Method for producing 3-(meth)acryloyl sulfolane

Abstract

To provide a method for producing 3-(meth)acryloyl sulfolane, which can suppress side reactions and, even when using crude 3-hydroxy sulfolane as a raw material without purification, enables production of a target product, 3-(meth)acryloyl sulfolane, in a sufficiently high rection rate and yield.SOLUTION: Provided is a method of producing 3-(meth)acryloyl sulfolane, comprising reacting 3-hydroxy sulfolane with (meth)acrylic acid derivative selected from (meth)acrylic acid anhydride and a (meth)acrylic acid halide in the presence of an inorganic compound, where, when the (meth)acrylic acid derivative is a (meth)acrylic acid halide, the inorganic compound is an inorganic salt.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing 3-(meth)acryloyl sulfolane. [Background technology]

[0002] Unsaturated carboxylic acid esters of 3-hydroxysulfolane (for example, 3-(meth)acryloylsulfolane) are used as sulfur-containing monomers in the polymerization of various polymers. Patent Document 1 describes an example in which a methacrylic acid ester of 3-hydroxysulfolane (ie, 3-methacryloylsulfolane) is produced by transesterification of 3-hydroxysulfolane with methyl methacrylate.

[0003] Furthermore, Patent Document 2 and Non-Patent Document 1 disclose a method for producing 3-methacryloylsulfolane by reacting 3-hydroxysulfolane with methacrylic acid chloride in the presence of triethylamine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-153763 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-234166 [Non-patent literature]

[0005] [Non-Patent Document 1] Fujii, S et al., “Sulfone-Containing Methacrylate Homopolymers: Wetting and Thermal Properties”, Langmuir 2016, 32, 765-771 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the findings of the present inventors, when an unsaturated carboxylic acid ester of 3-hydroxysulfolane is produced by the transesterification reaction described in Patent Document 1, the transesterification reaction requires a high reaction temperature, which causes the resulting monomer to undergo polymerization. Furthermore, if the raw material 3-hydroxysulfolane is subjected to the transesterification reaction in its crude form without purification, the reaction does not proceed, which is a disadvantage. Furthermore, in the methods described in Patent Document 2 and Non-Patent Document 1, there was a problem in that when crude 3-hydroxysulfolane was reacted with methacrylic acid chloride in the presence of triethylamine, the yield of 3-methacryloylsulfolane was significantly reduced. In order to solve the above-mentioned problems, the present inventors conducted extensive research and discovered that when 3-hydroxysulfolane and (meth)acrylic acid chloride were reacted in the presence of aqueous sodium hydroxide to produce 3-methacryloylsulfolane using the Schotten-Baumann reaction, a large amount of by-products was generated. This by-product, primarily 2-sulfolene, has a boiling point close to that of the target product, 3-methacryloylsulfolene, making it difficult to separate during the purification process (distillation). Furthermore, when 3-hydroxysulfolane was reacted with (meth)acrylic acid using the dehydration esterification method to produce 3-methacryloylsulfolane, the yield of 3-methacryloylsulfolane was expected to be low due to the insufficient reactivity of 3-hydroxysulfolane, which is a secondary alcohol. The present invention has been made in view of the above circumstances, and aims to provide a method for producing 3-(meth)acryloylsulfolane, which can suppress side reactions that produce 2-sulfolene and the like, and which enables the production of the target product, 3-(meth)acryloylsulfolane, at a sufficiently high reaction rate and yield even when 3-hydroxysulfolane is used as a raw material in its crude form without purification. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] The following formula (I) [ka] and 3-hydroxysulfolane represented by the following formula (II): [ka] [In formula (II), R 1 represents a hydrogen atom or a methyl group, and Y represents a group represented by the following formula (II-a) or a halogen atom: [ka] (In formula (II-a), R 2 represents a hydrogen atom or a methyl group, and * represents a bond.) in the presence of an inorganic compound, However, when Y in the formula (II) is a halogen atom, the inorganic compound is an inorganic salt. Method for producing 3-(meth)acryloyl sulfolane. [2] The method for producing 3-(meth)acryloylsulfolane according to [1], wherein the (meth)acrylic acid derivative is (meth)acrylic anhydride represented by the following formula (II-b): [ka] (In formula (II-b), R 1 and R 2 is as defined above, and R 1 and R 2 may be the same or different.) [3] The method for producing 3-(meth)acryloyl sulfolane according to [1], wherein the (meth)acrylic acid derivative is a (meth)acrylic acid halide. [4] The method for producing 3-(meth)acryloyl sulfolane according to [1], wherein when Y in formula (I) is a group represented by formula (II-a), the inorganic compound is at least one selected from the group consisting of inorganic salts and inorganic oxides. [5] The method for producing 3-(meth)acryloyl sulfolane according to any one of [1] to [4], wherein the inorganic salt is at least one carbonate selected from the group consisting of lithium carbonate, sodium carbonate, potassium carbonate, calcium carbonate, and magnesium carbonate. [Effects of the Invention]

