Method for producing fluorine-containing dioxolane, and composition useful for producing the same

Abstract

To provide a composition suitable for producing a 1,3-dioxolane compound having a 2-(difluoromethylene) structure with reduced by-production of HF adducts.SOLUTION: Provided is a composition comprising at least one compound selected from the group consisting of compounds represented by formula (3) and formula (4), and carbon dioxide [where, R1 to R4 each represent F or a C1-C7 fluoroalkyl group, M represents an alkali metal or alkaline earth metal atom, and Y represents H or an alkyl group in which one or more H atoms may be substituted with F].SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a fluorine-containing dioxolane and compositions useful for the production thereof. [Background technology]

[0002] 1,3-dioxolane compounds having a 2-(difluoromethylene) structure, such as perfluoro(2-methylene-4-methyl-1,3-dioxolane), are used as raw material monomers for fluororesins constituting optical fibers. Known methods for producing this perfluorodioxolane include, for example, a method in which perfluoro(-3,6-bismethyl-1,4-dioxane-2-one is used as a raw material and converted into a 2-COF product, a 2-carboxylate, and a 2-methylene product, as shown in the following formula (e.g., Patent Document 1 and Patent Document 2). [ka]

[0003] In this method, the carbonyl fluoride is generally saponified with a base to convert it into a carboxylate, which is then thermally decomposed by heating to produce the desired difluoromethylene. However, if water, which is a proton source, is present during the thermal decomposition of the carboxylate obtained from the carbonyl fluoride, not only the desired difluoromethylene but also an HF adduct in which HF is added to the double bond in the difluoromethylene (for example, the following 2-hydro-perfluoro(2,4-dimethyl-1,3-dioxolane)): [ka] Also produced is a benzoyl peroxide, resulting in a decrease in the yield of the desired product.

[0004] Furthermore, since the boiling point of this HF adduct is close to that of the desired difluoromethylene compound, it is not easy to separate the HF adduct from the desired difluoromethylene compound by distillation.

[0005] For this reason, attention has been focused on reducing the amount of water coexisting with carboxylates. For example, Patent Document 3 describes the following: "The present inventors have intensively studied methods for producing perfluoro(2-methylene-4-methyl-1,3-dioxolane), and as a result, have discovered a method for producing perfluoro(2,4-dimethyl-2-fluoroformyl-1,3-dioxolane), which comprises reacting at least one of the raw material perfluoro(2,4-dimethyl-2-fluoroformyl-1,3-dioxolane) and its hydrolysis product with a basic aqueous solution containing one or more cations selected from the group consisting of alkali metal ions and alkaline earth metal ions, and then separating the resulting liquid containing perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylate alkali metal salt or perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylate alkaline earth metal salt by a liquid separation operation, and then removing water by a separation operation to remove ... It has been newly discovered that by carrying out one or more of the above-mentioned moisture content reduction treatments and then using the resulting mixture in a liquid-phase decarboxylation reaction, it is possible to obtain perfluoro(2-methylene-4-methyl-1,3-dioxolane) in high yield while suppressing the production of 2-hydro-perfluoro(2,4-dimethyl-1,3-dioxolane), which is difficult to separate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2020 / 166632 [Patent Document 2] International Publication No. 2020 / 230822 [Patent Document 3] International Publication No. 2020 / 095915 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present disclosure is to provide a new method for producing a 1,3-dioxolane compound having a 2-(difluoromethylene) structure (e.g., 2-(difluoromethylene)-4,4,5-trifluoro-5-(trifluoromethyl)-1,3-dioxolane) from a corresponding carboxylate, in which the by-production of an HF adduct (e.g., 2-hydroperfluoro(2,4-dimethyl-1,3-dioxolane)) is suppressed. An object of the present disclosure is to provide a composition containing the above-mentioned carboxylate, which is useful for producing a 1,3-dioxolane compound having a 2-(difluoromethylene) structure, while suppressing the by-production of an HF adduct. [Means for solving the problem]

[0008] The present inventors have found that in a production process for a 1,3-dioxolane compound having a 2-(difluoromethylene) structure, when the pH of the product (or the aqueous solution of the product if the product is a non-aqueous solution) obtained by saponifying a carbonyl fluoride with a base and converting it into a carboxylate exceeds 11.0, by adjusting the pH to within the range of 6.0 to 11.0 using carbon dioxide gas, the by-production of an HF adduct can be suppressed by the subsequent thermal decomposition of the carboxylate, thereby obtaining a high-purity target product, and that corrosion of a reaction vessel, etc. can be suppressed compared to pH adjustment using an acid such as hydrofluoric acid.

[0009] The present disclosure typically encompasses the following aspects. Section 1. Formula (1): [ka] [In the formula, R 1 ~R 4 are each independently a fluorine atom or a C1-C7 fluoroalkyl group which may contain an etheric oxygen.] A method for producing a compound represented by the following formula: A manufacturing method including the following steps A, B, C, and D. (Process A) Formula (2): [ka] [In the formula, X is a hydroxy group, a fluorine atom, a chlorine atom, or a C1-C3 alkoxy group in which one or more hydrogen atoms may be substituted by a fluorine atom; R 1 ~R 4 is the same as above.] The compound represented by with at least one base selected from the group consisting of hydroxides, carbonates, and alkoxides of alkali metals and alkaline earth metals; Formula (3): [ka] [In the formula, M is an alkali metal atom or an alkaline earth metal atom, and R 1 ~R 4 is the same as above.] to obtain a reaction product having a pH in the range exceeding pH 11.0. (Process B) Step B is to add carbon dioxide gas to the reaction product obtained in step A or to a liquid obtained by mixing the reaction product with water to adjust the pH to 6.0 to 11.0, thereby obtaining a pH-adjusted liquid. (Process C) Step C is to concentrate the pH-adjusted solution obtained in step B to obtain a concentrate. (Process D) Step D involves heating the concentrate obtained in step C to thermally decompose the compound represented by formula (3) to produce the compound represented by formula (1). Section 2. R 1 ~R 4 are each independently a fluorine atom, a perfluoro C1-C7 alkyl group, or a perfluoro C1-C7 alkoxy group. Section 3. R 1 is a trifluoromethyl group or a fluorine atom, and R 2 ~R 4 are each a fluorine atom. Section 4. 4. The method according to any one of items 1 to 3, wherein X is a hydroxy group, a fluorine atom, a chlorine atom, methoxy, ethoxy, n-propoxy, i-propoxy, trifluoromethoxy, or 2,2,2-trifluoroethoxy. Section 5. 5. The method according to any one of items 1 to 4, wherein the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, magnesium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, potassium hydroxide, sodium hydroxide, magnesium hydroxide, potassium methoxide, sodium methoxide, magnesium methoxide, potassium ethoxide, sodium ethoxide, and magnesium ethoxide. Section 6. Items 1 to 5, wherein the pH range of 6.0 to 11.0 in the step B is 6.0 to 10.0. 13. The method for producing a semiconductor device according to any one of the preceding claims. Section 7. 7. The method according to any one of items 1 to 6, wherein the amount of carbon dioxide gas added in step B is 100 to 10,000 mol % based on the content of the compound represented by formula (3) in the reaction product obtained in step A. Section 8. 8. The production method according to any one of Items 1 to 7, wherein the step C and the step D are carried out continuously in the same reactor. Section 9. R 1 is a trifluoromethyl group or a fluorine atom, R 2 ~R 4 are all fluorine atoms, X is a fluorine atom, methoxy, ethoxy, n-propoxy, or i-propoxy; the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide; The M is a potassium atom or a sodium atom, The pH range of 6.0 to 11.0 in the step B is 6.5 to 8.5, the amount of carbon dioxide gas added in the step B is 500 to 6000 mol % based on the content of the compound represented by formula (3) in the reaction product obtained in the step A; Item 9. The method for producing according to any one of Items 1 to 8. Section 10. R 1 is a trifluoromethyl group or a fluorine atom, R 2 ~R 4 are all fluorine atoms, X is a fluorine atom or methoxy, the base is at least one compound selected from the group consisting of potassium carbonate and potassium hydroxide; The M is a potassium atom, The pH range of 6.0 to 11.0 in the step B is 6.9 to 7.9, the amount of carbon dioxide gas added in the step B is 600 to 5000 mol % based on the content of the compound represented by formula (3) contained in the reaction product obtained in the step A; Item 10. The method for producing according to any one of Items 1 to 9. Section 11. Formula (3): [ka] [In the formula, R 1 ~R 4 are each independently a fluorine atom or a C1-C7 fluoroalkyl group which may contain an etheric oxygen, and M is an alkali metal atom or an alkaline earth metal atom. A compound represented by the formula: Formula (4): [ka] [In the formula, Y is a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms may be substituted by a fluorine atom; R 1 ~R 4 is the same as above.] At least one compound selected from the group consisting of compounds represented by the formula: Carbon dioxide A composition comprising: When the composition is an aqueous solution of at least one compound selected from the group consisting of compounds represented by formula (3) and compounds represented by formula (4), the pH of the aqueous solution is within the range of 6.0 to 11.0, and when the composition is a non-aqueous solution, the pH of the aqueous solution obtained by adding water to the composition is within the range of 6.0 to 11.0. Section 12. Item 12. The composition according to item 11, further comprising at least one base selected from the group consisting of hydroxides, carbonates, and alkoxides of alkali metals and alkaline earth metals. Section 13. R 1 ~R 4 are each independently a fluorine atom, a perfluoro C1-C7 alkyl group, or a perfluoro C1-C7 alkoxy group. Section 14. R 1 is a trifluoromethyl group or a fluorine atom, and R 2 ~R 4 are each a fluorine atom. Section 15. 15. The composition according to any one of items 11 to 14, wherein Y is a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, trifluoromethyl, or 2,2,2-trifluoroethyl. Section 16. Item 16. The composition according to any one of Items 12 to 15, wherein the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, magnesium carbonate, sodium bicarbonate, potassium bicarbonate, potassium hydroxide, sodium hydroxide, magnesium hydroxide, potassium methoxide, sodium methoxide, magnesium methoxide, potassium ethoxide, sodium ethoxide, and magnesium ethoxide. Section 17. Item 17. The composition according to any one of items 11 to 16, wherein the aqueous solution has a pH value within the range of 6.0 to 10.0. Section 18. Item 17. The composition according to any one of items 11 to 16, wherein the aqueous solution has a pH value within the range of 6.5 to 10.0. Section 19. R 1 is a trifluoromethyl group or a fluorine atom, R 2 ~R 4 are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide; Y is methyl, ethyl, n-propyl, or i-propyl; The M is a potassium atom or a sodium atom, The pH of the aqueous solution is within the range of 6.5 to 8.5; The content of the carbon dioxide gas is 0.2 to 30% by mass relative to the mass of the composition. 19. The composition according to any one of items 12 to 18. Section 20. R 1 is a trifluoromethyl group or a fluorine atom, R 2 ~R 4 are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate and potassium hydroxide; Y is methyl; The M is a potassium atom, The pH of the aqueous solution is within the range of 6.9 to 7.9; The content of the carbon dioxide gas is 0.3 to 17% by mass relative to the mass of the composition. 20. The composition according to any one of items 12 to 19. Section 21. Formula (3): [ka] [In the formula, R 1 ~R 4are each independently a C1-C7 fluoroalkyl group which may contain a fluorine atom or an etheric oxygen, and M is an alkali metal atom or an alkaline earth metal atom. A compound represented by the formula: Formula (4): [ka] [In the formula, Y is a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms may be substituted by a fluorine atom; R 1 ~R 4 is the same as above.] At least one compound selected from the group consisting of compounds represented by the formula: A composition containing carbon dioxide gas, A composition having a carbon dioxide gas content of 0.05 to 1000% by mass relative to the mass of the composition. Section 22. Item 22. The composition according to item 21, wherein the carbon dioxide gas content is 0.1 to 500% by mass based on the mass of the composition. Section 23. Item 22. The composition according to item 21, wherein the content of the carbon dioxide gas is 0.1 to 100% by mass based on the mass of the composition. Section 24. R 1 ~R 4 each independently represents a fluorine atom, a perfluoro C1-C7 alkyl group, or a perfluoro C1-C7 alkoxy group. Section 25. R 1 is a trifluoromethyl group or a fluorine atom, and R 2 ~R 4 Both are fluorine atoms. 25. The composition according to any one of items 21 to 24, Section 26. 26. The composition according to any one of items 21 to 25, wherein Y is a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, trifluoromethyl, or 2,2,2-trifluoroethyl. Section 27. The composition further comprises a base; R 1 is a trifluoromethyl group or a fluorine atom, R 2 ~R 4 are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide; Y is methyl, ethyl, n-propyl, or i-propyl; The M is a potassium atom or a sodium atom, The pH of the aqueous solution is within the range of 6.5 to 8.5; The content of the carbon dioxide gas is 0.2 to 30% by mass relative to the mass of the composition. 27. The composition according to any one of items 21 to 26. Section 28. The composition further comprises a base; R 1 is a trifluoromethyl group or a fluorine atom, R 2 ~R 4 are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate and potassium hydroxide; Y is methyl; The M is a potassium atom, The pH of the aqueous solution is within the range of 6.9 to 7.9; The content of the carbon dioxide gas is 0.3 to 17% by mass relative to the mass of the composition. 28. The composition according to any one of items 21 to 27. Effect of the Invention

