JPH07330663A - Method for producing 2-chloroterephthalic acid chloride - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for industrially producing high-purity 2-chloroterephthaloyl chloride in a high yield. [Structure] 4-Methylbenzoyl chloride was used as a starting material to react with chlorine, and 3-chloro-4-methylbenzoic acid chloride was separated from the obtained reaction product.
Chloro-4-methylbenzoic acid chloride was reacted with chlorine under light irradiation to give 3-chloro-4-trichloromethylbenzoic acid chloride, and the resulting 3-chloro-4-
This is a method for producing highly pure 2-chloroterephthalic acid chloride by hydrolyzing trichloromethylbenzoic acid chloride in the presence of a Lewis acid catalyst. [Effects] High-purity 2-chloroterephthalic acid chloride is obtained in high yield by using 4-methylbenzoic acid chloride, which is inexpensive and easily industrially available, as a raw material and does not pass through a difficult-to-handle high-melting-point substance as an intermediate. It can be produced, and is industrially very advantageous in terms of raw materials, reaction equipment, and economy.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing 2-chloroterephthalic acid chloride, and more particularly to 3-chloro-4
-The present invention relates to a method of using trichloromethylbenzoyl chloride as a reaction raw material. 2-Chloroterephthalic acid chloride is an industrial raw material useful as an intermediate for industrial chemicals, particularly as a monomer for functional polymer compounds such as aromatic polyamide and aromatic polyester.

[0002]

2. Description of the Related Art The method for producing 2-chloroterephthalic acid chloride can be roughly divided into two methods. The first method is nuclear chlorination of terephthalic acid chloride by directly introducing chlorine into the aromatic nucleus of terephthalic acid chloride. The second method is the method of synthesizing 2-chloro-1,4-bistrichloromethylbenzene, which is reacted with an organic acid in the presence of a Lewis acid catalyst, via a hexachloroxylene mononuclear chloride. Is the way.

As the first method for nuclear chlorination of terephthalic acid chloride, 2-chloroterephthalic acid chloride is obtained by reacting molten terephthalic acid chloride with chlorine in the presence of a ferric chloride catalyst. (JP-A-4-273845) or a method of reacting terephthalic acid chloride melted with chlorine in the presence of a ferric chloride catalyst to give 2-chloroterephthalic acid chloride in the reaction mixture in an amount of 30 to 41. A method has been proposed in which the concentration of 2-chloroterephthalic acid chloride is increased by cooling the reaction mixture when it reaches the weight% to separate crystals (Japanese Patent Laid-Open No. 2-258471).

However, this nuclear chlorination reaction of terephthaloyl chloride is a sequential reaction, and the reaction easily proceeds from the monochloro body to the dichloro body and further to the trichloro body, and only the target monochloro body has a high purity. It is difficult to obtain, and the boiling point of the monochloro compound is 137 ° C /
It is industrially difficult to separate 2-chloroterephthalic acid chloride by distillation because the temperature is as high as 5 mmHg and is close to the boiling point of the dichloro compound, and the melting point of terephthalic acid chloride is as high as 85 ° C. JP-A-2-
Even in the case of Japanese Patent No. 258741, the dichloro compound is contained in an amount of 19% by weight or more with respect to the monochloro compound, and high-purity 2-chloroterephthalic acid chloride cannot be obtained.

The second method, which is via the hexachloroxylene mononuclear chlorinated product, is that paraxylene is photochlorinated under irradiation with light containing ultraviolet rays to produce 1,4-bistrichloromethylbenzene. This is subjected to nuclear chlorination to distill away 2-chloro-1,4-bistrichloromethylbenzene from the reaction product, and further the obtained 2-chloro-1,4-bistrichloromethylbenzene is treated with Lewis acid. A method in which 2-chloroterephthalic acid chloride is distilled and separated from the reaction product by reacting with an organic acid in the presence of a catalyst (JP-A-4-31251), or para-xylene is subjected to nuclear chlorination to remove the reaction product from the reaction product. 2-Chloroparaxylene is distilled off and then chlorinated under irradiation with UV-containing light to produce 2-chloro-1,4-bistrichloromethylbenzene, A method of reacting the obtained 2-chloro-1,4-bistrichloromethylbenzene with an organic acid in the presence of a Lewis acid catalyst to distill and separate 2-chloroterephthalic acid chloride from the reaction product (Japanese Patent Laid-Open Publication No. Hei. -32
7557).