[0008] According to the method for producing 3-(meth)acryloylsulfolane of the present invention, side reactions can be suppressed, and even when 3-hydroxysulfolane is used as a raw material in its crude form without being purified, the target product, 3-(meth)acryloylsulfolane, can be produced at a sufficiently high reaction rate and yield. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following definitions apply throughout the specification and claims. The symbol "to" indicating a range of values means that the values before and after it are included as the lower and upper limits. Room temperature means 20 to 30°C unless otherwise specified. Unless otherwise specified, pH values are at room temperature. The water content was determined by sending a sample to a Karl Fischer reagent and measuring the water content by Karl Fischer coulometric titration.

[0010] The method for producing 3-(meth)acryloyl sulfolane according to the present embodiment comprises reacting a compound represented by the following formula (I): [ka] and 3-hydroxysulfolane represented by the following formula (II): [ka] [In formula (II), R 1 represents a hydrogen atom or a methyl group, and Y represents a group represented by the following formula (II-a) or a halogen atom: [ka] (In formula (II-a), R 2 represents a hydrogen atom or a methyl group, and * represents a bond.) in the presence of an inorganic compound, However, when Y in the formula (II) is a halogen atom, the inorganic compound is an inorganic salt.

[0011] <3-hydroxysulfolane> In the present invention, 3-hydroxysulfolane produced by a known method can be used. For example, 3-hydroxysulfolane produced by the method described in Patent Document 1 can be used. Specifically, 3-hydroxysulfolane can be produced by treating sulfolene (3-sulfolene) with an aqueous alkaline solution, neutralizing it to obtain a neutralized solution containing 3-hydroxysulfolane, distilling off most of the water from the neutralized solution, adding acetone to dissolve and extract 3-hydroxysulfolane, and precipitating the neutralized salt, which is then filtered off. Alternatively, the solvent of the neutralized solution may be azeotropically replaced with an organic solvent that dissolves the 3-hydroxysulfolane and forms an azeotropic mixture with water. Specific examples of the method for producing 3-hydroxysulfolane in this case (hereinafter sometimes referred to as the "azeotropic replacement method") include the following. a step of treating 3-sulfolene represented by the following formula (I-0) with an alkaline aqueous solution to obtain an aqueous solution containing 3-hydroxysulfolane (hydration step); A step of neutralizing the aqueous solution with an acid to obtain a neutralized solution (neutralization step); A method for producing 3-hydroxysulfolane, comprising a step of azeotropically replacing the solvent of the neutralized solution with an organic solvent that dissolves the 3-hydroxysulfolane and forms an azeotropic mixture with water (solvent replacement step).

[0012] [ka]

[0013] According to this azeotropic substitution method, the neutralization salt and water can be removed from the neutralization solution while ensuring the amount of liquid in the reactor, thereby improving production efficiency. The azeotropic substitution method will be specifically described below.

[0014] Agitation tanks are commonly used in industrial synthesis. Agitation tanks are equipped with a cylindrical, bottomed, hollow vessel (reactor), a stirring blade whose rotation axis is the central axis of the vessel, and a motor connected to the shaft of the stirring blade. Baffles may be installed to improve stirring efficiency. In multipurpose agitation tanks, due to the motor's capacity and the presence of baffles, it is preferable that the contents to be stirred have a low viscosity. The distance from the vessel bottom to the stirring blade is often set to about one-third of the vessel's height, which places a lower limit on the amount of contents that can be stirred.

[0015] <Hydration process> In the hydration process, the raw material 3-sulfolene is treated with an alkaline aqueous solution to produce 3-hydroxysulfolane through a hydration reaction, resulting in an aqueous solution containing 3-hydroxysulfolane. Specifically, 3-sulfolene is dissolved in an alkaline aqueous solution, and the solution is stirred at a temperature ranging from room temperature to 80° C. for 1 to 100 hours to carry out the hydration reaction.

[0016] Examples of the alkali include sodium hydroxide, potassium hydroxide, calcium hydroxide, etc. From the viewpoints of cost, practicality, and reaction efficiency, sodium hydroxide is preferred. The concentration of the aqueous alkaline solution is preferably 1 to 10N, more preferably 1 to 8N, and even more preferably 1 to 4N, from the viewpoints of ease of handling, suppression of side reactions, suppression of coloration, and the like.