[0010] According to the present disclosure, when a 1,3-dioxolane compound having a 2-(difluoromethylene) structure is produced by thermally decomposing a corresponding carboxylate, the production of a by-product, 2-hydro-2-trifluoromethyl compound, can be reduced, and a high-purity target product can be produced. According to the present disclosure, after preparing the carboxylate, the pH of the reaction solution is adjusted to 6.0 to 11.0 using carbon dioxide gas, which makes it possible to avoid the use of inorganic acids (sulfuric acid, hydrochloric acid, hydrofluoric acid, etc.) and suppress corrosion of equipment (e.g., reaction vessel) caused by inorganic acids. When the composition of the present disclosure is used as a raw material for producing a 1,3-dioxolane compound having a 2-(difluoromethylene) structure, the production of by-products can be suppressed and a high-purity 1,3-dioxolane compound having a 2-(difluoromethylene) structure can be obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The remainder of the disclosure more particularly exemplifies example embodiments. In several places in this disclosure, guidance is provided through examples, which examples can be used in various combinations. In each instance, the exemplary group can serve as a non-exclusive and representative group. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety.

[0012] term Unless otherwise specified, the symbols and abbreviations in this specification should be understood to have the meanings commonly used in the technical field to which this disclosure pertains, in accordance with the context of this specification.

[0013] As used herein, the phrase "comprising" is intended to encompass the phrases "consisting essentially of" and "consisting of."

[0014] Unless otherwise specified, any process, treatment or operation described herein may be carried out at room temperature. In this specification, room temperature can mean a temperature within the range of 10 to 40°C.

[0015] In this specification, the notation "Cn-Cm" (wherein n and m are each a number) indicates that the number of carbon atoms is n or more and m or less, as is commonly understood by those skilled in the art.

[0016] In this specification, unless otherwise specified, examples of the "alkyl group" include linear or branched C1-C10 (preferably C1-C7, more preferably C1-C6, even more preferably C1-C4, particularly preferably C1-C3) alkyl groups such as methyl, ethyl, propyl (e.g., n-propyl, isopropyl), butyl (e.g., n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl (e.g., n-pentyl, tert-pentyl, neopentyl, isopentyl, sec-pentyl, 3-pentyl), hexyl, heptyl, octyl, nonyl, and decyl; and cyclic C3-C10 (e.g., C3-C6, C4-C6, C3-C5, C5-C6) alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and adamantyl.

[0017] In this specification, unless otherwise specified, an "alkoxy group" can be a group represented by RO-[wherein R is an alkyl group (e.g., a C1-C10 alkyl group, a C1-C7 alkyl group, a C1-C6 alkyl group, a C1-C4 alkyl group, a C1-C3 alkyl group)]. Examples of alkoxy groups include methoxy, ethoxy, propoxy (e.g., n-propoxy, isopropoxy), butoxy (e.g., n-butoxy, isobutoxy, sec-butoxy, tert-butoxy), pentyloxy (e.g., n-pentyloxy, tert-pentyloxy, neopentyloxy, isopentyloxy, sec-pentyloxy, 3-pentyloxy), hexyloxy, heptyloxy, octyloxy, nonyloxy, and decyloxy. and cyclic C3-C10 (e.g., C3-C6, C4-C6, C3-C5, C5-C6) alkoxy groups such as linear or branched C1-C10 (preferably C1-C7, more preferably C1-C6, even more preferably C1-C4), particularly preferably C1-C3) alkoxy groups.

[0018] In this specification, unless otherwise specified, a "fluoroalkyl group" refers to an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and also includes a perfluoroalkyl group in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms. The fluoroalkyl group can have 1 to 10 carbon atoms, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 1 to 3, 1 to 2, or 1 carbon atom. Examples of fluoroalkyl groups are methyl having 1 to 3 fluorine atoms, ethyl having 1 to 5 fluorine atoms, propyl having 1 to 7 fluorine atoms (e.g., n-propyl, isopropyl), butyl having 1 to 9 fluorine atoms (e.g., n-butyl, isobutyl, se).

[0043] Fluorine groups include linear or branched C1-C10 (preferably C1-C7, more preferably C1-C6, even more preferably C1-C4, and particularly preferably C1-C3) fluoroalkyl groups (preferably perfluoroalkyl groups), such as pentyl having 1 to 11 fluorine atoms (e.g., n-pentyl, tert-pentyl, neopentyl, isopentyl, sec-pentyl, 3-pentyl), hexyl having 1 to 13 fluorine atoms, heptyl having 1 to 15 fluorine atoms, octyl having 1 to 17 fluorine atoms, nonyl having 1 to 19 fluorine atoms, and decyl having 1 to 21 fluorine atoms. The number of fluorine atoms contained in the fluoroalkyl group may be from 1 to the maximum number that can be substituted, for example, 1 to 21, 1 to 19, 1 to 17, 1 to 15, 1 to 13, 1 to 11, 1 to 9, 1 to 7, 1 to 5, 1 to 3, etc.

[0019] In this specification, unless otherwise specified, a "fluoroalkoxy group" refers to an alkoxy group in which at least one hydrogen atom is replaced with a fluorine atom, and also includes a perfluoroalkoxy group in which all hydrogen atoms of an alkoxy group are replaced with fluorine atoms. The fluoroalkoxy group can have 1 to 10, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 1 to 3, 1 to 2, or 1 carbon atom. Examples of the fluoroalkoxy group include methoxy having 1 to 3 fluorine atoms, ethoxy having 1 to 5 fluorine atoms, propoxy having 1 to 7 fluorine atoms (e.g., n-propoxy, isopropoxy), butoxy having 1 to 9 fluorine atoms (e.g., n-butoxy, isobutoxy, sec-butoxy, tert-butoxy), pentyloxy having 1 to 11 fluorine atoms (e.g., n-pentyloxy, tert-pentyloxy, neopentyloxy, isopentyloxy, sec-pentyloxy, 3-

[0043] These include linear or branched C1-C10 (preferably C1-C7, more preferably C1-C6, still more preferably C1-C4, particularly preferably C1-C3) fluoroalkoxy groups (preferably perfluoroalkoxy groups), such as pentyloxy having 1 to 13 fluorine atoms, hexyloxy having 1 to 15 fluorine atoms, heptyloxy having 1 to 17 fluorine atoms, nonyloxy having 1 to 19 fluorine atoms, and decyloxy having 1 to 21 fluorine atoms. The number of fluorine atoms contained in the fluoroalkoxy group may be from 1 to the maximum number that can be substituted, for example, 1 to 21, 1 to 19, 1 to 17, 1 to 15, 1 to 13, 1 to 11, 1 to 9, 1 to 7, 1 to 5, 1 to 3, etc.

