Method for producing intermediate for the production of cyclaniliprole

Abstract

Provided is a method for producing a production intermediate of high-purity cyclaniliprole.　According to this method, a production intermediate of high-purity cyclaniliprole can be produced at a high yield by reacting a compound represented by formula (II) or a salt thereof with a compound represented by formula (III) or a salt thereof in the presence of a condensing agent and / or a base. By using this intermediate, high-purity cyclaniliprole can be produced.

Description

[Technical field]

[0001] The present invention relates to a method for producing an intermediate for the production of cyclaniliprole. The present invention also relates to a method for producing cyclaniliprole using the intermediate for the production of cyclaniliprole. [Background technology]

[0002] Cyclaniliprole (3-bromo-N-[2-bromo-4-chloro-6-[[(1-cyclopropylethyl)amino]carbonyl]phenyl]-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide; a compound represented by formula (IV) described below) is described in Patent Document 1 as Compound No. 16, and is a useful compound as an active ingredient of commercially available agricultural insecticides. Methods for producing cyclaniliprole are known in, for example, Patent Documents 2 to 4. Compounds having a structure similar to cyclaniliprole and methods for producing the same are also known (for example, Patent Documents 5 to 10). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2005 / 077934 [Patent Document 2] International Publication No. 2008 / 072745 [Patent Document 3] International Publication No. 2008 / 072743 [Patent Document 4] International Publication No. 2008 / 155990 [Patent Document 5] International Publication No. 2003 / 016283 [Patent Document 6] International Publication No. 2004 / 011453 [Patent Document 7] International Publication No. 2006 / 062978 [Patent Document 8] International Publication No. 2008 / 070158 [Patent Document 9] International Publication No. 2019 / 207595 [Patent Document 10] China Patent Application Publication No. 102285964 Summary of the Invention [Problem to be solved by the invention]

[0004] When cyclaniliprole is industrially produced as an agricultural chemical raw material, it must conform to certain specifications. The problem to be solved by the present invention is to produce high-purity cyclaniliprole at high yield and low cost. More specifically, the present invention aims to produce cyclaniliprole at high yield and high purity by suppressing the inclusion of impurities (B) described below in cyclaniliprole as an agricultural chemical raw material.

[0005] Patent Document 1 describes a method that can be used to produce cyclaniliprole as reaction [A]. However, the present inventors have found that when cyclaniliprole represented by formula (IV) is produced according to reaction [A] as shown in the following scheme, an impurity compound represented by formula (B) (hereinafter also referred to as impurity (B)) is by-produced, and it is very difficult to remove this impurity (B) from the obtained cyclaniliprole, and therefore the method described in Patent Document 1 is not suitable for producing high-purity cyclaniliprole that meets the standards for an agricultural chemical raw material.

[0006] [ka] Patent Document 1 does not include any description of the by-production of such impurity (B), and does not recognize the problem of the production of impurity (B).

[0007] The present inventors further investigated the above problem and found that the generation of the impurity (B) is caused by the presence of Br on the benzene ring. Therefore, it was considered that the method described in Patent Document 1 cannot sufficiently suppress the by-production of the impurity (B).

[0008] On the other hand, Patent Document 2 discloses a method for producing cyclaniliprole via reaction [N] as a method for producing cyclaniliprole using a raw material that does not have Br on the benzene ring. However, in the specific example corresponding to reaction [N] in Patent Document 2, for example, the yield of Example 17(4) is very low, about 14%, and the yield of Example 19(2) is very low, about 37%, and a significant improvement in yield is required for use as an industrial production method of cyclaniliprole. In addition, Patent Document 2 does not mention or recognize the problem of the generation of impurity (B). [Means for solving the problem]

[0009] In order to solve the above problems, the present inventors have conducted various studies and found that the generation of the impurity (B) is due to the presence of Br on the benzene ring, and have considered the need to produce cyclaniliprole via a raw material that does not have Br on the benzene ring. Even when using a raw material that does not have Br on the benzene ring, the present inventors have found a production method that can produce a production intermediate of cyclaniliprole with a high yield and a very low impurity content by selecting a specific reaction reagent. The present inventors have also found that high-purity cyclaniliprole that meets the standards for agricultural chemicals can be produced from the production intermediate of cyclaniliprole produced in this way.

