WO2012024920A1 - Method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole - Google Patents

Abstract

Disclosed is a method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole (Fipronil) (II). This method comprises oxidating 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylthiopyrazole (formula (I)) used as a material by a solid oxidant in an acidic medium, recovering the reaction medium and obtaining Fipronil.

Description

 Method for preparing 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole

Technical field

 The present invention relates to a process for the preparation of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole. Background technique

 5-amino-3-cyano small (2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole, trade name Regent, common name Nitrile, a phenylpyrazole insecticide developed by Rhône-Planck in France from 1987 to 1989.

 The structure of fipronil is novel and its mechanism of action is unique. Its mechanism is mainly to control the metabolism of chloride by γ-aminobutyric acid (GABA) receptor. It has contact, stomach poisoning and moderate systemic action. It is on lepidoptera and flies. A series of pests such as the genus Coleoptera have high insecticidal activity. Moreover, it has many advantages such as no cross-resistance and safety of use with existing insecticides. The agent can be applied to the soil or foliar spray: Applying to the soil can effectively control the corn root beetle, golden worm and the ground tiger; when the leaf is sprayed, it has high levels of the diamondback moth, the cabbage butterfly, the rice glutinous horse, etc. It is effective and has a long-lasting effect.

 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylthiopyrazole is an important intermediate for the preparation of fipronil, After the trifluoromethylthio group of the intermediate is oxidized to a trifluoromethylsulfinyl group, fipronil is obtained.

 In the early literature, 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoro) was obtained using m-chloroperoxybenzoic acid and/or hydrogen peroxide as the oxidizing agent and dichloromethane as the solvent. Oxidation of methylphenyl)-4-trifluoromethylthiopyrazole to fipronil. The disadvantage of this method is that it takes a long time, about 2 days, and the use of m-chloroperoxybenzoic acid is quite expensive. It is difficult to carry out large-scale industrial production.

 Document CN1332730A discloses the use of trifluoroacetic acid as a solvent and hydrogen peroxide as an oxidizing agent, and it has been found to have better selectivity and yield. However, the trifluoroacetic acid solvent itself is quite expensive and must be recycled for use in order to achieve true industrial production. However, experiments have shown that the recovery of trifluoroacetic acid in this process is quite difficult. Summary of the invention

 The object of the present invention is to overcome the shortcomings of the prior art solvent recovery, and to provide a solvent-recoverable preparation of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl). a method of 4-trifluoromethylsulfinylpyrazole.

The inventors of the present invention have found that although CN1332730A proposes to recover trifluoroacetic acid by adding chlorobenzene and distilling off trifluoroacetic acid, it is inevitable to introduce a large amount of water into the reaction system by using hydrogen peroxide as an oxidizing agent. Acetic acid and water easily form an azeotropic mixture, so that the recovered trifluoroacetic acid is contained There is a large amount of water, plus trifluoroacetic acid and water miscible, the recovered trifluoroacetic acid has a water content of more than 8%. At the same time, the oxidation reaction of fipronil with aqueous trifluoroacetic acid as a solvent and the use of hydrogen peroxide as an oxidant introduce a large amount of water into the oxidation reaction system, resulting in low reaction conversion and selectivity. Therefore, it is difficult to achieve recycling of trifluoroacetic acid.

 The invention provides a preparation method of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole, The 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole has the formula (Π) shown below Structure:

 (11).

 Wherein the preparation method of the 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole comprises an acidic medium In the oxidation reaction conditions, the solid oxidant is represented by the formula (I)

 (I)

 The invention adopts a solid oxidant instead of hydrogen peroxide as an oxidant, reduces the water content in the recovered acidic medium (such as trifluoroacetic acid), realizes the recycling of an acidic medium (such as trifluoroacetic acid), and is suitable for industrial production. Further, the method of the present invention has the advantages of mild reaction conditions and high safety by using a solid oxidizing agent instead of hydrogen peroxide as an oxidizing agent. Detailed ways

According to the present invention, the compound represented by the following formula (I) is contacted with a solid oxidizing agent in the presence of an acidic medium, and the reaction medium is recovered to obtain a compound represented by the formula (Π). The reaction process is as follows:

按照本发明， 所述式 （ I ) 化合物与固态氧化剂的摩尔比可以 1 : 0.9-6.0， 优选可以为 1 : 1-3， 进一步优选为 1 : 1.2-1.7, 更进一步优选为 1 : 1.3-1.5。

According to the present invention, the molar ratio of the compound of the formula (I) to the solid oxidizing agent may be 1: 0.9-6.0, preferably 1 : 1-3, more preferably 1: 1.2 - 1.7, still more preferably 1: 1.3 - 1.5.

