JPH038343B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides 4-4, which is useful as a stabilizer for organic materials, an active ingredient in herbicides, etc., or as an intermediate thereof.
Regarding the method for producing a benzoyl-5-hydroxypyrazole compound (hereinafter abbreviated as BPO), in detail, a pyrazolone compound, a halogenated alkylbenzene compound, and carbon tetrachloride are condensed in the presence of aluminum halide, and this is hydrolyzed. hand
Regarding the method of manufacturing BPO.

Previously, BPO was published in Japanese Patent Application Publication No. 126830/1983, 51-
138672, 54-148786, etc., by reacting a pyrazolone compound and a benzoyl halide compound to produce a 5-benzoyloxypyrazole compound, and then rearranging the benzoyl group at the 5-position of this compound to the 4-position. Therefore, it is manufactured.

However, the benzoyl halide compounds used in this method are irritating, difficult to handle, and expensive, so improvements are needed.

In addition, the applicant previously proposed in Japanese Patent Application No. 55-29829 (Japanese Unexamined Patent Publication No. 58-35996) that 4-benzoyl-5-hydroxy proposed a new method for producing pyrazole compounds,
The disadvantage is that the raw material benzotrichloride compound is still relatively expensive.

The present inventors condensed and hydrolyzed a pyrazolone compound, a benzene compound, and carbon tetrachloride in the presence of aluminum halide, and found that
Having obtained the knowledge that the desired BPO can be produced, I applied for a patent on the method of using halogenated benzene as a benzene-based compound as a raw material.
56-121691) (Japanese Unexamined Patent Publication No. 58-23668), it has now been discovered that the desired reaction proceeds also in a method using a halogenated alkylbenzene, and the present invention has been completed.

That is, in the present invention, in the presence of aluminum halide, the general formula () (In the formula, R ¹ is a hydrogen atom or an alkyl group,
R ² is an alkyl group) and a pyrazolone compound represented by the general formula () (In the formula, X is a halogen atom, Y is an alkyl group, m is an integer of 1 to 3, and n is 1 to 2
is an integer of ) and carbon tetrachloride are condensed,
This condensation product is hydrolyzed to give the general formula () This is a method for producing a 4-benzoyl-5-hydroxypyrazole compound represented by the formula (wherein R ¹ , R ² , X, Y, m and n are as described above).

R ¹ , R ² and Y of () to () in the above general formula
Examples of the alkyl group of X include methyl, ethyl, isopropyl, tert-butyl, etc., and examples of the halogen atom of X include chlorine atom, bromine atom, iodine atom, etc. Examples of aluminum halides include anhydrous aluminum chloride and anhydrous aluminum bromide.

Furthermore, examples of halogenated alkylbenzenes include 2,4-dichlorotoluene, 2,6
-dichlorotoluene, 2,3,6-trichlorotoluene, 2,5-dichlorotoluene, 2,4,6
-trichlorotoluene, 2,4-dichloroethylbenzene, 2,6-dichloroethylbenzene,
Examples include 4,5-dichloro-0-xylene and 2,4-dichloro-m-xylene.

According to the method of the present invention, the desired BPO can be produced at a high yield of, for example, 90% or more using inexpensive and easy-to-handle halogenated alkylbenzene compounds and carbon tetrachloride, which is industrially advantageous compared to conventional methods. It is.

In the method of the present invention, generally a pyrazolone compound,
A halogenated alkylbenzene compound and carbon tetrachloride are added in the presence of aluminum halide from 0 to 0.
condensation at a temperature of 100°C, preferably 10-70°C,
A reaction is then carried out to hydrolyze this condensation product. This condensation product can be once taken out of the reaction system and then subjected to the hydrolysis reaction, but water is added as it is without being taken out of the reaction system, and it cannot be subjected to the normal hydrolysis reaction. It is preferable to use a method that allows

The amounts of raw materials and aluminum halide to be used in the method of the present invention vary depending on the substances involved in the condensation reaction, reaction conditions, etc., and cannot be unconditionally defined. It is desirable to use it in a slightly excess amount. If the amount used is less than the reaction theoretical amount, the yield will decrease, while if it is in excess, a large amount of by-products will be produced, which is undesirable. However, in general, 1 to 1 to 1 halogenated alkylbenzene compound is used per mole of pyrazolone compound. 3 moles, 1 to 5 carbon tetrachloride
2 to 3 moles of aluminum halide are used.

Although the condensation reaction of the present invention does not necessarily require the use of a solvent, it is preferable to carry out the reaction in the presence of a solvent. Any solvent can be used as long as it does not particularly inhibit the progress of the condensation reaction, specifically methylene chloride, dichloroethane,
Trichloroethane, tetrachloroethane, carbon disulfide, etc. can be used.

When the condensation reaction of the present invention is carried out industrially, it is carried out by selecting appropriate conditions from the above-mentioned conditions.
If necessary, it is desirable to carry out the reaction after adding anhydrous aluminum chloride to the solution containing one or two of the remaining raw materials.