However, the present inventors conducted 1,4
According to the experiment of the nuclear chlorination reaction of bistrichloromethylbenzene, chlorine was introduced into 1,4-bistrichloromethylbenzene and the reaction was performed for 20 hours while maintaining the reaction temperature at 150 to 170 ° C. Although the rate is as low as 46.5%, the dichloro compound is already 7.0.
The production rate of the target product, that is, the monochloro body, is low, since the production rate is as high as wt%. Also, 2-chloro-1,4
-Bistrichloromethylbenzene has a boiling point of 165 ° C / 5
mmHg, melting point 78-80 ° C, which is a very high temperature,
It is industrially difficult to separate by distillation, so
When used as an intermediate raw material for producing chloroterephthalic acid chloride, impurities in the raw material 2-chloro-1,4-bistrichloromethylbenzene remain as impurities of the target product, and the target product is obtained in high purity. I can't.

According to the example of JP-A-4-327557, 2-chloroterephthalic acid chloride
Although it can be obtained with a purity of 9.6%, it is necessary to use 2-chloroterephthalic acid chloride as a polymer raw material.
A purity of 9.9% or higher is required, and a purity of 99.6% is too high in impurity level and necessitates re-purification, which is not preferable from the economical point of view. A polymer compound produced using 2-chloroterephthalic acid chloride having a purity of less than 99.9% as a raw material has a problem that desired functional characteristics cannot be guaranteed for the polymer compound due to variations in surface characteristics.

[0008]

As described above, it has been difficult to industrially produce high-purity 2-chloroterephthalic acid chloride that can be used as a polymer raw material. Therefore,
The inventors of the present invention have conducted earnest studies on a method capable of industrially easily producing high-purity 2-chloroterephthalic acid chloride, and as a result, hydrolyzed with 3-chloro-4-trichloromethylbenzoic acid chloride as a raw material. The present invention has been completed by finding that high-purity 2-chloroterephthalic acid chloride can be easily obtained in a high yield by causing a decomposition reaction.

Therefore, the object of the present invention is to obtain a high purity 2-
An object of the present invention is to provide a method for industrially producing chloroterephthaloyl chloride in a high yield. That is, in the process of producing a high melting point substance, the melting point, boiling point, and sublimation point are close to each other, and purification separation is difficult, and when temporarily stored at the intermediate stage, remelting is performed and then the next operation is performed. Problems such as need arise.

[0010]

That is, the present invention provides a highly pure 2-chloroterephthalic acid characterized by hydrolyzing 3-chloro-4-trichloromethylbenzoic acid chloride in the presence of a Lewis acid catalyst. It is a method for producing chloride.

Further, according to the present invention, 4-methylbenzoic acid chloride is reacted with chlorine to obtain 3
-Chloro-4-methylbenzoic acid chloride was separated, and this 3-chloro-4-methylbenzoic acid chloride was reacted with chlorine under light irradiation to give 3-chloro-4-trichloromethylbenzoic acid chloride, which was further obtained. 3-chloro-
A method for producing high-purity 2-chloroterephthalic acid chloride, which comprises hydrolyzing 4-trichloromethylbenzoic acid chloride in the presence of a Lewis acid.

The manufacturing method of the present invention will be described in detail below. In the present invention, 4-methylbenzoic acid chloride used as a starting material is, for example, chlorinating 4-methylbenzoic acid produced as a by-product during terephthalic acid production by air oxidation reaction of paraxylene with benzotrichloride or thionyl chloride. By doing so, it can be easily produced, and a highly pure product can be obtained inexpensively and industrially. In the reaction of the first step of the present invention, a nuclear chlorination reaction of 4-methylbenzoic acid chloride is carried out to give 3-chloro-4
-Methyl benzoyl chloride is produced. This reaction is a liquid phase reaction and is carried out by blowing chlorine gas into 4-methylbenzoic acid chloride as a raw material in the presence of a Lewis acid catalyst such as aluminum chloride, antimony chloride, zinc chloride and ferric chloride. The reaction form may be either a batch method or a continuous method. As the Lewis acid catalyst, ferric chloride is particularly preferable from the viewpoints of easy handling and economy. The amount of the catalyst used is 0.01 to 5% by weight, preferably 0.2 to 2 with respect to 4-methylbenzoyl chloride as a raw material.
It is in the range of% by weight. When the amount of the catalyst is less than 0.01% by weight, the reaction is remarkably slowed, and when it is more than 5% by weight, the reaction is accelerated, but perchlorates such as dichloro compounds are often produced, which is not preferable.