 According to the present invention, the solid oxidizing agent may be various oxidizing agents capable of oxidizing a trifluoromethylthio group to a trifluoromethylsulfinyl group at room temperature, preferably including sodium perborate, potassium peroxymonosulfate or sodium percarbonate. And one or more of calcium peroxide and magnesium peroxide, further preferably potassium peroxymonosulfate and/or sodium perborate, wherein the sodium perborate may be hydrated sodium perborate having 1 or 4 crystal waters. .

The acidic medium may be a liquid acidic medium and may be selected from one or more of the organic carboxylic acids having the following structural formula:

Represents R ^ to C ₆ (d preferably to C ₄₎ alkyl, d to C ₆ (d preferably to C ₄₎ a halogenated hydrocarbon group, a halogen or a hydrogen, X and Y represents a halogen or hydrogen. More preferably, at least one of R, X and Y is a halogen.

 When R is halogen or hydrogen, R, X, and Y may be the same or different.

 The halogen may be fluorine, chlorine, bromine or iodine, preferably fluorine.

 Preferably, the acidic medium may be one or more of trifluoroacetic acid, difluoroacetic acid, dichloroacetic acid, monofluorodichloroacetic acid and difluoromonochloroacetic acid, further preferably trifluoroacetic acid, difluoroacetic acid One or more of acetic acid and difluoromonochloroacetic acid.

 The present inventors have found that while using at least one of R, X and Y as an acidic medium of fluorine, hydrated sodium perborate having one or four crystal waters is used as a solid oxidant, and the recovery is lowered. The water content of the acidic medium also reduces the corrosion of the glass container. This may be due to the presence of by-product sodium borate or, possibly, due to the lower water content in the reaction system, which inhibits the production of small amounts of hydrofluoric acid by-products from the fluorine-containing acidic medium, thereby reducing corrosion of the glass container. Accordingly, it is preferred in the present invention that the acidic medium be an acidic medium in which at least one of R, X and Y is fluorine, and the solid oxidant is hydrated sodium perborate.

The inventors have also found that when dichloroacetic acid is used as an acidic medium, compared with the use of a fluorine-containing acidic medium, Reduces corrosion of the glass container. The reason may be that a small amount of hydrofluoric acid by-product produced by a fluorine-containing acidic medium corrodes the glass container, and the use of dichloroacetic acid does not cause corrosion of the glass container due to the absence of the above-mentioned hydrofluoric acid by-product. It can also be seen that the use of dichloroacetic acid in combination with various solid oxidants does not present the problem of corrosion of the glass container. Therefore, in the present invention, it is also preferred that the acidic medium is dichloroacetic acid.

 The inventors have also found that when an aqueous solution of sulfuric acid is used as an acidic medium, it also has better selectivity and yield, and, compared to trifluoroacetic acid, difluoroacetic acid, dichloroacetic acid, monofluorodichloroacetic acid, difluoroacetic acid. An acidic medium such as monochloroacetic acid, which is much easier to obtain in an aqueous solution of sulfuric acid and which is relatively inexpensive, is more suitable for industrial production. Therefore, the acidic medium may also be an aqueous sulfuric acid solution, and the aqueous sulfuric acid solution may have a concentration of 70 to 90% by weight, preferably 80 to 88% by weight.

 According to the present invention, the weight ratio of the compound of the formula (I) to the acidic medium may be from 1:2 to 10, preferably from 1:3 to 8, more preferably from 1:3.5 to 5.

 According to the present invention, the oxidation reaction condition of the compound represented by the formula (I) and the solid oxidizing agent may be carried out by adding the compound of the formula (I) to an acidic medium at -10 ° C to 50 ° C until it is sufficiently dissolved. The solid oxidizing agent is added, and the reaction temperature may be -10 ° C to 50 ° C, preferably 5 to 20 ° C, and more preferably 8 to 12 ° C. The reaction time may be from 1 to 48 hours, preferably from 4 to 6 hours.

