Method for producing phenyl esters

Abstract

To provide a method for efficiently producing a phenyl ester from a phenol and an aromatic carboxylic acid, involving dehydration, in the absence of an additive.SOLUTION: The present invention discloses a method for esterification from a phenol and an aromatic carboxylic acid without generation of by-products such as a salt. The method includes reacting these organic compounds with each other in the presence of a catalyst including an ion exchange resin and a boron compound as components, allowing the reaction to proceed, involving dehydration, through generation of a boric acid ester.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a phenyl ester from a phenol and an aromatic carboxylic acid, and a catalyst used in the phenyl esterification reaction. [Background technology]

[0002] The reaction to synthesize phenyl esters is known as an important reaction for constructing the main structures in the production of various chemical products such as electronic materials, pharmaceuticals, and agricultural chemicals. Generally, the reaction of directly converting phenol and aromatic carboxylic acid into a phenyl ester by dehydration has low reactivity, and therefore requires the addition of an additive or catalyst to dramatically improve the reactivity.

[0003] For example, a method for producing phenyl esters is known in which a carboxylic acid and a chloroformate are mixed in the presence of a base and then phenol is added (Patent Document 1). Alternatively, a method for producing phenyl esters is known in which various sulfonic acids are added to a carboxylic acid and then phenol is allowed to react with the mixture (Patent Document 1). However, these methods require the addition of bases or strong acids into the reaction vessel, which causes problems in the production process such as corrosion of the vessel. In addition, because the methods use additives such as chloroformates in the same amount as the raw materials, they generate large amounts of by-products derived from the additives as well as the target compound. Therefore, a lot of energy is required for the purification process of the product, and the disposal of the by-products from the purification process is also time-consuming and costly.

[0004] As a method for producing phenyl esters with fewer additives, a method for producing phenyl esters that combines boric acid with a mineral acid such as sulfuric acid has been reported (Non-Patent Document 1). Furthermore, a method for producing phenyl esters from carboxylic acids and phenols that combines sulfuric acid, boric acid, and dialkylmalonic acid is known (Patent Document 2). However, these methods also use sulfuric acid, which corrodes the production vessel and requires complicated post-treatment of the strong acid, and therefore cannot be said to be industrially useful.

[0005] As a method that does not use a base or strong acid, a method for producing a phenyl ester by reacting an acid anhydride with phenol using scandium triflate is known (Non-Patent Document 2). However, this method has problems such as the cost due to the use of a compound derived from scandium metal and the large amount of by-products generated due to the use of a dehydrating agent, and can be said to be an industrially disadvantageous method. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-342150 A [Patent Document 2] JP 2011-105667 A [Non-patent literature]

[0007] [Non-Patent Document 1] Tetrahedron.Lett.1971,37,3453 [Non-Patent Document 2] J. Org. Chem. 1996, 61, 4560 Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, conventional reactions using strong acids, bases, or metal complexes have problems in terms of both energy conservation and quality, such as corrosion of containers and disposal of by-product waste.

[0009] Furthermore, because additives are added in large proportions to the raw materials, there are issues from both the perspectives of energy conservation and quality, such as the cost of removing them and the degradation of the product and reduced yields due to their inclusion in the product as impurities.

[0010] The present invention has been made in consideration of the above circumstances, and has an object to provide a method for efficiently synthesizing a phenyl ester directly from a phenol and an aromatic carboxylic acid via dehydration under relatively mild reaction conditions by using an ion exchange resin instead of a strong acid and in the coexistence of a boron-containing catalyst such as boric acid or an alkoxyborane under metal-free conditions, and to provide a phenyl esterification catalyst by which a phenyl ester can be efficiently synthesized directly from a phenol and an aromatic carboxylic acid via dehydration under relatively mild reaction conditions without using a strong acid. [Means for solving the problem]

[0011] The present invention has the following aspects. [1] A method for directly producing a phenyl ester from a phenol and an aromatic carboxylic acid by dehydration, comprising the steps of: A method for producing a phenyl ester, comprising contacting the two organic compounds in the presence of a catalyst containing an ion exchange resin and a boron compound. [2] The method for producing a phenyl ester according to [1], wherein the ion exchange resin is made of a polymer having a sulfonic acid group on its surface. [3] The method for producing a phenyl ester according to [1] or [2], wherein the boron compound is selected from boric acid or an alkoxyborane. [4] The method for producing a phenyl ester according to any one of [1] to [3], wherein, among the boric acid or alkoxyborane, a boron compound represented by the following formula (i) is used:

[0012] [ka] (In formula (i), R 1 is an alkyl group, an aryl group, a hydroxyl group or an alkoxy group. In formula (i), R 2 and R 3 are each independently a hydrogen atom, an alkyl group, an aryl group, or a hydroxyl group. 2 and R 3 may be bonded to each other to form a ring.2 or R 3 Either one of the groups is a hydrogen atom, or R 2 and R 3 When they are bonded to each other to form a ring, R 1 is a hydroxyl group.) [5] The amount of the boron compound contained in the catalyst is in the range of 1 to 400 mg per 1 mmol of the substrate, which is the smaller of a phenol or an aromatic carboxylic acid; The method for producing a phenyl ester according to any one of [1] to [4], wherein the amount of the boron compound contained in the catalyst is 0.01 to 20 mass % based on the total mass of the substrate. [6] The method for producing a phenyl ester according to any one of [1] to [5], wherein the aromatic carboxylic acid is a compound represented by the following formula (1), and the phenol is a compound represented by the following formula (2): [ka] (In formula (1), R 4 ~R 7 , and R 8 Each of R independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a nitro group. These groups may further have a substituent such as an alkyl group, an aryl group, or a halogen atom. 4 ~R 7 , and R 8 Two positions selected from may be bonded to each other to form a ring. [ka] (In formula (2), R 9 ~R 12 , and R 13 Each of R independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a nitro group. These groups may further have a substituent such as an alkyl group, an aryl group, or a halogen atom. 9 ~R 12 , and R 13 Two positions selected from may be bonded to each other to form a ring. [7] A phenyl esterification catalyst for directly synthesizing a phenyl ester from a phenol and an aromatic carboxylic acid while accompanying dehydration, the catalyst comprising an ion exchange resin and a boron compound as components. [8] The phenyl esterification catalyst according to [7], wherein the ion exchange resin is a strongly acidic ion exchange resin containing a sulfonic acid group. [9] The phenyl esterification catalyst according to [7] or [8], wherein the boron compound is selected from boric acid or an alkoxyborane.

[10] The phenyl esterification catalyst according to any one of [7] to [9], wherein, among the boric acid or alkoxyborane, a boron compound represented by the following formula (i) is used:

[0013] [ka] (In formula (i), R 1 is an alkyl group, an aryl group, a hydroxyl group or an alkoxy group. In formula (i), R 2 and R 3 are each independently a hydrogen atom, an alkyl group, an aryl group, or a hydroxyl group. 2 and R 3 may be bonded to each other to form a ring. 2 or R 3 Either one of the groups is a hydrogen atom, or R 2 and R 3 When they are bonded to each other to form a ring, R 1 is a hydroxyl group.) Effect of the Invention

[0014] According to the present invention, there is provided a method for efficiently producing an aromatic carboxylic acid phenyl ester from a phenol and an aromatic carboxylic acid under relatively mild reaction conditions accompanied by dehydration, without the concomitant presence of an additive such as a strong acid, by using a catalyst containing an ion exchange resin and a boron compound as constituent elements, and a catalyst containing an ion exchange resin and a boron compound as constituent elements which can efficiently produce an aromatic carboxylic acid phenyl ester from a phenol and an aromatic carboxylic acid under relatively mild reaction conditions accompanied by dehydration, without the concomitant presence of an additive. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing one embodiment of a method for producing a phenyl ester of the present invention using a catalyst containing an ion exchange resin and a boron compound as components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention will be described in detail below. The materials and the like exemplified in the following description are merely examples, and the present invention is not limited thereto, and can be appropriately modified and implemented within the scope of the present invention. In this specification, the use of "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0017] The method for producing a phenyl ester of the present invention is a method for producing a phenyl ester by dehydration from a phenol and an aromatic carboxylic acid. Hereinafter, the phenol and the aromatic carboxylic acid are also referred to as "substrates". In one embodiment of the method for producing a phenyl ester of the present invention, a substrate is reacted under dehydrating conditions using a batch reactor in the presence of a catalyst composed of an ion exchange resin and a boron compound (hereinafter also referred to as an "esterification catalyst"), and phenyl esters are produced at a predetermined reaction temperature.

[0018] <Esterification catalyst> The esterification catalyst in the present invention is composed of an ion exchange resin and a boron compound. Even without the coexistence of an additive, the substrate can be efficiently converted to a phenyl ester through a dehydration reaction. In addition, since the ion exchange resin and the boron compound do not decompose before or after the reaction, they can be reused by filtering and recovering the solution after the reaction.