The reaction temperature of the nuclear chlorination reaction is 20 to 160.
C., preferably 30 to 60.degree. Reaction temperature is 20 ℃
When it is lower, the reaction rate is lowered, so that the load for recovering the raw material is increased, and when it is higher than 160 ° C., the production rate of perchlorate such as dichloro compound is increased and the selectivity is lowered. . The amount of chlorine used in the nuclear chlorination reaction is 0.3 times or more moles, preferably 0.8 to 1.5 times moles, relative to 1 mole of 4-methylbenzoyl chloride as a raw material. 1 if the chlorine molar ratio is too low
The yield per cycle will be low, and if the amount of chlorine is increased more than necessary, the amount of perchlorinated products such as dichloro compounds will increase, which is not preferable. The chlorine content is 0.1% per hour with respect to 1 mol of 4-methylbenzoic acid chloride.
It is desirable to supply at a rate of 03 to 0.3 times mol.
The reaction time is appropriately in the range of 3 to 30 hours. This nuclear chlorination reaction can be carried out without using a solvent, but if necessary, a reaction solvent such as carbon tetrachloride, acetic acid, chloroform, tetrachloroethylene or carbon disulfide may be used.

Separation of 3-chloro-4-methylbenzoic acid chloride from the reaction mixture is usually carried out by distillation. Distillation may be continuous or batchwise, and the distillation pressure is 5
It is performed under a reduced pressure of about 10 mmHg, and the temperature is such that the temperature at the bottom of the distillation column is 120 to 150 ° C. By this distillation, unreacted starting materials 4-methylbenzoic acid chloride and 3-chloro-4-methylbenzoic acid chloride are obtained as distillates. In addition, 4 of the raw materials recovered as the first distillate
-Methylbenzoyl chloride can be recycled to the reactor and reused for the nuclear chlorination reaction. Here, perchlorates such as dichloro compounds are removed from the column bottom as high-boiling compounds.

3-Chloro-4 thus isolated
-Methylbenzoic acid chloride is converted to 3-chloro-4-trichloromethylbenzoic acid chloride by the side chain chlorination reaction of the second step of the present invention. The production of 3-chloro-4-trichloromethylbenzoic acid chloride was carried out under light irradiation.
For example, it is carried out by blowing chlorine into 3-chloro-4-methylbenzoic acid chloride under the irradiation of Hg lamp. The reaction form may be either a batch method or a continuous method. This photochlorination reaction can be carried out without using a solvent, but if necessary, a reaction solvent such as carbon tetrachloride may be used.

In this photochlorination reaction, the reaction temperature is 9
0 to 160 ° C., but 100 to 15 to reduce the time required to complete the reaction and suppress side reactions to increase the yield.
It is preferably carried out in the range of 0 ° C. The amount of chlorine used is at least the theoretical amount, but preferably 1.1 to the theoretical amount.
It is 1.6 times the molar amount. The obtained reaction product can be used for the next reaction as it is, but it is preferable to remove the low boiling point compound by simple distillation in advance. By this distillation, a low boiling point product containing 3,4-dichlorobenzoic acid chloride as a main component is obtained on the distillate side, and the target substance 3-chloro-4-trichloromethylbenzoic acid chloride as a main component is obtained. The substance to be obtained is obtained as a can residue.

The reaction of the third step of the present invention is a hydrolysis reaction of 3-chloro-4-trichloromethylbenzoic acid chloride in the presence of a Lewis acid catalyst, and this reaction gives 2-chloroterephthalic acid chloride. To be When 3-chloro-4-trichloromethylbenzoic acid chloride is used, a reaction using water or various carboxylic acids as an oxygen source is possible, but a reaction using water from the viewpoint of economy and reduction of impurity content. Systems are preferred. The amount of water used is 0.9 to 1.1 times the theoretical amount, preferably 0.95 to 1.05 times the molar amount relative to 1 mol of 3-chloro-4-trichloromethylbenzoic acid chloride. When it is less than 0.9 times by mole, the starting material 3-chloro-4-trichloromethylbenzoyl chloride remains, and when it is more than 1.1 times by mole, the produced 2-chloroterephthalic acid chloride is further hydrolyzed. In any case, the yield of the target product is lowered due to the decomposition.

