Method for producing (meth)acrylic acid esters

Abstract

To provide a method for producing a methacrylate of a hydroxy benzophenone.SOLUTION: The present invention discloses a method for producing a methacrylate of the following formula (2), by reacting an alcohol with a methacrylic acid anhydride in the presence of a metal or a salt thereof. (In the formula (2), R1 is a hydrogen atom, a halogen atom, a C1-10 alkyl group, or a C1-10 alkoxy group, and R2 is a hydrogen atom or a methyl group).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropionate. The reaction of phenone or its derivatives with (meth)acrylic anhydride gives 2-hydroxy- 4'-(2-hydroxyethoxy)-2-methylpropiophenone or its derivatives ( The present invention relates to a method for producing a meth)acrylic acid ester. [Background technology]

[0002] 2-Hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone As a method for producing a (meth)acrylic ester of the compound or its derivative, Patent Document 1 describes two methods: -Hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (hereinafter Dissolve methacrylic acid (hereinafter referred to as HHMP) in dichloromethane and add it with stirring at 0°C. Add the chloride dissolved in dichloromethane dropwise and stir at 0°C for 1 hour. This method generates hydrochloric acid and requires large amounts of solvent and amine. In addition, since this is a reaction that generates a lot of heat, in order to continue the reaction at a low temperature, The rate of acid chloride addition must be slow. And if the reactor is large, the amount of acid chloride added will be large compared to the volume. As a result, the contact area with the heat transfer medium becomes smaller, and the addition rate becomes significantly slower, which is not suitable for industrial use. It cannot be said to be a reaction. Patent Document 2 describes a method for dissolving HHMP and methacrylic anhydride in methylene chloride. Then, a solution of triethylamine in methylene chloride was added dropwise at 25°C. Patent Document 3 describes a method in which HHMP, tetrahydrofuran, Addition of methacrylic anhydride to a mixture of triethylamine and 4-dimethylaminopyridine The method described above involves stirring the mixture at 23°C for 5 hours. It requires equimolar amounts of amine and acrylic anhydride, and precise temperature control is also required. According to the investigations of the present inventors, in this method, the methacrylic acid ester is The carboxyl group of (meth)acrylic acid is attached to the unsaturated bond of the acryloyl group or acryloyl group. It was found that in addition to the production of Kel-added compounds, the products also partially decomposed. All of the above methods require time and energy to recover large amounts of solvent. In addition, because amine is used, column chromatography is required to remove residual amine. It requires purification such as [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 063943 [Patent Document 2] International Publication No. 2017 / 057537 [Patent Document 3] JP 2018-70868 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] The present invention relates to 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropionate. The reaction of phenone or its derivatives with (meth)acrylic anhydride gives 2-hydroxy- 4'-(2-hydroxyethoxy)-2-methylpropiophenone or its derivatives ( In the production of methacrylic esters, even with a small amount of solvent, the production of by-products is minimal, and the process is efficient. The purpose is to efficiently acquire the object. [Means for solving the problem]