[0020] In this specification, unless otherwise specified, the term "C1-C7 fluoroalkyl group which may contain etheric oxygen" includes the above-mentioned fluoroalkyl groups having 1 to 7 carbon atoms and C1-C7 fluoroalkyl groups which contain etheric oxygen. In addition, the term "C1-C7 fluoroalkyl group which may contain etheric oxygen" includes perfluoro C1-C7 alkyl groups which may contain etheric oxygen, in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms. The C1-C7 fluoroalkyl group containing an etheric oxygen includes a C1-C7 fluoroalkyl group (preferably a perfluoro C1-C alkyl group) having an etheric oxygen "-O-" at its end or inside. Therefore, the C1-C7 fluoroalkyl group containing an etheric oxygen can also be referred to as a group having an etheric oxygen atom at the end or between the carbon-carbon bond of the C1-C7 fluoroalkyl group. Trifluoromethoxy (CF3-O-) is an example of a fluoroalkyl group having "-O-" at the end, and perfluoro(methoxymethyl) (CF3-O-CF2-) is an example of a fluoroalkyl group having "-O-" inside the structure. The number of etheric oxygens contained in the C1-C7 fluoroalkyl group containing an etheric oxygen can be 1, 2, 3, etc., but 1 or 2 is preferred, and 1 is preferred. The C1-C7 fluoroalkyl group containing an etheric oxygen has 1 to 7 carbon atoms, preferably C1-C6, more preferably C1-C4, and even more preferably C1-C3.

[0021] The C1-C7 fluoroalkyl group containing an etheric oxygen includes a C1-C7 fluoroalkoxy group, a C1-C6 fluoroalkoxytrifluoromethyl group, a C1-C5 fluoroalkoxypentafluoroethyl group, and the like.

[0022] Examples of C1-C7 fluoroalkoxy groups include methoxy having 1 to 3 fluorine atoms, ethoxy having 1 to 5 fluorine atoms, propoxy having 1 to 7 fluorine atoms (e.g., n-propoxy, isopropoxy), butoxy having 1 to 9 fluorine atoms (e.g., n-butoxy, isobutoxy, sec-butoxy, tert-butoxy), pentyloxy having 1 to 11 fluorine atoms (e.g., n-pentyloxy, tert-pentyloxy, neopentyloxy, isopentyloxy, sec-pentyloxy, 3-pentyloxy), hexyloxy having 1 to 13 fluorine atoms, heptyloxy having 1 to 15 fluorine atoms, and the like.

[0023] The C1-C6 fluoroalkoxytrifluoromethyl group is C1-C6 fluoroalkoxy-CF2-. Examples of the C1-C6 fluoroalkoxy are described above in the examples of the "fluoroalkoxy group".

[0024] The C1-C5 fluoroalkoxypentafluoroethyl group is C1-C5 fluoroalkoxy-C2F4-. Examples of the C1-C5 fluoroalkoxy are described above in the examples of the "fluoroalkoxy group".

[0025] In this specification, unless otherwise specified, "C1-C3 alkyl group in which one or more hydrogen atoms may be substituted with fluorine atoms" includes C1-C3 alkyl group and C1-C3 alkyl group in which one or more hydrogen atoms are substituted with fluorine atoms. In other words, "C1-C3 alkyl group in which one or more hydrogen atoms may be substituted with fluorine atoms" includes C1-C3 alkyl group and C1-C3 fluoroalkyl group. In addition, C1-C3 alkyl group in which one or more hydrogen atoms are substituted with fluorine atoms includes perfluoro C1-C3 alkyl group in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms. Examples of the C1-C3 alkyl group and the C1-C3 fluoroalkyl group are given above in the examples of the alkyl group and the examples of the fluoroalkyl group.

[0026] In this specification, unless otherwise specified, "C1-C3 alkoxy group in which one or more hydrogen atoms may be substituted with fluorine atoms" includes C1-C3 alkoxy group and C1-C3 alkoxy group in which one or more hydrogen atoms are substituted with fluorine atoms. In other words, "C1-C3 alkoxy group in which one or more hydrogen atoms may be substituted with fluorine atoms" includes C1-C3 alkoxy group and C1-C3 fluoroalkoxy group. In addition, C1-C3 alkoxy group in which one or more hydrogen atoms are substituted with fluorine atoms includes perfluoro C1-C3 alkoxy group in which all hydrogen atoms of the alkoxy group are substituted with fluorine atoms. Examples of the C1-C3 alkoxy group and the C1-C3 fluoroalkoxy group are the same as those described above in the examples of the alkoxy group and the examples of the fluoroalkoxy group.

[0027] In this specification, unless otherwise specified, examples of the "alkali metal" include lithium, sodium, potassium, rubidium, cesium, and francium, preferred examples include lithium, sodium, and potassium, and more preferred examples include sodium and potassium.

[0028] In this specification, unless otherwise specified, examples of the "alkaline earth metal" include beryllium, magnesium, calcium, strontium, barium, and radium, and preferred examples include magnesium and calcium.

[0029] Method for producing a compound represented by formula (1) One embodiment of the present disclosure is a compound of formula (1): [ka] [In the formula, R 1 ~R 4 are each independently a fluorine atom or a C1-C7 fluoroalkyl group which may contain an etheric oxygen.] The present invention relates to a method for producing a compound represented by the following formula (sometimes referred to as compound (1) in this specification). The production method includes steps A, B, C, and D. Steps A, C, and D, excluding step B, may be carried out by known methods, for example, in accordance with the methods described in Patent Document 1, Patent Document 2, JP2005-002014A, U.S. Patent No. 3,308,107, or U.S. Patent No. 6,664,431, all of which are incorporated herein by reference.

[0030] R 1 ~R 4 may each independently be a fluorine atom, a linear or branched C1-C7 fluoroalkyl group, or a linear or branched C1-C7 fluoroalkyl group containing an etheric oxygen. R 1 ~R 4may each independently be a fluorine atom, a linear or branched C1-C6 fluoroalkyl group, or a linear or branched C1-C6 fluoroalkyl group containing an etheric oxygen. R 1 ~R 4 may each independently be a fluorine atom, a linear or branched C1-C5 fluoroalkyl group, or a linear or branched C1-C5 fluoroalkyl group containing an etheric oxygen. R 1 ~R 4 may each independently be a fluorine atom, a linear or branched C1-C4 fluoroalkyl group, or a linear or branched C1-C4 fluoroalkyl group containing an etheric oxygen. R 1 ~R 4 may each independently be a fluorine atom, a linear or branched C1-C3 fluoroalkyl group, or a linear or branched C1-C3 fluoroalkyl group containing an etheric oxygen.

[0031] R 1 ~R 4 may each independently be a fluorine atom, a linear or branched perfluoro C1-C7 alkyl group, or a linear or branched perfluoro C1-C7 alkyl group containing an etheric oxygen. R 1 ~R 4 may each independently be a fluorine atom, a linear or branched perfluoro C1-C6 alkyl group, or a linear or branched perfluoro C1-C6 alkyl group containing an etheric oxygen. R 1 ~R 4 may each independently be a fluorine atom, a linear or branched perfluoro C1-C5 alkyl group, or a linear or branched perfluoro C1-C5 alkyl group containing an etheric oxygen. R 1 ~R 4may each independently be a fluorine atom, a linear or branched perfluoro C1-C4 alkyl group, or a linear or branched perfluoro C1-C4 alkyl group containing an etheric oxygen. R 1 ~R 4 may each independently be a fluorine atom, a linear or branched perfluoro C1-C3 alkyl group, or a linear or branched perfluoro C1-C3 alkyl group containing an etheric oxygen.

[0032] R 1 ~R 4 may each independently be a fluorine atom, a perfluoro C1-C7 alkyl group, or a perfluoro C1-C7 alkoxy group. R 1 ~R 4 may each independently be a fluorine atom, a perfluoro C1-C6 alkyl group, or a perfluoro C1-C6 alkoxy group. R 1 ~R 4 may each independently be a fluorine atom, a perfluoro C1-C5 alkyl group, or a perfluoro C1-C5 alkoxy group. R 1 ~R 4 may each independently be a fluorine atom, a perfluoro C1-C4 alkyl group, or a perfluoro C1-C4 alkoxy group. R 1 ~R 4 may each independently be a fluorine atom, a perfluoro C1-C3 alkyl group, or a perfluoro C1-C3 alkoxy group.

[0033] R 1 ~R 4 at least one group is a fluorine atom, and the remaining groups, when there are a plurality of such remaining groups, may independently be a perfluoro C1-C2 alkyl group or a perfluoro C1-C3 alkoxy group. R 1 ~R 4at least two groups are fluorine atoms, and the remaining groups, when there are a plurality of such remaining groups, may independently be a perfluoro C1-C2 alkyl group or a perfluoro C1-C3 alkoxy group. R 1 ~R 4 At least three groups are fluorine atoms, and the remaining groups may be perfluoro C1-C3 alkyl groups or perfluoro C1-C2 alkoxy groups. R 1 ~R 4 At least three groups are fluorine atoms, and the remaining groups may be perfluoro C1-C3 alkyl groups. R 1 ~R 4 may all be fluorine atoms. R 1 is a trifluoromethyl group or a fluorine atom, and R 2 ~R 4 may each be a fluorine atom.

[0034] Specific examples of compound (1) are perfluoro(2-methylene-1,3-dioxolane), perfluoro(2-methylene-4-methyl-1,3-dioxolane), perfluoro(2-methylene-4-ethyl-1,3-dioxolane), perfluoro(2-methylene-4,5-dimethyl-1,3-dioxolane), perfluoro(2-methylene-4,5-diethyl-1,3-dioxolane), and perfluoro(2 -methylene-4-methoxymethyl-1,3-dioxolane), perfluoro(2-methylene-4-ethoxymethyl-1,3-dioxolane), 2-(difluoromethylene)-3a,4,4,6,6,6a-hexafluorotetrahydrofuro[3,4-d][1,3]dioxole, 2-(difluoromethylene)-3a,4,4,5,5,6,6,7,7,7a-decafluorohexahydrobenzo[d][1,3]dioxole, perfluoro(2-methylene-1,3-dioxolane), Perfluoro(2-methylene-4-methyl-1,3-dioxolane) is preferred.

[0035] Process A In step A, the compound of formula (2): [ka] [In the formula, X is a hydroxy group, a fluorine atom, a chlorine atom, or a C1-C3 alkoxy group in which one or more hydrogen atoms may be substituted by a fluorine atom; R 1 ~R 4 is the same as above.] (hereinafter, may be referred to as compound (2)) is reacted with at least one base selected from the group consisting of hydroxides, carbonates, and alkoxides of alkali metals and alkaline earth metals, Formula (3): [ka] [In the formula, M is an alkali metal atom or an alkaline earth metal atom, and R 1 ~R 4 is the same as above.] (sometimes referred to as compound (3) in this specification) to obtain a reaction product having a pH in the range exceeding pH 11.0.