[0017] The amount of alkali used is preferably within a range of 0.5 to 10 times by mole relative to 3-sulfolene. From the standpoints of reaction efficiency and cost, it is more preferably within a range of 1 to 5 times by mole relative to 3-sulfolene. From the standpoints of suppressing side reactions and shortening the reaction time, it is even more preferably within a range of 1 to 3 times by mole.

[0018] A reaction temperature of hydration above room temperature is likely to provide a good reaction rate, while a temperature of 80°C or below makes it difficult for the raw materials to decompose, and the production of by-products is likely to be suppressed. Specifically, the decomposition of 3-sulfolene into butadiene and sulfur dioxide gas undesirably produces by-products such as butadiene oligomers or polymers, which promote polymerization. A more practical reaction temperature is preferably within the range of room temperature to 60°C, and more preferably within the range of room temperature to 40°C in terms of the ease of suppressing coloration due to the reaction.

[0019] The reaction time for the hydration reaction is preferably 1 to 100 hours, more preferably 5 to 72 hours, and even more preferably 8 to 24 hours, from the standpoints of reaction efficiency and economy. However, from the standpoints of inhibiting coloration and purity, the reaction is preferably carried out for 24 hours or more.

[0020] If the hydration reaction has progressed completely, there is no need to consider removing the raw material 3-sulfolene. However, if unreacted raw material remains in the hydration reaction, it is preferable to remove the raw material 3-sulfolene by methods such as thermal decomposition, silica gel chromatography, or distillation. From the viewpoint of low cost, it is preferable to carry out thermal decomposition under reduced pressure at a temperature of 80 to 100°C at which the raw material 3-sulfolene decomposes. There is no restriction on the timing of carrying out thermal decomposition of the raw material 3-sulfolene. However, from the viewpoint of low possibility of polymerization of the butadiene produced by thermal decomposition, it is preferable to carry out thermal decomposition under reduced pressure during the water concentration step described below.

[0021] <Neutralization process> In the neutralization step, an acid is added to the aqueous solution containing 3-hydroxysulfolane obtained in the hydration step to neutralize it, thereby obtaining a neutralized solution. Examples of the acid include hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, nitric acid, etc. From the viewpoints of workability and separability between the target product 3-hydroxysulfolane and the neutralized salt, hydrochloric acid and sulfuric acid are preferred. The neutralized solution obtained in the neutralization step contains 3-hydroxysulfolane, water, and neutralized salts.

[0022] The end point of neutralization is preferably pH 5 to 8, more preferably pH 6 to 7. If the pH is 8 or lower, coloration of the neutralized solution is suppressed. If the pH is 5 or higher, the dehydration reaction of 3-hydroxysulfolane is suppressed. If the dehydration reaction of 3-hydroxysulfolane occurs, 2-sulfolene, an isomer of 3-sulfolene, is produced as a by-product, which is undesirable.

[0023] <Solvent substitution process> In the solvent substitution step, the solvent of the neutralized solution is azeotropically substituted using an organic solvent that forms an azeotrope with water (hereinafter also referred to as an azeotropic solvent). The azeotropic solvent used is one that dissolves 3-hydroxysulfolane. The azeotropic substitution is preferably carried out by multi-stage azeotropy. Specifically, the water in the neutralized liquid is substituted with the azeotropic solvent by repeating the steps of adding an azeotropic solvent to the neutralized liquid, distilling off a mixture containing the azeotropic solvent and water (hereinafter referred to as the azeotropic mixture), adding the azeotropic solvent again, and distilling off the azeotropic mixture. Multi-stage azeotropy will be described later. The azeotropic displacement yields a solution containing 3-hydroxysulfolane, the neutralization salt, and the azeotropic solvent, with the water removed, and the resulting solution is filtered to remove the neutralization salt. The solution from which the neutralized salt has been removed (hereinafter also referred to as SFOH solution) can be used as is or after removing the azeotropic solvent in the method for producing 3-(meth)acryloylsulfolane of the present invention.

[0024] Examples of azeotropic solvents are listed in Table 1. The table shows the boiling point of each solvent at standard pressure (101.3 kPa), the azeotropic point of a mixture consisting of each solvent and water, and the content of each solvent during azeotropy (azeotropic composition).