[0005] The above problems are solved by the present invention described below. [1] It is composed of lithium, magnesium, calcium, barium, and strontium. In the presence of at least one metal selected from the group consisting of a cation exchanger represented by the following formula (1) The compound represented by the following formula (2) is obtained by reacting alcohol with (meth)acrylic anhydride. A method for producing meth)acrylic acid esters. [ka] (In formula (1), R 1 is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a carbon atom. It represents an alkoxy group having a prime number of 1 to 10. [ka] (In formula (2), R 1 is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a carbon atom. R represents an alkoxy group having a prime number of 1 to 10; 2 represents a hydrogen atom or a methyl group.) [2] The above-mentioned lithium, magnesium, calcium, barium, and strontium are selected from the group consisting of at least one metal or a salt thereof and an alcohol represented by the formula (1), The method is characterized in that the solvent is used in an amount 5 times or less than the total mass of meth)acrylic anhydride. A method for producing a (meth)acrylic acid ester according to [1]. [3] The above-mentioned lithium, magnesium, calcium, barium, and strontium are selected from the group consisting of at least one metal or a salt thereof and an alcohol represented by the formula (1), The method is characterized in that the solvent is used in an amount three times or less than the total mass of meth)acrylic anhydride. A method for producing a (meth)acrylic acid ester according to [1]. [4] The salt is an oxide, hydroxide, carbonate, hydrogencarbonate, or organic acid salt. The method for producing a (meth)acrylic acid ester according to any one of [1] to [3]. [5] The salt is at least one oxide selected from the group consisting of lithium, magnesium, and calcium. [1] to [3], characterized in that the compound is a compound, a hydroxide, a carbonate, a hydrogen carbonate, or an organic acid salt. A method for producing the (meth)acrylic acid ester according to any one of claims 1 to 7. [6] Any one of [1] to [5], characterized in that the reaction temperature is 40 to 100°C. The method for producing the (meth)acrylic acid ester according to claim 1 [7] Contains a structure represented by the following formula (1), and when the total amount is 100%, the Michael adduct is 0 A (meth)acrylic acid ester represented by the following formula (2), having a content of 0.2% or less: [ka] (In formula (1), R 1 is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a carbon atom. It represents an alkoxy group having a prime number of 1 to 10. [ka] (In formula (2), R 1 is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a carbon atom. R represents an alkoxy group having a prime number of 1 to 10; 2 represents a hydrogen atom or a methyl group.) Effect of the Invention

[0006] According to the method for producing a (meth)acrylic acid ester of the present invention, the formation of a Michael adduct is suppressed. 2-Hydroxy-4'-(2-hydroxyethoxy)-2-methyl (Meth)acrylic acid esters of propiophenone or its derivatives can be obtained efficiently and in good yield. In addition, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methyl Reduce the purification burden of (meth)acrylic acid esters of propiophenone or its derivatives come. [Brief description of the drawings]

[0007] [Figure 1] 1H-NMR measurement results in Production Example 11 of (meth)acrylic acid ester. [Diagram 2] 1H-NMR measurement results in Comparative Example 4 for the production of (meth)acrylic acid ester. [Diagram 3] 1H-NMR measurement results in Comparative Example 5 for the production of (meth)acrylic acid ester. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described in detail. In this specification, (meth)acrylic acid refers to acrylic acid and / or methacrylic acid. (Meth)acrylic anhydride means acrylic anhydride and / or methacrylic and (meth)acrylic acid ester means acrylic acid ester and / or The Michael adduct is a methacrylic acid ester represented by the formula (2). ) The unsaturated bond of the methacryloyl group or acryloyl group of the acrylic ester (meth) ) refers to a compound formed by Michael addition of the carboxy group of acrylic acid.

[0009] In the present invention, an alcohol represented by the following formula (1) is reacted with (meth)acrylic anhydride. This reaction produces a (meth)acrylic acid ester represented by the following formula (2). [ka] (In formula (1), R 1 is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a carbon atom. It represents an alkoxy group having a prime number of 1 to 10. [ka] (In formula (2), R 1 is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a carbon atom. R represents an alkoxy group having a prime number of 1 to 10; 2 represents a hydrogen atom or a methyl group.)

[0010] R of the alcohol represented by formula (1) 1 From the viewpoint of corrosiveness, hydrogen atoms and carbon atoms with 1 to 1 Preferably, the alkyl group has 10 carbon atoms or the alkoxy group has 1 to 10 carbon atoms. From the viewpoint of compound stability, R 1 and / or R 2 is preferably a hydrogen atom or a methyl group. From the viewpoint of stability, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methyl Propiophenone is most preferred.

