WO2022191139A1

WO2022191139A1 - Method for producing 3-bromo-1-(3-chloropyridin-2-yl)-1h-pyrazole-5-carboxylic acid ester

Info

Publication number: WO2022191139A1
Application number: PCT/JP2022/009771
Authority: WO
Inventors: 堅一浅川; 祐樹高橋; 大介森戸; 敦基釘屋
Original assignee: 石原産業株式会社
Priority date: 2021-03-09
Filing date: 2022-03-07
Publication date: 2022-09-15
Also published as: JPWO2022191139A1; CN116940560A; KR20230155447A

Abstract

The purpose of the present invention is to provide a method for producing an intermediate for the production of a high-purity anthranilamide-based pesticide with high yield and high efficiency.　Provided is a method for producing a compound represented by formula (I) or a salt thereof, the method being characterized by comprising: (1) a step for reacting a compound represented by formula (II) or a salt thereof with POBr₃ without using a solvent or in a solvent; (2) a step for post-treating a reaction mixture produced in the step (1) to produce a compound represented by formula (III) or a salt thereof; and (3) a step for reacting the compound represented by formula (III) or the salt thereof produced in the step (2) with a peroxydisulfuric acid salt in a solvent comprising at least one amide-type solvent without adding sulfuric acid. This production method makes it possible to produce an intermediate for the production of a high-purity anthranilamide-based pesticide with high yield and high efficiency. The formulae (I), (II) and (III) are as described in the description.

Description

Method for producing 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester

The present invention provides highly pure 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylic acid ester and 3-bromo-1-(3-chloro The present invention relates to a production method suitable for high-yield and efficient industrial production of pyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester.

3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylic acid ester and 3-bromo-1-(3-chloropyridin-2-yl)- 1H-pyrazole-5-carboxylic acid esters are important intermediates for the production of anthranilamide insecticides. Patent Document 1 and Patent Documents 3 to 4 are known as methods for producing these production intermediates. In addition, a method for producing a compound analogous to 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester is also known (for example, Patent Document 2 and Non-Patent Document 1 ).

Patent Document 1 discloses 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylic acid ester and 3-bromo-1-(3-chloropyridine -2-yl)-1H-pyrazole-5-carboxylic acid esters are disclosed in Scheme 2 and Scheme 3.

In Scheme 2 of Patent Document 1, halogenation is carried out by reacting a compound containing 2-(3-chloropyridin-2-yl)-5-oxopyrazolidine-3-carboxylic acid ester with a halogenating agent in a solvent. reactions are described. In Example 9A of Patent Document 1, ethyl 2-(3-chloropyridin-2-yl)-5-oxopyrazolidine-3-carboxylate and POBr3 were reacted in an acetonitrile solvent, and then post-treatment was carried out. The preparation of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate with multiple filtration purifications is disclosed.

Then, in Scheme 3 of Patent Document 1, 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylic acid in the presence of an acid in a solvent Oxidation reactions are described in which a compound, including an ester, is reacted with an oxidizing agent. Example 12 of Patent Document 1 contains acetonitrile solvent, 98% sulfuric acid and ethyl 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate A method of producing ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate by adding potassium peroxodisulfate to a reaction vessel is disclosed. The reaction yield of Example 12 of Patent Document 1 is 90%, and the reaction product, ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, is about 1 % of one unknown structure and 0.5% acetonitrile was observed by ¹ H-NMR.

In addition, Patent Documents 5 to 7 also disclose specific examples corresponding to

Schemes

2 and 3 of Patent Document 1.

WO2003/016283 WO2015/058021 Chinese Patent Application Publication No. 104557860 Chinese Patent Application Publication No. 104496967 WO2003/015518 WO2003/015519 WO 2003/024222

When industrially producing anthranilamide insecticides as active ingredients for agricultural chemicals, it is necessary to produce high-purity anthranilamide insecticides at a high yield and at a low cost so as to meet the prescribed standards. For this purpose, intermediates for the production of anthranilamide insecticides need to be produced with high purity and high yield, and a more efficient production method is desired.

The present inventors prepared 3-bromo-1-(3-chloropyridin-2-yl)-4,5 represented by formula (V) according to scheme [A] below according to scheme 3 of Patent Document 1. -3-bromo-1-(3-chloropyridin-2-yl)-1H- represented by formula (IV) from ethyl dihydro-1H-pyrazole-5-carboxylate (hereinafter also referred to as compound (V)) When ethyl pyrazole-5-carboxylate (hereinafter also referred to as compound (IV)) is produced, the reaction yield is lower than the yield described in Example 12 of Patent Document 1, and the product contains the compound ( It was observed from the HPLC chromatogram (FIG. 1) and ¹ H-NMR spectrum (FIG. 2) that multiple impurities of unknown structure were contained in addition to IV). Figure 1 reveals that the product contains two impurities exceeding 1%. Furthermore, it was confirmed that the product contained a plurality of impurities in addition to the two types of impurities, and the total amount of impurities exceeded 6%. In order to remove these impurities from the product obtained by the production method described in Patent Document 1, for example, the reaction product is filtered and purified as described in Example 9A of Patent Document 1. It can be said that the method for producing compound (IV) from compound (V) described in Patent Document 1 is inefficient in terms of operation, because it is assumed that the operation to carry out is required multiple times. Therefore, the method for producing compound (IV) from compound (V) described in Patent Document 1 is not suitable for producing a high-purity intermediate for producing anthranilamide insecticides in high yield and efficiency. be.

In Patent Document 1 and Patent Documents 5 to 7, in the production of compound (IV) from compound (V), compound (IV), which is a reaction product, contains about 1% of an impurity of unknown structure and 0.5% of acetonitrile, but there is no description of the formation of other impurities and means of suppressing the formation of impurities.

On the other hand, in step b of Scheme 1 of Patent Document 2, 3-(3-chloro-4,5-dihydropyrazol-1-yl)pyridine having no alkoxycarbonyl group on the dihydro-1H-pyrazole ring is converted to dimethyl An oxidation reaction is described involving potassium peroxodisulfate in formamide solvent. However, in Example 2 of Patent Document 2, the reaction yield is as low as 54%, and significant improvement in yield is required for use in industrial production methods. Furthermore, there is no description of the preparation of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester and its impurities.