As a catalyst for the hydrolysis reaction, Lewis acid catalysts such as aluminum chloride, antimony chloride, zinc chloride and ferric chloride are used. Ferric chloride is easy to handle and economical. Is particularly preferable. The amount used is 0.01 to 1.0% by weight with respect to 3-chloro-4-trichloromethylbenzoic acid chloride. The reaction temperature is 90 to 150 ° C, preferably 120 to 140 ° C,
The reaction is continued until the starting material, 3-chloro-4-trichloromethylbenzoic acid chloride, disappears. Here, if the reaction temperature is lower than 90 ° C., the time required to complete the reaction becomes long, and if it exceeds 150 ° C., a side reaction proceeds to produce a polymer or the like, so that the selectivity of the target product decreases. This is not preferable. The water used here is preferably pure water, but ordinary tap water may be used from the viewpoint of handling and economy.

Separation of the desired product, 2-chloroterephthalic acid chloride, from the reaction mixture obtained by this hydrolysis reaction is carried out by distillation. The distillation operation may be continuous or batchwise, and distillation under a reduced pressure of about 5 mmHg absolute is preferable. With this distillation, 99.9% or more of 2-
Chloroterephthalic acid chloride is obtained, and perchlorates such as dichloro compounds are removed from the column bottom as high-boiling compounds.

[0020]

The reaction in the present invention proceeds by the following reaction mechanism.

[Chemical 1]

The above-mentioned first step is a nuclear chlorination reaction in the liquid phase of 4-methylbenzoic acid chloride. In this reaction, the production rate of the monochloro compound in the sequential reaction is higher than that in the conventional liquid phase nuclear chlorination reaction of paraxylene, 1,4-bistrichloromethylbenzene and terephthalic acid chloride. Table 1 shows the production ratio of the monochloro compound and the dichloro compound when the above-mentioned compound was subjected to the nuclear chlorination reaction under typical conditions. From this, it is understood that the production rate of the monochloro compound is high in the case of the reaction of the present invention, that is, the nuclear chlorination reaction of 4-methylbenzoic acid chloride.

[0022]

[Table 1]

Further, 3- produced by this nuclear chlorination reaction
The boiling point of chloro-4-methylbenzoyl chloride is 123.
C / 10 mmHg, 1,4-used in the conventional method
Since the boiling point of the monochloro compound produced from bistrichloromethylbenzene and terephthalic acid chloride is low, it can be easily separated.

Further, in the first step and the second step which is the side chain chlorination reaction step, since each target product is obtained in a yield of 80% or more, the overall yield is increased, resulting in economical efficiency. It is more advantageous than the conventional method. Further, in these reaction steps, the reaction products can be easily separated by applying a commonly used distillation means.

Further, in the third step, since the hydrolysis is carried out in the presence of a Lewis acid catalyst, the reaction proceeds at a low temperature, so that the side reaction does not proceed and it is possible to suppress the inclusion of impurities due to the production of by-products. Therefore, the target substance can be easily separated from the reaction mixture by distillation.

Therefore, according to the method of the present invention, 4-methylbenzoic acid chloride, which is inexpensive and easily industrially available, is used as the raw material, and Lewis acid is particularly easy to handle and is economical as the catalyst among Lewis acids. Highly pure 2-chloroterephthalic acid chloride can be easily and efficiently obtained by using each of ferric chloride.

[0027]

EXAMPLES The contents of the present invention will be specifically described below based on Examples and Comparative Examples.

Example 1 [First Step] 4-Methylbenzoyl chloride 6510
kg (41.9 kmol), ferric chloride 12 kg
(0.2 wt%) is added and stirred. 150k chlorine gas
It was introduced while bubbling at a flow rate of g / hour, and the reaction was carried out for 18 hours while maintaining the reaction temperature at 40 to 50 ° C. The total amount of chlorine used is 2692 kg (38.0 kmo
l).

The reaction mixture was analyzed by gas chromatography to find that the composition was 13.6% by weight of unreacted 4-methylbenzoic acid chloride, 83.5% by weight of 3-chloro-4-methylbenzoic acid chloride and dichloro-. It was 2.9% by weight of 4-methylbenzoyl chloride.