[0036] Compound (2) is a known compound and can be produced, for example, by the method described in Patent Document 1 or 2, or by appropriately modifying said method.

[0037] X can be a hydroxy group, a fluorine atom, a chlorine atom, or a C1-C3 alkoxy group in which one or more hydrogen atoms may be replaced by fluorine atoms. X can be a hydroxy group, a fluorine atom, a chlorine atom, methoxy, ethoxy, n-propoxy, i-propoxy, trifluoromethoxy, or 2,2,2-trifluoroethoxy. X can be a hydroxy group, a fluorine atom, methoxy, ethoxy, trifluoromethoxy, or 2,2,2-trifluoroethoxy. X can be a fluorine atom, a chlorine atom, or a C1-C3 alkoxy group in which one or more hydrogen atoms may be replaced by a fluorine atom. X can be a fluorine atom, a chlorine atom, methoxy, ethoxy, n-propoxy, i-propoxy, trifluoromethoxy, or 2,2,2-trifluoroethoxy. X can be a fluorine atom, methoxy, ethoxy, trifluoromethoxy, or 2,2,2-trifluoroethoxy. X can be a fluorine atom, methoxy, ethoxy, n-propoxy, or i-propoxy. X can be a fluorine atom, methoxy, or trifluoromethoxy. X can be a fluorine atom or methoxy.

[0038] Specific examples of compound (2) include perfluoro(2-formyl-2,4-dimethyl-1,3-dioxolane), 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carbonyl chloride, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid methyl ester, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid ethyl ester, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid n-propyl ester, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid i-propyl ester, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid trifluoromethyl ester, and 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid 2,2,2-trifluoroethyl ester. Suitable specific examples of compound (2) include perfluoro(2-formyl-2,4-dimethyl-1,3-dioxolane), 4,4,5-trifluoro-2,5-bis(trifluoromethyl )-1,3-dioxolane-2-carboxylic acid, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid methyl ester, and 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid trifluoromethyl ester.

[0039] The base includes hydroxides, carbonates, and alkoxides of alkali metals, and hydroxides, carbonates, and alkoxides of alkaline earth metals, and may be used alone or in combination of two or more. Examples of hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, and barium hydroxide. Examples of carbonates include sodium carbonate, potassium carbonate, lithium carbonate, magnesium carbonate, calcium carbonate, barium carbonate, sodium bicarbonate, potassium bicarbonate, and lithium bicarbonate. Examples of alkoxides include sodium methoxide, sodium ethoxide, sodium butoxide, potassium methoxide, potassium ethoxide, potassium butoxide, lithium methoxide, lithium ethoxide, magnesium methoxide, magnesium ethoxide, calcium methoxide, and calcium ethoxide.

[0040] The base is preferably at least one selected from the group consisting of potassium carbonate, sodium carbonate, magnesium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, potassium hydroxide, sodium hydroxide, magnesium hydroxide, potassium methoxide, sodium methoxide, magnesium methoxide, potassium ethoxide, sodium ethoxide, and magnesium ethoxide. The base is more preferably at least one selected from the group consisting of potassium carbonate, sodium carbonate, magnesium carbonate, potassium hydroxide, and sodium hydroxide. The base is even more preferably at least one selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide. The base is particularly preferably at least one selected from the group consisting of potassium carbonate and sodium hydroxide.

[0041] Compound (3) is a carboxylate of compound (2) corresponding to the base used in step A. Specific examples and preferred specific examples of compound (3) are carboxylates corresponding to the specific examples and preferred specific examples of compound (2) above, respectively. M can be an alkali metal atom or an alkaline earth metal atom. M is preferably an alkali metal atom, more preferably a potassium atom or a sodium atom, and even more preferably a potassium atom. M can be a group corresponding to the base used in step A. Thus, if the base is a potassium salt, M can be a potassium atom.

[0042] Step A may be carried out in the presence or absence of a solvent. As the solvent, water or an organic solvent may be used. The solvent may be used alone or in combination of two or more.

[0043] Examples of the organic solvent include alkyl alcohol solvents, ether solvents, aromatic solvents, saturated hydrocarbon solvents, nitrile solvents, sulfoxide solvents, and halogenated hydrocarbon solvents. Suitable examples of the organic solvent include alkyl alcohol solvents, ether solvents, halogenated hydrocarbon solvents, and nitrile solvents.

[0044] Examples of alkyl alcohol solvents include linear or branched C1-C10 alkyl alcohols. The alcohol is preferably a linear or branched C1-5 alkyl alcohol, more preferably a linear or branched C1-4 alkyl alcohol, even more preferably methanol, ethanol, n-propanol, isopropanol, n-butyl alcohol, sec-butyl alcohol, or tert-butyl alcohol, and particularly preferably methanol or ethanol.

[0045] Suitable specific examples of the ether solvent include dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, 1,2-dimethoxyethane, and crown ethers.

[0046] Suitable examples of aromatic solvents include benzene, toluene, and xylene. Suitable examples of saturated hydrocarbon solvents include n-pentane, n-hexane, cyclohexane, and n-heptane. Suitable examples of nitrile solvents include 1,4-dicyanobutane, acetonitrile, and benzonitrile. Suitable examples of sulfoxide solvents include dimethyl sulfoxide and sulfolane. Suitable examples of halogenated hydrocarbon solvents include methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,2-dichlorobenzene, chlorobenzene, and perfluorohexane.

[0047] Suitable examples of organic solvents include methanol, ethanol, dimethyl ether (DME), diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,4-dicyanobutane, methylene chloride, chloroform, tetrahydrofuran, perfluorohexane, and acetonitrile.

[0048] The amount of the base used in step A can be within a range of 0.05 to 10 mol, a range of 0.1 to 10 mol, a range of 0.1 to 5 mol, etc., relative to 1 mol of compound (2), preferably within a range of 0.5 to 10 mol, more preferably within a range of 0.5 to 5 mol. The amount of base is preferably an amount such that the pH of the reaction product obtained in step A or a liquid obtained by mixing the reaction product with water exceeds 11.0.

[0049] When a solvent is used in step A, the amount of the solvent used should be an amount that can function as a solvent based on common technical knowledge, etc.

[0050] The reaction temperature in step A may be preferably within the range of -50 to 120°C, more preferably within the range of -20 to 100°C, and further preferably within the range of -10 to 70°C.

[0051] The reaction time in step A is not particularly limited as long as the target substance is produced, but is preferably within the range of 0.1 to 48 hours, more preferably within the range of 0.1 to 24 hours, and even more preferably within the range of 0.1 to 12 hours.

[0052] In step A, compound (2) is converted to compound (3) to obtain a reaction product containing compound (3). The reaction product may be an aqueous or non-aqueous solution. Aqueous solutions include aqueous solutions of compound (3). Non-aqueous solutions include organic solvents containing compound (3) and solids containing compound (3). When water or a mixture of water and other solvents is used as the solvent in step A, the reaction The product may be obtained as an aqueous solution of compound (3). When an organic solvent is used as the solvent in step A, the reaction product can be obtained as an organic solvent (including a slurry) containing compound (3). When no solvent is used in step A, the reaction product can be obtained as a solid (including a slurry) containing compound (3). The pH of the reaction product may range above 11.0, and may range up to 12.0 or greater. The reaction product is subjected to the next step B.

[0053] Process B Step B is a step of adjusting the pH of the reaction product (which may be a liquid) obtained in step A having a pH in the range exceeding 11.0 to a range of 6.0 to 11.0 using carbon dioxide gas before subjecting it to the next concentration step C. This pH may be 6.0 to 10.0, 6.5 to 10.0, etc., preferably 6.5 to 9.0, more preferably 6.5 to 8.5, and particularly preferably 6.9 to 7.9. Before adjusting the pH, the pH of the reaction product obtained in step A may be measured to confirm that the pH of the reaction product exceeds 11.0. The pH-adjusted reaction product (which may be referred to as a "pH-adjusted liquid") is subjected to step C.

[0054] Explain pH measurement. The pH can be measured using pH test paper, a pH meter (e.g., a HORIBA benchtop pH water quality analyzer) F-74), or a value determined by titration with a pH indicator, preferably p This is the value specified by the H meter. The reaction product obtained in step A may be a liquid or a solid. In the pH measurement for confirming the pH of the reaction product obtained in step A, it is not necessary to measure the pH of the entire reaction product obtained in step A, and the pH may be measured on a part of the reaction product. When the reaction product obtained in step A is an aqueous solution of compound (3), a part or all of this aqueous solution can be subjected to pH measurement. When the reaction product obtained in step A is an organic solvent containing compound (3) (including an organic solvent solution in which compound (3) is dissolved (e.g., an alcohol solution in which compound (3) is dissolved)), the same applies below), a mixture obtained by mixing water with a part or all of this organic solvent can be subjected to pH measurement. Note that when the mixture is allowed to stand and separates into an aqueous phase and an organic phase, the aqueous phase can be subjected to pH measurement. When the reaction product obtained in step A is a solid containing compound (3), a liquid obtained by mixing a part or all of this solid with water to dissolve compound (3) can be subjected to pH measurement.

[0055] Carbon dioxide gas is used to adjust the pH. By using carbon dioxide gas, the by-production of HF adducts (e.g., 2-hydroperfluoro(2,4-dimethyl-1,3-dioxolane)) in which HF is added to the double bond in the difluoromethylene compound is suppressed more than by other pH adjustment treatments (e.g., acidic solution treatment). The target of the carbon dioxide gas treatment is not particularly limited as long as the pH can be adjusted by carbon dioxide gas treatment. The reaction product may be subjected to the pH adjustment treatment as it is, the filtrate obtained by filtering the reaction product may be subjected to the pH adjustment treatment, or a concentrate obtained by concentrating the reaction product may be subjected to the pH adjustment treatment. When the reaction product obtained in step A is an aqueous solution of compound (3), this aqueous solution can be subjected to a carbon dioxide gas treatment. When the reaction product obtained in step A is an organic solvent solution in which compound (3) is dissolved, this organic solvent solution can be subjected to carbon dioxide gas treatment. When the reaction product obtained in step A is an organic solvent containing compound (3), a mixture obtained by mixing this organic solvent with water, or an aqueous phase obtained by separating the mixture, is subjected to the carbon dioxide gas treatment. obtain. When the reaction product obtained in step A is a solid containing compound (3), this solid can be mixed with water or an organic solvent to dissolve compound (3), and the resulting liquid can be subjected to carbon dioxide gas treatment.

