Process for producing a hexafluoroisopropyl ester of an unsaturated carboxylic acid

Abstract

To provide a method for industrially advantageously manufacturing unsaturated carboxylic acid hexafluoro isopropyl ester with a simple operation, high yield and in an economic view point.SOLUTION: The present invention pertains to a manufacturing method of an ester represented by the following formula (1): [In formula (1), X represents a hydrogen atom, a halogen atom, or a methyl group], which comprises contacting hexafluoroisopropanol and an unsaturated carboxylic acid halide represented by the following formula (2) in a mixed solvent containing a water-immiscible organic solvent and water.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a hexafluoroisopropyl ester of an unsaturated carboxylic acid.

Background Art

[0002] Hexafluoroisopropyl esters of unsaturated carboxylic acids are useful compounds as raw material monomers for polymers and the like. For example, hexafluoroisopropyl α-chloroacrylate, which is one of the hexafluoroisopropyl esters of unsaturated carboxylic acids, is used as a raw material monomer for a copolymer used as a main-chain scission type positive resist in the field of semiconductor manufacturing and the like (see, for example, Patent Document 1).

[0003] As a method for producing such a hexafluoroisopropyl ester of an unsaturated carboxylic acid, for example, Patent Document 2 discloses a method of reacting methacrylic acid chloride with 1,1,1,3,3,3-hexafluoroisopropanol (hereinafter sometimes simply referred to as "hexafluoroisopropanol") in pyridine under heating conditions, and a method of reacting acrylic acid with trifluoroacetic anhydride as a dehydrating condensing agent to form acrylic anhydride, and further reacting this acrylic anhydride with hexafluoroisopropanol.

[0004] Further, Patent Document 3 discloses a method of reacting hexafluoroisopropanol with methacrylic acid in the presence of phosphoric anhydride as a dehydrating condensing agent as a method for producing a hexafluoroisopropyl ester of an unsaturated carboxylic acid.

[0005] Furthermore, Patent Document 4 discloses a method for producing a hexafluoroisopropyl ester of an unsaturated carboxylic acid, characterized in that water coexists as a solvent when reacting hexafluoroisopropanol with acrylic anhydride or methacrylic anhydride in the presence of a base.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] Here, hexafluoroisopropanol, which is a raw material for unsaturated carboxylic acid hexafluoroisopropyl ester, contains two trifluoromethyl groups, which are strong electron-withdrawing groups, and is a secondary alcohol with a high acidity. Therefore, its reactivity is low, and the esterification reaction of unsaturated carboxylic acid hardly occurs. For this reason, in the method of reacting methacrylic acid chloride disclosed in Patent Document 2 with hexafluoroisopropanol in pyridine, even under heating conditions, the yield of unsaturated carboxylic acid hexafluoroisopropyl ester is extremely low. Also, in the method of reacting acrylic acid with trifluoroacetic anhydride as a dehydrating condensing agent to produce acrylic anhydride and further reacting this acrylic anhydride with hexafluoroisopropanol, the yield of unsaturated carboxylic acid hexafluoroisopropyl ester is low.

[0008] In the method of Patent Document 3, although unsaturated carboxylic acid hexafluoroisopropyl ester can be obtained in a relatively high yield, since phosphoric anhydride, which is a dehydrating condensing agent, easily absorbs moisture, there is a problem that it is very difficult to handle. Further, the phosphoric anhydride after the reaction reacts with water to form phosphoric acid, which makes the reaction mixture viscous, and thus there is also a problem that it becomes difficult to take out this reaction mixture from the reactor. Furthermore, when acrylic acid is used as a raw material, the yield of the resulting ester is low and oligomers are formed. Therefore, in the method of Patent Document 2, it is necessary to use methacrylic acid as a raw material, that is, there is also a problem that only methacrylic acid hexafluoroisopropyl ester can be obtained as a product.

[0009] In the method of Patent Document 4, since water is used as a solvent, separation and purification of the product after the reaction are easy, and unsaturated carboxylic acid hexafluoroisopropyl ester can be obtained in a high yield. However, it is difficult to obtain acrylic anhydride and methacrylic anhydride, which are raw materials, in high purity and in large quantities. As a result, acrylic anhydride and methacrylic anhydride tend to be very expensive. Therefore, there is a problem that it is disadvantageous to use these raw materials from the viewpoint of economy industrially.

[0010] The present invention has been made under such circumstances, and an object of the present invention is to provide a method for producing unsaturated carboxylic acid hexafluoroisopropyl ester with good yield by a simple operation and advantageously industrially in terms of economy.

Means for Solving the Problems

[0011] The present inventor has intensively studied to achieve the above object. Then, the present inventor has found that when hexafluoroisopropanol and an unsaturated carboxylic acid halide are brought into contact under a predetermined mixed solvent, unsaturated carboxylic acid hexafluoroisopropyl ester can be produced with good yield by a simple operation and advantageously industrially in terms of economy, and has completed the present invention.