[0011] The (meth)acrylic acid ester represented by the formula (2) can be produced by the use of lithium, magnesium, At least one metal selected from calcium, barium, and strontium, or a salt thereof The reaction is carried out in the presence of a catalyst such as lithium, magnesium, calcium, etc. Preferably, the metal is at least one selected from the group consisting of sodium and tungsten, and more preferably a salt thereof. Salts include oxides, hydroxides, carbonates, bicarbonates, sulfates, chlorides, nitrates, and phosphates. salts with inorganic acids such as borates; salts with organic acids such as acetates, (meth)acrylates, and benzoates acid salts; acetylacetonates, complex salts such as cyclopentadienyl complexes, and the like. From the viewpoint of activity, the oxidation of lithium, magnesium, calcium, barium, and strontium The preferred are hydroxides, carbonates, hydrogen carbonates, chlorides, and organic acid salts, and do not contain halogens. Therefore, oxides, hydroxides, carbonates, hydrogen carbonates, and organic acid salts are more preferable. These may be entirely soluble, or partly soluble. In the reaction, the above-mentioned catalyst compound may be used in the system. The catalyst may be used alone or in combination of two or more kinds. For example, the total amount is charged to the reactor at first, or a portion is charged at first and the remainder is fed later. Examples of methods include: The amount of catalyst used is 0.0001 to 0.002 moles relative to the alcohol represented by formula (1). In order to ensure smooth reaction, the molar ratio is preferably 0.0005 or more. On the other hand, from the viewpoint of removing the catalyst and suppressing side reactions, This molar ratio is preferably 0.2 times or less, and more preferably 0.1 times or less.

[0012] The amount of (meth)acrylic anhydride used is determined based on the moles of the alcohol represented by the following formula (1): The ratio is 0.5 to 5 times. In terms of the yield of (meth)acrylic acid ester based on alcohol, This molar ratio is preferably 1 or more, more preferably 1.1 or more, It is more preferable that the ratio is 1.2 times or more. In addition, in order to reduce the burden of treating the remaining (meth)acrylic anhydride at the end of the reaction, The ratio is preferably 2 times or less, more preferably 1.5 times or less, and more preferably 1.3 times or less. It is even more preferable that:

[0013] In the present invention, a solvent can be used. Examples of the solvent include hexane, Aliphatic hydrocarbons such as heptane, pentane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene Aromatic hydrocarbons; diethyl ether, diisopropyl ether, methyl tert-butyl ether Ethers such as ether, tetrahydrofuran, etc.; acetone, methyl ethyl ketone, diisopropyl Ketones such as propyl ketone and methyl isobutyl ketone can be used. Acetone, methyl ethyl ketone, diisopropyl ketone, methyl isobutyl ketone, etc. The amount of the solvent used is preferably 100%. At least one metal selected from the group consisting of tungsten, tungsten, strontium, and a salt thereof, and a compound represented by the formula (1) 0.01 to 10 times the total mass of the alcohol represented by the formula (I) and (meth)acrylic anhydride However, from the viewpoint of reaction rate and purification load, the amount of solvent used is preferably 3 times or less. From the viewpoint of the dissolution amount, the amount of the solvent used is preferably 0.05 times or more. , 0.1 times or more is more preferable.

[0014] The reaction temperature can be in the range of 0 to 130°C. The reaction can proceed smoothly. Therefore, the reaction temperature is more preferably 20° C. or higher, and even more preferably 40° C. or higher. In order to suppress side reactions, the reaction temperature is preferably 110° C. or less, and more preferably 100° C. or less. It is preferable that the temperature is 90° C. or lower, and more preferable that the temperature is 90° C. or lower.

[0015] The reaction time may be appropriately determined based on the charge ratio and reaction temperature, but is usually 0.5 to 48 hours. The time when the conversion rate of the alcohol represented by formula (1) reaches 70% or more is preferable, and the time when the conversion rate reaches 90% or more is preferable. On the other hand, from the viewpoint of productivity, the reaction time is preferably 18 hours or less. , more preferably 12 hours or less, and even more preferably 8 hours or less.