[0056] Methods for carbon dioxide gas treatment include, for example, bubbling, which supplies carbon dioxide gas into the target liquid, pressurizing carbon dioxide gas into the target liquid in a sealed container, and adding dry ice (which may be in powder or solid form) during the reaction and utilizing the vaporized carbon dioxide gas. However, the method is not limited as long as the pH of the target substance can be adjusted to within the desired range using carbon dioxide gas. The conditions for the carbon dioxide gas treatment are not limited as long as the pH of the target substance can be adjusted to within a desired range. The amount of carbon dioxide gas added can be, for example, 100 to 10,000 mol %, 300 to 10,000 mol %, etc., preferably 300 to 6,000 mol %, further preferably 500 to 6,000 mol %, and particularly preferably 600 to 5,000 mol %, relative to the content of the compound represented by formula (3) in the reaction product obtained in step A. The temperature of the carbon dioxide gas treatment may be, for example, -100 to 100°C, and preferably -10 to 40°C. The time for the carbon dioxide gas treatment may be, for example, 0.1 to 72 hours, and preferably 0.5 to 24 hours. Carbonation may be carried out under elevated pressure, reduced pressure, or at atmospheric pressure. The pH-adjusted liquid obtained by the carbon dioxide treatment is subjected to the next step C.

[0057] Process C In step C, the pH-adjusted solution obtained in step B is concentrated.

[0058] The concentration step can be carried out in accordance with a known concentration method. Examples of the concentration method include vacuum distillation, drying, extraction, precipitation, distillation, chromatography, etc., which can be used alone or in combination of two or more. The preferred concentration methods are vacuum distillation and drying. Examples of the concentration conditions include vacuum distillation at 0 to 150°C and drying at 0 to 150°C. The concentrate obtained by concentration can be in the form of a liquid, a gel, or a solid. In the concentrating step, the compound (3) is concentrated until its concentration becomes, for example, 90% by mass or more, 92% by mass or more, or 94% by mass or more.

[0059] Process D In step D, the concentrate obtained in step C is heated. By heating the concentrate, compound (3) contained in the concentrate is decarboxylated to produce compound (1) in high purity. Step D can be carried out in the reactor in which the concentration treatment in step C was carried out.

[0060] Step D may be carried out in an organic solvent or without a solvent. The organic solvent is not particularly limited as long as it is a solvent capable of decarboxylating compound (3). The organic solvent may be a solvent known to be usable for decarboxylating compound (3). Examples and preferred examples of the organic solvent are the same as those of the organic solvent in step A. Specific preferred examples of the organic solvent include 1,2-dimethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,4-dicyanobutane, and acetonitrile.

[0061] The amount of the organic solvent used in step D may be an amount that is sufficient to function as a solvent, based on common technical knowledge and the like.

[0062] In the case where the object to be heated contains a solvent, the reaction temperature in step D is preferably within a range of 50 to 400° C., more preferably within a range of 70 to 300° C., and even more preferably within a range of 100 to 200° C. When the object to be heated does not contain a solvent, the temperature is preferably within the range of 100 to 400°C, more preferably within the range of 150 to 400°C, and even more preferably within the range of 150 to 350°C.

[0063] The reaction time in step D is not particularly limited as long as compound (1) is produced, but may be preferably within the range of 0.1 to 48 hours, more preferably within the range of 0.1 to 24 hours, and even more preferably within the range of 0.1 to 12 hours.

[0064] The reaction of step D may be carried out in the presence or absence of an inert gas (eg, nitrogen gas), and is preferably carried out in the absence of an inert gas.

[0065] Step D may be carried out under reduced pressure, atmospheric pressure, or elevated pressure.

[0066] Compound (1) produced in step D can be isolated or purified, if desired, by a conventional method such as extraction, dissolution, concentration, precipitation, dehydration, adsorption, distillation, rectification, chromatography, or a combination thereof.

[0067] Composition (1) One embodiment of the present disclosure is a compound of formula (3): [ka] [In the formula, R 1 ~R 4 are each independently a fluorine atom or a C1-C7 fluoroalkyl group which may contain an etheric oxygen, and M is an alkali metal atom or an alkaline earth metal atom. A compound represented by the formula: Formula (4): [ka] [In the formula, Y is a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms may be substituted by a fluorine atom; R 1 ~R 4 is the same as above.] At least one compound selected from the group consisting of compounds represented by the formula (4) (hereinafter, may be referred to as compound (4)), and A composition containing carbon dioxide gas, When the composition is an aqueous solution of at least one compound selected from the group consisting of compound (3) and compound (4), the pH of the composition (aqueous solution) is within the range of 6.0 to 11.0. When the composition is a non-aqueous solution, the pH of the aqueous solution obtained by adding water to the composition (non-aqueous solution) is within the range of 6.0 to 11.0 (sometimes referred to as composition (1) in this specification).

[0068] The composition may be an aqueous or non-aqueous solution. The aqueous solution contains compounds (3) and (4). The non-aqueous solution includes an organic solvent containing at least one compound selected from the group consisting of compounds (3) and (4) (an organic solvent solution in which at least one compound selected from the group consisting of compounds (3) and (4) is dissolved (e.g., an alcohol solution in which at least one compound selected from the group consisting of compounds (3) and (4) is dissolved)) (hereinafter the same). If the composition is an aqueous solution, its pH is within the range of 6.0 to 11.0, and if it is a non-aqueous solution, the pH of the aqueous solution obtained by adding water to the composition may be within the range of 6.0 to 11.0. The pH of either of these solutions may be 6.0 to 10.0, 6.5 to 10.0, etc., preferably 6.5 to 9.0, even more preferably 6.5 to 8.5, and particularly preferably 6.9 to 7.9. When the non-aqueous solution is an organic solvent solution in which at least one compound selected from the group consisting of compounds (3) and (4) is dissolved, the pH of this solution may be within the range of 6.0 to 11.0. The pH may be 6.0 to 10.0, 6.5 to 10.0, etc., preferably 6.5 to 9.0, even more preferably 6.5 to 8.5, and particularly preferably 6.9 to 7.9. When the non-aqueous solution is an organic solvent containing at least one compound selected from the group consisting of compounds (3) and (4), the pH of the mixture obtained by mixing this organic solvent with water or the aqueous phase obtained by separating the mixture may be within the range of 6.0 to 11.0. The pH may be 6.0 to 10.0, 6.5 to 10.0, etc., preferably 6.5 to 9.0, even more preferably 6.5 to 8.5, and particularly preferably 6.9 to 7.9.

[0069] Y can be a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms may be substituted with a fluorine atom. Y can be a hydrogen atom, a C1-C3 alkyl group, or a perfluoro C1-C3 alkyl group. Y can be a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms are substituted with a fluorine atom. Y can be a hydrogen atom or a C1-C3 alkyl group. Y can be a hydrogen atom or a perfluoro C1-C3 alkyl group.

[0070] Examples of Y include a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, perfluoro n-propyl, and perfluoro i-propyl. Y may be a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, trifluoromethyl, or 2,2,2-trifluoroethyl. Y may be a hydrogen atom, methyl, ethyl, or trifluoromethyl. Y can be methyl, ethyl, n-propyl, i-propyl, trifluoromethyl, or 2,2,2-trifluoroethyl. Y can be methyl, ethyl, n-propyl, or i-propyl. Y can be methyl.

[0071] Compound (3), Compound (4), R 1 ~R 4 For details of and M, the above explanations regarding them apply.

[0072] Specific examples of compound (4) include 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid methyl ester, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid ethyl ester, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid n-propyl ester, Examples of the 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid i-propyl ester include 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid trifluoromethyl ester and 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid 2,2,2-trifluoroethyl ester. Specific examples of suitable compound (4) include 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid, 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid methyl ester, and 4,4,5-trifluoro-2,5-bis(trifluoromethyl)-1,3-dioxolane-2-carboxylic acid trifluoromethyl ester.

[0073] Since compound (3) is produced by the step A, composition (1) can be a pH-adjusted solution after the carbon dioxide gas treatment. Therefore, this composition can be produced, for example, by the step B. On the other hand, this composition can also be produced by mixing at least one compound selected from the group consisting of compound (3) and compound (4), and carbon dioxide gas.

[0074] The composition (1) may contain at least one compound selected from the group consisting of the compound (3) and the compound (4) in an amount of, for example, 0.1 to 99.9 mass%, preferably 1 to 90 mass%, and more preferably 5 to 80 mass%, based on the mass of the composition (1).

[0075] When composition (1) contains compound (3) and compound (4), the content of compound (3) can be, for example, 0.1 to 99.9 mass%, preferably 50 to 99.9 mass%, and more preferably 75 to 99.9 mass%, based on the total of compound (3) and compound (4).

[0076] Composition (1) may contain carbon dioxide gas in an amount, for example, from 0.05 to 1000 mass%, from 0.1 to 500 mass%, etc., preferably from 0.1 to 100 mass%, more preferably from 0.2 to 50 mass%, even more preferably from 0.2 to 30 mass%, and particularly preferably from 0.3 to 17 mass%, based on the mass of composition (1).

[0077] The composition (1) may contain water and / or an organic solvent. For details of the organic solvent, the description of the organic solvent explained in the production method above can be applied. The composition (1) may contain water in an amount of, for example, 5 to 90 mass %, preferably 10 to 80 mass %, and more preferably 10 to 70 mass %, based on the mass of the composition (1). The composition (1) may contain the organic solvent in an amount of, for example, 5 to 90 mass %, preferably 10 to 80 mass %, and more preferably 10 to 70 mass %, based on the mass of the composition (1).

[0078] Composition (1) may contain other components in addition to at least one compound selected from the group consisting of compound (3) and compound (4) and carbon dioxide gas. Examples of other components include bases, alkali metal or alkaline earth metal salts of hydrogen halides, and alkali metal or alkaline earth metal salts of inorganic acids. The description of the base in the production method of the present disclosure can be applied to the base. Composition (1) can contain other components in an amount of, for example, 0.1 to 30% by mass, 0.1 to 20% by mass, etc., based on the mass of composition (1).

