JPH064548B2 - Method for producing 5-butyl-2,3,6-trichlorotoluene - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing 5-butyl-2,3,6-trichlorotoluene, more specifically, 5-butyl-2,3 from a specific toluene derivative. , 6-trichlorotoluene selectively and efficiently.

[Prior Art and Problems to be Solved by the Invention] As a method for producing 2,3,6-trichlorotoluene, a mixture of chlorinated compounds is obtained by chlorinating p-toluenesulfonic acid. 2,3,6-trichlorotoluene sulfonic acid is separated from the product and heated in sulfuric acid for desulfonation (Chem. Ab. 94: 208).
488), after chlorinating p-nitrotoluene to form a trichloro body, reducing the nitro group to form p-aminotrichlorotoluene, and then deaminating by Sandmeyer reaction (Rev. Roum. Chem. 1974, 19
(7), p1221), or a method of chlorinating p-tert-butyltoluene to form a trichloro form and then debutylating (Soviet Patent No. 319,209) and the like are known.

However, in these conventional methods, during chlorination, 2,
In addition to 3,6-trichloro form, dichloro form such as 2,5-, 2,6- or 2,3-, 2,3,5-trichloro form, chloro form such as 2- or 3-, and further methyl Since a chlorinated product of the group is simultaneously produced, a complicated separation operation such as precision distillation and crystallization is finally required.

Further, according to the research conducted by the present inventors, 2,3,6-trichlorotoluene was obtained by stirring 5-butyl-2,3,6-trichlorotoluene in toluene or benzene in the presence of aluminum chloride. It turned out to be easily obtainable.

However, if 5-butyl-2,3,6-trichlorotoluene is produced according to the above-mentioned method, a complicated separation operation cannot be avoided as in the case of producing 2,3,6-trichlorotoluene. I understood it.

[Means for Solving the Problems]

Therefore, the present inventors have studied various methods capable of efficiently producing 5-butyl-2,3,6-trichlorotoluene without the need for the complicated separation operation. As a result, while using a specific toluene derivative as a raw material,
It has been found that the object can be achieved by using Friedel-Crafts catalyst and sulfuryl chloride in a relatively low temperature range below room temperature. The present invention has been completed based on such findings.

That is, the present invention relates to 3,5-dibutyltoluene; 3,5
At least one toluene derivative selected from the group consisting of -dibutyl-2-chlorotoluene and 3,5-dibutyl-2,6-dichlorotoluene in the presence of Friedel-Crafts catalyst at a temperature of 0 to 30 ° C. 5-Butyl-2,3,6-, characterized by reacting with sulfuryl chloride
A method for producing trichlorotoluene is provided.

In the method of the present invention, the toluene derivative used as a raw material is 3,5-dibutyltoluene;
Dibutyl-2-chlorotoluene or 3,5-dibutyl-2,6-dichlorotoluene, which may be used alone or in combination of two or more. Here, especially when the target compound is 5-tert-butyl-2,3,6-trichlorotoluene, 3,5-di-tert
-Butyltoluene; 3,5-di-tert-butyl-2-chlorotoluene or 3,5-di-tert-butyl-2,
6-dichlorotoluene may be used. If the butyl group of the target compound is n-, iso-, sec-butyl group,
A raw material compound having a corresponding butyl group may be used.

Among the toluene derivatives that are the above raw materials, 3,5-
Dibutyltoluene can be obtained by butylating toluene, and if it is chlorinated by a conventional method,
It is possible to easily obtain 3,5-dibutyl-2-chlorotoluene and 3,5-dibutyl-2,6-dichlorotoluene.

Since these toluene derivatives are solid at room temperature,
When used in the method of the present invention, it may be dissolved in a solvent and used for the reaction if necessary.

Examples of the solvent that can be used in the method of the present invention include hydrocarbons such as hexane and heptane and halogenated hydrocarbons such as carbon tetrachloride, chloroform and methylene chloride. The amount of solvent used is
The amount is sufficient as long as it can dissolve the toluene derivative to the extent that stirring during the reaction is not hindered, and the amount may be the same as or more than that of the toluene derivative, and there is no particular limitation.

Also, when carrying out a reaction (chlorination reaction or chlorination and debutylation reaction) using a toluene derivative as a raw material,
It is necessary to use Friedel-Crafts catalysts as catalysts. Commonly known Friedel-Crafts catalysts include SbCl ₃ , AlCl ₃ , FeCl ₃ , SnCl ₄ , BF ₃ , and ZnC.
Various materials such as l ₂ , SbCl ₅ , TeCl ₃ , TiCl ₄ , and HF can be used. If necessary, S ₂ Cl ₂ or the like can be added as a co-catalyst.