The conditions of gas chromatography and the retention time of the compound are as follows. Model: Shimadzu GC-14
A, column: SE-52, 5% Uniport HP
60/80 #, detector: FID, sensitivity; 10 ³ ,
H ₂ ; 0.6 kg / cm ² , Air; 0.5 kg / cm
² , temperature: column; constant temperature of 160 ° C, inlet: 250 ° C,
Detector; 250 ° C., carrier gas: N ₂ , 50 ml /
min, 1.2 kg / cm ² , retention time: 4-methylbenzoic acid chloride; 1.1 min, 3-chloro-4-methylbenzoic acid chloride; 2.0 min.

The above reaction mixture was distilled under reduced pressure (reflux ratio: 1).
Then, 5005 kg of 3-chloro-4-methylbenzoic acid chloride having a boiling point of 122 to 123 ° C./10 mmHg (26.
4 kmol) was obtained. The obtained 3-chloro-4-methylbenzoic acid chloride had a purity of 99.7% and a yield of 63.2%. The recycling yield for reuse of unreacted 4-methylbenzoic acid chloride was 96.9%.

[Second Step] 3-Chloro-4-methylbenzoyl chloride 5005k obtained in the first step
Chlorine gas was bubbled into g (26.4 kmol) under Hg lamp irradiation while appropriately changing the flow rate between 50 and 150 kg / hour, and the reaction temperature was kept at 130 ± 10 ° C. for 65 hours to carry out the reaction. went. The total amount of chlorine used is 6604k
It was g (93.1 kmol), and the chlorine reaction rate was 85%.

As a result of analyzing the reaction mixture by gas chromatography, its composition was 3-chloro-
86.6% by weight of 4-trichloromethylbenzoic acid chloride, 9.1% by weight of 3-chloro-4-dichloromethylbenzoic acid chloride, 3.7% of 3,4-dichlorobenzoic acid chloride, and 0.6% by weight of others. there were. The yield of the reaction product solution was 7280 kg.

The reaction mixture was distilled under reduced pressure (reflux ratio 4).
Then, the low boiling point was distilled to 175 ° C / 10 mmHg to obtain 5520 kg (18.9 kmol) of 3-chloro-4-trichloromethylbenzoic acid chloride as a bottom residue. The purity of the obtained 3-chloro-4-trichloromethylbenzoic acid chloride was 99.9%, and the yield was 71.6%. The recycling yield considering the loss of the distillation column is 88.
It was 1%.

[Third step] 5520 kg (18.9 kmol) of 3-chloro-4-trichloromethylbenzoic acid chloride obtained in the second step was mixed with 13 parts of ferric chloride.
kg (0.2% by weight) was added and stirred. Water 10-15
It was introduced dropwise at a flow rate of kg / hour, the reaction temperature was kept at 130 ± 5 ° C., the reaction was carried out for 29 hours, and the mixture was aged for 6 hours.
The amount of water used was 335 kg (18.6 kmol).

The yield of the reaction completed liquid was 4350 kg,
The purity of 2-chloroterephthalic acid chloride is 99.6%.
Met. The reaction mixture was distilled under reduced pressure (reflux ratio 1),
2 with boiling point of 134-135 ° C / 5.0 mmHg as bottoms
-Chloroterephthalic acid chloride 2305 kg (9.7
mol) was obtained. The obtained 2-chloroterephthalic acid chloride had a purity of 99.999% and a yield of 51.3.
%Met. The recycling yield was 78.0% in consideration of the loss in the distillation column.

The conditions of gas chromatography and the retention times of the main compounds in the second and third steps are as follows. Model: Shimadzu GC-14A, Column: SE-52.5%
Uniport HP 60/80 #, detector: FI
D, sensitivity 10 ³ , H ₂ ; 0.6 kg / cm ² , Ai
r; 0.5 kg / cm ² , temperature: column; initial temperature 11
0 ° C, heating rate 3 ° C / min, final temperature 180 ° C, inlet: 250 ° C, detector: 250 ° C, carrier gas: N
₂ , 50 ml / min, 1.2 kg / cm ² , retention time: 3-chloro-4-methylbenzoic acid chloride;
0 min, 3-chloro-4-trichloromethylbenzoic acid chloride; 20.5 min, 2-chloroterephthalic acid chloride; 13.0 min.

Example 2 [First Step] 500 g (2.6 m) of 3-chloro-4-methylbenzoyl chloride obtained in the first step of Example 1
ol), and 1.0 to 4.0 g of chlorine gas under Hg lamp irradiation.
The flow velocity is appropriately changed between 1 / min and is introduced in the form of a bubble,
The reaction temperature was kept at 130 ± 10 ° C. and the reaction was carried out for 8 hours.
The total amount of chlorine used is 885 g (12.5 mol),
The chlorine reaction rate was 75%.