[0025] [Table 1]

[0026] When 3-hydroxysulfolane obtained by the azeotropic displacement method is used in a reaction with a (meth)acrylic acid derivative (described later), it is preferable that the boiling point of the azeotropic solvent is lower than that of the (meth)acrylic acid derivative, since the azeotropic solvent can be easily distilled off after mixing the SFOH solution with the (meth)acrylic acid derivative. For example, the boiling point of the azeotropic solvent at standard pressure is preferably 100°C or lower, and more preferably 90°C or lower from the viewpoint of separation efficiency. When the azeotropic solvent is an alcohol, a side reaction is likely to occur in the reaction with a (meth)acrylic acid derivative described below, so it is preferable to remove the azeotropic solvent from the SFOH solution before this reaction. The azeotropic solvent is more preferably acetonitrile or ethyl methyl ketone, since the SFOH solution obtained in the solvent substitution step can be easily used as it is for the reaction with a (meth)acrylic acid derivative.

[0027] Table 2 is an example for explaining multi-stage azeotropy, and shows the theoretical values when multi-stage azeotropy is performed using acetonitrile (referred to as "ATN" in the table) as the azeotropic solvent. In the table, "parts" indicates "parts by mass." In the example in Table 2, the amount of the neutralization liquid is 100 parts by mass, and is composed of 21.1 parts by mass of a solute containing 3-hydroxysulfolane and a neutralization salt, and 78.9 parts by mass of water as a solvent. First, a part of the water (50 parts by mass) is distilled off from the neutralized liquid (water concentration step) to obtain a concentrated liquid (liquid volume 50 parts by mass) with a water content of 58% by mass. Next, 31.8 parts by mass of acetonitrile are added (Addition 1), and acetonitrile and water are azeotroped to distill off 31.8 parts by mass of the azeotropic mixture (Distillation 1). Assuming that the acetonitrile content in the distilled off azeotropic mixture is 84.2% by mass, the 31.8 parts by mass of the azeotropic mixture consists of 5 parts by mass of water and 26.8 parts by mass of acetonitrile. This results in a solution with a water content reduced to 48% by mass (liquid volume 50.0 parts by mass). Next, 31.8 parts by mass of acetonitrile are added (addition 2), and acetonitrile and water are azeotroped to distill off 31.8 parts by mass of the azeotropic mixture (distillation 2). As a result, a solution with a water content reduced to 38% by mass (liquid volume 50.0 parts by mass) is obtained. In this way, 31.8 parts by mass of acetonitrile is added (Additions 3 to 6), and 31.8 parts by mass of the azeotropic mixture is distilled off (Distillation 3 to 6). By repeating this process, the water content gradually decreases, and 50.0 parts by mass of a solution consisting of 21.1 parts by mass of solute, -1.2 parts by mass of water, and 30.1 parts by mass of acetonitrile is obtained. The resulting solution is filtered to remove the neutralized salt, yielding an SFOH solution.

[0028] [Table 2]

[0029] In this way, by azeotropically replacing the solvent of the neutralization liquid with an azeotropic solvent, water can be removed from the neutralization liquid while ensuring the amount of liquid in the reactor. In the solvent substitution step, azeotropic substitution is preferably carried out until a solution having a water content of 1% by mass or less, preferably 0.1% by mass or less, is obtained.

[0030] In the solvent substitution step, it is not essential to first distill off water (water concentration step) before adding the azeotropic solvent, but by distilling off a portion of the water contained in the neutralized solution prior to azeotropic substitution, the water contained in the neutralized solution can be efficiently removed. As a result, the number of times (number of stages) to repeat the operation of adding the azeotropic solvent and distilling off the azeotropic mixture can be reduced. When only water is distilled off (concentrated) before the addition of the azeotropic solvent, if the amount of water distilled off is too large, it becomes difficult to stir the liquid in the reactor with the stirring blades, so the amount of water distilled off is set so as not to cause such a problem. The number of stages in the multi-stage azeotropy is not particularly limited, but for example, 1 to 10 stages is preferred, and from the viewpoints of cost and suppression of polymerization due to heat, 1 to 4 stages is more preferred.

[0031] In the multi-stage azeotropy, the amount of azeotropic solvent added and the amount distilled off immediately thereafter may be the same or different. The amount of azeotropic solvent added in each stage may be the same or different. Furthermore, the amount distilled off in each stage may be the same or different. The amount of liquid in the solvent substitution step may be increased or decreased within a range not exceeding the amount of liquid that can be accommodated in the reactor and not less than the amount of liquid that can be stirred with the stirring blade. If the amount of the neutralized liquid to be subjected to the solvent substitution step is taken as 100% by mass, the amount of liquid after distillation is, for example, preferably 50% by mass or more, and more preferably 30% by mass or more from the viewpoint of efficiency, although this depends on the structure of the reactor.