[0019] Ion exchange resins are easy to use, and are stable and easy to recover and reuse, as polymer resins with a styrene skeleton with sulfonic acid groups on the surface. Examples of such polymers include sulfonic acid group-containing ion exchange resins for catalysts, and among these, strong acidic sulfonic acid group-containing ion exchange resins for catalysts. Examples of such resins include Amberlyst15DRY and Amberlyst15JWET manufactured by Organo Corporation. Both Amberlyst15DRY and Amberlyst15JWET are catalog products with a total exchange capacity of 1 or more when wet, and 4 or more per dry resin. The total exchange capacity is determined by actually passing ions through the resin and titrating the amount of exchange. Since resins are susceptible to thermal decomposition at temperatures above 120°C, it is desirable to set the reaction conditions so that the reaction temperature does not exceed 120°C.

[0020] Various boron compounds can be used, from boric acid to alkyl-substituted boric acid, aryl-substituted boric acid, etc., as long as they have one boron-hydroxyl group structure, and it is believed that aromatic carboxylic acids and boron compounds first react to produce boric acid esters, which then react with phenol to produce phenyl esters. Therefore, it is believed that boron compounds in which alkyl or aryl groups are directly substituted on the boron atom of a boron compound contribute more to improving catalytic activity than hydroxyl or alkoxy groups.

[0021] An example of such a boron compound is a boron compound represented by the following formula (i).

[0022] [ka]

[0023] In formula (i), R 1 is an alkyl group, an aryl group, a hydroxyl group or an alkoxy group. In formula (i), R 2 and R 3 are each independently a hydrogen atom, an alkyl group, an aryl group, or a hydroxyl group. 2 and R 3 may be bonded to each other to form a ring. 2 or R 3 Either one of the groups is a hydrogen atom, or R 2 and R 3 When they are bonded to each other to form a ring, R 1 is a hydroxyl group.

[0024] R 1 In the above formula, examples of the alkyl group include linear or branched alkyl groups having 1 to 15 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, and an n-octyl group. The alkyl group may have a substituent such as an aryl group or a halogen atom. The aryl group may be, for example, a monocyclic, polycyclic or fused ring aromatic hydrocarbon group having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms. Specific examples include a phenyl group, a tolyl group, a xylyl group, anisyl group, a nitrophenyl group, a naphthyl group, a methylnaphthyl group, an anthryl group, a phenanthryl group, a biphenyl group, etc. The aryl group may have a substituent such as an alkyl group or a halogen atom. Examples of the alkoxy group include a methoxy group, an ethoxy group, a t-butoxy group, etc. The alkoxy group may have a substituent such as an alkyl group or a halogen atom.

[0025] R 2 and R 3In the above formula, examples of the alkyl group include linear or branched alkyl groups having 1 to 15 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, and an n-octyl group. The alkyl group may have a substituent such as an aryl group or a halogen atom. The aryl group may be, for example, a monocyclic, polycyclic or fused ring aromatic hydrocarbon group having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms. Specific examples include a phenyl group, a tolyl group, a xylyl group, anisyl group, a nitrophenyl group, a naphthyl group, a methylnaphthyl group, an anthryl group, a phenanthryl group, a biphenyl group, etc. The aryl group may have a substituent such as an alkyl group or a halogen atom.

[0026] R 2 and R 3 are bonded together to form R 2 and R 3 The ring formed by each of them together with the carbon atom to which they are bonded may be an aromatic ring or an alicyclic ring. Examples of the aromatic ring include a monocyclic, polycyclic or fused aromatic hydrocarbon ring having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms. Examples of the alicyclic ring include a monocyclic, polycyclic or fused saturated hydrocarbon ring having 3 to 10 carbon atoms. In a preferred embodiment, the boron compound is phenylboronic acid, boric acid, or isopropylboronic acid. Two or more kinds of boron compounds may be used in combination.