As a result of analyzing the reaction mixture by gas chromatography, its composition was 3-chloro-
It was 80.6% by weight of 4-trichloromethylbenzoic acid chloride, 18.1% by weight of 3,4-dichlorobenzoic acid chloride and 1.3% by weight of others. Reaction product yield is 7
It was 52 g.

The above reaction mixture was used as it was without purification by distillation, and 1.5 g of ferric chloride (0.2% by weight relative to the reaction raw material) was added and stirred. Water was introduced dropwise at a flow rate of 0.5 g / min, the reaction temperature was 130 ± 5 ° C., the reaction was carried out for 1.5 hours, and the mixture was matured for 0.5 hour. The amount of water used was 37.8 g (2.1 mol).

As a result of analyzing the reaction product liquid by gas chromatography, the composition was found to be 81.0% by weight of 2-chloroterephthalic acid chloride, 18.5% by weight of 3,4-dichlorobenzoic acid chloride and 0.5% by weight of others. Met. The yield of the reaction product solution was 500 g.

This reaction product solution was distilled under reduced pressure under the same conditions as in Example 1 to obtain 207 g (0.87) of 2-chloroterephthalic acid chloride having a boiling point of 134 to 135 ° C./5.0 mmHg.
mol) was obtained. The purity of the obtained 2-chloroterephthalic acid chloride was 99.99%, and 3-chloro-4-
Overall yield from methyl benzoyl chloride is 33.5%
Met.

Comparative Example 0.5 kg (0.3% by weight) of ferric chloride was added to 175 kg (862 mol) of terephthaloyl chloride and stirred. Chlorine gas was introduced while bubbling at a flow rate of 2 kg / hour, and the reaction was carried out for 20 hours while maintaining the reaction temperature at 160 ± 10 ° C. The total amount of chlorine used is 39.1 kg
(551 kmol).

As a result of analyzing the reaction mixture by gas chromatography, the composition was found to be 56.3% by weight of unreacted terephthalic acid chloride (TPC), 34.9% by weight of 2-chloroterephthalic acid chloride (CTPC) and dichloroterephthalic acid. Chloride (DCTPC) 6.5% by weight,
Trichloroterephthalic acid chloride (TCTPC) 1.
It was 5% by weight. The yield of the reaction product solution was 176.6 kg. The above reaction mixture was subjected to vacuum distillation (reflux ratio: 2) by a conventional method. The results are shown in Table 2, but the desired product, 2-chloroterephthalic acid chloride, was not purified and separated properly.

[0045]

[Table 2]

[0046]

INDUSTRIAL APPLICABILITY According to the present invention, 4-methylbenzoic acid chloride, which is inexpensive and easily available industrially, is reacted as a starting material with chlorine, and 3-chloro-4-methyl is obtained from the obtained reaction product. The benzoic acid chloride was separated and this 3
-Chloro-4-methylbenzoic acid chloride was reacted with chlorine under light irradiation to give 3-chloro-4-trichloromethylbenzoic acid chloride, and the obtained 3-chloro-4-trichloromethylbenzoic acid chloride was used as a Lewis acid catalyst. By hydrolyzing in the presence of, it is possible to produce high-purity 2-chloroterephthalic acid chloride in a high yield by a method that does not pass through a difficult-to-handle high-melting point substance as an intermediate. It is industrially very advantageous from the viewpoint of sex.

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Claims (3)

[Claims] 1. 3-Chloro-4 in the presence of a Lewis acid catalyst.
-A method for producing high-purity 2-chloroterephthalic acid chloride, which comprises hydrolyzing trichloromethylbenzoic acid chloride. 2. A reaction product obtained by reacting 4-methylbenzoic acid chloride with chlorine is treated with 3-chloro-4-
Methylbenzoyl chloride was isolated and the 3-chloro-
The method for producing 2-chloroterephthalic acid chloride according to claim 1, wherein 4-methylbenzoic acid chloride is reacted with chlorine under irradiation with light to obtain 3-chloro-4-trichloromethylbenzoic acid chloride as a raw material. 3. A Lewis acid catalyst selected from aluminum chloride, antimony chloride, zinc chloride and ferric chloride.
Claim 1 or Claim 2 which is a kind or a combination of two or more kinds.
A method for producing the described 2-chloroterephthalic acid chloride.