[0032] The azeotropic substitution may be carried out under reduced pressure. This is preferable because the azeotropic point is lowered under reduced pressure, and the heating temperature for distilling off the azeotropic mixture can be lowered. In the solvent substitution step, the internal temperature is the treatment temperature, and the treatment temperature is preferably from room temperature to 80°C, more preferably from 40°C to 60°C. In the solvent substitution step, when the internal pressure is taken as the treatment pressure, the treatment pressure is preferably 30 hPa to 500 hPa, more preferably 30 hPa to 400 hPa, and even more preferably 30 hPa to 300 hPa. In one distillation step (one stage), the treatment temperature and treatment pressure may be constant or may vary with time. In the present invention, one preferred embodiment is to react 3-hydroxysulfolane with the (meth)acrylic acid derivative following the step of producing 3-hydroxysulfolane by the above-described azeotropic substitution method.

[0033] The 3-hydroxysulfolane used in the present invention may be a crude product obtained by the above-described method (hereinafter also referred to as "crude 3-hydroxysulfolane"), or a purified product obtained by further subjecting it to a purification step (hereinafter also referred to as "purified 3-hydroxysulfolane"). Here, the purification step can be carried out by a known distillation method such as thin-film distillation. Incidentally, omission of the purification step provides various advantages, such as reduced production costs, simplified equipment, and improved production efficiency. Therefore, one preferred embodiment of the present invention is to react the produced 3-hydroxysulfolane in a crude state with the (meth)acrylic acid derivative without subjecting it to a purification step. Furthermore, since the azeotropic substitution method makes it easy to produce 3-hydroxysulfolane with high purity, it is also preferred to produce 3-hydroxysulfolane by the azeotropic substitution method and then react the crude 3-hydroxysulfolane with the (meth)acrylic acid derivative without subjecting it to a purification step.

[0034] <(Meth)acrylic acid derivatives> In the formula (II), when Y is a group represented by the formula (II-a), the (meth)acrylic acid derivative is a (meth)acrylic anhydride represented by the following formula (II-b). [ka] In formula (II-b), R 1 and R 2 is as defined above, and R 1 and R 2 may be the same or different. Specific examples of (meth)acrylic anhydride include acrylic anhydride, methacrylic anhydride, and acrylic-methacrylic anhydride, and mixtures thereof are also acceptable. Among these, methacrylic anhydride is preferred from the viewpoint of availability, etc.

[0035] When Y in the formula (II) is a halogen atom, the (meth)acrylic acid derivative is a (meth)acrylic acid halide ((meth)acryloyl halide). Specific examples of the (meth)acrylic acid halide include (meth)acrylic acid chloride, (meth)acrylic acid fluoride, (meth)acrylic acid bromide, and (meth)acrylic acid iodide. A mixture of methacrylic acid halide and acrylic acid halide may also be used. Of these, (meth)acrylic acid chloride is preferred from the viewpoint of availability, and methacrylic acid chloride is more preferred.

[0036] The amount of the (meth)acrylic acid derivative used is preferably 0.8 to 2.0, more preferably 0.9 to 1.5, when Y in formula (II) is a halogen atom (i.e., when the (meth)acrylic acid derivative is a (meth)acrylic acid halide). Furthermore, when Y in the formula (I) is a group represented by the formula (II-a) (i.e., when the (meth)acrylic acid derivative is (meth)acrylic anhydride), it is preferably 0.8 to 2.0, and more preferably 0.9 to 1.5. When the amount of the (meth)acrylic acid derivative used is within the above range, there is an advantage that the target product can be obtained in good yield while suppressing the load on post-treatment steps.

[0037] <Inorganic compounds> In the present invention, the reaction between the 3-hydroxysulfolane and the (meth)acrylic acid derivative is carried out in the presence of an inorganic compound. Here, when Y in the formula (II) is a halogen atom (that is, when the (meth)acrylic acid derivative is a (meth)acrylic acid halide), the inorganic compound is an inorganic salt. Furthermore, when Y in formula (I) is a group represented by formula (II-a) (i.e., when the (meth)acrylic acid derivative is (meth)acrylic anhydride), the inorganic compound is preferably at least one selected from the group consisting of inorganic salts and inorganic acids, and more preferably an inorganic salt from the viewpoint of improving the yield of the target product, 3-(meth)acryloylsulfolane.