Although the so-called catalyst amount is sufficient for the addition amount of these catalysts,
Specifically, 1 to 10 mol% of the toluene derivative as a raw material
The degree is appropriate.

Further, in the reaction of the present invention, it is necessary to use sulfuryl chloride. In the method of the present invention, this sulfuryl chloride mainly acts as a chlorinating agent, and the amount of the sulfuryl chloride used is 5-butyl-2,3, which is the objective of chlorinating the toluene derivative which is the above raw material. The amount of chlorine sufficient to produce 6,6-trichlorotoluene or more may be selected as a guide. That is, the following reaction formulas: , 3,5-dibutyltoluene (eg 3,
3 mol of sulfuryl chloride is necessary for 1 mol of (5-di-tert-butyltoluene).
One mole of 2-chlorotoluene (eg 3,5-di-tert-butyl-2-chlorotoluene) requires 2 moles of sulfuryl chloride and 3,5-dibutyl-2,6-dichlorotoluene (eg 3 , 5-di-tert-butyl-2,6
-Dichlorotoluene) requires an equivalent amount of sulfuryl chloride. In order to carry out the reaction more reliably, it is preferable to add sulfuryl chloride in an amount 1.1 to 1.4 times the required number of moles. Adding more sulfuryl chloride has little effect, requires post-treatment such as decomposing excess sulfuryl chloride after the reaction, and is not economical.

The reaction will occur even if another chlorinating agent is used instead of sulfuryl chloride, but the object of the present invention is not sufficiently achieved. For example, when chlorine gas is used as the chlorinating agent,
Chlorination of 3,5-dibutyltoluene gives 2,3,6
-A compound containing chlorine at the 4-position is produced as a by-product in addition to the trichloroform.

Further, the temperature at which the sulfuryl chloride is reacted with the toluene derivative needs to be in the range of 0 to 30 ° C. In this case, it is not practical to carry out the reaction at a temperature lower than 0 ° C. because the solubility of the raw materials in the solvent is greatly reduced. On the other hand, when the temperature exceeds 30 ° C, for example, 60 to 70 ° C, the target 5- (tert-) butyl-2,3,6-trichlorotoluene is scarcely obtained and 3,5-di (tert-) butyl is obtained. -2
6-Dichlorotoluene becomes the main product (for example, it is also shown in the examples described in JP-B-47-26495 and JP-A-62-5930). By the way, the reaction temperature in the case of chlorination with sulphonyl chloride in the presence of a Lewis acid catalyst using 3,5-dibutyltoluene as a raw material is as follows: It has been said that it is performed at a temperature of 10 to 70 ° C. in consideration of the property.
For example, JP-A-62-5930 describes that the temperature is 10 to 70 ° C. However, in the examples, both of the above two publications are 6
The reaction is carried out at 0 to 70 ° C. and 3,5-di (tert-) butyl-
There is only a description that 2,6-dichlorotoluene can be obtained. That is, it seems that no detailed study has been carried out at temperatures of 30 ° C. or below, and it is inconceivable that nothing has been recognized so far regarding the occurrence of a specific phenomenon in the reaction on the low temperature side. As a result of a detailed study of the range including 10 to 70 ° C., the present inventor irrespective of whether or not a solvent is used, other than that, a relatively low temperature of about room temperature or less, specifically a range of 0 to 30 ° C. Then 3,5-di (ter
It was found that t-) butyl-2,6-dichlorotoluene was scarcely obtained, and that 5- (tert-) butyl-2,3,6-trichlorotoluene could be specifically produced in an extremely high yield.

After completion of the reaction, if necessary, extraction with a suitable organic solvent such as hexane, ether, chloroform, carbon tetrachloride, methylene chloride, etc., washing with hydrochloric acid, water, etc., and then distilling off the solvent, High-purity 5-butyl-
2,3,6-trichlorotoluene (5-tert-butyl-
2,3,6-trichlorotoluene) can be obtained.

〔Example〕

 Next, the present invention will be described in more detail with reference to examples.

Example 1 In a 200 ml three-necked flask equipped with a stirring blade and a reflux condenser, 3,5-di-tert-butyltoluene (DBT) 5.1 g (2
(5 mmol), 0.32 g (1.4 mmol) of antimony chloride and 0.1 g (0.74 mmol) of sulfur chloride, 13.5 g (100 mmol) of sulfuryl chloride were added dropwise, and the mixture was stirred at 30 ° C. for 36 hours. 50 ml of hexane was added to the obtained reaction solution.
Was added, and the mixture was washed with 10% hydrochloric acid and distilled water until no solid substance was seen in the aqueous layer, filtered, and separated to obtain a hexane solution. After the hexane solution was dried with Glauber's salt, hexane was distilled off to give 98% pure 5-tert-butyl-2,3,3.
6.3 g of powder of 6-trichlorotoluene (BTCT)
(24.54 mmol) was obtained. The yield of BTCT based on the raw material DBT was 98.1%.