[0012] That is, the object of the present invention is to advantageously solve the above problems, and the present invention provides the following formula (1): [Chemical formula] [In formula (1), X represents a hydrogen atom, a halogen atom, or a methyl group.] A method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester represented by the formula (1), comprising 1,1,1,3,3,3-hexafluoroisopropanol and the following formula (2): [Chemical formula] [In formula (2), X is the same as X in formula (1), and Y represents a halogen atom selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.] A method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester represented by the formula (1), comprising contacting an unsaturated carboxylic acid halide with a mixed solvent containing a water-immiscible organic solvent and water, wherein the mixed solvent contains at least one alkali metal salt selected from the group consisting of alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal phosphates, and alkali metal hydrogen phosphates, and a phase transfer catalyst. Such a method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester can produce an unsaturated carboxylic acid hexafluoroisopropyl ester with a good yield by a simple operation and is industrially advantageous in terms of economy.

[0013] In the method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention, the phase transfer catalyst is preferably at least one salt selected from the group consisting of alkylammonium halide salts and alkylammonium sulfate salts. If the phase transfer catalyst is at least one salt selected from the above-listed group, an unsaturated carboxylic acid hexafluoroisopropyl ester can be produced with a better yield by a simpler operation and is more industrially advantageous in terms of economy.

[0014] In the method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention, the unsaturated carboxylic acid halide represented by the formula (2) is preferably at least one compound selected from the group consisting of acrylic acid chloride, α-chloroacrylic acid chloride, and α-bromoacrylic acid chloride. If the unsaturated carboxylic acid halide represented by the formula (2) is at least one compound selected from the above-listed group, the unsaturated carboxylic acid hexafluoroisopropyl ester can be produced more industrially advantageously in terms of economy.

[0015] In the method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention, X in the formula (1) is preferably a hydrogen atom, a chlorine atom, or a methyl group. Since the unsaturated carboxylic acid hexafluoroisopropyl ester in which X in the formula (1) is a hydrogen atom, a chlorine atom, or a methyl group has good stability, it can be more advantageously used as a monomer used in the production of polymers.

Effects of the Invention

[0016] According to the present invention, a method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester with good yield by a simple operation and industrially advantageously in terms of economy can be provided.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described in detail. Here, the unsaturated carboxylic acid hexafluoroisopropyl ester produced using the method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention is not particularly limited, and for example, it can be advantageously used as a monomer used in the production of polymers. Specifically, it can be advantageously used for the production of polymers that are preferably used as main-chain cleavage type positive resists and whose main chains are cleaved by irradiation with ionizing radiation such as electron beams or short-wavelength light such as ultraviolet light to reduce the molecular weight.

[0018] (Method for producing unsaturated carboxylic acid hexafluoroisopropyl ester) The method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention includes a step of contacting 1,1,1,3,3,3-hexafluoroisopropanol ((CF3)2CHOH) with an unsaturated carboxylic acid halide represented by the formula (2) described below in a mixed solvent containing a water-immiscible organic solvent and water. The mixed solvent also contains at least one alkali metal salt selected from the group consisting of alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal phosphates, and alkali metal hydrogen phosphates, and a phase transfer catalyst. According to the method for producing the unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention, the unsaturated carboxylic acid hexafluoroisopropyl ester can be produced in good yield by simple operations and in an industrially advantageous manner in terms of economic efficiency. The reason why the unsaturated carboxylic acid hexafluoroisopropyl ester can be produced in good yield by simple operations is not necessarily clear, but is presumed to be as follows.

[0019] First, hexafluoroisopropanol, which is a raw material for unsaturated carboxylic acid hexafluoroisopropyl ester, has six fluorine atoms, but has the property of being mixed with water in any ratio, so water can be suitably used as a solvent. In addition, hexafluoroisopropanol has two trifluoromethyl groups with very large electron-withdrawing properties, so it has the property of being highly acidic among alcohols. In the present invention, by using it in a mixed solvent containing a water-immiscible organic solvent and water, in water, from hexafluoroisopropanol and an alkali metal salt acting as a base, a hexafluoroisopropoxide salt (since it is dissolved in water, it may exist in an ion-dissociated state) is formed by a weak acid-alkali reaction. When the formed hexafluoroisopropoxide salt comes into contact with an unsaturated carboxylic acid halide, it is considered that an unsaturated carboxylic acid hexafluoroisopropyl ester is generated. And, since the generated unsaturated carboxylic acid hexafluoroisopropyl ester exists in the water-immiscible organic solvent and the by-produced alkali metal halide exists in water, the unsaturated carboxylic acid hexafluoroisopropyl ester can be easily separated. Further, the phase transfer catalyst contained in the mixed solvent facilitates the contact between the hexafluoroisopropoxide salt and the unsaturated carboxylic acid halide, and as a result, the production of the unsaturated carboxylic acid hexafluoroisopropyl ester can be promoted. For the above reasons, it is considered that the unsaturated carboxylic acid hexafluoroisopropyl ester can be produced with good yield by a simple operation.