[0038] The inorganic salt is preferably an alkali metal salt or an alkaline earth metal salt. Examples of alkali metal elements constituting alkali metal salts include lithium, sodium, potassium, rubidium, and cesium. Examples of alkaline earth metal elements constituting alkaline earth metal salts include calcium, magnesium, and barium. Among these, from the viewpoint of improving the yield of the target product, 3-(meth)acryloylsulfolane, alkali metal salts are preferred, lithium salts, and potassium salts are more preferred, and sodium salts and potassium salts are even more preferred. The inorganic salt may be at least one selected from inorganic acid salts and organic acid salts. Examples of inorganic acid salts include carbonates, bicarbonates, sulfates, nitrates, phosphates, monohydrogen phosphates, dihydrogen phosphates, pyrophosphates, chlorates, bromates, and borates. From the viewpoint of improving the yield of the target product, 3-(meth)acryloylsulfolane, carbonates and bicarbonates are preferred, and carbonates are more preferred. Examples of organic acid salts include carboxylates such as sodium acetate and sodium (meth)acrylate. Among these, inorganic acid salts are preferred from the viewpoint of improving the yield of the target product, 3-(meth)acryloylsulfolane. Specific examples include carbonates such as sodium carbonate, potassium carbonate, lithium carbonate, calcium carbonate, and magnesium carbonate; bicarbonates such as sodium bicarbonate and potassium bicarbonate; sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, rubidium sulfate, cesium sulfate, calcium sulfate, and magnesium sulfate; phosphates such as trilithium phosphate, trisodium phosphate, and tripotassium phosphate; monohydrogen phosphates such as disodium hydrogen phosphate and dipotassium hydrogen phosphate; dihydrogen phosphates such as sodium dihydrogen phosphate and potassium dihydrogen phosphate; pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; chlorates such as sodium chloride and potassium chloride; bromates such as sodium bromide and potassium bromide; and borates such as sodium borate and potassium borate. Among these inorganic acid salts, carbonates such as sodium carbonate and potassium carbonate are preferred from the viewpoint of improving the yield of the target product, 3-(meth)acryloylsulfolane.

[0039] Examples of inorganic oxides include silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, tin oxide, lead oxide, titanium oxide, zirconium oxide, zinc oxide, yttrium oxide, etc. Among these, from the viewpoint of improving the yield of the target product, 3-(meth)acryloylsulfolane, magnesium oxide, zinc oxide, etc. are preferred, and magnesium oxide is more preferred.

[0040] The amount of the inorganic compound used is preferably 0.01 to 5 mol % relative to 3-hydroxysulfolane, and from the standpoints of cost and ease of processing the inorganic compound, it is more preferably 0.1 to 2 mol %.

[0041] <Reaction conditions, etc.> The reaction pressure when carrying out the reaction is not particularly limited, and the reaction can be carried out under reduced pressure, normal pressure, or increased pressure. The reaction temperature during the reaction varies depending on the reaction pressure. For example, when the (meth)acrylic acid derivative is a (meth)acrylic acid halide, the reaction temperature is preferably −20° C. to 60° C., and more preferably −10° C. to 40° C. On the other hand, when the (meth)acrylic acid derivative is a (meth)acrylic acid anhydride, the reaction temperature is preferably 20° C. to 130° C., and more preferably 40° C. to 110° C. When the reaction temperature is equal to or higher than the lower limit, the reaction rate and the yield of the target product, 3-(meth)acryloylsulfolane, can be further increased. When the reaction temperature is equal to or lower than the upper limit, the polymerization of the (meth)acrylic acid derivative and the target product, 3-(meth)acryloylsulfolane, can be more reliably prevented. The reaction time is preferably 0.5 to 50 hours, and from the viewpoint of practicality and efficiency, more preferably 1 to 36 hours.

[0042] According to the method of the present invention, the reaction can be carried out at a lower reaction temperature than in conventional transesterification methods, and therefore there is little need to take measures to prevent polymerization in the reaction system. However, in order to more reliably prevent polymerization of the (meth)acrylic acid derivative and the target product, 3-(meth)acryloylsulfolane, adding a polymerization inhibitor to the reaction system is also a preferred embodiment of the present invention. The type of polymerization inhibitor is not particularly limited. One type of polymerization inhibitor may be used, or two or more types may be used in combination.