[0010] That is, the present invention provides a compound represented by formula (I) or a salt thereof (hereinafter, also simply referred to as compound (I)):

[0011] [ka]

[0012] The present invention relates to a method for producing a compound represented by formula (II) or a salt thereof (hereinafter, also simply referred to as compound (II)):

[0013] [ka]

[0014] and a compound represented by formula (III) or a salt thereof (hereinafter also simply referred to as compound (III)):

[0015] [ka]

[0016] [In the formula (III), R is OH or halogen] In addition, the present invention also provides a method for producing cyclaniliprole, which comprises reacting compound (I) thus produced with a brominating agent. Effect of the Invention

[0017] According to the present invention, compound (I) useful for the production of cyclaniliprole can be produced in high yield and high purity. Furthermore, from compound (I) obtained by the present invention, cyclaniliprole of high purity that satisfies the standard as an agricultural chemical raw material can be produced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] [Method for producing compound (I)] The method for producing compound (I) of the present invention is characterized in that compound (II) and compound (III) are reacted in the presence of a condensing agent and / or a base. When R is OH, compound (II) and compound (III) are preferably reacted in the presence of a condensing agent and a base, and when R is halogen, compound (II) and compound (III) are preferably reacted in the presence of a base. This reaction may be carried out in the presence of a solvent.

[0019] The salts of compound (I), compound (II) or compound (III) include any salts that are agriculturally acceptable, such as alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts (magnesium salt, calcium salt, etc.), ammonium salts, alkylammonium salts (dimethylammonium salt, triethylammonium salt, etc.), acid addition salts (hydrochloride, perchlorate, sulfate, nitrate, acetate, methanesulfonate, etc.), etc. Examples of halogens represented by R include chlorine, bromine, iodine, etc., and chlorine is preferred.

[0020] The amounts of compound (II) and compound (III) used are not particularly limited as long as the reaction proceeds. For example, 0.8 to 1.2 mol, preferably 0.9 to 1.1 mol, and more preferably 0.95 to 1.05 mol of compound (III) can be used per mol of compound (II).

[0021] Compound (II) and compound (III) in the present invention can be produced by a method known in the art, for example, the methods described in Patent Documents 2, 5, 7, etc., or methods similar thereto, or commercially available products can be used. In addition, when compound (III) in which R is a halogen is used, compound (III) in which R is a halogen can also be obtained by reacting compound (III) in which R is OH with a halogenating agent (such as an acid halide such as thionyl chloride or oxalyl chloride) according to a method known in the art.

[0022] The condensing agent used in this reaction is preferably a sulfonyl chloride (e.g., methanesulfonyl chloride, p-toluenesulfonyl chloride, etc.) or an acid halide (e.g., thionyl chloride, oxalyl chloride, etc.), and among these, from the viewpoint of the yield and the purity of the obtained compound (I), sulfonyl chloride is more preferable, and methanesulfonyl chloride is particularly preferable. The amount of the condensing agent used is not particularly limited as long as the reaction proceeds, but is, for example, 1 to 2 moles, preferably 1 to 1.8 moles, more preferably 1 to 1.5 moles relative to 1 mole of compound (II).

[0023] The base used in this reaction is preferably an organic base such as pyridine, picoline (e.g., 2-picoline, 3-picoline, 4-picoline), and an inorganic base such as an alkali metal carbonate or alkali metal hydrogen carbonate, an alkaline earth metal carbonate or alkaline earth metal hydrogen carbonate, and among these, from the viewpoint of the yield and the purity of the obtained compound (I), pyridine, picoline (e.g., 2-picoline, 3-picoline, 4-picoline), an alkali metal carbonate or an alkali metal hydrogen carbonate is more preferable, pyridine or picoline (e.g., 2-picoline, 3-picoline, 4-picoline) is further preferable, and among them, 3-picoline is particularly preferable. The above-mentioned base used in this reaction may be one kind or two or more kinds. The amount of the base used is not particularly limited as long as the reaction proceeds, but is, for example, 0 to 10 mol, preferably 1 to 7 mol, and more preferably 1 to 4 mol, relative to 1 mol of Compound (II).