[0079] Composition (1) is subjected to the step C to be concentrated, and the concentrate is heated in the step D to decarboxylate compound (3) and produce high-purity compound (1). During this process, the production of a by-product, an HF adduct which is not easily separated from compound (1), is reduced. This is because composition (1) contains carbon dioxide gas and has a pH of 6.0 to 11.0, 6.0 to 11.0, or 6.0 to 11.0. This is presumably because the molecular weight is within the range of 10.0, 6.5 to 10.0, 6.5 to 9.0, 6.5 to 8.5, or 6.9 to 7.9. Composition (1) is useful as a supply source of compound (1).

[0080] Composition (2) One embodiment of the present disclosure is a compound of formula (3): [ka] [In the formula, R 1 ~R 4 are each independently a fluorine atom or a C1-C7 fluoroalkyl group which may contain an etheric oxygen, and M is an alkali metal atom or an alkaline earth metal atom. A compound represented by the formula: Formula (4): [ka] [In the formula, Y is a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms may be substituted by a fluorine atom; R 1 ~R 4 is the same as above.] At least one compound selected from the group consisting of compounds represented by the formula: A composition containing carbon dioxide gas, The carbon dioxide gas content is 0.05 to 1000% by mass relative to the mass of the composition (sometimes referred to as composition (2) in this specification).

[0081] Compound (3), Compound (4), R 1 ~R 4 For details of M and Y, the above explanations thereof apply.

[0082] Since compound (3) is produced by the step A, composition (1) may be the pH-adjusted solution after the carbon dioxide gas treatment or the concentrate after the concentration treatment. Therefore, this composition can be produced, for example, by the step B or C. In addition, this composition can also be produced by mixing at least one compound selected from the group consisting of compound (3) and compound (4), and carbon dioxide gas.

[0083] Composition (2) may contain at least one compound selected from the group consisting of compound (3) and compound (4) in an amount of, for example, 1 to 99.9 mass%, preferably 10 to 99.9 mass%, and more preferably 50 to 99.9 mass%, based on the mass of composition (2).

[0084] When composition (2) contains compound (3) and compound (4), the content of compound (3) can be, for example, 0.1 to 99.9 mass%, preferably 50 to 99.9 mass%, and more preferably 75 to 99.9 mass%, based on the total of compound (3) and compound (4).

[0085] Composition (2) may contain carbon dioxide gas in an amount of, for example, 0.1 to 10,000 mol %, preferably 0.1 to 7,000 mol %, more preferably 0.1 to 5,000 mol %, and even more preferably 1 to 5,000 mol %, based on the content of compound (3). Composition (2) may contain carbon dioxide gas in an amount of, for example, 0.05 to 1000 mass%, 0.1 to 500 mass%, etc., preferably 0.1 to 100 mass%, more preferably 0.2 to 50 mass%, even more preferably 0.2 to 30 mass%, and particularly preferably 0.3 to 17 mass%, based on the mass of composition (2).

[0086] The composition (2) may contain water and / or an organic solvent. For details of the organic solvent, the description of the organic solvent explained in the production method above can be applied. The composition (2) may contain water in an amount of, for example, 0.001 to 90 mass %, preferably 0.001 to 80 mass %, and more preferably 0.001 to 70 mass %, based on the mass of the composition (2). The composition (2) may contain the organic solvent in an amount of, for example, 0.001 to 90 mass %, preferably 0.001 to 80 mass %, and more preferably 0.001 to 70 mass %, based on the mass of the composition (2).

[0087] Composition (2) may contain other components in addition to at least one compound selected from the group consisting of compound (3) and compound (4) and carbon dioxide gas. Examples of other components include bases, alkali metal or alkaline earth metal salts of hydrogen halides, and alkali metal or alkaline earth metal salts of inorganic acids. The description of the base in the production method of the present disclosure can be applied to the base. Composition (2) can contain other components in an amount of, for example, 0.1 to 30% by mass, 0.1 to 20% by mass, etc., based on the mass of composition (2).

[0088] Composition (2) is subjected to the step C to be concentrated, and the concentrate is heated in the step D, or, if composition (2) is sufficiently concentrated, composition (2) is heated in the step D to decarboxylate compound (3) and produce high-purity compound (1). At this time, the production of a by-product HF adduct that is not easily separated from compound (1) is reduced. This is presumably because composition (2) contains carbon dioxide gas, and the content of carbon dioxide gas is 0.05 to 1000 mass% relative to the mass of composition (2). Composition (2) is useful as a supply source of compound (1).

[0089] In the present disclosure, the amount of carbon dioxide can be determined by the Orsat method, gas absorption method, electrical conductivity method, thermal conductivity method, infrared absorption method, gas chromatography method, mass spectrometry, ion electrode method, measurement of gas phase pressure and liquid phase temperature, a method of conversion from pH and alkalinity, etc. When the amount of carbon dioxide differs depending on the determination method, the amount of carbon dioxide determined by measurement of gas phase pressure and liquid phase temperature, specifically, the method described in the examples, is used.

[0090] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. EXAMPLES

[0091] Hereinafter, one embodiment of the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited thereto.

[0092] In the examples, pH measurements were performed using a HORIBA F-74 benchtop pH / water quality analyzer. The amount of carbon dioxide was calculated from the gas phase pressure and liquid phase temperature, and was expressed as the amount (mol%) relative to the amount of compound (3). More specifically, the amount of carbon dioxide was calculated by subtracting the amount of carbon dioxide when the temperature and pressure in the reactor became roughly constant after introduction from the initial amount of carbon dioxide introduced into the reactor (amount of carbon dioxide added). The latter amount of carbon dioxide was calculated by subtracting the amount of carbon dioxide when the temperature and pressure in the reactor became roughly constant after introduction from the initial amount of carbon dioxide introduced into the reactor (amount of carbon dioxide added). and calculated by measuring the space volume.

[0093] The symbols and abbreviations in the examples are used with the following meanings. GC: Gas chromatography Compounds a to e: Compounds represented by the following formulae [ka]

[0094] Preparation Example 1: Preparation of Compounds a and b A crude product (purity 95%) containing compound a was synthesized according to the description in Reference Example 1 of Patent Document 3, and a crude product (purity 98%) containing compound b was synthesized according to the description in Example 5 of Patent Document 1, and these were used as raw materials in the comparative examples and examples.

[0095] Comparative Example 1 12.1 g (purity 95%) of crude material containing compound a was added to a reaction vessel, 5.3 g of potassium carbonate and 10 g of water were further added, and the mixture was stirred at 0 to 10 ° C for 3 hours to obtain a reaction liquid. The reaction liquid was filtered, concentrated, and analyzed by NMR, and found to be a concentrate containing 12.6 g of compound e (yield 98%). 1 g of the concentrate was dissolved in 50 g of water and the pH was measured, which was 12.0. The obtained concentrate was added to a reactor and heated at 200 ° C for 4 hours and then at 300 ° C for 1 hour. The product was collected in a -78 ° C trap and analyzed by NMR and GC, and a product containing compound c was obtained in a yield of 63% (compound c: compound d = 88: 12 (molar ratio)).

[0096] Comparative Example 2 41 g (purity 98%) of crude material containing compound b was added to a reaction vessel, and 7.4 g of potassium hydroxide and 42 g of methanol were further added and stirred at 20 ° C for 1 hour to obtain a reaction liquid. The reaction liquid was filtered, concentrated, and analyzed by NMR, and found to be a concentrate containing 42.7 g of compound e (yield 95%). 1 g of the concentrate was dissolved in 50 g of water and the pH was measured, which was 13.6. The obtained concentrate was added to a reactor and heated at 200 ° C for 4 hours and at 300 ° C for 1 hour. The product was collected in a -78 ° C trap and analyzed by NMR and GC, and the product containing compound c was obtained in a yield of 72% (compound c: compound d = 90: 10 (molar ratio)).

[0097] Reference example 1 12.1 g (purity 95%) of crude material containing compound a was added to a reaction vessel, 6.2 g of potassium carbonate and 10 g of water were further added, and the mixture was stirred at 0 to 10 ° C for 3 hours to obtain a reaction liquid. The entire reaction liquid was filtered and the pH was confirmed to be pH 12.0. Hydrofluoric acid was added to the reaction liquid to prepare a pH-adjusted liquid of pH 7.9 (composition (A): composition containing compound e, potassium carbonate, KF, and water). The pH-adjusted liquid was filtered and concentrated to obtain a concentrate. The obtained concentrate was analyzed by NMR and found to contain 12.6 g of compound e (yield 98%). After the reaction, the inside of the SUS reactor was confirmed to be corroded. The obtained concentrate was added to the reactor and vacuum dried at 140 ° C for 15 hours, and after confirming that it had become a highly concentrated product (composition (B): composition containing compound e, potassium carbonate, KF, and water (97 ppm)), the temperature was raised to 300 ° C and further heated at 300 ° C for 1 hour. The product was collected in a -78 ° C trap. The product was analyzed by NMR and GC, and as a result, it was found that a product containing compound c was obtained in a yield of 70% (compound c:compound d=>99:<1 (molar ratio)).

[0098] Reference example 2 41.0 g (purity 98%) of crude material containing compound b was added to a reaction vessel, 8.4 g of potassium hydroxide and 42 g of methanol were further added, and the mixture was stirred at 20 ° C for 1 hour to obtain a reaction liquid. The entire reaction liquid was filtered, and 1 g of the reaction liquid was added to 10 g of water, vigorously stirred, and then allowed to stand. The pH of the aqueous phase was confirmed to be pH 12.0. Hydrofluoric acid was added to the reaction liquid to prepare a pH 7.5 adjusted solution (composition (C): compound b (2.0 GC%), compound e, potassium hydroxide, water). The pH adjusted solution was filtered and concentrated to obtain a concentrate. The obtained concentrate was analyzed by NMR and found to contain 42.8 g of compound e (yield 95%). After the reaction, the inside of the SUS reactor was checked and it was confirmed that the surface of the vessel was corroded. The obtained product was added to a reactor and vacuum dried at 140°C for 15 hours. After confirming that it had become a highly concentrated product (composition (D): a composition containing compound e, potassium hydroxide, and water (54 ppm)), the temperature was raised to 300°C and further heated at 300°C for 1 hour. The product was collected in a -78°C trap. As a result of analyzing the product by NMR and GC, a product containing compound c was obtained in a yield of 80% (compound c:compound d => 99: < 1 (molar ratio)).