[0016] In the present invention, a polymerization inhibitor can be used. The polymerization inhibitor is introduced into the reactor. However, it can also be introduced into piping, the top of a reflux cooling tower, or midway through the tower. Polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, and benzoxazole. Quinone polymerization inhibitors such as 2,6-di-tert-butylphenol, 2,4-di- tert-Butylphenol, 2-tert-butyl-4,6-dimethylphenol, 2 ,6-Di-tert-butyl-4-methylphenol, 2,4,6-tri-tert- Alkylphenol-based polymerization inhibitors such as ethylphenol, alkylated diphenylamines, N Amine-based polymerization inhibitors such as N'-diphenyl-p-phenylenediamine and phenothiazine , 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzo Zoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl and 4-acetate Hindered amines such as 2,2,6,6-tetramethylpiperidine-N-oxyl Polymerization inhibitors, metallic copper, copper sulfate, copper dimethyldithiocarbamate, diethyldithiocarbamate Copper dithiocarbamate polymerization inhibitors such as copper dithiocarbamate and copper dibutyldithiocarbamate These polymerization inhibitors may be used alone or in combination of two or more. Good too. The amount of polymerization inhibitor to be added depends on the type and conditions, but it is usually 0.01 to 0.01% by weight of the reaction solution. It is used in the range of 1 to 10,000 ppm. Also, oxygen-containing gas is bubbled into the reaction solution. By this, the polymerization inhibition effect may be improved.

[0017] There are two ways to charge the raw materials into the reactor: 1) charging all the raw materials at once before the reaction; ) A method in which one of the raw materials is charged in its entirety into the reactor, and the other raw material is charged after the other raw material; 3) A method in which one of the raw materials is charged in its entirety into the reactor, and the other raw material is charged after the other raw material; 4) All of the raw materials are charged into the reactor and only a portion of the other raw material is charged. In the case of partial charging, the remaining raw materials can be added in portions or in separate portions after the start of the reaction. may be supplied in any manner, including continuously.

[0018] As a reaction method, for example, all raw materials are charged into a single reactor and the reaction is completed. Batch type, continuous type in which raw materials are continuously fed into a reactor and reacted continuously, and continuous type in which a reactor and a mixing tank are used. The raw materials are circulated between the reactor and the blending tank while reacting in the reactor. The reaction may be carried out while recovering the by-product (meth)acrylic acid. The pressure may be reduced, atmospheric, or increased. The reaction solution is concentrated, distilled, washed, treated with an adsorbent, crystallized, or the like to obtain the product represented by formula (2). It is possible to purify a (meth)acrylic acid ester represented by the following formula:

[0019] If (meth)acrylic anhydride remains after the reaction is complete, it can be removed by distillation or extraction. It may be removed by removing the reaction product with compounds that react easily with (meth)acrylic anhydride, such as water and alcohol. The reaction may be carried out to convert the compound into a (meth)acrylic acid ester or (meth)acrylic acid. It reacts with a basic substance and an acidic substance or an aqueous solution thereof to produce (meth)acrylic acid or (meth)acrylic acid. The (meth)acrylic acid ester and (meth)acrylic acid salt may be formed. Salts of acrylic acid and (meth)acrylic acid can be removed by the above-mentioned distillation, extraction, and washing. Alcohols include methyl alcohol, ethyl alcohol, and n-propyl alcohol. Coal, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, Linear or branched chain aliphatic alcohols such as tert-butyl alcohol and isobutyl alcohol Unsaturated alcohols such as choline and allyl alcohol, cyclopentanol, cyclohexanoic acid cyclic alcohols such as phenol, aromatic alcohols such as phenol and benzyl alcohol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol Polyhydric alcohols such as 1,3-butanediol, 1,4-butanediol, and glycerin Among these alcohols, the generated (meth)acrylic acid From the viewpoint of removing esters, alcohols having 4 or less carbon atoms are preferred, and methyl alcohol or , ethyl alcohol is more preferred.

[0020] The temperature for the alcohol treatment is preferably in the range of 0 to 100° C. In terms of the heat treatment time, The treatment temperature is preferably 20° C. or higher, and more preferably 40° C. or higher. From the viewpoint of suppressing the reaction, the treatment temperature is preferably 100° C. or less, more preferably 80° C. or less. It is.