[0024] The solvent that may be used in this reaction is not particularly limited as long as it does not adversely affect the reaction, and examples thereof include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), nitriles (acetonitrile, propionitrile, etc.), ethers (tetrahydrofuran, diethyl ether, etc.), halogenated hydrocarbons (dichloromethane, dichloroethane, chloroform, chlorobenzene, etc.), esters (ethyl acetate, isopropyl acetate, etc.), polar solvents (dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, etc.), aromatic hydrocarbons (toluene, xylene, etc.), pyridines (pyridine, picoline, etc.), and mixed solvents thereof. Among these, from the viewpoint of yield and purity of the obtained compound (I), it is preferable to use one or more selected from the group consisting of ketones, nitriles, ethers, halogenated hydrocarbons, polar solvents, and pyridines, and it is more preferable to use one or more selected from the group consisting of ketones, nitriles, ethers, polar solvents, and pyridines. The amount of the solvent used is not particularly limited as long as the reaction proceeds, but it is, for example, 0 to 50 times (V / W), preferably 0 to 30 times (V / W), more preferably 0 to 20 times (V / W), and even more preferably 1 to 20 times (V / W) relative to compound (II).

[0025] In this reaction, the order of addition of compound (II), compound (III), condensing agent, base, and if necessary, solvent is not particularly limited, and may be added and mixed in any order. The addition of these components to the reaction system may be performed at once or in portions, or may be continuous. For example, the order of addition may be such that all components are mixed at once, or some components may be added later. Specific examples of such addition include, for example, (i) mixing compound (II), base, and solvent, and adding compound (III) and condensing agent thereto, and (ii) mixing compound (II), compound (III), base, and solvent, and adding condensing agent thereto.

[0026] The reaction temperature is usually about 0 to 50° C., preferably about 0 to 30° C. The reaction time is usually about 1 to 24 hours, preferably about 1 to 5 hours. In this specification, "room temperature" usually means about 0 to 40° C., more specifically, 10 to 30° C.

[0027] After the completion of this reaction, compound (I) can be isolated, if necessary, by carrying out post-treatment by a conventional method such as neutralization, extraction, washing and drying. Compound (I) may then be purified by a conventional method such as recrystallization and repulping, if necessary. Alternatively, compound (I) can be used in the next reaction as it is without isolation or without purifying the isolated compound (I).

[0028] The purity of compound (I) obtained by this reaction is usually 95% by weight or more, preferably 97% by weight or more, more preferably 98.5% by weight or more. In addition to compound (I) obtained by this reaction, a compound represented by the following formula (A) or a salt thereof (hereinafter, simply referred to as impurity (A)) is contained as an impurity.

[0029] [ka]

[0030] The content of is usually 1% by weight or less, preferably 0.3% by weight or less, more preferably substantially free of impurity (A) based on the total amount of the compound represented by formula (I) or its salt and the impurity (A). Here, substantially free of impurity (A) means that it may be mixed in an amount equivalent to the amount of impurities, for example, the content of impurity (A) is less than 0.1% by weight. By producing cyclaniliprole using such compound (I), it is possible to produce cyclaniliprole of high purity that meets the standards for an agricultural chemical raw material.

[0031] [Method of manufacturing cyclaniliprole] Cyclaniliprole can be produced by reacting the compound (I) obtained as described above with a brominating agent. This reaction may be carried out in the presence of a base and a solvent. The brominating agent used in this method includes bromine, hypobromous acid, etc., and among these, bromine is preferred.

[0032] The amount of the brominating agent used is not particularly limited as long as the reaction proceeds, but for example, 0.5 to 5 moles, preferably 1 to 3 moles, and more preferably 1 to 2 moles of the brominating agent can be used per mole of compound (I).

[0033] The base that may be used in this reaction is preferably a metal hydroxide (sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.), a metal hydride (sodium hydride, potassium hydride, etc.), or a metal alkoxide (sodium methoxide, sodium ethoxide, potassium t-butoxide, etc.), and among these, a metal hydroxide is more preferred, and sodium hydroxide and potassium hydroxide are even more preferred. The above-mentioned base used in this reaction may be one type or two or more types. The amount of the base used is not particularly limited as long as the reaction proceeds, but is, for example, 1 to 10 mol, preferably 1.5 to 5 mol, and more preferably 1.5 to 3.5 mol relative to 1 mol of Compound (I).