The hydrolysis reaction of the present invention is generally carried out by adding water to the reaction product of the aforementioned condensation reaction. For example, after confirming the completion of the above-mentioned condensation reaction, the reaction product is not taken out of the reaction system, and the alcohol containing the basic substance is This is carried out by adding an aqueous solution or an aqueous solution of a mineral acid such as hydrochloric acid or sulfuric acid.

Although the reaction time of the condensation and hydrolysis of the present invention cannot be absolutely defined due to differences in other reaction conditions,
Usually 0.2 to 10 hours. After the reaction is complete, the reaction mixture is subjected to conventional separation and purification methods such as solvent extraction, acid treatment, and distillation to obtain the desired 4-benzoyl-
A 5-hydroxypyrazole compound is obtained.

Next, examples of the method of the present invention will be described.

Example 1 16.7 g of anhydrous aluminum chloride was added to a mixed solution of 5.6 g of 1,3-dimethyl-5-pyrazolone and 40 ml of dichloroethane while cooling with water, and 10.5 g of 2,6-dichlorotoluene and carbon tetrachloride were added in advance. A mixed solution of 10 g and 20 ml of dichloroethane was added dropwise at 30 to 35°C over 30 minutes, and a condensation reaction was carried out at the same temperature for 4 hours. This reaction solution was poured into 250 ml of ice water, washed with water, and separated to obtain a dichloroethane solution.

Add 4 ml of sulfuric acid and 2 ml of water to this dichloroethane solution.
was added dropwise at 60 to 65°C, and the hydrolysis reaction was carried out at the same temperature for 2 hours. The reaction product was poured into water, washed with water, extracted with a 5% aqueous sodium hydroxide solution, treated with hydrochloric acid, extracted with methylene chloride, dried over Glauber's salt, and the solvent was distilled off to give 1,3-dimethyl-4-(2 , 4-dichloro-3-methylbenzoyl)-5-hydroxypyrazole (13.8 g) was obtained.

Example 2 In Example 1 above, 40 ml of dichloroethane and 20 ml of dichloroethane used as a solvent to dissolve the raw material
40 ml each of 1,1,2-trichloroethane
The condensation reaction and post-treatment were carried out in the same manner except that the volume was changed to 20 ml and 20 ml. Next, a hydrolysis reaction was carried out in the same manner as in Example 1, and purification was performed to obtain 11.1 g of 1,3-dimethyl-4-(2,4-dichloro-3-methylbenzoyl)-5-hydroxypyrazole. .

Example 3 To a mixed solution of 4.9 g of 3-methyl-5-pyrazolone and 40 ml of dichloroethane, 16.7 g of anhydrous aluminum chloride was added while cooling with water, and 10.5 g of 2,6-dichlorotoluene was added dropwise at 30°C. A solution of 10 g of carbon tetrachloride and 20 ml of dichloroethane was added dropwise thereto at 25-30°C over 1 hour, and then heated to 30°C.
Condensation reaction was carried out for 90 minutes and further at 50°C for 30 minutes. This reaction solution was poured into 250 ml of ice water, washed with water, and separated to obtain a dichloroethane solution. Next, a hydrolysis reaction was carried out in the same manner as in Example 1, and a purification treatment was performed to obtain 3-methyl-4-(2,4-dichloro-3
13.2 g of -methylbenzoyl)-5-hydroxypyrazole were obtained.

Example 4 1,3-dimethyl-5-pyrazolone 5.6g, dichloroethane 60ml, 2,4-dichlorotoluene
16.7 g of anhydrous aluminum chloride was added to a mixed solution of 10.5 g and 10 g of carbon tetrachloride at 20°C over 1 hour, followed by a condensation reaction at 30°C for 2 hours and at 40°C for 1 hour. This reaction solution was poured into 300ml of ice water and washed with water.
The layers were separated to obtain a dichloroethane solution.

Next, a hydrolysis reaction was carried out in the same manner as in Example 1, and a purification treatment was performed to obtain 1,3-dimethyl-
4-(2,4-dichloro-3-methylbenzoyl)
14.3 g of -5-hydroxypyrazole was obtained.

Example 5 The condensation reaction was carried out in the same manner as in Example 1, except that a solution using 12.7 g of 2,3,6-trichlorotoluene was added dropwise at 40°C over 30 minutes, and the condensation reaction was carried out at the same temperature for 2 hours. Hydrolysis reaction and purification treatment yielded 1,3-dimethyl-4-(2,3,5-trichloro-4-methylbenzoyl)-5-hydroxypyrazole and 1,3-dimethyl-4-(2,
4,5-trichloro-3-methylbenzoyl)-
14.7 g of a mixture of 5-hydroxypyrazole was obtained.

Claims (1)

[Claims] 1. In the presence of aluminum halide, the general formula (In the formula, R ¹ is a hydrogen atom or an alkyl group,
R ² is an alkyl group) and a pyrazolone compound represented by the general formula (In the formula, X is a halogen atom, Y is an alkyl group, m is an integer of 1 to 3, and n is 1 to 2
is an integer of ) and carbon tetrachloride are condensed,
This condensation product is hydrolyzed to give the general formula 4-benzoyl-5-hydroxypyrazole compound represented by the formula (wherein R ¹ , R ² , X, Y, m and n are as described above). - A method for producing a hydroxypyrazole compound.