Scheme 1 of Non-Patent Document 1 describes the same raw materials and the same oxidation reaction as Step b of Scheme 1 of Patent Document 2. However, like Patent Document 2, Non-Patent Document 1 does not describe the production of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester and its impurities.

On the other hand, in

Patent Documents

3 and 4, there is no specific description regarding the production of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester and its impurities.

The present inventors have made various studies to produce 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester of higher purity in high yield and efficiency. did As a result of the investigation, in the production of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester, sulfuric acid was used in the oxidation reaction using peroxodisulfate as an oxidizing agent. It was found that the production of impurities can be suppressed by not adding Ni.

Then, the present inventors further investigated the reaction conditions, and carried out the oxidation reaction under substantially anhydrous conditions to obtain 3-bromo-1-(3-chloropyridin-2-yl)-1H with higher purity. -pyrazole-5-carboxylic acid esters can be produced in high yields.

Furthermore, in order to efficiently produce 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ester with higher purity, 3-bromo-1- Efficient production of (3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylic acid ester with high purity is desired. Therefore, the present inventors prepared 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole by the method described in Patent Document 1 and Patent Documents 5-7. When ethyl -5-carboxylate is produced, multiple filtration purification steps are required in the post-treatment step, the operation is very complicated, and the loss of the reaction product is large. Therefore, in the methods described in Patent Document 1 and Patent Documents 5 to 7, highly pure 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carvone It was found to be unsuitable for efficiently producing acid esters in high yields.

Therefore, by selecting a specific solvent and a specific reaction reagent, and improving the reaction conditions and post-treatment method, anthranilamide with a very low content of impurities, which does not require complicated operations as in the conventional methods, can be obtained. It was found that intermediates for the production of pesticides can be produced efficiently with high yield. Furthermore, it was found that the production method of the present invention can be scaled up and is suitable for industrial production.

That is, the present invention provides a compound represented by formula (I) or a salt thereof (hereinafter simply referred to as compound (I)):

(Wherein, R is an alkyl group having 1 to 3 carbon atoms)
A manufacturing method of
(1) a compound represented by formula (II) or a salt thereof (hereinafter also simply referred to as compound (II)) in the absence or in a solvent:

(Wherein, R is as described above)
reacting _POBr3 with
(2) post-treating the reaction mixture obtained in step (1) above to obtain a compound represented by formula (III) or a salt thereof (hereinafter also simply referred to as compound (III)):

(Wherein, R is as described above)
and (3) the compound represented by the formula (III) obtained in the above step (2) or a salt thereof in a solvent containing at least one or more amide solvents without adding sulfuric acid reacting the peroxodisulfate with
A method for producing a compound represented by formula (I) or a salt thereof is provided, comprising:

According to the present invention, compound (I) and compound (III), which are useful production intermediates for the production of anthranilamide insecticides, can be produced with high purity and high yield. Furthermore, compared with conventional methods for producing compound (I) and compound (III), the present invention can produce highly purified compound (I) and compound (III) in a higher yield and more efficiently. .

2 is a chromatogram obtained by HPLC analysis of the product obtained in Comparative Example 2. FIG. 1 is a ¹ H-NMR spectrum of the product obtained in Comparative Example 2. FIG.

[Method for producing compound of formula (I)]
The method for producing compound (I) of the present invention comprises step (1) of reacting compound (II) with POBr ₃ in a solvent, and post-treating the reaction mixture obtained in step (1) to give compound (III). and reacting the compound (III) obtained in step (2) with peroxodisulfate in a solvent containing at least one or more amide solvents without adding sulfuric acid. It is characterized by including step (3).

Salts of the compounds represented by formula (I), (II) or (III) include all pesticide-acceptable salts, such as alkali metal salts (e.g., sodium salts, potassium salts, etc.). ), alkaline earth metal salts (e.g., magnesium salts, calcium salts, etc.), ammonium salts, alkylammonium salts (e.g., dimethylammonium salts, triethylammonium salts, etc.), acid addition salts (hydrochlorides, hydrobromides, phosphates (monohydrogen phosphate, dihydrogen phosphate, etc.), perchlorates, sulfates, nitrates, acetates, methanesulfonates, etc.); The alkyl group having 1 to 3 carbon atoms represented by R in formula (I), (II) or (III) is not particularly limited as long as the reaction proceeds, but methyl, ethyl, n-propyl and isopropyl Preferred, more preferred is ethyl.

Compound (II) in the present invention can be produced by methods known in the art, for example, methods described in

Patent Documents

1, 5 to 7, or methods analogous thereto, or commercially available products can be used. can also

The amount of compound (II) and POBr ₃ used in the reaction of step (1) is not particularly limited as long as the reaction proceeds. , 0.4 to 1.5 mol, more preferably 0.5 to 1 mol of POBr ₃ can be used.

The solvent used in the reaction of step (1) is not particularly limited as long as it does not adversely affect the reaction of step (1). Examples include nitrile solvents (e.g., acetonitrile, propionitrile, butyronitrile), halogen solvent (e.g., dichloromethane, dichloroethane, chloroform, chlorobenzene, etc.), ether solvent (e.g., tetrahydrofuran, diethyl ether, anisole, etc.), ester solvent (e.g., ethyl acetate, butyl acetate, etc.), ketone solvent (e.g., Acetone, methyl ethyl ketone, cyclohexanone, etc.), amide solvents (e.g., dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.), aromatic hydrocarbon solvents (e.g., toluene, xylene, etc.), polar solvents (e.g., dimethylsulfoxide, acetic acid, etc.), or a mixed solvent thereof. The reaction of step (1) can also be carried out under solvent-free conditions. Among these, from the viewpoint of the reaction yield of each step (1) or step (3) and the purity of each compound (I) or (III) obtained, nitrile solvents, halogen solvents and aromatic carbonization At least one selected from the group consisting of hydrogen solvents is preferred, at least one selected from the group consisting of nitrile solvents and halogen solvents is more preferred, and from the group consisting of acetonitrile, dichloromethane, dichloroethane and chlorobenzene. More preferably, at least one or more are selected. The amount of the solvent used is not particularly limited as long as the reaction in step (1) proceeds. Double volume (V/W), more preferably 2 to 5 times volume (V/W).

