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, R1 and R2 each denote a hydrogen atom, a halogen atom, a nitro group, an alkyl group, or an alkoxy group).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a hydroxybenzophenone-based compound by reacting a hydroxybenzophenone with a (meth)acrylic anhydride, The present invention relates to a method for producing a (meth)acrylic acid ester of a hydroxybenzophenone. [Background technology]

[0002] As a method for producing (meth)acrylic esters of hydroxybenzophenones, Patent Document 1 discloses a method for the synthesis of (meth)acrylic acid chloride in anhydrous acetone in the presence of triethylamine. A method for reacting benzophenone with 4-hydroxybenzophenone has been described. In addition to generating acid, it requires an equimolar amount of amine and a large amount of solvent to react with (meth)acrylic acid chloride. In Patent Document 1, triethylamine is used to react with (meth)acrylic anhydride. In this method, the amine must be used in equal moles to the (meth)acrylic anhydride. In addition, a large amount of solvent is required. A method of reacting acrylic anhydride is described, but it uses highly corrosive sulfuric acid. Therefore, it is necessary to use equipment made of highly corrosion-resistant materials, and the action of sulfuric acid can cause the fleece to corrode. Side reactions such as rearrangement and coloring of the reaction solution proceed. The method of reacting (meth)acrylic anhydride using sodium acrylate or sodium acetate is described. According to the investigations of the present inventors, in this method, the methacrylic acid of the compound of formula (2) is The unsaturated bond of the aryl group reacts with the carboxyl group of methacrylic acid to form a Michael adduct. It was found that the Michael adduct was generated and the yield decreased. The aim is to obtain high-purity (meth)acrylic acid esters of hydroxybenzophenones. It was found that the yield was significantly reduced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-261506 A [Patent Document 2] Special Publication No. 2012-512216 [Patent Document 3] Special Publication No. 2016-539913 [Non-patent literature]

[0004] [Non-Patent Document 1] (J.Appl.Polym.Sci.,57(8),997(1995)) DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] The present invention relates to a method for producing a (meth)acrylic acid ester of a hydroxybenzophenone. In this way, the by-production of Michael adducts is suppressed, and the (meth)acrylic acid of hydroxybenzophenones is improved. The object of the present invention is to produce an acid ester in a high yield and reduce the purification load. [Means for solving the problem]

[0006] 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) A copolymer represented by the following formula (2) obtained by reacting alcohol with (meth)acrylic anhydride. A method for producing (meth)acrylic acid esters. [ka] (In formula (1), R 1 , R 2 are each independently a hydrogen atom, a halogen atom, a nitro group, or a carbon atom. It represents an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. [ka] (In formula (2), R 1 , R 2 are each independently a hydrogen atom, a halogen atom, a nitro group, or a carbon atom. R represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. 3 is 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 three 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 equal to or less than 1 times 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 or hydroxide selected from magnesium and calcium. Any of [1] to [3], characterized in that the compound is a salt, a carbonate, a hydrogen carbonate, or an organic acid salt. A method for producing the (meth)acrylic acid ester according to any one of the preceding claims. [6] 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), which has a content of 0.5% or less: [ka] (In formula (1), R 1 , R 2 are each independently a hydrogen atom, a halogen atom, a nitro group, or a carbon atom. It represents an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. [ka] (In formula (2), R 1 , R 2 are each independently a hydrogen atom, a halogen atom, a nitro group, or a carbon atom. R represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. 3 is a hydrogen atom or a methyl group.) Effect of the Invention

[0007] According to the method for producing a (meth)acrylic acid ester of the present invention, the formation of a Michael adduct is suppressed. It is highly effective in producing (meth)acrylic esters of hydroxybenzophenones with few impurities. In addition, the (meth)acryloyl group of hydroxybenzophenones can be obtained in good yield. The burden of purifying acid esters can be reduced. 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 ester represented by the following formula (2). [ka] (In formula (1), R 1 , R 2 are each independently a hydrogen atom, a halogen atom, a nitro group, or a carbon atom. It represents an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. [ka] (In formula (2), R 1 , R 2 are each independently a hydrogen atom, a halogen atom, a nitro group, or a carbon atom. R represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. 3 is a hydrogen atom or a methyl group.)