 In the process of adding the solid oxidant, the oxidizing agent is added in portions, which is more favorable for improving the selectivity of the reaction. For example, the solid oxidizing agent may be added in 3 to 6 portions, wherein the first time is added to the solid oxidizing agent equimolar to the compound represented by the formula (I), and the remaining amount of the solid oxidizing agent may be equally divided into 2 to 5 parts.

 According to the present invention, the mixture obtained by contacting the solid oxidizing agent with the compound of the formula (I) may be contacted with a reducing agent to remove excess oxidizing agent.

 Wherein, the reducing agent may be one or more of insurance powder, sodium sulfite, sulfur dioxide and other reducing agents, preferably insurance powder and/or sodium sulfite.

 Wherein, the reducing agent is added in such a manner that the amount of the reducing agent is added so as to be able to remove the excess oxidizing agent. For example, a reducing agent may be added so that the mixture just does not allow the starch potassium iodide test paper to change color.

 According to the present invention, when the acidic medium is an organic carboxylic acid represented by the above structural formula, the acidic medium can be distilled off under reduced pressure after removing an excessive amount of the oxidizing agent.

 According to the present invention, when the acidic medium is an aqueous sulfuric acid solution, after removing excess oxidant, the reaction liquid after removing excess oxidant may be diluted with water at a temperature of -5 ° C to 5 ° C, and then filtered to obtain a solid. The product, wherein the weight ratio of the amount of water used for dilution to the aqueous solution of sulfuric acid is 1-3:1.

 The method provided by the present invention may further comprise recrystallizing the product after distilling off the acidic medium under reduced pressure. The solvent used for the recrystallization may be one or more of toluene, chlorobenzene, ethyl acetate, and an alcohol having 1 to 4 carbon atoms.

The method of recrystallization may be: firstly purifying the solid product of the acidic medium under water pressure to remove residual acid and inorganic salt, and then dissolving the solid product by heating with a solvent until the solid is completely dissolved, and slowly cooling the clear solution. Recrystallization from 0 to 5 ° C, then at 0-5 ° C for 2 hours, filtering to obtain crystal Body product. Here, the amount of water for washing may be 0.8 to 3 parts by weight, and the amount of solvent used for recrystallization may be 0.2 to 2 parts by weight, based on 1 part by weight of the product obtained by distilling off the acidic medium under reduced pressure.

 The present invention is more advantageous in the recovery of trifluoroacetic acid than the hydrogen peroxide and trifluoroacetic acid systems because of the large amount of water present in the system due to oxidation using a solid oxidizing agent.

 The invention will be further illustrated by the following examples. It is to be noted that the following examples are merely preferred or specific embodiments of the invention, and the scope of the invention is not limited to the following examples. Example 1

To a 1000 ml reaction flask was added 5-(amino-3cyano-1-(2,6-dichloro-4trifluoromethylanilinophenyl)-4-trifluoromethylthiopyrazole 126.3 g (0.3 mol) 500 g of trifluoroacetic acid, dissolved by stirring, and cooled to 10 V. The temperature of the reaction system was maintained at 10-12 ° C, and sodium perborate monohydrate (NaB0 ₃ _H ₂ 0) 41.9 g (0.42 mol) was added in one portion. The reaction was carried out for 6 h, and the degree of reaction was monitored by gas chromatography (GC) until the conversion of the raw material was more than 98%. Sodium sulfite was added in portions to remove the oxide (0.1 g per batch) to terminate the reaction, and the total amount of sodium sulfite added did not allow the reaction system to just happen. The starch potassium iodide test paper was discolored, and the mixture was stirred for 5 minutes. The trifluoroacetic acid was distilled under reduced pressure to obtain 410 g of trifluoroacetic acid having a water content of less than 1% by weight. 500 g of water was added to the solid after evaporation of the solvent, and the mixture was stirred for 30 minutes. To below 0 ° C, filtration, the solid obtained by filtration was heated to 300 g of chlorobenzene to completely dissolve, and then slowly cooled at 0-5 ° C, and then kept for 2 hours, filtered and dried to obtain 122 g of a white solid, which was detected by GC. The main component of the white solid is 5-amino-3-cyano- 1-(2,6-Dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole having a purity of 95% and a yield of 93%. The above 1000 ml reaction flask was used to repeat the above After 10 experiments, it was found that the inner wall of the bottom of the reaction bottle was still very smooth, and there was no wear and hairiness, indicating that the reaction bottle did not have obvious corrosive effect.