Example 2 Using 10 cc of carbon tetrachloride as a solvent, DBT5.1
g (25 mmol), antimony chloride 0.17 g (0.74 mmol) and sulfur chloride 0.1 g (0.74 mmol) were added, and sulfuryl chloride 12.2 g (90 mmol) was added dropwise, and the mixture was stirred at 20 ° C. for 48 hours. 50 ml of hexane was added in the same manner as in Example 1, and the mixture was washed with 10% hydrochloric acid and distilled water until solids were not visible in the aqueous layer, filtered and separated, and hexane was distilled off to obtain a 5-% pure product having a purity of 97%. tert-butyl-2,3,6
-Trichlorotoluene (BTCT) powder 6.4 g (24.
75 mmol) was obtained. The yield of BTCT based on DBT was 99.0%.

Example 3 Using 10 cc of carbon tetrachloride as a solvent, DBT5.1
g (25 mmol), aluminum chloride 0.2 g (1.5 mmol), sulfur chloride 0.1 g (0.74 mmol), and sulfuryl chloride 15.5 g (115 mmol) was added dropwise at 27 ° C.
And stirred for 4 hours. 50 ml of hexane was added in the same manner as in Example 1, and the mixture was washed with 10% hydrochloric acid and distilled water until no solid substance was seen in the aqueous layer, filtered and separated, and hexane was distilled off to give a 5-purity mixture of 84%. tert-butyl-2,3,6
-Trichlorotoluene (BTCT) powder 6.4 g (2
(1.4 mmol) was obtained. The yield of BTCT based on DBT was 85.6%.

Example 4 3,5-di-tert-butyl-2,6-dichlorotoluene (DBT) 5.5 g (20.0 mmol), 3,5-in a 200 ml three-necked flask equipped with a calcium chloride drying tube.
1.3 g (5 mmol) of di-tert-butyl-2-chlorotoluene, 0.2 g (1.5 mmol) of aluminum chloride and 10 ml of carbon tetrachloride were added, 8 g (59 mmol) of sulfuryl chloride was added dropwise, and the mixture was stirred at 24 ° C. for 4 hours. did. Hexane (50 ml) was added to the reaction solution, which was washed with 15% hydrochloric acid, and then washed with water until it became neutral. The obtained hexane solution was dried with sodium sulfate, and then hexane was distilled off to obtain a powder. When quantified by gas chromatography, 17.6 mmol of BTCT was obtained. The yield of BTCT with respect to the raw material dibutyl body was 85%.

Comparative Example 1 Carbon tetrachloride (10 ml) was added as a solvent, and 10 g of chlorine gas was introduced over 4 hours instead of sulfuryl chloride to carry out the reaction and post-treatment under the same conditions as in Example 1. As a result of gas chromatography, 5-tert-butyl-2,3,6-trichlorotoluene (13.7 mmol)
In addition to the above, a mixture containing a chlorine-containing trichloro compound and a dichloro compound at the 4-position was obtained. The yield of TCBT based on DBT was 54.8%.

〔The invention's effect〕

As described above, according to the method of the present invention, highly pure 5-butyl-butane can be easily obtained without performing a complicated separation operation.
2,3,6-Trichlorotoluene can be produced.

Further, the 5-butyl-2,3,6-trichlorotoluene thus obtained can be converted into 2,3,6-trichlorotoluene by performing a debutylation reaction.

5-Butyl-2,3,6 produced by the method of the present invention
-Trichlorotoluene includes various pesticides such as 2,3,6-trichlorotoluene (eg Chlorfenac: 2,
(3,6-trichlorophenylacetic acid, etc.) as a synthetic intermediate, and as a raw material for various other fine chemicals.

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Claims (1)

[Claims] 1. 3,5-Dibutyltoluene; 3,5-dibutyl-2-chlorotoluene and 3,5-dibutyl-2,
5-butyl-2, characterized in that at least one toluene derivative selected from the group consisting of 6-dichlorotoluene is reacted with sulfuryl chloride at a temperature of 0 to 30 ° C. in the presence of a Friedel-Crafts catalyst. A method for producing 3,6-trichlorotoluene.