Regarding the reaction mode of step (1), the order of addition of compound (II), POBr ₃ and solvent is not particularly limited, and they may be added and mixed in any order. Addition of compound (II), POBr ₃ and solvent to the reaction system may be carried out at once or in portions, or may be carried out continuously. For example, as the order of addition, all components may be mixed at once, or some components may be added later. Specific examples of such addition include compounds ( II) and solvent are mixed and POBr ₃ is added thereto.

The reaction temperature in step (1) is usually room temperature (20-30°C) to about 100°C, preferably about 70-90°C. The reaction time of the step (1) is usually about 0.5 to 48 hours, preferably about 1 to 24 hours, more preferably about 1 to 8 hours.

After completion of the reaction in step (1), in step (2), compound (III) is obtained by post-treatment by conventional methods such as neutralization, extraction, distillation, solvent distillation, washing, filtration and drying. can be obtained, eg isolated. Thereafter, if necessary, compound (III) may be purified by conventional methods such as recrystallization, washing, and column chromatography. Alternatively, without isolating compound (III) or purifying the isolated compound (III), the obtained compound (III) can be used as it is for the next reaction. From the viewpoint of improving the purity of the compound represented by formula (I), the post-treatment is preferably neutralization, extraction and distillation, and more preferably a combination thereof.

Step (2) is preferably characterized by including the following steps.
(2-1): A step of mixing the reaction mixture obtained in step (1) with a base to obtain a mixture, and (2-2): Step (1) from the mixture obtained in step (2-1) to obtain a mixture containing the compound represented by formula (III) or a salt thereof.

Further, step (2) is more preferably characterized by including the following steps after step (2-2).
(2-3): A step of obtaining an extract containing the compound represented by formula (III) or a salt thereof and a solvent from the mixture obtained in step (2-2) using a solvent, and (2-4) ): A step of replacing the solvent contained in the extract obtained in step (2-3) with an amide solvent.

Examples of the base used in step (2-1) include alkali metal hydroxides (e.g. sodium hydroxide, potassium hydroxide, etc.), alkali metal carbonates (e.g., sodium carbonate, potassium carbonate, etc.), alkali metal Hydrogen carbonates (e.g., sodium hydrogen carbonate, potassium hydrogen carbonate, etc.), alkaline earth metal hydroxides (e.g., calcium hydroxide, etc.), alkaline earth metal carbonates (e.g., calcium carbonate, etc.), alkaline earth metal Hydrogen carbonates (such as calcium hydrogen carbonate), or mixtures thereof. Among these, alkali metal hydroxides (e.g., sodium hydroxide, potassium hydroxide, etc.) and alkali metal hydrogen carbonates (e.g., sodium bicarbonate, etc.) are preferred, alkali metal hydroxides (eg, sodium hydroxide, potassium hydroxide, etc.) are more preferred, and sodium hydroxide and potassium hydroxide are even more preferred. The form of the base is not particularly limited as long as it can quench the reaction in step (1), and examples thereof include solids and aqueous solutions. When the form of the base is an aqueous solution, the concentration of the base in the aqueous solution is, for example, 1 to 50% by weight, preferably 5 to 40% by weight, more preferably 10 to 30% by weight. The amount of the base to be used is not particularly limited as long as it can quench the reaction in step (1). Yes, more preferably 1.7 to 2 mol. The temperature at which the reaction mixture and the base are mixed is usually about 0 to 60°C, preferably about 10 to 30°C. The time required for this step is usually about 0.5 to 24 hours, preferably about 0.5 to 8 hours, more preferably about 1 to 8 hours.

Furthermore, from the viewpoint of the reaction yield of each step (1) or step (3) and the purity of each compound (I) or (III) obtained, the reaction mixture obtained in the above step (1) is The pH of the mixture obtained by mixing with is, for example, 6-12, preferably 7-10, more preferably 8-9.

As the operation for removing the solvent of step (1) from the mixture of step (2-1) in step (2-2), a conventional method such as distilling off the solvent under reduced pressure or normal pressure can be used.

The solvent used in the extraction in step (2-3) is not particularly limited as long as it does not adversely affect the reaction yield and purity of step (1) or step (3). For example, halogen-based solvents ( Examples thereof include dichloromethane, dichloroethane, chloroform, chlorobenzene, etc.), ester solvents (eg, ethyl acetate, butyl acetate, etc.), aromatic hydrocarbon solvents (eg, toluene, xylene, etc.), and mixed solvents thereof. Among these, from the viewpoint of the reaction yield of each step (1) or step (3) and the purity of each compound (I) or (III) obtained, it is used for extraction in step (2-3) The solvent is preferably at least one selected from the group consisting of halogen solvents and ester solvents, more preferably at least one selected from the group consisting of dichloromethane, ethyl acetate and butyl acetate, dichloromethane and acetic acid At least one selected from the group consisting of ethyl is particularly preferred. The amount of the solvent used in the extraction is, for example, 0.5 to 15 times (V/W), preferably 1 to 10 times (V/W) the amount of compound (III). , more preferably 1 to 8 times (V/W). A mixture containing compound (III) and the solvent used in the extraction can be obtained by an extraction operation in step (2-3), for example, a conventional method such as liquid separation.

Examples of amide-based solvents used in replacing the solvent in step (2-4) include dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoric acid triamide, and mixed solvents thereof. Among these, the amide-based solvent is not particularly limited as long as it does not adversely affect the reaction in step (3), and preferred examples include dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, and mixed solvents thereof. In particular, from the viewpoint of the reaction yield in step (3) and the purity of the resulting compound (I), the amide solvent is preferably at least one selected from the group consisting of dimethylformamide, diethylformamide, and dimethylacetamide. , dimethylformamide, and dimethylacetamide are more preferred. The amount of the amide-based solvent used is not particularly limited as long as it does not adversely affect the reaction yield and purity of step (3). , preferably 2 to 15 times (V/W), more preferably 3 to 10 times (V/W). An operation of replacing with an amide solvent in step (2-4), for example, the solvent used in the extraction of step (2-3) is distilled off to obtain compound (III), and then the obtained compound (III ) and the above amide solvent, a mixture containing compound (III) and the amide solvent can be obtained.