To a 1000 ml reaction flask was added 5-(amino-3cyano-1-(2,6-dichloro-4trifluoromethylanilinophenyl)-4-trifluoromethylthiopyrazole 126.3 g (0.3 mol) 500 g of trifluoroacetic acid, dissolved by stirring, cooled to 10 ° C. The temperature of the reaction system was maintained at 10-12 ° C, and 49.9 g (concentration: 30%, 0.44 mol) H ₂ 0 ₂ was slowly added dropwise, time control At 2h; keep the temperature at 10-12 ° C for 5h, GC to monitor the completion of the reaction, until the conversion of raw materials is greater than 98%; add 350g of chlorobenzene, azeotropic distillation under reduced pressure to recover a mixture of trifluoroacetic acid, chlorobenzene and water 440 g of trifluoroacetic acid having a water content of 8.5% was obtained by liquid separation. After the azeotropic distillation under reduced pressure, the chlorobenzene was distilled under reduced pressure until no fraction was obtained. 500 g of water was added to the solid after evaporation of the solvent, and the mixture was stirred for 30 minutes. 0 ° C or less, filtered, the filtered solid was heated to 95% by weight in an aqueous ethanol solution to completely dissolve, and then slowly cooled 0-5 ° C, and then kept for 2 hours, and then filtered to obtain a white solid, dried to obtain a solid The product, 112.5 g of a white solid, was subjected to GC detection. The white solid was mainly composed of 5-amino-3-cyano-1-(2) 6-Dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole, purity 94%, yield 86%. The above experiment was repeated 10 times using the above 1000 ml reaction flask, and the contact was found. Reaction bottle The bottom is no longer transparent and the edges are blurred, indicating that the reaction system has a certain corrosive effect on the glass. Example 2

To a 1000 ml reaction flask was added 5-(amino-3cyano-1-(2,6-dichloro-4trifluoromethylanilinophenyl)-4-trifluoromethylthiopyrazole 126.3 g (0.3 mol) ), 500g of trifluoroacetic acid, dissolved by stirring, cooled to 10 V. Maintain the temperature of the reaction system at 10-12 °C, first add 29.95g of sodium perborate hydrate (NaB0 ₃ H ₂ 0) (0.3mol), keep warm After stirring for 3 hours, 12.8 g (0.13 mol) of sodium perborate monohydrate was divided into 4 portions and added in 4 portions. The reaction was further incubated for 3 hours, and the degree of reaction was monitored by GC until the conversion of the raw material was more than 98%, and sodium sulfite was added in portions. In order to remove the oxide, (0.1g per batch), the reaction was terminated. The total amount of sodium sulfite added was such that the reaction system could not change the color of the starch potassium iodide test paper, and the mixture was stirred for 5 minutes, and trifluoroacetic acid was distilled under reduced pressure to obtain water content. 415g of trifluoroacetic acid is less than 1% by weight, 500g of water is added to the solid after evaporation of the solvent, stirred for 30min, cooled to below 0 °C, filtered, and the solid obtained by filtration is heated to completely dissolve in 120g of methanol, and then slowly cooled. To 0-5 ° C, keep warm for 2 hours, filter and dry 119 g of a white solid were obtained, which was determined by GC. The white solid was mainly composed of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethyl Sulfonylpyrazole, purity 96%, yield 91%. The above experiment was repeated 10 times using the above 1000 ml reaction bottle, and it was found that the inner wall of the bottom of the reaction bottle was still very smooth, without abrasion and hairiness, indicating that the reaction bottle did not appear obvious. Corrosion effect. Example 3