[0010] The alcohol represented by formula (1) includes 2-hydroxybenzophenone, 2-hydroxy 2-Hydroxy-5-methylbenzophenone, 2-Hydroxy-4-methylbenzophenone, 4-hydroxy-4-methoxybenzophenone, 5-chloro-2-hydroxybenzophenone, 5-Chloro-2-hydroxy-4-methylbenzophenone, 4'-chloro-5-fluoro -2-hydroxybenzophenone, 4-allyloxy-2-hydroxybenzophenone, 2,4-Dimethoxy-4'-hydroxybenzophenone, 2',5-dichloro-2-hydroxy 5-bromo-2-hydroxybenzophenone, 2-hydroxy- 4-n-Octyloxybenzophenone, 3-Hydroxybenzophenone, 4-Fluoro -4'-hydroxybenzophenone, 4-chloro-4'-hydroxybenzophenone, 2 Hydroxybenzophenones such as 4-dimethoxy-4'-hydroxybenzophenone From the viewpoint of corrosiveness, a structure that does not contain halogen atoms is preferable, and from the viewpoint of reaction rate, From the viewpoint of compound stability, R 1 and / or R 2 is preferably hydrogen or an alkyl group. From the standpoint of reaction rate and stability, 4-hydroxy Dibenzophenone 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 In terms of the amount of Michael adduct by-product, lithium, malic acid, and ethylenediaminetetraacetate are used as catalysts. At least one metal selected from magnesium and calcium or a salt thereof is preferred. These include oxides, hydroxides, carbonates, hydrogen carbonates, sulfates, chlorides, nitrates, phosphates, Salts with inorganic acids such as borates; organic acids such as acetates, (meth)acrylates, and benzoates Salts: acetylacetonate, cyclopentadienyl complexes and other complex salts. From the viewpoint of properties, oxides of lithium, magnesium, calcium, barium, and strontium , hydroxides, hydrogen carbonates, chlorides, and organic acid salts are preferred. Since they do not contain halogens, The more preferred are oxides, hydroxides, carbonates, hydrogencarbonates, and organic acid salts. Acrylates are more preferred. These may be completely dissolved or partially dissolved. In the reaction, the above-mentioned catalyst compound may be used in the reaction system. The catalyst may be used alone or in combination of two or more. For example, a method of charging the entire amount into the reactor at first, a method of charging a part of it at first and feeding the rest later etc. 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 expressed as a molar ratio relative to the alcohol represented by formula (1). It is recommended to use 0.5 to 5 times the alcohol. (Meth)acrylic acid ester From the viewpoint of yield, this molar ratio is preferably 0.9 times or more, and more preferably 1 times or more. It is more preferable, and even more preferable that it is 1.1 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 90°C or less. Preferred.

[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 at which the conversion rate of the alcohol represented by formula (1) reaches 70% or more is preferable, and the time at which 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 liquid is concentrated, distilled, washed, treated with an adsorbent, crystallized, etc. to obtain the product represented by formula (2). The (meth)acrylic acid ester represented by the formula (I) can be purified.

[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 produce 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. 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. 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:

[0020] These treatments are performed even if catalysts and other substances remain, after removing them by washing or extraction, as described below. is also good. 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.

[0021] 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. 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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 time is preferably about 1 to 120 minutes, and more preferably about 3 to 60 minutes.

[0026] 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 The (meth)acrylic acid ester represented by formula (2) is brought into contact with an adsorbent. In this case, a solvent may be used. As the solvent, those listed above can be used. Mass of the solvent The amount is preferably 0.1 to 30 times, and more preferably 0.5 to 5 times, the amount of the reaction solution.

[0027] 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

[0028] 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.

[0029] In the examples, the analysis was performed by gas chromatography (hereinafter referred to as GC). The analysis was carried out under the following conditions, using anisole as the internal standard and acetone as the dilution solvent. . Column: J&B Scientific DB-1, length 30m x inner diameter 0.53 mm Film thickness: 3μm Injection temperature: 200℃ Detector temperature: 250℃ Column temperature and time: 60℃ for 1 minute, increase temperature at 10℃ / min, hold at 250℃

[0030] 4-Hydroxybenzophenone and 4-methacryloyloxybenzophenone were weighed. Quantitative analysis was performed by the linear method, and the conversion rate and the yield based on 4-hydroxybenzophenone were calculated. Methacrylic acid is added to the methacryloyl group of 4-methacryloyloxybenzophenone. The yield of the Michael adduct was calculated based on the GC peak area of ​​each compound using the following formula. A: GC peak area of ​​Michael adduct B: GC peak area of ​​4-hydroxybenzophenone C: GC peak area of ​​4-methacryloyloxybenzophenone Michael adduct yield (%) = A / (A+B+C) x 100

[0031] Example 1 Methacrylic anhydride (manufactured by Aldrich Co.) was distilled into a five-neck flask equipped with a reflux condenser. The distilled and purified product was 18.5 g (0.12 mol), 4-hydroxybenzophenone (Tokyo Chemical Magnesium oxide (Fujifilm) 19.8g (0.1mol) (Wako Pure Chemical Industries, Ltd.) 0.20 g (0.005 mol), methyl isobutyl ketone 5 g, 10 mg of 2,6-di-tert-butyl-p-cresol (Tokyo Chemical Industry Co., Ltd.) The mixture was heated in an oil bath at 80°C for 5 hours. The reaction solution was analyzed and found to be: The conversion rate of 4-hydroxybenzophenone was 99.8%, and that of 4-methacryloyloxybenzophenone was 99.8%. The yield of the enone (MBP) was 99.5%. The yield of the Michael adduct was 0.2%.