[0034] The solvent that may be used in this reaction is not particularly limited as long as it does not adversely affect the reaction, and examples thereof include ethers (diethyl ether, butyl methyl ether, tetrahydrofuran, dioxane, dimethoxyethane, etc.), halogenated hydrocarbons (chlorobenzene, dichlorobenzene, dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, dichloroethylene, etc.), aromatic hydrocarbons (benzene, toluene, xylene, etc.), aliphatic hydrocarbons (pentane, hexane, heptane, octane, cyclohexane, etc.), esters (methyl acetate, ethyl acetate, propyl acetate (isopropyl acetate, normal propyl acetate, etc.), butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, cyclohexanone, etc.), nitriles (acetonitrile, propionitrile, etc.), amides (for example, N,N-dimethylformamide, dimethyl sulfoxide, hexamethylphosphoric triamide, dimethylacetamide, N-methylpyrrolidone, etc.), and mixed solvents thereof. Among these, from the viewpoint of yield and purity of the obtained cyclaniliprole, it is preferable to use one or more selected from the group consisting of ethers, halogenated hydrocarbons and esters, and it is more preferable to use one or more selected from the group consisting of esters. The amount of the solvent used is not particularly limited as long as the reaction proceeds, but is, for example, 0 to 50 times (V / W), preferably 1 to 30 times (V / W), more preferably 3 to 20 times (V / W) relative to compound (I).

[0035] In this reaction, the order of addition of compound (I) and a brominating agent, and optionally a base and a solvent, is not particularly limited, and they may be mixed in any order. These components may be added to the reaction system all at once or in portions, or may be added continuously. For example, the order of addition may be (i) compound (I) and a brominating agent, and optionally a solvent, and then a base is added thereto, or (ii) compound (I) and a base, and optionally a solvent, and then a brominating agent is added thereto.

[0036] The reaction temperature is usually about −20 to 120° C., preferably about 0 to 50° C. The reaction time is usually about 0.5 to 48 hours, preferably about 1 to 24 hours.

[0037] After the completion of this reaction, cyclaniliprole can be isolated by performing post-treatment by a conventional method such as neutralization, extraction, washing and drying, if necessary. Depending on the reaction and / or post-treatment conditions, cyclaniliprole may be isolated as a salt or solvate. In that case, it can be converted to free cyclaniliprole by a conventional method such as neutralization and desolvation. Thereafter, cyclaniliprole can be purified by a conventional method such as recrystallization and repulping, if necessary. The purity of cyclaniliprole obtained by this reaction is usually 90% by weight or more, preferably 95% by weight or more, more preferably 97% by weight or more. In addition to cyclaniliprole obtained by this reaction, a compound represented by the following formula (B) or a salt thereof contained as an impurity:

[0038] [ka]

[0039] The content of is usually 1% by weight or less, preferably 0.3% by weight or less, more preferably substantially free of impurity (B), based on the total amount of cyclaniliprole and the compound represented by formula (B). Here, substantially free of impurity (B) means that it may be mixed in in an amount equivalent to the amount of impurity, for example, the content of impurity (B) is less than 0.1% by weight.

[0040] The various components in the method of the present invention can be appropriately selected from the multiple examples and conditions described above, for example, from the examples and conditions in the normal range as well as the examples and conditions in the preferred range, and can be combined with each other.

[0041] 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:

[0042] [ka]

[0043] A method for producing A compound represented by formula (II) or a salt thereof:

[0044] [ka]

[0045] and a compound represented by formula (III) or a salt thereof:

[0046] [ka]

[0047] [In the formula (III), R is OH or halogen] in the presence of a condensing agent and / or a base. [2] When R is OH, the production method according to [1], comprising reacting a compound represented by formula (II) or a salt thereof with a compound represented by formula (III) or a salt thereof in the presence of a condensing agent and a base. [3] The method according to [1], wherein when R is halogen, a compound represented by formula (II) or a salt thereof is reacted with a compound represented by formula (III) or a salt thereof in the presence of a base. [4] The method according to [1] or [2], wherein the condensing agent is a sulfonyl chloride or an acid halide. [5] The method according to [1] or [2], wherein the condensing agent is a sulfonyl chloride. [6] The method according to [1] or [2], wherein the condensing agent is methanesulfonyl chloride. [7] The method according to any one of [1] to [6], wherein the base is one or more selected from the group consisting of pyridine, picoline, an alkali metal carbonate, and an alkali metal hydrogen carbonate. [8] The method according to any one of [1] to [6], wherein the base is pyridine or picoline. [9] The method according to any one of [1] to [6], wherein the base is pyridine or 3-picoline.

[10] The method according to any one of [1] to [9], wherein the reaction is carried out in the presence of a solvent.

[11] The method according to

[10] , wherein the solvent is one or more selected from the group consisting of ketones, nitriles, ethers, halogenated hydrocarbons, polar solvents, pyridines and aromatic hydrocarbons.

[12] The production method according to

[10] , wherein the solvent is one or more selected from the group consisting of ketones, nitriles, ethers, halogenated hydrocarbons, polar solvents, and pyridines.