[0020] <Unsaturated carboxylic acid halide> The unsaturated carboxylic acid halide used in the method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention is a compound represented by the following formula (2). [Chemical formula]

[0021] In the formula (2), X is the same as X in the formula (1) described below. That is, in the formula (2), X represents a hydrogen atom, a halogen atom or a methyl group. Since the unsaturated carboxylic acid halide represented by the formula (2) is relatively inexpensive and can be obtained, by using this as a raw material, the unsaturated carboxylic acid hexafluoroisopropyl ester can be industrially advantageously produced in terms of economy. Examples of the unsaturated carboxylic acid halide represented by the formula (2) include acrylic acid chloride; methacrylic acid chloride, α-fluoroacrylic acid chloride, α-chloroacrylic acid chloride, α-bromoacrylic acid chloride, α-iodoacrylic acid chloride and other α-substituted acrylic acid chlorides; acrylic acid bromide; methacrylic acid bromide, α-chloroacrylic acid bromide, α-bromoacrylic acid bromide and other α-substituted acrylic acid bromides. Among these, at least one compound selected from the group consisting of acrylic acid chloride, methacrylic acid chloride, α-fluoroacrylic acid chloride, α-chloroacrylic acid chloride and α-bromoacrylic acid chloride is preferably used because it is cheaper, easier to obtain, and more industrially advantageous in terms of economy. More preferably, at least one compound selected from the group consisting of acrylic acid chloride, α-chloroacrylic acid chloride and α-bromoacrylic acid chloride is used.

[0022] Since acrylic acid chloride, methacrylic acid chloride, etc. are industrially produced, commercially available products can be used as they are. α-Substituted unsaturated carboxylic acid halides in which the α-position is substituted with a halogen atom can be synthesized according to the methods described in the following literature. α-Fluoroacrylic acid chloride can be synthesized, for example, according to the method described in JP-T-2004-505939. Specifically, 2-chloro-2-fluoropropionic acid obtained by reacting 2,2-dichloropropionic acid with hydrogen fluoride is treated with sodium hydroxide to form 2-fluoroacrylic acid, and the obtained 2-fluoroacrylic acid is mixed with thionyl chloride and heated under reflux to obtain the target 2-fluoroacrylic acid chloride (α-fluorine atom fluoroacrylic acid chloride). α-Chloroacrylic acid chloride can be synthesized, for example, according to the method described in JP-A-2002-173467. Specifically, α-chloroacrylic acid chloride can be obtained by reacting α-chloroacrylic acid with thionyl chloride or oxalyl chloride. α-bromoacryloyl chloride can be synthesized, for example, according to the method described in JP-A-2005-126340. Specifically, 2,3-dibromopropionyl chloride is reacted with triethylamine and dehydrogenated to obtain 2-bromoacryloyl chloride (α-bromoacryloyl chloride).

[0023] The amount of the unsaturated carboxylic acid halide represented by the formula (1) used is preferably 1.1 mol or more, more preferably 1.5 or more, preferably 3 mol or less, and more preferably 2.5 mol or less per 1 mol of hexafluoroisopropanol as a raw material. If the amount of the unsaturated carboxylic acid halide represented by the formula (1) used is at least the above lower limit, the yield of the target unsaturated carboxylic acid hexafluoroisopropyl ester can be improved. On the other hand, if the amount of the unsaturated carboxylic acid halide represented by the formula (1) used is at most the above upper limit, the co-occurrence of undesirable side reactions such as the formation of oligomers of acrylic acids can be suppressed.

[0024] <Alkali metal salt> The alkali metal salt used in the method for producing the unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention is at least one metal salt selected from the group consisting of alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal phosphates, and alkali metal hydrogen phosphates. Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, and the like. Examples of the alkali metal hydrogen carbonate include sodium hydrogen carbonate, potassium hydrogen carbonate, cesium hydrogen carbonate, and the like. Examples of the alkali metal phosphate include trisodium phosphate, tripotassium phosphate, and the like. Examples of the alkali metal hydrogen phosphate include disodium hydrogen phosphate, dipotassium hydrogen phosphate, and the like. Since an alkali metal salt can efficiently form a hexafluoroisopropoxide salt in water, it is preferably an alkali metal carbonate such as sodium carbonate, potassium carbonate, cesium carbonate, etc. From the viewpoint of economy, it is more preferably at least one alkali metal salt selected from the group consisting of sodium carbonate and potassium carbonate. Since an unsaturated carboxylic acid hexafluoroisopropyl ester can be produced in a higher yield, potassium carbonate is even more preferable.

[0025] The amount of the alkali metal salt used is preferably 1 mol or more, more preferably 1.2 mol or more, preferably 3 mol or less, and more preferably 2 mol or less per 1 mol of hexafluoroisopropanol as a raw material. If the amount of the alkali metal salt used is not less than the above lower limit, a hexafluoroisopropoxide salt can be efficiently formed in water, and the yield of the unsaturated carboxylic acid hexafluoroisopropyl ester can be improved. On the other hand, if the amount of the alkali metal salt used is not more than the above upper limit, insufficient dissolution in water and precipitation of the alkali metal salt during the reaction can be suppressed, and the post-treatment can be facilitated.

[0026] <Mixed solvent> The mixed solvent used in the method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention contains a water-immiscible organic solvent and water. The mixed solvent also contains at least one alkali metal salt selected from the group consisting of alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal phosphates, and alkali metal hydrogen phosphates, and a phase transfer catalyst.

[0027] The amount of water contained in the mixed solvent is not particularly limited as long as it can dissolve the alkali metal salt, but is preferably 2 times or more, more preferably 3 times or more, preferably 50 times or less, and more preferably 10 times or less by mass based on the hexafluoroisopropanol as a raw material. If the amount of water is equal to or greater than the above lower limit, it is possible to suppress the concentration of the alkali metal salt from becoming too high, suppress the reaction from proceeding abruptly, and suppress the occurrence of undesirable side reactions. On the other hand, if the amount of water is equal to or less than the above upper limit, the amount of wastewater is reduced, and the post-treatment after the reaction can be facilitated.