[0027] The esterification catalyst can be prepared by mixing the ion exchange resin and the boron compound in a solvent. The amount of the ion exchange resin and the boron compound used in preparing the esterification catalyst may be within a certain range relative to the substrate, as described below. In addition, a wide range of solvents can be used for preparing the esterification catalyst, including aromatic compounds such as toluene and xylene, aliphatic compounds such as octane and heptane, and ketones such as isobutyl methyl ketone. Solvents that do not decompose under the conditions of the ester synthesis reaction and are in a liquid state under the reaction conditions of the ester synthesis reaction can be suitably used. The solvent is preferably 0.1 to 1000 times, more preferably 1 to 100 times, in mass ratio to the total mass of the substrate (total mass of phenols and aromatic carboxylic acid) so that it can be used as a liquid medium in the esterification reaction described below. The solution containing the esterification catalyst obtained by mixing the ion exchange resin and the boron compound in the solvent can be used as it is as a reaction solution for producing a phenyl ester.

[0028] <Substrate> The substrates in the production method of the present invention are phenols and aromatic carboxylic acids. The aromatic carboxylic acids are not particularly limited as long as they can produce phenyl esters in the production method of the present invention. The phenols are also not particularly limited as long as they are allenols having various substituents. Examples of substrates include compounds (compound 1) having a carboxylic acid attached to an aromatic ring, such as a compound represented by the following formula (1) (hereinafter also referred to as "compound (1)") and a compound represented by the following formula (2) (hereinafter also referred to as "compound (2)"), and arenol compounds (compound 2) having various substituents attached to an aromatic ring.

[0029] [ka]

[0030] [ka]

[0031] In formula (1) and formula (2), R 4 ~R 12 , and R 13 each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a nitro group. These groups may further have a substituent such as an alkyl group, an aryl group, or a halogen atom. In formula (1), R 4 ~R 7 , and R 8 Two positions selected from the above may be bonded to each other to form a ring. In formula (2), R 9 ~R 12 , and R 13 Two positions selected from the above may be bonded to each other to form a ring.

[0032] In formula (1) and formula (2), R 4 ~R 12 , and R 13 Examples of the alkyl group which may have a substituent include linear or branched alkyl groups having a carbon number of 1 to 15. Specific examples include a methyl group, an ethyl group, a propyl group, and an n-octyl group.

[0033] In formula (1) and formula (2), R 4 ~R 12 , and R 13 Examples of the alkoxy group which may have a substituent include a linear or branched alkyl group having a carbon number of 1 to 15. Specific examples include a methoxy group, an ethoxy group, an i-propyl group, and a t-butyl group.

[0034] Specific examples of the substrate include aromatic carboxylic acids such as benzoic acid, 4-methylbenzoic acid, 4-methoxybenzoic acid, and 3-methylbenzoic acid. Examples of phenols include phenol, 4-methylphenol, 4-methoxyphenol, 4-bromophenol, and 4-nitrophenol.

[0035] <Esterification> By mixing the substrates in the presence of an esterification catalyst, the esterification reaction proceeds with dehydration of the substrates. An example of a method for contacting substrates together under dehydrating conditions is to place the substrates together and a liquid medium in a container and stir them in air.

[0036] The amount of the esterification catalyst used for the ion exchange resin is, for example, 1 to 400 mg, preferably 10 to 200 mg, more preferably 50 to 150 mg per millimole of the phenols or aromatic carboxylic acid used in the same amount. Usually, it is preferable to use the same amount of the phenols and aromatic carboxylic acid as the substrate. However, the ratio of the phenols and aromatic carboxylic acid is not limited as long as the phenyl ester can be produced. When the amount of either the phenols or the aromatic carboxylic acid used is small, the amount of the esterification catalyst used may be within the above range per millimole of the smaller substrate. When the amount of the esterification catalyst used is equal to or greater than the lower limit of the above range, the esterification reaction of the substrate is more likely to proceed. When the amount of the esterification catalyst used exceeds the upper limit of the above range, the added catalyst may hinder stirring, resulting in a decrease in catalytic activity.

[0037] The amount of the esterification catalyst used, in the case of a boron compound, is, for example, 0.01 to 20 mass %, preferably 0.01 to 10 mass %, and more preferably 0.05 to 5 mass %, relative to the total mass (100 mass %) of the substrate. When the amount of the esterification catalyst used is equal to or greater than the lower limit of the above range, the esterification reaction of the substrate is more likely to proceed. When the amount of the esterification catalyst used exceeds the upper limit of the above range, the added catalyst may hinder stirring, resulting in a decrease in catalytic activity.

[0038] As the liquid medium, all common organic solvents can be used, for example, toluene, octane, etc. These liquid media may be used alone or in combination of two or more kinds. The amount of the liquid medium used is preferably 0.1 to 1000 times, and more preferably 1 to 100 times, the total mass of the substrate, in terms of mass ratio.