[0043] Examples of polymerization inhibitors include phenolic compounds such as hydroquinone, p-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 4-tert-butylcatechol, 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), and 2-sec-butyl-4,6-dinitrophenol; N,N-diisopropylparaphenylenediamine, N,N-di-2-naphthylparaphenylenediamine, and N-phenylene-N- Examples include amine compounds such as (1,3-dimethylbutyl)paraphenylenediamine, N,N'-bis(1,4-dimethylphenyl)-paraphenylenediamine, and N-(1,4-dimethylphenyl)-N'-phenyl-paraphenylenediamine; N-oxyl compounds such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)sebacate; and metal compounds such as copper, copper(II) chloride, and iron(III) chloride.

[0044] The amount of the polymerization inhibitor used can be set appropriately. For example, it is preferably 50 ppm or more relative to the (meth)acrylic acid derivative used, and more preferably 100 ppm or more to obtain a sufficient polymerization inhibitory effect. On the other hand, from the viewpoint of cost, the amount of the polymerization inhibitor used is preferably 10,000 ppm or less, and from the viewpoint of coloring of the product and convenience in use, it is more preferably 5,000 ppm or less.

[0045] It is also preferable to bubble an oxygen-containing gas such as air into the reaction solution to prevent polymerization. The amount of oxygen-containing gas introduced can be appropriately set so as to obtain the desired polymerization-inhibiting effect. For example, when air is used as the oxygen-containing gas, it is preferable to bubble it at a rate of 0.5 to 3.0 mL / min per mole of the (meth)acrylic acid derivative used. From the viewpoint of amplifying the polymerization-inhibiting effect, it is particularly preferable to add a polymerization inhibitor to the reaction solution and simultaneously introduce an oxygen-containing gas such as air into the reaction solution while carrying out the reaction.

[0046] The reaction is preferably carried out in an organic solvent, examples of which include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ethers such as tetrahydrofuran, t-butyl methyl ether, and diisopropyl ether, esters such as ethyl acetate, nitriles such as acetonitrile, aromatic compounds such as toluene and xylene, and hydrocarbons such as hexane, heptane, and cyclohexane.

[0047] The reactor used in the reaction may be a known one, and may be a batch reactor or a continuous reactor. Examples of continuous reactors include a fixed bed flow reactor, a fluidized bed reactor, and a continuous stirring reactor.

[0048] After the reaction is completed, it is preferable to recover the inorganic compound and unreacted 3-hydroxysulfolane by a known purification method such as washing with an alkaline aqueous solution or an acid aqueous solution, washing with water, or filtration, as necessary, and purify the target product, 3-(meth)acryloylsulfolane. 3-(meth)acryloylsulfolane is usually a solid at room temperature, and can be purified by known purification methods such as vacuum distillation and recrystallization. [Example]

[0049] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. The reaction was followed by gas chromatography (Agilent, 6890N GC), and the yield of 3-methacryloyloxysulfolane was calculated from the peak area of the peak derived from each raw material compound using the following formula. Yield of 3-methacryloyloxysulfolane (%) = [3-methacryloyloxysulfolane ratio (%) / (3-hydroxysulfolane ratio (%) + 3-methacryloyloxysulfolane ratio (%))] × 100 (In the formula, "ratio (%) of 3-methacryloyloxysulfolane" and "ratio (%) of 3-hydroxysulfolane" mean the area ratio (%) of the peak derived from 3-methacryloyloxysulfolane and the area ratio (%) of the peak derived from 3-hydroxysulfolane, respectively, relative to the total area (100%) of peaks in a chromatogram obtained by gas chromatography analysis of the reaction product.) 3-Hydroxysulfolane synthesized according to the method described in Patent Document 1 was used.

[0050] Example 1 A glass flask was charged with 1.00 g (7.3 mmol) of crude 3-hydroxysulfolane (containing 2-sulfolene as an impurity, with the peak area attributable to 2-sulfolene accounting for 4.0% of the total area (100%) of peaks in the chromatogram obtained by gas chromatography), 1.36 g (8.8 mmol) of methacrylic anhydride, 3.1 mL of methyl ethyl ketone, 78 mg (0.7 mmol) of sodium carbonate, and 1.0 mg (4.5 μmol) of 2,6-di-tert-butyl-4-methylphenol, and the mixture was stirred at 75°C for 2 hours. After completion of the reaction, gas chromatography analysis confirmed that the yield of 3-methacryloyloxysulfolane was 89%. Furthermore, the 2-sulfolene content was 4.4%, suggesting that it was not increased by side reactions. The results are shown in Table 1.

[0051] <Example 2> The same procedure as in Example 1 was repeated except that potassium carbonate was used instead of sodium carbonate. The results are shown in Table 1. The yield of 3-methacryloyloxysulfolane was 90%.