[0021] The treatment temperature for converting the (meth)acrylic acid salt is preferably in the range of 0 to 100° C. From the viewpoint of treatment time, the treatment temperature is preferably 10° C. or higher, and more preferably 20° C. or higher. On the other hand, in order to suppress polymerization and side reactions, the treatment temperature is preferably 80°C or less, and more preferably 60°C or less. The following is more preferred:

[0022] These treatments can be carried out with the catalyst remaining or after it has been removed by washing or extraction. The washing and extraction methods include those described above. In these treatments, a solvent inert to the reaction may be used. Examples of the inert solvent include: The amount of the solvent used is the (meth)acrylic acid ester represented by formula (2). The amount can be 0.1 to 50 times the mass of the compound. The treatment time is usually 0.01 to 48 hours. In order to eliminate the oxidative stress, the treatment time is preferably 0.1 hours or more, and more preferably 0.2 hours or more. From the viewpoint of suppressing polymerization and side reactions, the treatment time is preferably 24 hours or less, more preferably 12 hours or less. Preferably, the time is 6 hours or less, more preferably.

[0023] As a method for purifying the (meth)acrylic acid ester represented by formula (2) by distillation, for example, Examples of distillation methods include simple distillation, and distillation using a multi-stage distillation tower (rectification tower). For example, stainless steel, glass, ceramic, etc., Raschig rings, Lessing rings, Packings with shapes such as Dixon packing, Pall ring, saddle, and Sulzer packing Packed columns using sieve materials, perforated plate columns, bubble cap columns, and other plate columns can be used. The connection is in the form of a distillation column connected to the top of the reactor, or the top of a separate vessel connected to the reactor. A distillation column is connected to the reactor. A reactor is connected to the distillation column at any position from the top to the bottom. In any of the connection forms, the path between the reactor and the distillation column is the same. There may be one or more, and a device such as a heat exchanger may be interposed in between. An internal reflux system that does not use a reflux vessel or a system that uses a reflux vessel to control the reflux ratio can be used.

[0024] The distillation temperature can be in the range of 10 to 250°C. The temperature is preferably 200°C or less, more preferably 150°C or less. Therefore, the distillation temperature is preferably 40°C or higher, more preferably 60°C or higher.

[0025] The (meth)acrylic acid ester represented by formula (2) can be washed with water, salt, or Examples of the method include washing with an aqueous solution of a salt such as sodium sulfate or an aqueous solution of a basic substance. Examples of basic substances include alkali metals such as sodium hydroxide and potassium hydroxide. hydroxides of alkaline earth metals such as calcium hydroxide and magnesium hydroxide; Alkali metal carbonates such as sodium carbonate and potassium carbonate; calcium carbonate, magnesium carbonate carbonates of alkaline earth metals such as sodium; Hydrogen carbonates of potassium metals; alkaline earth metals such as calcium hydrogen carbonate and magnesium hydrogen carbonate pyridine, 4-(dimethylamino)pyridine, triethylamine, etc. Organic bases and the like. Two or more of these basic substances can also be used in combination. It is also possible to wash the substrate once or multiple times. After washing with a basic substance, the basic substance remaining in the organic layer is removed. It is preferable to wash the material with water. The water used for washing may be distilled water or indigo. It is preferable to use pure water that has been deionized using an ion exchange resin or the like.

[0026] Also, before washing with an aqueous solution of a basic substance, wash the surface with water or an aqueous solution of an acidic substance. The acidic substances include sulfuric acid, nitric acid, phosphoric acid, boric acid, hydrochloric acid and heteropoly acid. Inorganic acids such as phosphoric acid, acetic acid, methanesulfonic acid, paratoluenesulfonic acid, camphorsulfonic acid, etc. and organic acids such as carboxylic acid.

[0027] A solvent may be used to wash the (meth)acrylic acid ester represented by formula (2). The solvent used should be one that dissolves 20g or less in 100g of water. The mass of the solvent is preferably 0.1 to 30 times, more preferably 0.5 to 5 times, the mass of the reaction solution. When the amount of solvent is small, the (meth) Acrylic acid ester may migrate. If there is a large amount of acrylic acid ester, a large reactor is required. The more time it is concentrated, the greater the energy becomes.