[0032] (Examples 2 to 14) The heavy magnesium oxide in Example 1 was replaced with 0.005 mol of the catalyst shown in Table 1. The same operation as in 1. was carried out. The liquid after the reaction was analyzed and the results are shown in Table 1.

[0033] (Comparative Examples 1 to 4) The heavy magnesium oxide in Example 1 was replaced with 0.005 mol of the catalyst shown in Table 1. The same operation as in 1. was carried out. The liquid after the reaction was analyzed and the results are shown in Table 1.

[0034] [Table 1]

[0035] 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 carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Lithium chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Magnesium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Magnesium chloride (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.) Strontium hydroxide (Sigma-Aldrich) 4-Dimethylaminopyridine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Sodium methoxide (Tokyo Chemical Industry Co., Ltd.) Sodium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Calcium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0036] (Examples 15 to 19) The heavy magnesium oxide in Example 1 was replaced with 0.0005 mol of the catalyst shown in Table 2, and methyl The same procedure as in Example 1 was carried out except that isobutyl ketone was not used and the reaction was carried out at 90°C for 5 hours. The liquid after the reaction was analyzed and the results are shown in Table 2.

[0037] [Table 2]

[0038] (Example 20) The heavy magnesium oxide in Example 1 was changed to 0.0001 mol, and methyl isobutyl ketone was added. The same procedure as in Example 1 was carried out except that no amine was used and the reaction was carried out at 90° C. for 7 hours. Analysis of the liquid showed that the conversion rate of 4-hydroxybenzophenone was 99.4%, and that of 4-methacrylonitrile was 99.4%. The yield of trimethyloxybenzophenone (MBP) was 99.2%. was 0.1%.

[0039] Example 21 In Example 1, 38.5 g of methyl isobutyl ketone was added as the solvent at the beginning. The same operation as in Example 1 was carried out. The liquid after the reaction was analyzed, and it was found that 4-hydroxybenzoyl Phenone conversion rate was 99.2%, and 4-methacryloyloxybenzophenone (MBP) yield was 99.2%. The yield of the Michael adduct was 0.2%.

[0040] Comparative Example 5 In Comparative Example 3, except that 120 g of methyl isobutyl ketone was added first, The same operation was carried out as in Example 1. Analysis of the liquid after the reaction revealed that 4-hydroxybenzophenone had been converted. The reaction rate was 66.1%, and the 4-methacryloyloxybenzophenone (MBP) yield was 63.8%. The yield of the Michael adduct was 2.0%.

[0041] In all of Examples 1 to 21, the 4-hydroxybenzophenone conversion rate and the 4-methacryloyl The yield of oxybenzophenone (MBP) was very high, while the yield of Michael adduct was low. On the other hand, in Comparative Examples 1 to 5 in which the catalyst was different from that of the present invention, 4-methacryloyloxy The yield of 2,4-dimethoxybenzophenone (MBP) was low, and a large amount of Michael adduct was produced as a by-product.

[0042] From the above examples, it can be seen that the production method of the present invention has an excellent 4-hydroxybenzophenone conversion rate and The yield of 4-methacryloyloxybenzophenone (MBP) and the by-product Michael adduct are shown. This makes it possible to sufficiently suppress the above-mentioned problems and reduce the purification load.

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 magnesium (meth)acrylate. 【Chemistry 1】 (In formula (1), R １ , R ２ each independently represents a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. 【Chemistry 2】 (In formula (2), in formula (1), R １ , R ２ each independently represents a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; R ３ represents a hydrogen atom or a methyl group.)

2. 2. The method for producing a (meth)acrylic acid ester according to claim 1, wherein a solvent is used in an amount three times or less relative to a total mass of the magnesium (meth)acrylate, the alcohol represented by the formula (1), and the (meth)acrylic anhydride.

3. 2. The method for producing a (meth)acrylic acid ester according to claim 1, wherein a solvent is used in an amount equal to or less than 1 times the total mass of the magnesium (meth)acrylate, the alcohol represented by the formula (1), and the (meth)acrylic anhydride.

4. 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 gas chromatography analysis of the reaction product, a ratio of a peak area of ​​the Michael adduct to a total (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 0.1% or less. 【Chemistry 3】 (In formula (1), R １ , R ２ each independently represents a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. 【Chemistry 4】 (In formula (2), in formula (1), R １ , R ２ each independently represents a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; R ３ represents a hydrogen atom or a methyl group.)

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