To a 1000 ml reaction flask was added 5-(amino-3cyano-1-(2,6-dichloro-4-trifluoromethylanilinylphenyl)-4-trifluoromethylthiopyrazole 126.3 g (0.3 mol) 500 g of trifluoroacetic acid, dissolved by stirring, and cooled to 10 ° C. 64.7 g of sodium perborate tetrahydrate (NaBO ₃ _4H ₂ O) (0.42 mol) was added in 5 portions over a period of 3 hours. At 10-12 ° C, the reaction was further incubated for 3 h, and the degree of completion of the reaction was monitored by GC until the conversion of the raw material was more than 99%, and sodium sulfite was added in portions to remove the oxide (0.1 g per batch) to terminate the reaction. The total amount or the total amount, so that the reaction system just does not change the color of the starch potassium iodide test paper, and the mixture is stirred for 5 minutes, and trifluoroacetic acid is distilled off under reduced pressure to obtain 405 g of trifluoroacetic acid having a water content of less than 1% by weight, and the solvent is distilled off. 500g of water was added to the subsequent solid, stirred for 30min, cooled to below 0 °C, filtered, and the solid obtained by filtration was heated to 250 g of a 95% by weight aqueous solution of ethanol to completely dissolve, and then slowly cooled to 0-5 °C. , kept for another 2 hours, filtered and dried to give a white solid 124 .5g, the main component of the white solid by GC detection is 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfin Acylpyrazole, purity 97%, yield 94%.

The above experiment was repeated 10 times using the above 1000 ml reaction bottle, and it was found that the inner wall of the bottom of the reaction bottle was still very smooth, and there was no abrasion and hairiness, indicating that the reaction bottle did not have obvious corrosive effect. Example 4

To a 1000 ml reaction flask was added 5-(amino-3cyano-1-(2,6-dichloro-4-trifluoromethylanilinylphenyl)-4-trifluoromethylthiopyrazole 126.3 g (0.3 mol). ), dichloroacetic acid (Cl ₂ CHCOOH) 500g, dissolved by stirring, cooled to 10 ° C. Add potassium peroxymonosulfate (2K ₂ S0 ₅ KHS0 ₄ K ₂ S04 ) 240g (0.39mol) in 4 hours in 3 hours. The temperature of the reaction system was maintained at 10-12 ° C, and the reaction was further incubated for 5 h. The degree of completion of the reaction was monitored by GC until the conversion of the raw material was greater than 98%, and sodium sulfite was added in portions to remove the oxide (0.1 g per batch). To terminate the reaction. Control the batch or total amount of sodium sulfite added, so that the reaction system can not just change the color of the starch potassium iodide test paper, stir for 5 minutes, dichloroacetic acid is distilled off under reduced pressure to obtain 420 g of anhydrous dichloroacetic acid. 500 g of water was added to the solid after evaporation of the solvent, stirred for 30 min, cooled to below 0 ° C, filtered, and the solid obtained by filtration was heated to 250 g of a 95% by weight aqueous solution of ethanol to completely dissolve, and then slowly cooled to 0-5. °C, kept for another 2 hours, filtered and dried to give a white solid 110g The main component of the white solid was 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyridinium by GC. The azole was 92% pure and the yield was 84%. The above experiment was repeated 10 times using the above 1000 ml reaction bottle, and it was found that the inner wall of the bottom of the reaction bottle was still very smooth, and there was no abrasion and hairiness, indicating that the reaction bottle did not have obvious corrosive effect. Example 5

To a 1000 ml reaction flask was added 5-(amino-3cyano-1-(2,6-dichloro-4-trifluoromethylanilinylphenyl)-4-trifluoromethylthiopyrazole 126.3 g (0.3 mol) a mixture of 100 g of monofluorodichloroacetic acid and 500 g of chloroacetic acid (ClCH ₂ COOH), stirred until dissolved, and cooled to 10 ° C. Once added sodium percarbonate (2Na ₂ C0 ₃ -3H ₂ 0 ₂ ) 114.24 g ( 0.42 mol). The temperature of the reaction system was maintained at 10-12 ° C, and the reaction was further incubated for 6 h. The degree of completion of the reaction was monitored by GC until the conversion of the raw material was greater than 98%, and sodium sulfite was added in portions to remove oxides (0.1 g per batch). To terminate the reaction. Control the batch or total amount of sodium sulfite added so that the reaction system just does not change the color of the starch potassium iodide test paper, stir for 5 minutes, and recover by distillation under reduced pressure to obtain a water content of less than 2% by weight of trifluoroacetic acid. 430 g of a mixed solvent of chloroacetic acid, 500 g of water was added to the solid after evaporation of the solvent, stirred for 30 min, cooled to below 0 ° C, filtered, and the solid obtained by filtration was heated to a complete dissolution in 250 g of a 95% by weight aqueous solution of ethanol. , slowly cool to 0-5 ° C, and then keep warm for 2 hours, filter Drying gave 117 g of a white solid, which was identified by GC. The white solid was mainly 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoro Methylsulfinylpyrazole, purity 96%, yield 89.2%. The above experiment was repeated 10 times using the above 1000 ml reaction flask, and it was found that the bottom of the reaction bottle contacting the reaction solution was no longer transparent and the edges were blurred, indicating that the reaction system had a certain glass. Corrosion effect. Example 6