[13] The production method according to

[10] , wherein the solvent is one or more selected from the group consisting of ketones, nitriles, ethers, polar solvents, and pyridines.

[14] The method according to

[10] , wherein the solvent is one or more selected from the group consisting of tetrahydrofuran, N-methylpyrrolidone, acetone, acetonitrile, 3-picoline and pyridine.

[15] The method according to any one of [1] to

[14] , wherein the purity of the obtained compound represented by formula (I) or a salt thereof is 95% by weight or more.

[16] In addition to the compound represented by formula (I) or a salt thereof obtained, a compound represented by the following formula (A) or a salt thereof is contained as an impurity:

[0048] [ka]

[0049] The method according to any one of [1] to

[15] , wherein the content of is 1% by weight or less based on the total amount of the compound represented by formula (I) or a salt thereof and the compound represented by formula (A) or a salt thereof.

[17] The method according to any one of [1] to

[15] , wherein the compound represented by formula (A) or a salt thereof is substantially not contained as an impurity other than the compound represented by formula (I) or a salt thereof obtained.

[0050]

[18] A method for producing cyclaniliprole, comprising reacting the compound represented by formula (I) or a salt thereof obtained by the production method according to any one of [1] to

[17] with a brominating agent.

[19] The method according to

[18] , wherein the brominating agent is bromine or hypobromous acid.

[20] The method according to

[18] or

[19] , wherein the reaction is carried out in the presence of a base.

[21] The method according to

[20] , wherein the base is one or more selected from the group consisting of metal hydroxides, metal hydrides and metal alkoxides.

[22] The method according to

[20] , wherein the base is a metal hydroxide.

[23] The method according to any one of

[18] to

[22] , wherein the reaction is carried out in the presence of a solvent.

[24] The method according to

[23] , wherein the solvent is one or more selected from the group consisting of ethers, halogenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons, esters, ketones, nitriles and amides.

[25] The method according to

[23] , wherein the solvent is one or more selected from the group consisting of ethers, halogenated hydrocarbons, and esters.

[26] The method according to

[23] , wherein the solvent is one or more selected from the group consisting of esters.

[27] The method according to

[23] , wherein the solvent is one or more selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate and butyl acetate.

[28] The method according to

[23] , wherein the solvent is one or more selected from the group consisting of methyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate.

[29] The method according to any one of

[18] to

[28] , wherein the purity of the obtained cyclaniliprole is 90% by weight or more.

[30] In addition to the obtained cyclaniliprole, a compound represented by the following formula (B) or a salt thereof is contained as an impurity:

[0051] [ka]

[0052] The method according to any one of

[18] to

[29] , wherein the content of is 1% by weight or less based on the total amount of cyclaniliprole and the compound represented by formula (B).

[31] The method according to any one of

[18] to

[28] , which is substantially free of the compound represented by formula (B) or a salt thereof as an impurity other than the obtained cyclaniliprole. EXAMPLES

[0053] Examples of the present invention will now be described, but the present invention is not to be construed as being limited thereto. The structures of compounds (IIIa), (IIIb) and compound (V) used in this example are shown below. ·Compound (IIIa):

[0054] [ka]

[0055] ·Compound (IIIb):

[0056] [ka]

[0057] ·Compound (V)

[0058] [ka]

[0059] The HPLC analysis conditions in this example are as follows. Equipment used: Shimadzu Corporation Nexera XS series Column: SunShell C18 (2.6 μm, 2.1 × 100 mm) manufactured by Chromanik Technologies Co., Ltd. Detection: UV detector (240 nm) Column temperature: 40℃ ·Flow rate: 0.5mL / min Mobile phase: Solution A: 0.1% formic acid aqueous solution, and Solution B: acetonitrile The gradient conditions are as follows:

[0060] [Table 1]

[0061] The purity (content ratio) is expressed as an area % value measured by high performance liquid chromatography (HPLC) and / or a weight % value converted from the area %. The area % values ​​are obtained by measuring the reaction products obtained from synthesis experiments by HPLC. The weight percent value is calculated, for example, by the conversion method described below. A measurement solvent is added to the cyclaniliprole standard to prepare a cyclaniliprole standard solution, and the standard solution is measured three times by HPLC. The average value of the area values ​​obtained by the HPLC measurement is calculated, and the average value is divided by the weight of the cyclaniliprole standard used in the measurement to calculate the unit area value. The unit area values ​​of the compound (I) standard, the impurity (A) standard, and the impurity (B) standard are calculated in the same manner. The unit area value of the reaction product described in the examples is also calculated in the same manner. The unit area value of the reaction product and the unit area value of the standard are compared, the ratio is calculated, and the weight percent value is calculated. It is also possible to calculate the sensitivity ratio from the unit area value of each of the above-mentioned standards, and convert the sensitivity ratio to obtain the impurity content.