[0028] The (meth)acrylic acid ester represented by formula (2) is treated with an adsorbent to reduce the amount of impurities. The methods include column chromatography, suspending the adsorbent to adsorb impurities, and then adsorption. Examples of adsorbents include activated clay and hydrotalcites. , porous polymers, ion exchange resins (cation exchange resins or anion exchange resins), activated carbon , adsorption resin, silica gel, silica alumina-based adsorbent, alumina gel, activated alumina, diacid Examples of the adsorbent include silicon oxide and zeolite. The amount of the adsorbent used is the (meth) acrylate represented by the formula (2). The amount is 0.05 to 20% by mass based on the amount of the acrylic acid ester, and 0.5 to 10% by mass is particularly preferred. If the amount is too small, the effect of reducing impurities is not sufficient, and if the amount is too large, the adsorbent is The total adsorption amount of the (meth)acrylic acid ester represented by the formula (2) increases. Losses due to adsorption of (meth)acrylic esters and when separating the adsorbent by filtration, etc. The load becomes large. When the (meth)acrylic acid ester represented by the formula (2) is contacted with the adsorbent, The temperature during the treatment is not particularly limited, but is usually 0 to 100° C. From this viewpoint, the temperature during contact is preferably 60° C. or less, and more preferably 40° C. or less. The time for contact with the adsorbent varies depending on the type of adsorbent and its amount used, but is usually The incubation time is preferably about 1 to 120 minutes, and more preferably about 3 to 60 minutes.

[0029] After the adsorption treatment with the adsorbent, the ion exchange reaction mixture represented by the formula (2) can be removed by a method such as filtration. The (meth)acrylic acid ester and the adsorbent can be separated. For example, a membrane filter made of a fluororesin such as polytetrafluoroethylene Examples include: When the (meth)acrylic acid ester represented by formula (2) is brought into contact with the adsorbent, a solvent is used. The solvent may be any of those listed above. The mass of the solvent is determined based on the mass of the reaction solution. The ratio is preferably 0.1 to 30 times, and more preferably 0.5 to 5 times.

[0030] The (meth)acrylic acid ester represented by formula (2) can be crystallized by dissolving it in a solvent. After that, the temperature of the solution is lowered to precipitate crystals. A method of precipitating crystals by condensing the solution of a (meth)acrylic acid ester represented by formula (2) The solvent may be the same as that described above. Two or more of these may be mixed and used. The solvent may be any of those listed above. The mass of the solvent is based on the reaction solution. The amount is preferably 0.1 to 30 times, and more preferably 0.5 to 5 times. EXAMPLES

[0031] The present invention will be described in detail below with reference to examples. The following examples are not intended to be limiting. The measurement and evaluation methods used in the present invention are as follows.

[0032] In the examples, the reaction mixture was analyzed by liquid chromatography (hereinafter referred to as HPLC). ) and 1 H-NMR was used. The HPLC analysis was carried out by dissolving the sample in acetonitrile under the following conditions. Column: ODS-3V Carrier: Acetonitrile / 10mM phosphoric acid=4 / 6 To make 10 mM phosphate, dissolve 0.78 g of sodium dihydrogen phosphate dihydrate in 1 L of ultrapure water. , It was prepared by adjusting the pH to 2.6 using approximately 0.34 ml of 85% phosphoric acid. ·Flow rate: 1ml / min ·Injection volume: 5μl ·Temperature: 40℃ ·Wavelength: 254nm

[0033] HHMP and its methacrylic acid ester (hereinafter referred to as HHMPMA) were Quantitative analysis was performed by a dose curve method, and the conversion rate and the yield based on HHMPMA were calculated. The yield of the Michael adduct of HHMPMA was calculated based on the HPLC peak area of ​​each compound. Calculated using the following formula. A: HPLC peak area of ​​Michael adduct B: HPLC peak area of ​​HHMP C: HPLC peak area of ​​HHMPMA Michael adduct yield (%) = A / (A+B+C) x 100