The step (3) comprises reacting the compound (III) obtained in the step (2) with a peroxodisulfate in a solvent containing at least one amide-based solvent without adding sulfuric acid. Characterized by In the present invention, by not adding sulfuric acid, the purity of the resulting compound (I) is improved, as shown in the examples below.

The peroxodisulfate used in the reaction of step (3) is not particularly limited as long as it does not adversely affect the reaction of step (3). Examples include sodium peroxodisulfate, potassium peroxodisulfate, ammonium peroxodisulfate, Or a mixture thereof. Among these, sodium peroxodisulfate and ammonium peroxodisulfate are preferred, and sodium peroxodisulfate is more preferred, from the viewpoint of the purity and reaction yield of compound (I) obtained in the reaction of step (3). The amount of compound (III) and peroxodisulfate used in the reaction of step (3) is not particularly limited as long as the reaction of step (3) proceeds. It is 3 mol, preferably 1.2 to 2.5 mol, more preferably 1.4 to 2 mol.

The amide solvent used in the reaction of step (3) is not particularly limited as long as it does not adversely affect the reaction of step (3). Examples include dimethylformamide, diethylformamide, dimethylacetamide and mixed solvents thereof. be done. Among these, from the viewpoint of the reaction yield in step (3) and the purity of the resulting compound (I), the amide-based solvent in step (3) is at least one selected from the group consisting of dimethylformamide and dimethylacetamide. The above are preferred, and dimethylformamide is more preferred. The amount of the amide solvent used in the reaction of step (3) is not particularly limited as long as the reaction of step (3) proceeds. W), preferably 2 to 15 times (V/W), more preferably 3 to 10 times (V/W).

When performing steps (2-1) to (2-4), in the reaction of step (3), a mixture containing compound (III) obtained in step (2-4) and an amide solvent and the above-described Peroxodisulfate may be used. In this case, the solvent for the reaction in step (3) may contain the solvent in step (2-3) as long as it does not adversely affect the reaction.

Regarding the form of reaction in step (3), the order of addition of compound (III), peroxodisulfate, and solvent is not particularly limited, and may be added and mixed in any order. Addition of compound (III), peroxodisulfate and solvent to the reaction system may be carried out at once or in portions, or may be carried out continuously. Here, when performing steps (2-4) to (3), a solvent may be added as necessary. For example, the order of addition includes adding peroxodisulfate to a mixture obtained by mixing compound (III) and a solvent. Among these, the temperature at which the peroxodisulfate is added to the mixture of compound (III) and solvent is usually room temperature (20 to 30°C) to 100°C, preferably about 50 to 80°C. The solvent used in step (3) is not particularly limited as long as the reaction in step (3) proceeds, but is preferably a solvent containing at least one or more amide solvents, and the proportion of the amide solvent is preferably 70 to 100%, more preferably 80 to 100%, still more preferably 100%.

Furthermore, the reaction in step (3) is preferably carried out under substantially anhydrous conditions. Substantially anhydrous conditions for the reaction in step (3) mean that the water content range of the mixture of the compound (III) and a solvent containing at least one amide solvent does not adversely affect the reaction in step (3). means no numeric range. The specific water content is not particularly limited as long as the reaction in step (3) proceeds. It is 000 ppm or less, preferably 3,000 ppm or less, more preferably 1,000 ppm or less. Operations for allowing the reaction in step (3) to proceed under substantially anhydrous conditions include, for example, operations such as not using sulfuric acid in the reaction in step (3), using a dehydrating solvent, or performing azeotropic dehydration. available. This operation allows the reaction of step (3) to be carried out under substantially anhydrous conditions.

The reaction temperature in step (3) is usually room temperature (20-30°C) to about 100°C, preferably about 60-80°C. The reaction time of step (3) is usually about 0.5 to 24 hours, preferably about 0.5 to 8 hours, more preferably about 1 to 5 hours.

After completion of the reaction in step (3), compound (I) can be isolated by performing post-treatments by conventional methods such as neutralization, extraction, washing, and drying, if necessary. Thereafter, if necessary, compound (I) may be purified by conventional methods such as recrystallization, washing, and column chromatography. Alternatively, the isolated compound (I) can be used as it is for the production of the next production intermediate for an anthranilamide insecticide without purification.

The purity of compound (I) obtained by this reaction is usually 90% or higher, preferably 95% or higher, more preferably 98% or higher. In addition, the amount of each impurity contained in compound (I) obtained by this reaction is usually 2% or less, preferably 1% or less, and more preferably substantially free of impurities. . The total amount of impurities contained in compound (I) obtained by this reaction is usually 2% or less, preferably 1% or less, and more preferably substantially no impurities. Here, "substantially free of impurities" means an amount of impurities that are unavoidably mixed in, and an amount that does not adversely affect the anthranilamide insecticide used. By using such compound (I) to produce an important production intermediate for anthranilamide pesticides, it is possible to produce high-purity anthranilamide pesticides that meet the standards for active ingredients of agricultural chemicals. .

Various constituent elements in the method of the present invention are appropriately selected from among the above-described multiple examples and conditions, for example, from not only the examples and conditions in the normal range described above but also the examples and conditions in the preferred range, and They can be combined with each other.

Examples of preferred embodiments of the present invention are listed below, but the present invention is not limited to these.
[1] A compound represented by formula (I) or a salt thereof:

(Wherein, R is an alkyl group having 1 to 3 carbon atoms)
A manufacturing method of
(1) a compound represented by formula (II) or a salt thereof in the absence or in a solvent:

(Wherein, R is as described above)
reacting _POBr3 with
(2) post-treating the reaction mixture obtained in step (1) to obtain a compound represented by formula (III) or a salt thereof (hereinafter also simply referred to as compound (III)):