[0099] Example 1 11.5 g (purity 95%) of crude material containing compound a was added to a reaction vessel, 5.5 g of potassium carbonate and 10 g of water were further added, and the mixture was stirred at 0 to 10 ° C for 3 hours to obtain a reaction liquid. The entire reaction liquid was filtered and the pH was confirmed to be pH 12.0. The filtrate was transferred to a 2.0 L SUS pressure vessel, and then 8.9 g (600 mol%) of carbon dioxide was added and stirred for 1 hour to prepare a pH-adjusted liquid of pH 7.9. At this time, the temperature inside the reaction vessel was 25 ° C and the pressure was 0.25 MPaG. The obtained pH-adjusted liquid was concentrated, and the concentrate was analyzed by NMR, and it was found to contain 11.6 g of compound e (yield 95%). After the reaction, the inside of the SUS reactor was checked, and no corrosion was observed on the surface of the vessel. The obtained concentrate was added to the reactor and vacuum dried at 140 ° C for 15 hours (step C), and after confirming that it had become a highly concentrated product (water content 100 ppm or less), the temperature was raised to 300 ° C and further heated at 300 ° C for 1 hour (step (D)). The product was collected in a trap at -78°C. The product was analyzed by NMR and GC, and as a result, a product containing compound c was obtained in a yield of 78% (compound c:compound d => 99: < 1 (molar ratio)).

[0100] The mass of the pH adjusting solution (compositions (1) and (2)) was 27 g, and the composition was 11.6 g of compound e, 10 g of water, 0.09 g of carbon dioxide gas (the molar ratio relative to compound e was 6 mol%, 0.3% by mass relative to the mass of the composition), 1.9 g of potassium fluoride, and a small amount of potassium carbonate. The amount of carbon dioxide gas was determined as follows, using the reaction vessel volume (2 L), the amount of carbon dioxide gas added (8.9 g; 600 mol%), the temperature inside the reaction vessel (25° C.), and the pressure inside the reaction vessel (0.25 MPaG). This determination method is similar to other examples.

[0101] In the gas equation of state: PV=nRT, P: 0.25 [MPaG] V: 1.985 [L] (calculated from reaction vessel volume - content volume) Content volume: Volume of solvent (weight / specific gravity used) + Volume of compound e (weight / specific gravity produced: 2.5 g / mL) + Volume of compound b (weight / specific gravity produced: 1.7 g / mL) The specific gravity of the solvent is 1.0 g / mL for water and 0.78 g / mL for methanol. n: The amount of carbon dioxide gas in the gas phase you want to find [mol] R: 8.31×10 3 [Pa L / (mol K)] T: 298[K](25[℃]) Rearrange the gas equation of state to n=PV / RT, n = (0.25 × 10 6 ×(2.0-(10 / 1+11.6 / 2.5) / 1000)) / (8.31×10 3 ×298) =0.199 The amount of carbon dioxide gas in the composition (0.201-0.199=0.002 mol (0.09 g)) was calculated by subtracting the amount of carbon dioxide gas in the gas phase (0.199 mol) from the amount of carbon dioxide gas added (8.9 g (0.201 mol)).

[0102] Example 2 11.0 g (purity 95%) of crude material containing compound a was added to a reaction vessel, 5.5 g of potassium carbonate and 10 g of water were further added, and the mixture was stirred at 0 to 10 ° C for 3 hours to obtain a reaction liquid. The entire reaction liquid was filtered and the pH was confirmed to be pH 12.0. The filtrate was transferred to a 2.0 L SUS pressure vessel, and then 21.4 g (1500 mol%) of carbon dioxide was added and stirred for 1 hour to prepare a pH-adjusted liquid with a pH of 7.4. At this time, the temperature inside the reaction vessel was 25 ° C and the pressure was 0.60 MPaG. The obtained pH-adjusted liquid was concentrated, and the concentrate was analyzed by NMR, and it contained 11.2 g of compound e (yield 96%). After the reaction, the inside of the SUS reactor was checked, and no corrosion was observed on the surface of the vessel. The obtained concentrate was added to a reactor and vacuum dried at 140°C for 15 hours (step C). After confirming that it was a highly concentrated product (water content 100 ppm or less), the temperature was raised to 300°C and further heated at 300°C for 1 hour (step (D)). The product was collected in a -78°C trap. As a result of analyzing the product by NMR and GC, a product containing compound c was obtained in a yield of 78% (compound c:compound d => 99: < 1 (molar ratio)).

[0103] The mass of the pH adjusting solution (compositions (1) and (2)) was 27 g, and its composition was as follows: compound e: 11.2 g, water: 10 g, carbon dioxide: 0.24 g (molar ratio relative to compound e: 17 mol%, 0.9 mass% relative to the mass of the composition), potassium fluoride: 1.8 g, and a small amount of potassium carbonate.

[0104] Example 3 11.2 g (purity 95%) of crude material containing compound a was added to a reaction vessel, 5.5 g of potassium carbonate and 10 g of water were further added, and the mixture was stirred at 0 to 10 ° C for 3 hours to obtain a reaction liquid. The entire reaction liquid was filtered and the pH was confirmed to be pH 12.0. The filtrate was transferred to a 2.0 L SUS pressure vessel, and then 74.2 g (5000 mol%) of carbon dioxide was added and stirred for 1 hour to prepare a pH-adjusted liquid with a pH of 6.9. At this time, the temperature inside the reaction vessel was 25 ° C and the pressure was 2.08 MPaG. The obtained pH-adjusted liquid was concentrated, and the concentrate was analyzed by NMR, and it was found to contain 11.7 g of compound e (yield 98%). After the reaction, the inside of the SUS reactor was checked, and no corrosion was observed on the surface of the vessel. The obtained concentrate was added to a reactor and vacuum dried at 140°C for 15 hours (step C). After confirming that it was a highly concentrated product (water content 100 ppm or less), the temperature was raised to 300°C and further heated at 300°C for 1 hour (step (D)). The product was collected in a -78°C trap. As a result of analyzing the product by NMR and GC, a product containing compound c was obtained in a yield of 82% (compound c:compound d => 99: < 1 (molar ratio)).

[0105] The mass of the pH adjusting solution (compositions (1) and (2)) was 28 g, and its composition was as follows: compound e: 11.7 g, water: 10 g, carbon dioxide: 0.96 g (molar ratio relative to compound e: 65 mol%, 3 mass% relative to the mass of the composition), potassium fluoride: 1.9 g, and a small amount of potassium carbonate.

[0106] Example 4 43.0 g (purity 98%) of crude material containing compound b was added to a reaction vessel, 8.1 g of potassium hydroxide and 42 g of methanol were further added, and the mixture was stirred at 20 ° C for 1 hour to obtain a reaction liquid. The entire reaction liquid was filtered, and 1 g of the filtrate was added to 10 g of water, vigorously stirred, and then allowed to stand. The pH of the aqueous phase was confirmed to be pH 13.6. The filtrate was transferred to a 10 L SUS pressure vessel, and 32.3 g (600 mol%) of carbon dioxide was added and stirred for 1 hour to prepare a pH-adjusted solution with a pH of 7.9. At this time, the temperature inside the reaction vessel was 25 ° C and the pressure was 0.17 MPaG. The obtained pH-adjusted solution was concentrated, and the concentrate was analyzed by NMR, and it contained 42.3 g of compound e (yield 93%). After the reaction, the inside of the SUS reactor was checked, and no corrosion was observed on the surface of the vessel. The obtained concentrate was added to a reactor and vacuum dried at 140°C for 15 hours (step C). After confirming that it was a highly concentrated product (water content 100 ppm or less), the temperature was raised to 300°C and further heated at 300°C for 1 hour (step (D)). The product was collected in a -78°C trap. As a result of analyzing the product by NMR and GC, a product containing compound c was obtained in a yield of 79% (compound c:compound d => 99: < 1 (molar ratio)).

[0107] The mass of the pH adjusting solution (compositions (1) and (2)) was 95 g, and its composition was compound e: 42.3 g, compound b: 0.76 g, methanol: 45.8 g, carbon dioxide gas: 2.3 g (molar ratio relative to compound e: 42 mol%, 2 mass% relative to the composition mass), potassium fluoride: 0.7 g, a small amount of potassium carbonate, and a small amount of water.

[0108] Example 5 44.5 g (purity 98%) of crude material containing compound b was added to a reaction vessel, 8.3 g of potassium hydroxide and 42 g of methanol were further added, and the mixture was stirred at 20 ° C for 1 hour to obtain a reaction liquid. The entire reaction liquid was filtered, and 1 g of the filtrate was added to 10 g of water, vigorously stirred, and then allowed to stand. The pH of the aqueous phase was confirmed to be pH 13.8. The filtrate was transferred to a 10 L SUS pressure vessel, and 81.5 g (1500 mol%) of carbon dioxide was added and stirred for 1 hour to prepare a pH-adjusted solution with a pH of 7.4. At this time, the temperature inside the reaction vessel was 25 ° C and the pressure was 0.43 MPaG. The obtained pH-adjusted solution was concentrated, and the concentrate was analyzed by NMR, and it contained 42.7 g of compound e (yield 91%). After the reaction, the inside of the SUS reactor was checked, and no corrosion was observed on the surface of the vessel. The obtained concentrate was added to a reactor and vacuum dried at 140°C for 15 hours (step C). After confirming that it was a highly concentrated product (water content 100 ppm or less), the temperature was raised to 300°C and further heated at 300°C for 1 hour (step (D)). The product was collected in a -78°C trap. As a result of analyzing the product by NMR and GC, a product containing compound c was obtained in a yield of 80% (compound c:compound d => 99: < 1 (molar ratio)).

[0109] The mass of the pH-adjusting solution (compositions (1) and (2)) was 100 g, and its composition was compound e: 42.7 g, compound b: 0.65 g, methanol: 45.9 g, carbon dioxide gas: 5.7 g (molar ratio relative to compound e: 105 mol%, 6 mass% relative to the composition mass), potassium fluoride: 0.7 g, a small amount of potassium carbonate, and a small amount of water.