To a 2000 ml reaction flask was added 5-(amino-3cyano-1-(2,6-dichloro-4-trifluoromethylanilinophenyl)-4-trifluoromethylthiopyrazole 126.3 g (0.3 mol). ), 900g of sulfuric acid at a concentration of 80% by weight, stirred to Dissolve and cool to 10 °C. Sodium perborate monohydrate (NaB0 ₃ H ₂ 0 ) 41.9 g (0.42 mol) was added in one portion. The temperature of the reaction system was maintained at 10-12 ° C, and the reaction was further incubated for 6 hours. The degree of completion of the reaction was monitored by GC until the conversion of the raw material was greater than 98%, and the SO ₂ gas was introduced to remove the oxide to terminate the reaction. Control the total amount of S0 ₂ gas inflow, so that the reaction system just can not make the starch potassium iodide test paper discoloration, stir for 5 minutes, put the reaction bottle in an ice water bath, add 1800g water to the reaction droplet, at the reaction liquid temperature After being reduced to 0 °, it was filtered to give a white solid, 110 g, which was determined by GC. The main component of the white solid was 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl) -4-trifluoromethylsulfinylpyrazole, purity 91%, yield 84%.

Claims

Claim  1. A 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinic acid represented by the following formula (II) Acylpyrazole method,

 (II)  Characterized in that the preparation method of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole is included in In an acidic medium, a solid oxidant is used to contact the object under the oxidation reaction conditions.

 The method according to claim 1, wherein the molar ratio of the compound of the formula (I) to the solid oxidizing agent is 1: 0.9-6.0.  The method according to claim 1 or 2, wherein the solid oxidizing agent is one or more of sodium perborate, potassium peroxymonosulfate, sodium percarbonate, calcium peroxide, and magnesium peroxide. 4. The method according to claim 3, wherein the sodium perborate is hydrated sodium perborate having one or four water of crystallization. 5. The method according to claim 1, wherein the weight ratio of the acidic medium to the compound of the formula (I) is from 2 to 10:1. 6. The method according to claim 1 or 5, wherein the acidic medium is selected from one or more of the group consisting of organic carboxylic acids having the following structural formula:

 Wherein R represents a C1 to C6 alkyl group, a C1 to C6 halogenated hydrocarbon group, a halogen or a hydrogen, and X and Y each represent a halogen or a hydrogen. 7. The method according to claim 6, wherein the acidic medium is one or more of trifluoroacetic acid, difluoroacetic acid, dichloroacetic acid, monofluorodichloroacetic acid, and difluoromonochloroacetic acid. 8. The method according to claim 6, wherein said R, X and Y are fluorine, and said solid oxide agent is hydrated sodium perborate having one or four water of crystallization. The method according to claim 1 or 5, wherein the acidic medium is an aqueous sulfuric acid solution, and the aqueous sulfuric acid solution has a concentration of 70 to 90% by weight. The method according to claim 1, wherein the oxidation reaction conditions include a reaction temperature of from -10 ° C to 50 ° C and a reaction time of from 1 to 48 hours. The method according to claim 6, wherein the method further comprises contacting the mixture obtained by contacting the solid oxidizing agent with the compound represented by the formula (I) with a reducing agent, and then distilling off the acidic medium under reduced pressure. The method according to claim 11, wherein the reducing agent is one or more of a safety powder, sodium sulfite, and sulfur dioxide. 13. The method according to claim 11, wherein the method further comprises recrystallizing a product obtained by distilling off the acidic medium under reduced pressure, wherein the solvent used for the recrystallization is toluene, chlorobenzene, ethyl acetate and carbon atoms. One or more of the alcohols of 1-4.