(Wherein, R is as described above)
and (3) with the compound represented by the formula (III) obtained in step (2) or a salt thereof in a solvent containing at least one or more amide solvents without adding sulfuric acid reacting with a peroxodisulfate;
A method for producing a compound represented by formula (I) or a salt thereof, comprising:
[2] The production method according to [1], wherein step (2) includes the following steps:
(2-1): A step of mixing the reaction mixture obtained in step (1) with a base to obtain a mixture, and (2-2): Step (1) from the mixture obtained in step (2-1) to obtain a mixture containing the compound represented by formula (III) or a salt thereof.
[3] The production method according to [2], which includes the following steps after step (2-2):
(2-3): A step of obtaining an extract containing the compound represented by formula (III) or a salt thereof and a solvent from the mixture obtained in step (2-2) using a solvent, and (2-4) ): A step of replacing the solvent contained in the extract obtained in step (2-3) with an amide solvent.
[4] The production method according to any one of [1] to [3], wherein the reaction with peroxodisulfate in step (3) is carried out under substantially anhydrous conditions.
[5] Any one of [1] to [4], wherein the solvent in step (1) is one or more selected from the group consisting of nitrile solvents, halogen solvents and aromatic hydrocarbon solvents. The manufacturing method described in .
[6] The production method according to [5], wherein the solvent in step (1) is one or more selected from the group consisting of acetonitrile, dichloromethane, dichloroethane and chlorobenzene.
[7] The base used in step (2-1) consists of an alkali metal hydroxide (such as sodium hydroxide, potassium hydroxide, etc.) and an alkali metal hydrogen carbonate (such as sodium hydrogen carbonate). The production method according to any one of [2] to [6], which is at least one selected from the group.
[8] The production method according to any one of [2] to [6], wherein the base in step (2-1) is an alkali metal hydroxide (eg, sodium hydroxide, potassium hydroxide, etc.). .
[9] The production method according to any one of [2] to [6], wherein the base in step (2-1) is sodium hydroxide or potassium hydroxide.
[10] The production method according to any one of [2] to [6], wherein the base in step (2-1) is sodium hydroxide, potassium hydroxide or sodium hydrogen carbonate.
[11] The production method according to any one of [3] to [10], wherein the solvent in steps (2-3) and (2-4) is a halogen solvent or an ester solvent.
[12] Any one of [3] to [11], wherein the solvent in steps (2-3) and (2-4) is at least one selected from the group consisting of dichloromethane, ethyl acetate and butyl acetate. 1. The manufacturing method according to item 1.
[13] Any one of [3] to [11], wherein the solvent in steps (2-3) and (2-4) is at least one selected from the group consisting of dichloromethane and ethyl acetate. Method of manufacture as described.
[14] of [1] to [13], wherein the peroxodisulfate in step (3) is at least one selected from the group consisting of sodium peroxodisulfate, potassium peroxodisulfate, and ammonium peroxodisulfate. The manufacturing method according to any one of the items.
[15] The production method according to any one of [1] to [13], wherein the peroxodisulfate in step (3) is sodium peroxodisulfate or ammonium peroxodisulfate.
[16] The production method according to any one of [1] to [13], wherein the peroxodisulfate in step (3) is sodium peroxodisulfate.
[17] The amide solvent in step (3) is at least one selected from the group consisting of dimethylformamide, diethylformamide and dimethylacetamide, according to any one of [1] to [16]. Production method.
[18] The production method according to any one of [1] to [17], wherein the amide solvent in step (3) is at least one selected from the group consisting of dimethylformamide and dimethylacetamide. .
[19] The production method according to any one of [1] to [18], wherein the amide solvent in step (3) is dimethylformamide.
[20] The production method according to any one of [1] to [18], wherein the amide solvent in step (3) is dimethylformamide and the peroxodisulfate is sodium peroxodisulfate.

Examples of the present invention are described below, but the present invention should not be construed as being limited to these.

The analysis conditions for ¹ H-NMR in this example are as follows.
・ Equipment used: JNM-ECX500 manufactured by JEOL Ltd.
・Measurement solvent: heavy dimethyl sulfoxide ・Resonance frequency: 500 MHz

The HPLC analysis conditions in this example are as follows.
[Reaction tracking]
・Equipment used: Nexera XS series manufactured by Shimadzu Corporation ・Column: SunShell C18 2.6 μm (2.1×100 mm) manufactured by Chromanic Technologies Inc.
・Detection: UV detector (254 nm)
・Column temperature: 40°C
・Flow rate: 0.5 ml/min
- Mobile phase: A solution: 0.1% formic acid aqueous solution, and B solution: acetonitrile Gradient conditions are as follows.

[Purity analysis]
・ Equipment used: 1260 Infinity manufactured by Agilent Technologies ・ Column: Cadenza CD-C18 3 μm 4.6 × 150 mm
・Detection: UV detector (254 nm)
・Column temperature: 45°C
・Flow rate: 1.0 ml/min
- Mobile phase: A solution: 0.1% formic acid aqueous solution, and B solution: acetonitrile Gradient conditions are as follows.

The analysis conditions for measuring the water content in this example are as follows.
・ Equipment used: AQ-2250 manufactured by Hiranuma Sangyo Co., Ltd.
・Reagent used: Hiranuma Sangyo Co., Ltd., Aqualite RS-A general moisture measurement generation solution ・Method: Coulometric method ・Electrolytic cell: One-chamber cell

[Example 1] Synthesis of compound (V) Ethyl 1-(3-chloropyridin-2-yl)-3-hydroxy-4,5-dihydro-1H-pyrazole-5-carboxylate with a purity of 96% (hereinafter referred to as A mixture of 14.0 g of phosphorus oxybromide and 15.1 g of acetonitrile was added dropwise to a mixture of 20 g of compound (VI) and 15.1 g of acetonitrile at room temperature to obtain a reaction mixture. The reaction mixture was heated to the reflux temperature and stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (V) was produced at 99.0 area %. The reaction mixture was cooled to 20-30° C., and 20 g of water was slowly added dropwise at the same temperature to obtain a mixture. 24 ml of 20% sodium hydroxide aqueous solution was added to the mixture between 60 and 62° C. to adjust the pH to about 8. The pH-adjusted mixture was stirred at 60° C. for 20 minutes, and acetonitrile was distilled off from the mixture under normal pressure, followed by extraction with 105.6 g of dichloromethane to obtain 124.2 g of a mixture containing compound (V) and dichloromethane. rice field.