[0039] There are no particular limitations on the reaction conditions for the esterification reaction, but the reaction temperature is preferably 0 to 150°C, more preferably 80 to 120°C. The reaction time depends on the amount of catalyst used, the reaction temperature, etc. and cannot be generally determined, but is usually within the range of 1 to 40 hours, preferably within the range of 6 to 18 hours.

[0040] The esterification reaction is preferably carried out in the absence of additives. By carrying out the esterification reaction in the absence of additives, the purity of the product is increased. In addition, the amount of energy input during purification after the reaction can be reduced.

[0041] Since the esterification reaction is known to be an equilibrium reaction involving dehydration, it is desirable to design a reactor that incorporates a mechanism for promoting dehydration from the reaction system, such as the Dean-Stark reaction. For example, it is effective to install a desiccant such as a molecular sieve at the top of the reaction vessel and incorporate a mechanism for promoting dehydration during reflux into the reactor together with the catalyst.

[0042] After completion of the reaction, the resulting product (phenyl ester compound, etc.) can be isolated by a conventional method such as distillation, chromatographic separation, recrystallization, or sublimation.

[0043] <product> As described above, the phenols and aromatic carboxylic acids as substrates are esterified with dehydration under specific reaction conditions in the presence of a liquid medium to obtain phenyl ester compounds as shown in the following formula (3).

[0044] [ka]

[0045] In formula (3), R 4 ~R 12 , and R 13are the same as defined above.

[0046] Specific examples of the resulting phenyl ester compounds include phenyl benzoate, (4-methyl)phenyl benzoate, (3-methyl)phenyl benzoate, (2-methyl)phenyl benzoate, (4-methoxy)phenyl benzoate, (4-bromo)phenyl benzoate, (4-chloro)phenyl benzoate, and (4-nitro)phenyl benzoate.

[0047] In the present invention described above, by using the above-mentioned esterification catalyst, phenol can be efficiently esterified under relatively mild conditions without the coexistence of an additive, and a phenyl ester compound can be obtained in high yield without producing by-products accompanied by dehydration. In addition, the above-mentioned esterification catalyst is an ion exchange resin and a boron compound, so that it does not decompose during esterification and can be reused. EXAMPLES

[0048] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. The conversion rate and yield in the esterification were calculated from the results of gas chromatography using the following formulas. Conversion rate (%) = (1 - moles of remaining raw material / moles of raw material used) x 100 Yield (%) = (number of moles of target compound / number of moles of raw material used) x 100

[0049] The chemical reaction formula in one embodiment of the method for producing a phenyl ester of the present invention is shown below. [ka] Example 1 A stirrer was placed in a 30φ test tube, 114 mg of Amberlyst 15DRY (Organo) was placed as an ion exchange resin, 30.5 mg of phenylboronic acid was placed as a boron compound, 941 mg of phenol (Tokyo Chemical Industry Co., Ltd.) and 1221 mg of benzoic acid (Tokyo Chemical Industry Co., Ltd.) were placed as substrates, and 5 mL of toluene (Nacalai Tesque, Inc.) was added as a liquid medium. The tube was connected to a reflux tube equipped with molecular sieves 4A and incubated under argon at 1 atm for 1 2 The mixture was stirred at 0° C. for 16 hours. Then, 373.3 mg of n-tetradecane (manufactured by Nacalai Tesque, Inc.) was added as an internal standard, and gas chromatography measurement was performed. As a result, the conversion rate was 77%, the yield of phenyl benzoate was 72%, and no other by-products were detected.

[0050] Example 2 Except for using boric acid instead of phenylboronic acid, the reaction was carried out under the same conditions as in Example 1. As a result, the conversion was 82% and the yield of phenyl benzoate was 74%.

[0051] Example 3 The reaction was carried out under the same conditions as in Example 1, except that Amberlyst 15JWET was used instead of Amberlyst 15DRY as the ion exchange resin. As a result, the conversion rate was 67%, and the yield of phenyl benzoate was 63%. From this result, the reactivity of the ion exchange resin is not affected whether or not it contains moisture within the resin.

[0052] Comparative Example 1 Of the catalysts, no ion exchange resin was used, and the reaction was carried out under the same conditions as in Example 1. As a result, the conversion rate was 0%.

[0053] Comparative Example 2 The solvent was replaced with toluene. Rue Except for using an ether, the reaction was carried out under the same conditions as in Example 1. As a result, no phenyl benzoate was detected.