[0110] Example 6 46.0 g of crude material containing compound b (purity 98%) was added to a reaction vessel, 8.0 g of potassium hydroxide and 42 g of methanol were further added, and the mixture was stirred at 20°C for 1 hour to obtain a reaction liquid. The reaction liquid was filtered, and 1 g of the filtrate was added to 10 g of water, vigorously stirred, and then allowed to stand. The pH of the aqueous phase was confirmed to be pH 13.6. The filtrate was transferred to a 10 L SUS pressure vessel, and then 277.4g (5000mol%) of carbon dioxide gas was added and stirred for 1 hour to prepare a pH-adjusted solution with a pH of 6.9. At this time, the temperature inside the reaction vessel was 25°C and the pressure was 1.46MPaG. The obtained pH-adjusted solution was concentrated, and the concentrate was analyzed by NMR, and found to contain 43.6g of compound e (yield 90%). After the reaction, the inside of the SUS reactor was checked, and no corrosion was found on the surface of the vessel. The obtained concentrate was added to the reactor and vacuum dried at 140°C for 15 hours (step C), and after confirming that it had become a highly concentrated product (water content 100ppm or less), the temperature was raised to 300°C and further heated at 300°C for 1 hour (step (D)). The product was collected in a -78°C trap. As a result of analyzing the product by NMR and GC, a product containing compound c was obtained in a yield of 84% (compound c:compound d => 99: < 1 (molar ratio)).

[0111] The mass of the pH-adjusting solution (compositions (1) and (2)) was 115 g, and its composition was compound e: 43.6 g, compound b: 0.41 g, methanol: 46.0 g, carbon dioxide gas: 19.4 g (molar ratio relative to compound e: 350 mol %, 17 mass % relative to the mass of the composition), potassium fluoride: 0.72 g, a small amount of potassium carbonate, and a small amount of water.

Claims

1. Formula (1): 【Chemistry 1】 [In the formula, R １ ~R ４ are each independently a fluorine atom or a C1-C7 fluoroalkyl group which may contain an etheric oxygen. A method for producing a compound represented by the following formula: A manufacturing method comprising the following steps A, B, C, and D. (Process A) Formula (2): 【Chemistry 2】 [In the formula, X is a hydroxy group, a fluorine atom, a chlorine atom, or a C1-C3 alkoxy group in which one or more hydrogen atoms may be substituted by a fluorine atom; R １ ~R ４ is the same as above.] The compound represented by with at least one base selected from the group consisting of hydroxides, carbonates, and alkoxides of alkali metals and alkaline earth metals; Formula (3): 【Chemistry 3】 [In the formula, M is an alkali metal atom or an alkaline earth metal atom, R １ ~R ４ is the same as above.] to obtain a reaction product having a pH in the range exceeding pH 11.

0. (Process B) Step B is to add carbon dioxide gas to the reaction product obtained in step A or a liquid obtained by mixing the reaction product with water to adjust the pH to 6.0 to 11.0, thereby obtaining a pH-adjusted liquid. (Process C) Step C is to concentrate the pH-adjusted solution obtained in step B to obtain a concentrate. (Process D) Step D comprises heating the concentrate obtained in step C to thermally decompose the compound represented by formula (3) to produce the compound represented by formula (1).

2. The R １ ~R ４ each independently represents a fluorine atom or a perfluoro C1-C7 alkyl group or a perfluoro C1-C7 alkoxy group.

3. The R １ is a trifluoromethyl group or a fluorine atom, and R ２ ~R ４ The method according to claim 1 or 2, wherein each of the is a fluorine atom.

4. The method according to claim 1 or 2, wherein X is a hydroxy group, a fluorine atom, a chlorine atom, methoxy, ethoxy, n-propoxy, i-propoxy, trifluoromethoxy, or 2,2,2-trifluoroethoxy.

5. 3. The method according to claim 1, wherein the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, magnesium carbonate, sodium bicarbonate, potassium bicarbonate, potassium hydroxide, sodium hydroxide, magnesium hydroxide, potassium methoxide, sodium methoxide, magnesium methoxide, potassium ethoxide, sodium ethoxide, and magnesium ethoxide.

6. The method according to claim 1 or 2, wherein the pH range of 6.0 to 11.0 in step B is 6.0 to 10.

0.

7. The method according to claim 1 or 2, wherein the amount of carbon dioxide gas added in the step B is 100 to 10,000 mol % based on the content of the compound represented by formula (3) in the reaction product obtained in the step A.

8. The method according to claim 1 or 2, wherein the steps C and D are carried out successively in the same reactor.

9. The R １ is a trifluoromethyl group or a fluorine atom, The R ２ ~R ４ are all fluorine atoms, X is a fluorine atom, methoxy, ethoxy, n-propoxy, or i-propoxy; the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide; M is a potassium atom or a sodium atom, The pH range of 6.0 to 11.0 in the step B is 6.5 to 8.5, the amount of carbon dioxide gas added in the step B is 500 to 6000 mol % based on the content of the compound represented by formula (3) in the reaction product obtained in the step A; Item 3. The method according to item 1 or 2.

10. The R １ is a trifluoromethyl group or a fluorine atom, The R ２ ~R ４ are all fluorine atoms, X is a fluorine atom or methoxy; the base is at least one compound selected from the group consisting of potassium carbonate and potassium hydroxide; The M is a potassium atom, The pH range of 6.0 to 11.0 in the step B is 6.9 to 7.9, the amount of carbon dioxide gas added in the step B is 600 to 5000 mol % based on the content of the compound represented by formula (3) in the reaction product obtained in the step A; Item 3. The method according to item 1 or 2.

11. Formula (3): 【Chemistry 4】 [In the formula, R １ ~R ４ are each independently a fluorine atom or a C1-C7 fluoroalkyl group which may contain an etheric oxygen, and M is an alkali metal atom or an alkaline earth metal atom. A compound represented by the formula: Formula (4): 【Chemistry 5】 [In the formula, Y is a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms may be substituted by a fluorine atom; R １ ~R ４ is the same as above.] At least one compound selected from the group consisting of compounds represented by the formula: Carbon dioxide A composition comprising: When the composition is an aqueous solution of at least one compound selected from the group consisting of compounds represented by formula (3) and compounds represented by formula (4), the pH of the aqueous solution is within the range of 6.0 to 11.0, and when the composition is a non-aqueous solution, the pH of the aqueous solution obtained by adding water to the composition is within the range of 6.0 to 11.

0.

12. 12. The composition of claim 11, further comprising at least one base selected from the group consisting of hydroxides, carbonates, and alkoxides of alkali and alkaline earth metals.

13. The R １ ~R ４ The composition according to claim 11 or 12, wherein each of the is independently a fluorine atom, a perfluoro C1-C7 alkyl group, or a perfluoro C1-C7 alkoxy group.

14. The R １ is a trifluoromethyl group or a fluorine atom, and R ２ ~R ４ The composition according to claim 11 or 12, wherein each of the is a fluorine atom.

15. The composition according to claim 11 or 12, wherein Y is a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, trifluoromethyl, or 2,2,2-trifluoroethyl.

16. 13. The composition of claim 12, wherein the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, magnesium carbonate, sodium bicarbonate, potassium bicarbonate, potassium hydroxide, sodium hydroxide, magnesium hydroxide, potassium methoxide, sodium methoxide, magnesium methoxide, potassium ethoxide, sodium ethoxide, and magnesium ethoxide.

17. The composition according to claim 11 or 12, wherein the pH of the aqueous solution is in the range of 6.0 to 10.

0.

18. The composition according to claim 11 or 12, wherein the pH of the aqueous solution is in the range of 6.5 to 10.

0.

19. The R １ is a trifluoromethyl group or a fluorine atom, The R ２ ~R ４ are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide; Y is methyl, ethyl, n-propyl, or i-propyl; M is a potassium atom or a sodium atom, the pH of the aqueous solution is in the range of 6.5 to 8.5; The content of the carbon dioxide gas is 0.2 to 30% by mass based on the mass of the composition. The composition of claim 12.

20. The R １ is a trifluoromethyl group or a fluorine atom, The R ２ ~R ４ are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate and potassium hydroxide; Y is methyl; The M is a potassium atom, The pH of the aqueous solution is in the range of 6.9 to 7.9; The content of the carbon dioxide gas is 0.3 to 17% by mass based on the mass of the composition. The composition of claim 12.

21. Formula (3): 【Chemistry 6】 [In the formula, R １ ~R ４ are each independently a C1-C7 fluoroalkyl group which may contain a fluorine atom or an etheric oxygen, and M is an alkali metal atom or an alkaline earth metal atom. A compound represented by the formula: Formula (4): 【Chemistry 7】 [In the formula, Y is a hydrogen atom or a C1-C3 alkyl group in which one or more hydrogen atoms may be substituted by a fluorine atom; R １ ~R ４ is the same as above.] At least one compound selected from the group consisting of compounds represented by the formula: A composition containing carbon dioxide gas, The carbon dioxide gas content is 0.05 to 1000% by mass based on the mass of the composition.

22. The composition according to claim 21, wherein the carbon dioxide gas content is 0.1 to 500% by mass based on the mass of the composition.

23. The composition according to claim 21, wherein the content of the carbon dioxide gas is 0.1 to 100% by mass based on the mass of the composition.

24. The R １ ~R ４ The composition according to claim 21 or 22, wherein each independently is a fluorine atom, a perfluoro C1-C7 alkyl group, or a perfluoro C1-C7 alkoxy group.

25. The R １ is a trifluoromethyl group or a fluorine atom, and R ２ ~R ４ The composition according to claim 21 or 22, wherein each of the is a fluorine atom.

26. The composition according to claim 21 or 22, wherein Y is a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, trifluoromethyl, or 2,2,2-trifluoroethyl.

27. The composition further comprises a base; The R １ is a trifluoromethyl group or a fluorine atom, The R ２ ~R ４ are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide; Y is methyl, ethyl, n-propyl, or i-propyl; M is a potassium atom or a sodium atom, the pH of the aqueous solution is in the range of 6.5 to 8.5; The content of the carbon dioxide gas is 0.2 to 30% by mass based on the mass of the composition.

22. The composition of claim 21.

28. The composition further comprises a base; The R １ is a trifluoromethyl group or a fluorine atom, The R ２ ~R ４ are all fluorine atoms, the base is at least one compound selected from the group consisting of potassium carbonate and potassium hydroxide; Y is methyl; The M is a potassium atom, The pH of the aqueous solution is in the range of 6.9 to 7.9; The content of the carbon dioxide gas is 0.3 to 17% by mass based on the mass of the composition.

22. The composition of claim 21.

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