[0052] Example 3 The same procedure as in Example 1 was repeated, except that crude 3-hydroxysulfolane was replaced with purified 3-hydroxysulfolane (containing 2-sulfolene as an impurity at an area ratio of 6.3%) purified by thin-film distillation. The results are shown in Table 1. The yield of 3-methacryloyloxysulfolane was 89%.

[0053] Example 4 The same procedure as in Example 3 was repeated except that potassium carbonate was used instead of sodium carbonate. The results are shown in Table 1. The yield of 3-methacryloyloxysulfolane was 89%.

[0054] <Example 5> The same procedure as in Example 3 was repeated except that magnesium oxide was used instead of sodium carbonate. The results are shown in Table 1. The yield of 3-methacryloyloxysulfolane was 70%.

[0055] Example 6 A glass flask was charged with 1.00 g (7.3 mmol) of crude 3-hydroxysulfolane (containing 4.0% of 2-sulfolene as an impurity, based on the area ratio), 7.3 mL of methyl ethyl ketone, and 1.12 g (8.1 mmol) of potassium carbonate, and the mixture was cooled to 0°C. 0.78 mL (8.1 mmol) of methacrylic acid chloride was added dropwise, and the mixture was stirred at 0°C for 1 hour, followed by stirring at room temperature for 4 hours. After completion of the reaction, gas chromatography analysis confirmed that the yield of 3-methacryloyloxysulfolane was 97%. The results are shown in Table 1.

[0056] <Comparative Example 1> The same procedure as in Example 6 was repeated except that potassium carbonate was replaced with triethylamine. The results are shown in Table 3. The yield of 3-methacryloyloxysulfolane was 21%.

[0057] [Table 3]

[0058] As shown in Table 3, by reacting methacrylic anhydride with 3-hydroxysulfolane in the presence of an inorganic salt or an inorganic oxide, 3-methacryloyloxysulfolane could be produced in high yields (70-90%) at a sufficiently high reaction rate, regardless of whether the 3-hydroxysulfolane was crude or purified (Examples 1 to 5). Furthermore, when methacrylic acid chloride was reacted with crude 3-hydroxysulfolane in the presence of an inorganic salt, 3-methacryloyloxysulfolane could be produced at a sufficiently high reaction rate in a very high yield (97%) (Example 6). Furthermore, in all Examples, no increase in 2-sulfolene, which has a boiling point close to that of the target product, 3-methacryloylsulfolene, and is difficult to separate in the purification step (distillation), was observed. On the other hand, in Comparative Example 1 in which methacrylic acid chloride was reacted with crude 3-hydroxysulfolane in the presence of triethylamine, the yield of 3-methacryloyloxysulfolane was as low as 21%, which was significantly poor.

Claims

1. The following formula (I) 【Chemical 1】 and 3-hydroxysulfolane represented by the following formula (II): 【Chemistry 2】 [In formula (II), R １ represents a hydrogen atom or a methyl group, and Y represents a group represented by the following formula (II-a) or a halogen atom: 【Chemistry 3】 (In formula (II-a), R ２ represents a hydrogen atom or a methyl group, and * represents a bond. in the presence of at least one compound selected from the group consisting of alkali metal salts, alkaline earth metal salts, silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, tin oxide, lead oxide, titanium oxide, zirconium oxide, zinc oxide, and yttrium oxide, However, when Y in the formula (II) is a halogen atom, the compound is at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts. Method for producing 3-(meth)acryloyl sulfolane.

2. The method for producing 3-(meth)acryloyl sulfolane according to claim 1, wherein the (meth)acrylic acid derivative is (meth)acrylic anhydride represented by the following formula (II-b): 【Chemistry 4】 (In formula (II-b), R １ and R ２ is as defined above, and R １ and R ２ may be the same or different.)

3. The method for producing 3-(meth)acryloyl sulfolane according to claim 1, wherein the (meth)acrylic acid derivative is a (meth)acrylic acid halide.

4. 2. The method for producing 3-(meth)acryloylsulfolane according to claim 1, wherein when Y in formula (II) is a group represented by formula (II-a), the compound is at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, magnesium oxide, and zinc oxide.

5. The method for producing 3-(meth)acryloylsulfolane according to any one of claims 1 to 4, wherein the compound is at least one carbonate selected from the group consisting of lithium carbonate, sodium carbonate, potassium carbonate, calcium carbonate, and magnesium carbonate.

6. The method for producing 3-(meth)acryloyl sulfolane according to claim 1, wherein the 3-hydroxysulfolane is obtained by treating 3-sulfolene with an aqueous alkali solution to obtain an aqueous solution containing the 3-hydroxysulfolane (hydration step).

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