[0062] [Example 1] Synthesis of Compound (I) A mixture of 0.5 g of compound (II), 0.6 g of compound (IIIa), 0.59 g of 3-picoline and 10 mL of tetrahydrofuran was cooled on ice, and 0.31 g of methanesulfonyl chloride was slowly added dropwise under ice cooling. After the dropwise addition, the mixture was warmed to room temperature and stirred at the same temperature overnight. The reaction was checked by HPLC, and compound (I) was produced at 88.1 area %. No impurity (A) was detected.

[0063] [Example 2] Synthesis of Compound (I) A mixture of 0.5 g of compound (II), 0.6 g of compound (IIIa), 0.59 g of 3-picoline and 10 mL of N-methylpyrrolidone was cooled on ice, and 0.31 g of methanesulfonyl chloride was slowly added dropwise under ice cooling. After the dropwise addition, the mixture was warmed to room temperature and stirred at the same temperature overnight. The reaction was checked by HPLC, and compound (I) was produced at 98.6 area %. No impurity (A) was detected.

[0064] [Example 3] Synthesis of compound (I) To a mixture of 0.83 g of compound (II), 1.0 g of compound (IIIa), 0.81 g of 3-picoline, and 10 mL of acetone, 0.5 g of methanesulfonyl chloride was slowly added dropwise at room temperature. After stirring overnight at the same temperature, the reaction was checked by HPLC, and compound (I) was produced at 89.7% by area. No impurity (A) was detected.

[0065] [Example 4] Synthesis of Compound (I) To a mixture of 0.83 g of compound (II), 1.0 g of compound (IIIa), 0.81 g of 3-picoline, and 10 mL of acetonitrile, 0.5 g of methanesulfonyl chloride was slowly added dropwise at room temperature. After stirring overnight at the same temperature, the reaction was checked by HPLC, and compound (I) was produced at 88.9 area %. No impurity (A) was detected.

[0066] [Example 5] Synthesis of Compound (I) Compound (II) 0.83g, 3-picoline 0.78g, and acetone 10mL were mixed, and compound (IIIb) 1.04g was slowly added dropwise to the mixture in an ice bath. After the addition, the mixture was warmed to room temperature and stirred overnight at the same temperature. The reaction was checked by HPLC, and compound (I) was produced at 89.4% by area. No impurity (A) was detected.

[0067] [Example 6] Synthesis of Compound (I) Compound (II) 0.83g, 3-picoline 0.78g, and acetonitrile 10mL were slowly dripped with compound (IIIb) 1.04g in an ice bath. After dripping, the mixture was heated to room temperature and stirred overnight at the same temperature. The reaction was checked by HPLC, and compound (I) was produced at 91.0% by area. No impurity (A) was detected.

[0068] [Example 7] Synthesis of Compound (I) To a mixture of 16.9 g of compound (II), 20 g of compound (IIIa), 12.3 g of pyridine, and 98 mL of acetone, 8.9 g of methanesulfonyl chloride was slowly added dropwise at room temperature. After stirring overnight at the same temperature, the reaction was checked by HPLC, and compound (I) was produced at 93.3 area %. At that time, impurity (A) was not detected. After confirming the completion of the reaction, 49 g of water was slowly added dropwise and stirred at the same temperature for 45 minutes. The slurry was filtered, and the obtained solid was washed with acetone water and dried overnight in a hot air dryer to obtain 32.6 g of compound (I) (yield: 92%; purity: 96 wt%, 98.4 area%). The above purity is converted from area % to weight % as follows. 15.41 mg of cyclaniliprole standard was weighed into a 25 mL volumetric flask, dissolved in 1 mL of dimethylformamide, 2 mL of water, and 20 mL of acetonitrile, and then diluted with acetonitrile to prepare a standard solution. The prepared standard solution was measured three times by HPLC. The average value of the area values ​​obtained by HPLC measurement was calculated. The calculated average value was divided by 15.41, which is the mass value of cyclaniliprole standard, to calculate the unit area value of 66069. In the same manner, the unit area values ​​of compound (I), impurity (A), and impurity (B) were calculated as 72447, 91829, and 81242. Next, the area value obtained by HPLC measurement and the unit area value of the standard were compared in the same manner to calculate the ratio of the compound (I) obtained by synthesis, and the weight percentage value indicating the content ratio of the impurities was calculated.