[Example 2] Synthesis of compound (IV) Dichloromethane in 62.1 g of the mixture containing compound (V) obtained in Example 1 and dichloromethane was replaced with 94.7 g (8 vol.) of dimethylformamide to obtain the compound (IV). A mixture containing V) and dimethylformamide was obtained. 17.6 g (2.0 eq.) of sodium peroxodisulfate was added to the mixture at 60° C. to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (IV) was produced at 92.0 area %. The reaction mixture was ice-cooled, and 142.1 g of water was slowly added dropwise at the same temperature to obtain a mixture. The mixture was stirred at 20-30° C. for 1 hour. The resulting slurry was filtered, and the resulting crystals were washed with water and dried overnight in a warm air dryer to obtain 10.1 g of compound (IV). (Yield: 85% (2 Steps), Purity: 99%)

[Example 3] Synthesis of compound (IV) (1) To a mixture of 900 g of compound (VI) having a purity of 99% and 1,415 g of acetonitrile, a mixture of 628 g of phosphorus oxybromide and 707 g of acetonitrile was added dropwise at room temperature to form a reaction mixture. got The reaction mixture was heated to the reflux temperature and stirred at the same temperature for 2 hours. A reaction check was performed by HPLC, and it was confirmed that compound (V) was produced at 99.4 area %. The reaction mixture was cooled to 20° C., and 900 g of water was slowly added dropwise at the same temperature to obtain a mixture. The pH was adjusted to about 9 by adding 1,219 g of 20% aqueous sodium hydroxide solution to the mixture. The pH adjusted mixture was stirred overnight at 20-30°C. Acetonitrile was distilled off from the mixture under reduced pressure, and extraction was performed with 2,376 g of dichloromethane to obtain a mixture containing compound (V) and dichloromethane. 5,947 g of dimethylformamide was added to the mixture, and the solvent was replaced with dimethylformamide under reduced pressure to obtain a mixture of compound (V) and dimethylformamide. At this time, it was confirmed from the results of purity analysis using HPLC that the reaction proceeded quantitatively, and the water content of the mixture of compound (V) and dimethylformamide was about 3,000 ppm.

(2) Subsequently, 1,268 g of sodium peroxodisulfate was added to the mixture of compound (V) obtained in the previous step (1) and dimethylformamide at 60-70°C to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (IV) was produced at 86.4 area %. The reaction mixture was cooled to 20° C., and 2,213 g of water was slowly added dropwise at the same temperature to obtain a mixture. The resulting mixture was stirred at 20-30° C. for 1 hour. The resulting slurry was filtered to obtain white crystals containing compound (IV). The resulting crystals were washed with water and dried overnight in a hot air dryer to obtain crude crystals of compound (IV) (yield: 65% (2 steps), purity: 74%). The crude crystals were suspended in water, filtered, and the obtained crystals were dried overnight in a warm air dryer to obtain crystals of compound (IV) (96.9% purity).

[Example 4]
To a mixture of 5 g of compound (V) and 28.3 g of dimethylformamide was added 7.16 g of sodium peroxodisulfate at 60-110° C. to obtain a reaction mixture. For Entries 2 to 4 in Table 3, water was added as appropriate to obtain the indicated moisture values. The resulting reaction mixture was stirred at the same temperature for 1 hour. The reaction mixture was cooled to room temperature, and 45.0 g of water was slowly added dropwise at the same temperature to obtain a mixture. The mixture was stirred at 20-30° C. for 1 hour. The resulting slurry was filtered to obtain crystals containing compound (IV). The resulting crystals were washed with water and dried overnight in a warm air dryer to obtain compound (IV). The water content and reaction temperature of the mixture of compound (V) and dimethylformamide were investigated, and the results are shown in Table 3 below. From the results, it was confirmed that, according to the reaction conditions of the present invention, highly pure compound (IV) can be obtained over a wide temperature range.

[Comparative Example 1]
28.3 g of dimethylformamide and 2.95 g of 97% concentrated sulfuric acid were added to 5.0 g of compound (V) to obtain a mixture. The water content of the resulting mixture was approximately 1,900 ppm. To the resulting mixture, 7.16 g of sodium peroxodisulfate was added at 60-70°C to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 1 hour. The reaction mixture was cooled to room temperature, and 45.0 g of water was slowly added dropwise at the same temperature to obtain a mixture. The resulting mixture was stirred at 20-30° C. for 1 hour. The resulting slurry was filtered to obtain crystals containing compound (IV). The resulting crystals were washed with water and dried overnight in a warm air dryer to obtain compound (IV). The reaction temperature and the reaction results were as shown in Table 4 below. Entry 1 described in Table 3 of Example 4 and Entry 10 described in Table 4 of Comparative Example 1 were compared, and under conditions where 97% concentrated sulfuric acid was added, compound (V), dimethylformamide and 97% concentrated sulfuric acid The water content of the mixture was high, and a decrease in reaction yield was observed.

[Comparative Example 2]
Based on the reaction conditions described in Patent Document 1, 6.0 g of 97% concentrated sulfuric acid was added to a mixture of 10 g of compound (V) and 75 mL of acetonitrile at room temperature to obtain a mixture. The water content of the resulting mixture was approximately 1,900 ppm. After that, 12.2 g of potassium peroxodisulfate was added to the mixture to obtain a reaction mixture. The resulting reaction mixture was heated to the reflux temperature and stirred at the same temperature for 2 hours. A reaction check was performed by HPLC to confirm the formation of compound (IV) and unreacted compound (V). The reaction mixture was cooled to 55° C., filtered to remove solids, and washed twice with 12 mL of acetonitrile. After concentrating the filtrate to about 50 mL, the concentrated reactant was added to 100 mL of water to obtain a mixture. The resulting mixture was stirred at the same temperature for 1 hour. The resulting slurry was filtered to obtain crude crystals containing compound (IV). The resulting crude crystals were washed with 25 mL of 20% aqueous acetonitrile solution and 20 mL of water, and dried overnight in a warm air dryer to obtain compound (IV). The water content, reaction temperature and reaction results of the mixture of compound (V) and acetonitrile were as shown in Table 5 below. The reaction was carried out under the reaction conditions described in Patent Document 1, but the reaction results described in Patent Document 1 (reaction yield 90%, and about 1% of one impurity in the reaction product compound (IV) ) was of lower purity and lower yield than Furthermore, as a result of comparing Entry 6 of Table 3 of Example 4 and Entry 11 of Table 5 of Comparative Example 2, the conditions of Entry 6 of Table 3 of Example 4 improved the purity and yield more than the conditions of Comparative Example 2. was accepted.

