).

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Claims (1)

[Claims] 1. Formula (1): A phthaloyl halide having the formula (wherein X represents a halogen atom) is heated in the presence of a metal catalyst. A process for the preparation of a halogenated benzoyl halide having the formula: wherein X has the significance given above.