[0028] The water-immiscible organic solvent contained in the mixed solvent is a solvent that is essentially immiscible with water. As the water-immiscible organic solvent, it is preferable to use a solvent having a boiling point higher than that of the target unsaturated carboxylic acid hexafluoroisopropyl ester. With such a water-immiscible organic solvent, the produced unsaturated carboxylic acid hexafluoroisopropyl ester and the water-immiscible organic solvent can be easily separated by distillation or the like. The water-immiscible organic solvent can be appropriately selected according to the type of the unsaturated carboxylic acid hexafluoroisopropyl ester. For example, ether solvents such as cyclopentyl methyl ether, 4-methyltetrahydropyran, and dibutyl ether, aromatic hydrocarbon solvents such as toluene, xylene, benzotrifluoride, bis(trifluoromethyl)benzene, and chlorobenzene can be mentioned. Among these, inexpensive solvents such as toluene, xylene, benzotrifluoride, and bis(trifluoromethyl)benzene can be preferably used. Also, although the reason is not clear, since the unsaturated carboxylic acid hexafluoroisopropyl ester can be produced with a higher yield, toluene or xylene can be preferably used as the water-immiscible organic solvent.

[0029] The amount of the water-immiscible organic solvent contained in the mixed solvent is preferably 0.5 times or more, more preferably 1 time or more, preferably 5 times or less, and more preferably 2 times or less, based on volume, relative to the amount of water. If the amount of the water-immiscible organic solvent used is equal to or greater than the above lower limit, the extraction amount of the target unsaturated carboxylic acid hexafluoroisopropyl ester increases, and the yield can be improved. On the other hand, if the amount of the water-immiscible organic solvent used is equal to or less than the above upper limit, it is possible to suppress the excessive amount used and produce the unsaturated carboxylic acid hexafluoroisopropyl ester economically advantageously. In addition, in this specification, the "amount of the water-immiscible organic solvent contained in the mixed solvent" means the amount of the water-immiscible organic solvent contained in the mixed solvent when hexafluoroisopropanol and an unsaturated carboxylic acid halide are brought into contact (reacted).

[0030] <Phase transfer catalyst> The phase transfer catalyst used in the method for producing the hexafluoroisopropyl unsaturated carboxylic acid ester of the present invention is not particularly limited as long as it is generally used in the reaction of a two-phase mixed solvent. For example, quaternary ammonium halides, quaternary phosphonium halides, and other quaternary salts; polyethers such as crown ethers and polyoxyalkylene glycols; amino alcohols, etc. Among these, quaternary salts are particularly preferred because they exist on the aqueous phase side after the reaction and are easy to separate. Quaternary salts consist of a cation (positive ion) formed by bonding four carbon-containing substituents to a heteroatom such as a nitrogen atom and a phosphorus atom, and a counter anion (negative ion).

[0031] The heteroatom is not particularly limited as long as it is an atom in Group 5B of the periodic table, but nitrogen atoms and phosphorus atoms are preferred. Since it has good compatibility with the hexafluoroisopropoxide ion formed in water and can improve the yield of the product, a nitrogen atom is particularly preferred. Further, when an unsaturated carboxylic acid chloride is used as the starting unsaturated carboxylic acid halide, a nitrogen atom is particularly preferred as the heteroatom because of its good compatibility with the chlorine atom. The carbon numbers of the four carbon-containing substituents of the heteroatom are not particularly limited, but are usually 1 or more and 30 or less, preferably 1 or more and 20 or less. Such carbon-containing substituents are not particularly limited as long as they contain carbon directly bonded to the heteroatom, and examples thereof include an alkyl group, an aryl group, an aralkyl group, an alkenyl group, and an alkynyl group. These carbon-containing substituents may include substituents that do not affect the reaction, such as an alkoxy group, a halogen atom, and an alkylthio group; and divalent substituents that do not affect the reaction, such as a carbonyl group, a sulfonyl group, and a sulfinyl group, within the structure of the carbon-containing substituent. Further, the carbon-containing substituents may be bonded to each other to form a ring. The carbon-containing substituents are preferably an alkyl group, an aryl group, and an aralkyl group.

[0032] Specific examples of the carbon-containing substituent include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a lauryl group, and a hexadecyl group; an aryl group such as a phenyl group, a 2-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, and a naphthyl group; and an aralkyl group such as a benzyl group, a 2-methylbenzyl group, a 4-methylbenzyl group, a 2-methoxybenzyl group, and a 4-methoxybenzyl group. In addition, examples of the quaternary salts in which the carbon-containing substituents are bonded to each other to form a ring include pyridinium and picolinium when the carbon-containing substituent is cyclic and bonded to a nitrogen atom. These carbon-containing substituents may have substituents that do not affect the reaction.

[0033] The quaternary salts preferably have three or more carbon-containing substituents having 2 or more carbon atoms, more preferably 3 or more carbon atoms, preferably 7 or less carbon atoms, and more preferably 5 or less carbon atoms bonded to the heteroatom. For quaternary salts having three or more carbon-containing substituents within the above range of carbon numbers, the yield of the hexafluoroisopropyl ester of the unsaturated carboxylic acid can be improved. The reason is not clear, but it is presumed to be due to the interaction with the hexafluoroisopropoxide ion formed in water and the solubility of the resulting cation in a water-immiscible organic solvent.