[0054] Comparative Example 3 The reaction was carried out under the same conditions as in Example 1, except that the reaction temperature was 80° C. As a result, the conversion was 10%, and the yield of phenyl benzoate was 8%.

[0055] The results of Examples 1 to 3 and Comparative Examples 1 to 3 in which phenol was used as the substrate are shown in Table 1.

[0056] [Table 1]

[0057] Table 2 shows Examples 4 to 9 in which esterification reactions using substrates in which various substituents were substituted on the aromatic ring of phenol were carried out under the same conditions as in Example 1, except that various substituted phenols were used instead of phenol. [Table 2]

[0058] Example 10 Except for using 4-acetamidophenol instead of phenol, the reaction was carried out under the same conditions as in Example 1. As a result, the conversion was 10%, and the yield of the target ester was 5%.

[0059] Comparative Example 4 Among the catalysts, no boron compound was used, and the reaction was carried out under the same conditions as in Example 10. As a result, the conversion rate was 0%.

[0060] Comparing Examples 1 to 3 with Example 10 and Comparative Examples 1 to 3 with Comparative Example 4, it was confirmed that phenyl esters can be obtained in high yields by using a catalyst containing an optimized ion exchange resin and a boron compound and by carrying out an esterification reaction in a reaction vessel and at a reaction temperature that promotes dehydration. From the results of Examples 4 to 9, it was confirmed that the present catalyst system is also effective for various substituted phenols and substituted aromatic carboxylic acids. [Industrial Applicability]

[0061] The reaction for synthesizing phenyl esters is known as an important reaction for forming a main structure in the production of various chemical products such as electronic materials, pharmaceuticals, agricultural chemicals, etc. According to the present invention, a phenyl ester compound can be efficiently produced using phenol and aromatic carboxylic acid as raw materials, with only water as a by-product, and with a simple catalyst mixing, while accompanying dehydration. Therefore, the present invention can be widely used, mainly in the fields of intermediates for pharmaceuticals, agricultural chemicals, etc., and raw materials for resins, etc.

Claims

1. A method for directly producing a phenyl ester from a phenol and an aromatic carboxylic acid by dehydration, comprising the steps of: The aromatic carboxylic acid is a compound represented by the following formula (1), and the phenol is a compound represented by the following formula (2), A method for producing a phenyl ester, comprising contacting the phenol with an aromatic carboxylic acid in the presence of a catalyst containing a strongly acidic ion exchange resin for sulfonic acid group-containing catalysts and a boron compound selected from boric acid or an alkoxyborane, and toluene, and reacting the phenol with the aromatic carboxylic acid at a temperature higher than 80°C and not higher than 120°C. 【Chemistry 1】 (In formula (1), R ４ ~R ７ , and R ８ Each of R independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a nitro group. These groups may further have a substituent such as an alkyl group, an aryl group, or a halogen atom. ４ ~R ７ , and R ８ Two positions selected from may be bonded to each other to form a ring.) 【Chemistry 2】 (In formula (2), R ９ ~R １２ , and R １３ Each of R independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a nitro group. These groups may further have a substituent such as an alkyl group, an aryl group, or a halogen atom. ９ ~R １２ , and R １３ Two positions selected from may be bonded to each other to form a ring.)

2. The method for producing a phenyl ester according to claim 1, wherein the ion exchange resin is made of a polymer having a sulfonic acid group on its surface.

3. The method for producing a phenyl ester according to claim 1 or 2, wherein a boron compound represented by the following formula (i) is used as the boric acid or alkoxyborane: 【Chemistry 3】 (In formula (i), R １ is an alkyl group, an aryl group, a hydroxyl group or an alkoxy group. In formula (i), R ２ and R ３ are each independently a hydrogen atom, an alkyl group, an aryl group, or a hydroxyl group. ２ and R ３ may be bonded to each other to form a ring. ２ Or R ３ is a hydrogen atom, or ２ and R ３ When they are bonded to each other to form a ring, R １ is a hydroxyl group.)

4. The method for producing a phenyl ester according to any one of claims 1 to 3, wherein the aromatic carboxylic acid is benzoic acid and the phenol is phenol.

5. the amount of the boron compound contained in the catalyst is in the range of 1 to 400 mg per 1 mmol of the substrate, which is the smaller of a phenol or an aromatic carboxylic acid; The method for producing a phenyl ester according to any one of claims 1 to 4, wherein the amount of the boron compound contained in the catalyst is 0.01 to 20 mass% based on the total mass of the substrate.

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