[Example 5] Synthesis of compound (V) To a mixture of 3 g of compound (VI) and 33.2 g of chlorobenzene was added dropwise a mixture of 3.19 g of phosphorus oxybromide and 13.2 g of chlorobenzene at room temperature to obtain a reaction mixture. The reaction mixture was heated to 100° C. and stirred overnight at the same temperature. A reaction check was performed by HPLC, and it was confirmed that compound (V) was produced at 97.8 area %.

[Example 6] Synthesis of compound (IV) To a mixture of 4 g of compound (V) and 29.3 g of dimethylformamide (water content: about 330 ppm), 6.27 g of potassium peroxodisulfate was added at 60°C to obtain a reaction mixture. . The resulting reaction mixture was stirred at the same temperature for 1.5 hours. A reaction check was performed by HPLC to confirm that compound (IV) was produced.

[Example 7] Synthesis of compound (IV) To a mixture of 5 g of compound (V) and 28.3 g of dimethylformamide (water content: about 953 ppm), 5.48 g of ammonium peroxodisulfate was added at 60°C to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 1 hour. A reaction check was performed by HPLC to confirm that compound (IV) was produced. After the conventional post-treatment described above, compound (IV) was obtained.

[Example 8]
Synthesis of isopropyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate (hereinafter also simply referred to as compound (VII)) (1) 1 with a purity of 91.8 area% 5 g of isopropyl-(3-chloropyridin-2-yl)-3-hydroxy-4,5-dihydro-1H-pyrazole-5-carboxylate (remaining 9.2% is compound (VI)) and 3.9 g of acetonitrile A mixture of 3.3 g of phosphorus oxybromide and 3.9 g of acetonitrile was added dropwise to the mixture at room temperature to obtain a reaction mixture. The reaction mixture was heated to the reflux temperature and stirred at the same temperature for 1 hour. The reaction was checked by HPLC, and isopropyl 3-bromo-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate (hereinafter also simply referred to as compound (VIII) ) was generated at 91.0 area %. The reaction mixture was cooled to 26° C., and 5 g of water was slowly added dropwise at the same temperature to obtain a mixture. 7.6 g of a 20% sodium hydroxide aqueous solution was added to the mixture to adjust the pH to about 7.8, and the mixture was stirred at 20 to 30° C. for 20 minutes. After acetonitrile was distilled off from the pH-adjusted mixture under normal pressure, extraction was performed with 19.8 g of dichloromethane to obtain a mixture containing compound (VIII) and dichloromethane. 33 g of dimethylformamide was added to a mixture containing compound (VIII) and dichloromethane, and the solvent was replaced with dimethylformamide under normal pressure to obtain a mixture of compound (VIII) and dimethylformamide.

(2) Subsequently, 6.7 g of sodium peroxodisulfate was added to the mixture of compound (VIII) obtained in the previous step (1) and dimethylformamide at 60-70°C to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (VII) was produced at 81.0 area %. After the usual post-treatment described above, crude crystals of compound (VII) were obtained. The obtained crude crystals were purified by column chromatography to obtain compound (VII) (purity: 97.5 area %).

[Example 9] Synthesis of compound (IV) (1) To a mixture of 10 g of compound (VI) having a purity of 99% and 7.9 g of acetonitrile, a mixture of 6.9 g of phosphorus oxybromide and 15.7 g of acetonitrile was added dropwise at room temperature. to obtain a reaction mixture. The reaction mixture was heated to the reflux temperature and stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (V) was produced at 93.0 area %. The reaction mixture was cooled to 20° C., 48.8 g of a 5% aqueous sodium hydroxide solution was added at the same temperature to adjust the pH to about 8, and the mixture was stirred at 20-30° C. for 15 minutes. Then, acetonitrile was distilled off from the pH-adjusted mixture under normal pressure, and 4.3 g of a 10% aqueous sodium hydroxide solution was added to the mixture after distillation to adjust the pH to about 7. The resulting mixture was extracted with 63 g of ethyl acetate to obtain a mixture containing compound (V) and ethyl acetate. 66 g of dimethylformamide was added to the mixture, and the solvent was replaced with dimethylformamide under normal pressure to obtain a mixture of compound (V) and dimethylformamide. At this time, it was confirmed from the results of purity analysis using HPLC that the reaction proceeded quantitatively. The water content of the obtained mixture of compound (V) and dimethylformamide was about 7,800 ppm.

(2) Subsequently, 27 g of ethyl acetate was added to the mixture of compound (V) and dimethylformamide obtained in the previous step (1), and azeotropic dehydration was performed under normal pressure, and the water content of the mixture was reduced to about 2,000 ppm. dehydrated to Furthermore, 27 g of ethyl acetate was added and azeotropic dehydration was carried out under normal pressure. As a result, the water content of the mixture of compound (V) and dimethylformamide was dehydrated to about 1,000 ppm. 13.6 g of sodium peroxodisulfate was added to the dehydrated mixture at 60-70° C. to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (IV) was produced at 94.6 area %. The reaction mixture was cooled to 20° C., and 100 g of water was slowly added dropwise at the same temperature to obtain a mixture. The resulting mixture was stirred at 20-30° C. for 1 hour. The resulting slurry was filtered to obtain white crystals containing compound (IV). The resulting crystals were washed with water and dried overnight in a warm air dryer to obtain crude crystals of compound (IV) (yield: 81.7% (2 steps), purity: 92%). The crude crystals were suspended in water, filtered, and the obtained crystals were dried overnight in a warm air dryer to obtain crystals of compound (IV) (yield: 79.6% (2 steps), Purity: 97.1%).