[0069] [Example 8] Synthesis of Compound (I) To a mixture of 0.79 g of compound (II), 1.0 g of compound (IIIa), 0.39 g of sodium carbonate, and 10 mL of acetone, 0.45 g of methanesulfonyl chloride was slowly added dropwise at room temperature. After stirring at the same temperature for 1 hour, the reaction was checked by HPLC, and compound (I) was produced at 75.5 area %. At that time, impurity (A) was not detected. Next, 0.15 g of sodium carbonate and 0.15 g of methanesulfonyl chloride were added to the reaction solution, and the mixture was stirred at room temperature overnight, and compound (I) was produced at 97.2 area %. At that time, impurity (A) was not detected.

[0070] [Example 9] Synthesis of cyclaniliprole A mixture of 11.6 g of compound (I) obtained according to Example 3 and 58 mL of ethyl acetate was cooled on ice, and 5.2 g of bromine was slowly added dropwise. Next, 13.8 g of aqueous sodium hydroxide solution was slowly added dropwise, and the mixture was stirred at the same temperature for 1 hour. After confirming that the reaction was complete, 12.7 g of aqueous sodium sulfite solution was added dropwise in an ice bath, and the mixture was stirred at the same temperature for 1 hour. The slurry was filtered, and the solid was washed with 11.6 g of water. 17.4 mL of methanol was added to the obtained solid, and the mixture was refluxed for 1 hour and then cooled to room temperature. The slurry was filtered, and the solid was dried overnight in a hot air dryer to obtain 12.9 g of cyclaniliprole (yield: 95%). In addition, impurity (B) was not detected in the obtained cyclaniliprole (purity: 98% by weight, 97.6% by area). The purity was converted from area % to weight % in the same manner as in Example 7.

[0071] [Example 10] Synthesis of Compound (I) A mixture of 0.5 g of compound (II), 0.67 g of compound (IIIa), 0.59 g of 3-picoline, and 2 mL of 3-picoline as a solvent was cooled on ice, and 0.29 g of methanesulfonyl chloride was slowly added dropwise under ice cooling. After the dropwise addition, the mixture was warmed to room temperature and stirred at the same temperature overnight. The reaction was checked by HPLC, and compound (I) was produced at 97.8 area %. No impurity (A) was detected.

[0072] [Example 11] Synthesis of Compound (I) A mixture of 0.5 g of compound (II), 0.63 g of compound (IIIa), 0.39 g of 3-picoline, and 5 mL of pyridine as a solvent was cooled on ice, and 0.26 g of methanesulfonyl chloride was slowly added dropwise under ice cooling. After the dropwise addition, the mixture was warmed to room temperature and stirred at the same temperature for 1 hour. The reaction was checked by HPLC, and compound (I) was produced at 96.8 area %. No impurity (A) was detected.

[0073] [Example 12] Synthesis of Compound (I) A mixture of 0.5 g of compound (II), 0.63 g of compound (IIIa), 0.39 g of 3-picoline and 5 mL of acetone was cooled on ice, and 0.26 g of methanesulfonyl chloride was slowly added dropwise under ice cooling. After the dropwise addition, the mixture was warmed to room temperature and stirred at the same temperature for 66 hours. The reaction was checked by HPLC, and compound (I) was produced at 93.0 area %. No impurity (A) was detected.

[0074] [Example 13] Synthesis of Compound (I) A mixture of 0.5 g of compound (II), 0.63 g of compound (IIIa), 0.39 g of 3-picoline and 5 mL of dimethylformamide was cooled on ice, and 0.26 g of methanesulfonyl chloride was slowly added dropwise to the mixture while cooling on ice. After the addition, the mixture was warmed to room temperature and stirred at the same temperature for 2 hours. The reaction was checked by HPLC, and compound (I) was produced at 97.6% by area. No impurity (A) was detected.

[0075] [Example 14] Synthesis of Compound (I) A mixture of 0.5 g of compound (II), 0.63 g of compound (IIIa), 0.39 g of 3-picoline and 5 mL of N-methylpyrrolidone was cooled on ice, and 0.26 g of methanesulfonyl chloride was slowly added dropwise under ice cooling. After the dropwise addition, the mixture was warmed to room temperature and stirred at the same temperature for 2 hours. The reaction was checked by HPLC, and compound (I) was produced at 92.4 area %. No impurity (A) was detected.