[0034] Examples of the counter anion (negative ion) include, for example, halides, hydroxides, hydrogen sulfate ions, etc., preferably halides or hydrogen sulfate ions, and more preferably halides. The halide is not particularly limited, and specifically, fluoride, bromide, chloride, iodide can be mentioned, and bromide and chloride are preferred.

[0035] Specific examples of the quaternary salts include quaternary ammonium halides, quaternary phosphonium halides, quaternary ammonium hydroxides, quaternary phosphonium hydroxides, quaternary ammonium hydrogen sulfate salts, quaternary phosphonium hydrogen sulfate salts, etc. Among these, quaternary ammonium halides, quaternary ammonium hydrogen sulfate salts or quaternary phosphonium halides are preferred, and quaternary ammonium halides or quaternary ammonium hydrogen sulfate salts are more preferred because they have good compatibility with hexafluoroisopropoxide ions formed in water and can improve the yield of unsaturated carboxylic acid hexafluoroisopropyl esters, and quaternary ammonium halides are even more preferred.

[0036] Specific examples of the quaternary ammonium halides include, for example, tetramethylammonium bromide, tetramethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrabutylammonium chloride, cetyltrimethylammonium bromide, benzyltriethylammonium chloride, trioctylmethylammonium chloride, etc. Examples of the quaternary ammonium hydrogen sulfate salts include tetramethylammonium hydrogen sulfate, tetrabutylammonium hydrogen sulfate, etc. Examples of the quaternary phosphonium halides include tetrabutylphosphonium bromide, benzyltriphenylphosphonium chloride, butyltriphenylphosphonium bromide, etc. Among those listed above, tetrabutylammonium bromide, tetrabutylammonium chloride, cetyltrimethylammonium bromide, benzyltriethylammonium chloride, trimethylbenzylammonium bromide, and tetrabutylammonium hydrogensulfate are preferred, and tetrabutylammonium bromide and tetrabutylammonium hydrogensulfate are more preferred.

[0037] Examples of the crown ethers include crown ethers such as 15-crown-5, 18-crown-6, dibenzo-18-crown-6, dibenzo-24-crown-8, and dicyclohexyl-18-crown-6. Examples of the polyoxyalkylene glycols include polyethylene glycol, polypropylene glycol, and polyethylene glycol monomethyl ether. Examples of the amino alcohols include tris[2-(2-methoxyethoxy)ethyl]amine and cryptate.

[0038] The phase transfer catalysts described above can be used alone or in combination of two or more.

[0039] The amount of the phase transfer catalyst used can be appropriately selected according to the reaction conditions. However, it is usually 0.001 mol or more, preferably 0.01 mol or more, more preferably 0.03 mol, usually 1 mol or less, preferably 0.1 mol or less, and more preferably 0.07 mol or less per 1 mol of hexafluoroisopropanol as the raw material.

[0040] <Additive> In the method for producing the unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention, an additive may be used within a range not contrary to the purpose. Examples of the additive include a polymerization inhibitor.

[0041] In the method for producing a hexfluoroisopropyl ester of an unsaturated carboxylic acid of the present invention, in order to prevent unexpected side reactions (polymerization) during the reaction, a polymerization inhibitor may be added to the reaction system as necessary. Examples of the polymerization inhibitor include phenolic compounds such as hydroquinone, p-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, tert-butyl-catechol, 2,6-di-tert-butyl-4-methylphenol, pentaerythritol, tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), 2-sec-butyl-4,6-dinitrophenol; amine compounds such as N,N'-diisopropyl paraphenylenediamine, N,N'-di-2-naphthyl paraphenylenediamine, N-phenylene-N'-(1,3-dimethylbutyl) paraphenylenediamine, N,N'-bis(1,4-dimethylphenyl)-paraphenylenediamine, 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, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate; metal compounds such as copper, copper(II) chloride, iron(III) chloride, etc.

[0042] The amount of the polymerization inhibitor used can be appropriately determined, but it is preferably 10 ppm or more, more preferably 50 ppm or more, based on the hexafluoroisopropanol as a raw material, because a good effect can be exhibited.

[0043] <Reaction conditions> In the method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester of the present invention, the contact between hexafluoroisopropanol and an unsaturated carboxylic acid halide is not particularly limited as long as it is carried out under the above-mentioned mixed solvent. For example, hexafluoroisopropanol can be added to an aqueous solution containing an alkali metal salt, and then a water-immiscible organic solvent and a phase transfer catalyst are added, and an unsaturated carboxylic acid halide is further dropped therein to carry out the reaction.

[0044] The temperature (reaction temperature) at which hexafluoroisopropanol and an unsaturated carboxylic acid halide are brought into contact is a temperature at which the aqueous solution of the alkali metal salt does not solidify and the reaction does not proceed excessively. It is preferably 0 °C or higher, more preferably 10 °C or higher, preferably 40 °C or lower, and more preferably 30 °C or lower. If the reaction temperature is at or above the above lower limit, the reaction rate can be efficiently advanced and the time until the reaction is completed can be shortened. On the other hand, if the reaction temperature is at or below the above upper limit, polymerization of raw materials, products, etc. can be suppressed.