[Example 10] Synthesis of compound (IV) (1) To a mixture of 5 g of compound (VI) having a purity of 99% and 11.7 g of acetonitrile, 30 to 40 g of a mixture of 3.8 g of phosphorus oxybromide and 7.8 g of acetonitrile was added. °C to obtain a reaction mixture. The reaction mixture was heated to reflux temperature and stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (V) was produced at 99.0 area %. The reaction mixture was cooled to 30° C., and 15 g of water was slowly added dropwise at the same temperature to obtain a mixture. 11.7 g of 20% potassium hydroxide aqueous solution was added to the mixture to adjust the pH to about 7.4. After stirring the pH-adjusted mixture at 20-30° C. for 15 minutes, acetonitrile was distilled off from the mixture under normal pressure. After adjusting the pH to 7.5 by adding 0.9 g of a 20% aqueous potassium hydroxide solution again, extraction was performed with 27 g of ethyl acetate to obtain a mixture containing compound (V) and ethyl acetate. 18.7 g of dimethylformamide was added to the mixture, and the solvent was replaced with dimethylformamide under normal pressure to obtain a mixture of compound (V) and dimethylformamide. The water content of the mixture of compound (V) and dimethylformamide was about 7,000 ppm.

(2) Subsequently, 17.8 g of ethyl acetate was added to the mixture of compound (V) obtained in the previous step (1) and dimethylformamide, and azeotropic dehydration was performed under normal pressure. The resulting mixture of compound (V) and dimethylformamide was dehydrated to a water content of about 2,500 ppm. To a mixture of dehydrated compound (V) and dimethylformamide, 6.9 g of sodium peroxodisulfate was added at 60-70°C to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 18 hours. A reaction check was performed by HPLC, and it was confirmed that compound (IV) was produced at 87.3 area %.
The reaction mixture was cooled to 20° C., and 40 g of water was slowly added dropwise at the same temperature to obtain a mixture. The resulting mixture was stirred at 20-30° C. for 1 hour. The resulting slurry was filtered to obtain white crystals containing compound (IV). The resulting crystals were washed with water and dried overnight in a warm air dryer to obtain compound (IV) (yield: 81.6% (2 steps), purity: 97.1%).

[Example 11] Synthesis of compound (IV) (1) To a mixture of 5 g of compound (VI) having a purity of 99% and 15.7 g of acetonitrile, a mixture of 3.5 g of phosphorus oxybromide and 3.9 g of acetonitrile was added dropwise at room temperature. to obtain a reaction mixture. The reaction mixture was heated to the reflux temperature and stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (V) was produced at 99 area %. The reaction mixture was cooled to 15° C., and 25 g of water was slowly added dropwise at the same temperature to obtain a mixture. 3.9 g of sodium bicarbonate was added to the mixture to adjust the pH to about 7.7. After the pH-adjusted mixture was stirred at 20-30° C. for 1 hour, acetonitrile was distilled off from the mixture under normal pressure. 22.1 g of butyl acetate was added to the resulting residue for extraction to obtain a mixture containing compound (V) and butyl acetate. 34.9 g of dimethylformamide was added to the mixture, and the solvent was replaced with dimethylformamide under normal pressure to obtain a mixture of compound (V) and dimethylformamide. The water content of the mixture of compound (V) and dimethylformamide was about 250 ppm.

(2) Subsequently, 5.68 g of sodium peroxodisulfate was added to the mixture of compound (V) obtained in the previous step (1) and dimethylformamide at 60-70°C to obtain a reaction mixture. The resulting reaction mixture was stirred at the same temperature for 1 hour. A reaction check was performed by HPLC, and it was confirmed that compound (IV) was produced at 95.2 area %. The reaction mixture was cooled to 30° C., and 44.5 g of water was slowly added dropwise at the same temperature to obtain a mixture. The resulting mixture was heated and dissolved in water, and then cooled to precipitate crystals. The resulting crystals were filtered to obtain crystals of compound (IV) (yield: 62% (2 steps), purity: 99%).
In addition, the entire contents of the specification, claims, abstract and drawings of Japanese Patent Application No. 2021-037729 filed on March 9, 2021 are cited here as disclosure of the specification of the present invention. , is to be incorporated.

Claims

A compound represented by formula (I) or a salt thereof

(Wherein, R is an alkyl group having 1 to 3 carbon atoms)
A manufacturing method of
(1) without solvent or in a solvent,
A compound represented by formula (II) or a salt thereof

(Wherein, R is as described above)
reacting POBr3 with
(2) post-treating the reaction mixture obtained in step (1) to obtain a compound represented by formula (III) or a salt thereof;

(Wherein, R is as described above)
and (3) in a solvent containing at least one or more amide solvents, without adding sulfuric acid,
a step of reacting the compound represented by the formula (III) obtained in the step (2) or a salt thereof with a peroxodisulfate;
A method for producing a compound represented by formula (I) or a salt thereof, comprising:
2. The method of claim 1, wherein step (2) comprises the steps of:
(2-1) a step of mixing the reaction mixture obtained in step (1) with a base to obtain a mixture; ) to obtain a mixture containing the compound represented by formula (III) or a salt thereof.
The production method according to claim 1 or 2, wherein the reaction with the peroxodisulfate in step (3) is performed under substantially anhydrous conditions.
The production method according to claim 2 or 3, characterized by comprising the following steps after the step (2-2):
(2-3) obtaining an extract containing the compound represented by formula (III) or a salt thereof and a solvent from the mixture obtained in step (2-2) using a solvent; and (2-4) ) A step of replacing the solvent contained in the extract obtained in the step (2-3) with an amide solvent.
The production method according to any one of claims 1 to 4, wherein the solvent in step (1) is at least one selected from the group consisting of nitrile solvents and halogen solvents.
The production method according to claim 5, wherein the solvent in step (1) is at least one selected from the group consisting of acetonitrile, dichloromethane, dichloroethane and chlorobenzene.
The production method according to any one of claims 1 to 6, wherein the peroxodisulfate is at least one selected from the group consisting of sodium peroxodisulfate, potassium peroxodisulfate and ammonium peroxodisulfate.
The production method according to any one of claims 2 and 4 to 6, wherein the base is at least one selected from the group consisting of sodium hydroxide and potassium hydroxide.
The production method according to claim 4, wherein the solvent in steps (2-3) and (2-4) is at least one selected from the group consisting of dichloromethane, ethyl acetate and butyl acetate.
The production method according to claim 4, wherein the solvent in steps (2-3) and (2-4) is at least one selected from the group consisting of dichloromethane and ethyl acetate.
The production method according to any one of claims 2 and 4 to 6, wherein the base is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide and sodium hydrogen carbonate.