[0076] [Comparative Example 1] Synthesis of Cyclaniliprole To a mixture of 1.11g of compound (V), 1.0g of compound (IIIa), 0.81g of 3-picoline and 10mL of acetone, 0.5g of methanesulfonyl chloride was slowly added dropwise at room temperature. After stirring overnight at the same temperature, the reaction was checked by HPLC, and 42.9% by area of ​​cyclaniliprole was produced. The amount of impurity (B) produced was 0.3% by area.

[0077] [Comparative Example 2] Synthesis of Cyclaniliprole To a mixture of 1.11g of compound (V), 1.0g of compound (IIIa), 0.81g of 3-picoline, and 10mL of acetonitrile, 0.5g of methanesulfonyl chloride was slowly added dropwise at room temperature. After stirring overnight at the same temperature, the reaction was checked by HPLC, and 79.9% by area of ​​cyclaniliprole was produced. The amount of impurity (B) produced was 5.3% by area.

[0078] [Comparative Example 3] Synthesis of Cyclaniliprole Compound (IIIb) 1.09g was slowly added dropwise to a mixture of compound (V) 1.11g, 3-picoline 0.78g, and acetone 13mL in an ice bath. After the addition, the mixture was warmed to room temperature and stirred overnight at the same temperature. The reaction was checked by HPLC, and cyclaniliprole was found to be produced at 73.0% by area. The amount of impurity (B) produced was 4.2% by area.

[0079] [Comparative Example 4] Synthesis of Cyclaniliprole Compound (V) 1.11g, 3-picoline 0.78g, acetonitrile 13mL, was slowly dripped with compound (IIIb) 1.09g in an ice bath. After dripping, the mixture was heated to room temperature and stirred overnight at the same temperature. The reaction was checked by HPLC, and cyclaniliprole was produced at 57.7% by area. The amount of impurity (B) produced was 6.4% by area.

[0080] Impurity (A) was not detected in Examples 1 to 14. Furthermore, unlike Comparative Examples 1 to 4, the cyclaniliprole of Example 9 obtained from compound (I) obtained by the method of the present invention did not show any generation of impurity (B), and it was possible to produce high-purity cyclaniliprole that meets the standards for an agricultural chemical raw material. The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2020-054157, filed on March 25, 2020, are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

1. A compound represented by formula (I) or a salt thereof: 【Chemistry 1】 A method for producing A compound represented by formula (II) or a salt thereof: 【Chemistry 2】 and a compound represented by formula (III) or a salt thereof: 【Chemistry 3】 [In formula (III), R is OH or halogen] in the presence of a condensing agent and / or a base, and the purity of the compound represented by formula (I) or a salt thereof obtained is 95% by weight or more, provided that the production method does not include a continuous process.

2. The method according to claim 1, wherein when R is OH, a compound represented by formula (II) or a salt thereof is reacted with a compound represented by formula (III) or a salt thereof in the presence of a condensing agent and a base.

3. The method according to claim 1, wherein when R is halogen, the compound represented by formula (II) or a salt thereof is reacted with the compound represented by formula (III) or a salt thereof in the presence of a base.

4. The process according to claim 1 or 2, wherein the condensing agent is a sulfonyl chloride.

5. The method according to any one of claims 1 to 4, wherein the base is one or more selected from the group consisting of pyridine, picoline, an alkali metal carbonate, and an alkali metal hydrogen carbonate.

6. In addition to the compound represented by formula (I) or a salt thereof obtained, a compound represented by the following formula (A) or a salt thereof is contained as an impurity: 【Chemistry 4】 The method according to any one of claims 1 to 5, wherein the content of the compound represented by formula (I) or a salt thereof and the compound represented by formula (A) or a salt thereof is 1% by weight or less based on the total amount of the compound represented by formula (I) or a salt thereof.

7. In addition to the compound represented by formula (I) or a salt thereof obtained, a compound represented by formula (A) or a salt thereof may be present as an impurity. 【Chemistry 5】 The method according to any one of claims 1 to 5, wherein the method is substantially free of

8. A method for producing cyclaniliprole, comprising producing a compound represented by formula (I) or a salt thereof by the method according to any one of claims 1 to 7, and reacting the compound represented by formula (I) or a salt thereof produced by the method with a brominating agent.

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