[0034] Example 1 Methacrylic anhydride (manufactured by Aldrich Co.) was distilled into a five-neck flask equipped with a reflux condenser. Distilled and purified 18.5g (0.12mol), HHMP (Tokyo Chemical Industry Co., Ltd.) 2 2.4g (0.1mol), heavy magnesium oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 0.40g (0.01mol), methyl isobutyl ketone (FUJIFILM Wako Pure Chemical Industries, Ltd. Co., Ltd.) 20 g, 2,6-di-tert-butyl-p-cresol (Tokyo Chemical Industry Co., Ltd. The mixture was heated in an oil bath at 60 to 70°C and reacted for 4 hours. Analysis of the resulting solution revealed that the conversion rate was 99.9% and the HHMPMA yield was 99.7%. The yield of the Michael adduct of HHMPMA was 0.1%. The results are shown in Table 1. vinegar.

[0035] (Examples 2 to 10) The magnesium oxide in Example 1 was replaced with 0.01 mol of the catalyst shown in Table 1, and the same procedure as in Example 1 was repeated. The results of analysis of the liquid after the reaction are shown in Table 1.

[0036] (Comparative Examples 1 to 3) The magnesium oxide in Example 1 was replaced with 0.01 mol of the catalyst shown in Table 1, and the same procedure as in Example 1 was repeated. The results of analysis of the liquid after the reaction are shown in Table 1.

[0037] [Table 1]

[0038] Details of each catalyst in the table are as follows: Heavy magnesium oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Lithium hydroxide (Tokyo Chemical Industry Co., Ltd.) Lithium chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Magnesium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Magnesium acetate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Magnesium methacrylate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Calcium oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Calcium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Calcium methacrylate (Tokyo Chemical Industry Co., Ltd.) Barium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 4-Dimethylaminopyridine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Triethylamine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Calcium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0039] Example 11 Methacrylic anhydride (manufactured by Aldrich Co.) was distilled into a five-neck flask equipped with a reflux condenser. Distilled and purified 18.5g (0.12mol), HHMP 5.6g (0.025mol) , heavy magnesium oxide 0.40g (0.01mol), 2,6-di-tert-butyl 10 mg of -p-cresol was added and heated in an oil bath at 60°C. HHM was applied every 30 minutes. P (5.6 g, 0.025 mol) was added three times, and the mixture was reacted at 60-70°C for 4 hours. Analysis of the liquid after the reaction showed that the conversion rate was 99.9% and the HHMPMA yield was 99. The yield of the Michael adduct of HHMPMA was 0.1%. 1 The H-NMR measurement results are shown in Figure 1.

[0040] Comparative Example 4 In Example 14, magnesium oxide was replaced with 0.01 mol of 4-dimethylaminopyridine. The same operation as in Example 1 was carried out. After the reaction, the liquid was analyzed and the conversion rate was found to be 99.4%. The yield of HHMPMA was 89.1%. The yield of the Michael adduct of HHMPMA was 6. The reaction mixture was 7%. 1 The results of H-NMR are shown in Figure 2. Some of the hydrogen signals (around 7.0 ppm) are shifted, which indicates that some of the substituents It is clear that the is changing.

[0041] Example 12 Methacrylic anhydride (manufactured by Aldrich Co.) was distilled into a five-neck flask equipped with a reflux condenser. Distilled and purified 18.5g (0.12mol), HHMP 11.2g (0.05mol) , heavy magnesium oxide 0.40g (0.01mol), 2,6-di-tert-butyl 10 mg of -p-cresol was added and heated in an oil bath at 60°C. After 30 minutes, HHMP 11.2g (0.05mol) was suspended in 20g of methyl isobutyl ketone and left for 10 minutes. The mixture was added in three portions to the reaction mixture. The mixture was then reacted at 60-70°C for 4 hours. As a result, the conversion rate was 99.9% and the yield of HHMPMA was 99.8%. The yield of the Michael adduct of MA was 0.1%.