[0045] The reaction time can be appropriately determined depending on the reaction temperature and the like, but it is preferably 0.5 hours or more, more preferably 1 hour or more, preferably 20 hours or less, and more preferably 10 hours or less. If the reaction time is at or above the above lower limit, the reaction can be completed and the yield can be improved. On the other hand, if the reaction time is at or below the above upper limit, polymerization of raw materials, products, etc. can be suppressed.

[0046] After the reaction is completed, for example, in order to separate the water-immiscible organic solvent phase and the aqueous phase, a step of allowing the mixed solvent containing the product to stand, a step of separating the water-immiscible organic solvent phase and the aqueous phase, a step of removing the aqueous phase from the separated mixed solvent, a step of washing the remaining water-immiscible organic solvent phase with a dilute acid such as dilute hydrochloric acid, saturated sodium bicarbonate water, and saturated brine, a step of drying (dehydrating) the washed water-immiscible organic solvent phase with a desiccant such as magnesium sulfate, and a step of distilling the dried water-immiscible organic solvent phase. Any step such as these may be carried out. Incidentally, the progress of the reaction can be monitored by gas chromatography or the like. The completion of the reaction can be confirmed by the disappearance of the raw material hexafluoroisopropanol.

[0047] <Hexafluoroisopropyl unsaturated carboxylate> The hexafluoroisopropyl unsaturated carboxylate obtained by the method for producing a hexafluoroisopropyl unsaturated carboxylate of the present invention is a compound represented by the following formula (1).

Chemical formula

[0048] In formula (1), X represents a hydrogen atom, a halogen atom or a methyl group. That is, examples of the hexafluoroisopropyl unsaturated carboxylate represented by formula (1) include hexafluoroisopropyl acrylate, hexafluoroisopropyl methacrylate, hexafluoroisopropyl α-fluoroacrylate, hexafluoroisopropyl α-chloroacrylate, hexafluoroisopropyl α-bromoacrylate, and hexafluoroisopropyl α-iodoacrylate. X in formula (1) has good stability and can be more advantageously used as a monomer used in the production of polymers. Therefore, it is preferably a hydrogen atom, a chlorine atom or a methyl group. That is, the hexafluoroisopropyl unsaturated carboxylate represented by formula (1) is preferably hexafluoroisopropyl acrylate, hexafluoroisopropyl α-chloroacrylate or hexafluoroisopropyl methacrylate.

Examples

[0049] Hereinafter, the present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited by the following examples. Unless otherwise specified, “%” represents “% by mass”.

[0050] The analysis conditions for the gas chromatography analysis (GC analysis) conducted in the examples and comparative examples are as follows.

[0051] <Analysis Conditions> Apparatus: Agilent-7890 (manufactured by Agilent Technologies) Column: Inert Cap-1 (manufactured by GL Sciences, length 60 m, inner diameter 0.25 mm, film thickness 1.5 μm) Column temperature: Held at 60 °C for 10 minutes, then heated to 260 °C at a heating rate of 20 °C / min, and then held at 260 °C for 10 minutes Injection temperature: 250 °C Detector temperature: 250 °C Carrier gas: Nitrogen Split ratio: 100 / 1 Detector: FID

[0052] [Synthesis Example 1] Synthesis of α-chloroacrylic acid chloride Into a 1 L three-necked flask equipped with a condenser and a dropping funnel, 53.3 g (0.5 mol) of 2-chloroacrylic acid, 2 g of p-methoxyphenol, and 300 ml of methylene chloride were added and dissolved. The flask (reactor) was immersed in a water bath, and the contents were stirred at room temperature. Then, 10 drops of N,N-dimethylformamide were added thereto. A solution prepared by dissolving 82.5 g (0.65 mol) of oxalyl chloride in 100 ml of methylene chloride was added dropwise into the reactor from the dropping funnel over 2 hours. During that time, the gas generated during the reaction was led from the top of the condenser into a gas washing bottle containing 500 ml of water. After the dropwise addition of oxalyl chloride was completed, the contents were stirred as they were for 1.5 hours, and then heated to 35 °C in a water bath. When the generation of gas stopped and the system became negative pressure about 40 minutes after the start of heating, the heating was stopped. Using a rotary evaporator, while heating to 35 °C, most of the methylene chloride and unreacted oxalyl chloride were distilled off from the contents in the reactor. 1 g of p-methoxyphenol was added to the obtained residual liquid, and distillation was carried out under a reduced pressure of 10 kPa. The fraction with a boiling point of 47 - 49 °C was collected to obtain 36 g of α-chloroacrylic acid chloride (yield: 57%).

[0053] [Synthesis Example 2] Production of α-bromoacrylic acid chloride 25 g (0.1 mol) of 2,3-dibromopropionic acid chloride and 120 ml of methylene chloride were placed in a 300-ml three-necked flask equipped with a condenser and a dropping funnel. The flask (reactor) was immersed in an ice-water bath, and while stirring the contents, 15.2 g (0.15 mol) of triethylamine was added dropwise from the dropping funnel over 25 minutes. Thirty minutes after the completion of the dropwise addition, the reactor was removed from the ice-water bath and stirred at room temperature for 1 hour. The salt formed by the reaction was removed by filtration under reduced pressure. While heating to 35°C using a rotary evaporator, most of the methylene chloride was distilled off from the obtained filtrate. Using the obtained residue, distillation was carried out under a reduced pressure of 2 kPa, and the fraction having a boiling point of 39 to 40°C was collected to obtain 12.5 g of α-bromoacrylic acid chloride (yield 74%).