[0042] Comparative Example 5 HHMP 12.8g (0.057mol), tetrahydrofuran (FUJIFILM Wako Pure Chemical 50g of triethylamine (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) Pharmaceutical grade) 6.7g (0.066mol) and dimethylaminopyridine (Tokyo Chemical Industry Co., Ltd. The mixture was mixed with 0.70 g (0.0057 mol) of 1,000 sucrose (manufactured by Aldrich Co., Ltd.). 9.2g (0.06mol) of distilled and purified methacrylic anhydride manufactured by Co., Ltd. was added. The mixture was stirred at 23° C. for 5 hours. Analysis of the reaction mixture after the reaction showed that the conversion rate was 95.4%. The yield of HHMPMA was 92.5%. The yield of the Michael adduct of HHMPMA was 1.8 %. In addition, the reaction mixture 1 The results of H-NMR are shown in Figure 3. Some of the hydrogen signals (around 7.0 ppm) are shifted, which indicates that some of the substituents It is clear that things are changing.

[0043] Comparative Example 6 In Comparative Example 4, except that 120 g of methyl isobutyl ketone was added first, The same operation was carried out as in Example 1. The liquid after the reaction was analyzed, and the conversion rate was The yield of HHMPMA was 55.8%. The adduct was 0.3%.

[0044] In all of Examples 1 to 12, the HHMP conversion rate and the HHMPMA yield were very high. The yield of the Michael adduct of MA was low. In Comparative Examples 1 to 6, the HHMP conversion rate and HHMPMA yield were low, and the amount of HHMPMA was A large amount of aryl adducts was produced as by-products. From the above examples, it can be seen that the production method of the present invention exhibits excellent HHMP conversion and HHMPMA yield. This effectively suppresses the by-production of Michael adducts of HHMPMA and reduces the purification load. It was possible.

Claims

1. A method for producing a (meth)acrylic acid ester represented by the following formula (2), which is obtained by reacting an alcohol represented by the following formula (1) with (meth)acrylic anhydride in the presence of at least one metal selected from the group consisting of lithium, magnesium, calcium, barium, and strontium, or a salt thereof: 【Chemistry 1】 (In formula (1), R １ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. 【Chemistry 2】 (In formula (2), R １ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; R ２ represents a hydrogen atom or a methyl group.)

2. 2. The method for producing a (meth)acrylic ester according to claim 1, wherein a solvent is used in an amount 5 times or less relative to a total mass of the at least one metal selected from lithium, magnesium, calcium, barium, and strontium or a salt thereof, the alcohol represented by formula (1), and the (meth)acrylic anhydride.

3. 2. The method for producing a (meth)acrylic ester according to claim 1, wherein a solvent is used in an amount three times or less relative to a total mass of the at least one metal selected from lithium, magnesium, calcium, barium, and strontium or a salt thereof, the alcohol represented by formula (1), and the (meth)acrylic anhydride.

4. The method for producing a (meth)acrylic acid ester according to any one of claims 1 to 3, wherein the salt is an oxide, a hydroxide, a carbonate, a hydrogencarbonate, or an organic acid salt.

5. The method for producing a (meth)acrylic acid ester according to any one of claims 1 to 3, wherein the salt is at least one oxide, hydroxide, carbonate, hydrogencarbonate, or organic acid salt selected from the group consisting of lithium, magnesium, and calcium.

6. The method for producing a (meth)acrylic acid ester according to any one of claims 1 to 5, characterized in that the reaction temperature is 40 to 100°C.

7. A reaction product of an alcohol represented by the following formula (1) and (meth)acrylic anhydride, the reaction product containing a (meth)acrylic acid ester represented by the following formula (2), wherein in a liquid chromatography analysis of the reaction product, a ratio of a peak area of ​​the Michael adduct to a total amount (100%) of a peak area of ​​a Michael adduct of the alcohol, a peak area of ​​the alcohol, and a peak area of ​​the (meth)acrylic acid ester is 0.2% or less. 【Chemistry 3】 (In formula (1), R １ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. 【Chemistry 4】 (In formula (2), R １ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; R ２ represents a hydrogen atom or a methyl group.)

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