[0054] [Example 1] To a 200 ml round-bottomed flask equipped with a dropping funnel and a stir bar, 10.36 g (0.075 mol) of potassium carbonate and 30 ml of water were added, and this was stirred to dissolve the potassium carbonate. The round-bottomed flask was immersed in an ice-water bath, and 8.4 g (0.05 mol) of 1,1,1,3,3,3-hexafluoroisopropanol was added. After stirring for about 10 minutes, 30 ml of toluene and 0.8 g (0.0025 mol) of tetrabutylammonium bromide as a phase transfer catalyst were added, and it was vigorously stirred. Then, 6.8 g (0.075 mol) of acryloyl chloride was added dropwise from the dropping funnel over about 20 minutes. After stirring the contents as they were for 30 minutes, stirring was continued at 20 °C for an additional 6 hours. The contents were transferred to a separatory funnel, and after separating the aqueous phase, the remaining water-immiscible organic solvent phase was washed with 20 ml each of hydrochloric acid (concentration: 5 mass %), saturated aqueous sodium bicarbonate, and saturated brine, and this was dried over magnesium sulfate. Magnesium sulfate was removed while washing with a small amount of toluene, and a 29.52 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 8.19 g of hexafluoroisopropyl acrylate was contained (yield: 73.7%).

[0055] [Example 2] In Example 1, various operations were carried out in the same manner as in Example 1 except that all of the toluene as the water-immiscible organic solvent was changed to cyclopentyl methyl ether, and a 26.67 g cyclopentyl methyl solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 7.12 g of hexafluoroisopropyl acrylate was contained (yield: 64.1%).

[0056] [Example 3] In Example 1, various operations were carried out in the same manner as in Example 1, except that 0.8 g (0.0025 mol) of tetrabutylammonium bromide as the phase transfer catalyst was changed to 0.57 g (0.0025 mol) of benzyltriethylammonium chloride, and a 28.46 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography, 7.92 g of hexafluoroisopropyl acrylate was contained (yield: 71.3%).

[0057] [Example 4] In Example 1, various operations were carried out in the same manner as in Example 1, except that 0.8 g (0.0025 mol) of tetrabutylammonium bromide as the phase transfer catalyst was changed to 0.43 g (0.0025 mol) of tetramethylammonium hydrogen sulfate, and a 24.81 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as the standard substance, 7.87 g of hexafluoroisopropyl acrylate was contained (yield: 70.9%).

[0058] [Example 5] In Example 1, various operations were carried out in the same manner as in Example 1, except that 0.8 g (0.0025 mol) of tetrabutylammonium bromide as the phase transfer catalyst was changed to 1.01 g (0.0025 mol) of trioctylmethylammonium chloride, and a 25.85 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as the standard substance, 6.73 g of hexafluoroisopropyl acrylate was contained (yield: 60.6%).

[0059] [Example 6] In Example 1, except that 0.8 g (0.0025 mol) of tetrabutylammonium bromide as the phase transfer catalyst was changed to 0.85 g (0.0025) of tetrabutylammonium hydrogensulfate, various operations were carried out in the same manner as in Example 1, and a 27.37 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as the standard substance, 8.38 g of hexafluoroisopropyl acrylate was contained (yield: 75.5%).

[0060] [Example 7] In Example 1, except that 0.8 g (0.0025 mol) of tetrabutylammonium bromide as the phase transfer catalyst was changed to 0.85 g (0.0025 mol) of tetrabutylphosphonium bromide, various operations were carried out in the same manner as in Example 1, and a 25.96 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as the standard substance, 6.64 g of hexafluoroisopropyl acrylate was contained (yield: 59.8%).

[0061] [Example 8] In Example 6, except that 10.36 g (0.075 mol) of potassium carbonate was changed to 5.83 g (0.075 mol) of sodium carbonate, various operations were carried out in the same manner as in Example 6, and a 29.75 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as the standard substance, 7.49 g of hexafluoroisopropyl acrylate was contained (yield: 67.5%).

[0062] [Example 9] In Example 6, various operations were carried out in the same manner as in Example 6 except that 10.36 g (0.075 mol) of potassium carbonate was changed to 7.51 g (0.075 mol) of potassium hydrogen carbonate, and a 29.24 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 6.92 g of hexafluoroisopropyl acrylate was contained (yield: 62.3%).

[0063] [Example 10] In Example 6, various operations were carried out in the same manner as in Example 6 except that 10.36 g (0.075 mol) of potassium carbonate was changed to 13.06 g (0.075 mol) of dipotassium hydrogen phosphate, and a 24.34 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 7.18 g of hexafluoroisopropyl acrylate was contained (yield: 64.6%).

[0064] [Example 11] In Example 6, various operations were carried out in the same manner as in Example 6 except that 10.36 g (0.075 mol) of potassium carbonate was changed to 10.65 g (0.075 mol) of disodium hydrogen phosphate, and a 25.86 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 7.02 g of hexafluoroisopropyl acrylate was contained (yield: 63.2%).

[0065] [Example 12] In Example 6, various operations were carried out in the same manner as in Example 6 except that 10.36 g (0.075 mol) of potassium carbonate was changed to 10.61 g (0.05 mol) of tripotassium phosphate, and a 30.05 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography, 7.48 g of hexafluoroisopropyl acrylate was contained (yield: 67.3%).

[0066] [Example 13] In Example 6, except that 6.8 g (0.075 mol) of acrylic acid chloride was changed to 7.8 g (0.075 mol) of methacrylic acid chloride and all of the non-aqueous miscible organic solvent toluene was changed to p-xylene, various operations were carried out in the same manner as in Example 6 to obtain 30.70 g of a p-xylene solution containing the product. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 9.826 g of hexafluoroisopropyl methacrylate was contained (yield: 83.2%).

[0067] [Example 14] In Example 13, except that 7.8 g (0.075 mol) of methacrylic acid chloride was changed to 9.38 g (0.075 mol) of 2-chloroacrylic acid chloride obtained in Synthesis Example 1, various operations were carried out in the same manner as in Example 13 to obtain 29.44 g of a p-xylene solution containing the product. When this solution was analyzed by gas chromatography using α-chlorohexafluoroisopropyl acrylate as a standard substance, 8.78 g of α-chlorohexafluoroisopropyl acrylate was contained (yield: 68.5%).

[0068] [Example 15] In Example 13, except that 7.8 g (0.075 mol) of methacrylic acid chloride was changed to 12.76 g (0.075 mol) of 2-bromoacrylic acid chloride obtained in Synthesis Example 2, various operations were carried out in the same manner as in Example 13 to obtain 30.29 g of a p-xylene solution containing the product. When this solution was analyzed by gas chromatography using α-bromohexafluoroisopropyl acrylate as a standard substance, 9.54 g of α-bromohexafluoroisopropyl acrylate was contained (yield: 63.2%).

[0069] [Comparative Example 1] Into a 100 ml round-bottomed flask equipped with a dropping funnel and a stir bar, 8.4 g (0.05 mol) of 1,1,1,3,3,3-hexafluoroisopropanol, 6.8 g (0.075 mol) of acryloyl chloride, and 70 ml of dry cyclopentyl methyl ether were added and stirred. The reactor was cooled with ice water, and 6.0 g (0.075 mol) of pyridine was added dropwise through the dropping funnel over about 15 minutes, and the mixture was stirred for about 1 hour. Thereafter, the temperature of the reactor was raised to 25 °C, and stirring was continued for an additional 7 hours. The contents were transferred to a separatory funnel and washed successively with 40 ml of water, 30 ml of 5 wt% hydrochloric acid, 30 ml of saturated aqueous sodium bicarbonate, and 30 ml of saturated brine, and the organic phase was dried over magnesium sulfate. Magnesium sulfate was removed while washing with a small amount of cyclopentyl methyl ether to obtain a 55.01 g solution of cyclopentyl methyl ether containing the product. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 0.89 g of hexafluoroisopropyl acrylate was contained (yield: 8.0%).

[0070] [Comparative Example 2] In Example 1, various operations were carried out in the same manner as in Example 1 except that tetrabutylammonium bromide as a phase transfer catalyst was not added, and a 27.29 g toluene solution containing the product was obtained. When this solution was analyzed by gas chromatography using hexafluoroisopropyl acrylate as a standard substance, 5.38 g of hexafluoroisopropyl acrylate was contained (yield: 34.7%).

[0071] As is clear from the results of the above Examples and Comparative Examples, it can be seen that the method for producing hexafluoroisopropyl unsaturated carboxylate of the present invention is a method for producing hexafluoroisopropyl unsaturated carboxylate with good yield by a simple operation and is industrially advantageous in terms of economy.

Industrial Applicability

[0072] According to the present invention, a method for producing an unsaturated carboxylic acid hexafluoroisopropyl ester with good yield by a simple operation and industrially advantageously in terms of economy can be provided.

Claims

1. The following formula (1): 【Chemical 1】 [In formula (1), X represents a hydrogen atom, a halogen atom, or a methyl group.] A method for producing a hexafluoroisopropyl unsaturated carboxylate represented by the formula: 1,1,1,3,3,3 - hexafluoroisopropanol and The following formula (2): 【Chemical 2】 [In formula (2), X is the same as X in formula (1), and Y represents a halogen atom selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.] Contacting an unsaturated carboxylic acid halide represented by the formula with a mixed solvent containing a water - immiscible organic solvent and water, the method for producing a hexafluoroisopropyl unsaturated carboxylate, wherein The mixed solvent contains at least one alkali metal salt selected from the group consisting of alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal phosphates, and alkali metal hydrogen phosphates, and a phase - transfer catalyst.

2. The method for producing a hexafluoroisopropyl unsaturated carboxylate according to claim 1, wherein the phase - transfer catalyst is at least one salt selected from the group consisting of alkylammonium halide salts and alkylammonium hydrogen sulfate salts.

3. The method for producing a hexafluoroisopropyl unsaturated carboxylate according to claim 1 or 2, wherein the unsaturated carboxylic acid halide represented by the formula (2) is at least one compound selected from the group consisting of acrylic acid chloride, α - chloroacrylic acid chloride, and α - bromoacrylic acid chloride.

4. The method for producing a hexafluoroisopropyl unsaturated carboxylate according to any one of claims 1 to 3, wherein X in the formula (1) is a hydrogen atom, a chlorine atom, or a methyl group.

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