JP7440334B2 - Method for producing vinylsulfonyl fluoride - Google Patents

Description

The present invention relates to a method for producing vinylsulfonyl fluoride. More specifically, it relates to a method for producing in good yield vinylsulfonyl fluoride, that is, a sulfonic acid group-containing monomer, which can be used as a raw material for fluoropolymer electrolytes such as diaphragms for fuel cells, catalyst binder polymers for fuel cells, and diaphragms for salt electrolysis. .

（式（Ｉ）中、ｐは０～６の整数、ｑは１～６の整数、ｋ及びｌは１以上の整数である。） Conventionally, a perfluoropolymer represented by the following general formula (I) has been mainly employed as a main component of diaphragms for fuel cells, diaphragms for salt electrolysis, and the like.

(In formula (I), p is an integer of 0 to 6, q is an integer of 1 to 6, and k and l are integers of 1 or more.)

（式（ＩＩ）中、ｐ及びｑは上記一般式（Ｉ）と同じである。） The polymer represented by general formula (I) can be produced by subjecting a copolymer of a fluorinated monomer represented by general formula (II) below and tetrafluoroethylene (TFE) to saponification reaction and acid treatment. It has been known.

(In formula (II), p and q are the same as in the above general formula (I).)

Among the fluorinated monomers represented by the above general formula (II), polymers produced from monomers in which p=1 and q=2 to 4 are widely used as the main components of the above-mentioned diaphragm. It is known that such a monomer in which p=1 and q=2 to 4 can be produced by the following route.

By the way, the polymer in which p=0 in the above general formula (I) has a shorter spacer portion between the main chain and the sulfonic acid group than the polymer in which p is 1 or more, so It is also known that it exhibits a high glass transition temperature and high strength.

However, the fluorinated monomer represented by the above general formula (II) where p=0, which is a raw material for this polymer, has a problem in that it is difficult to synthesize. That is, decarboxylation/vinylation reaction is performed from CF ₃ CF(COF)O(CF ₂ ) _q SO ₂ F in the same manner as in the case of the fluorinated monomer represented by the above general formula (II) where p=1. It is known that since the cyclization reaction becomes the main reaction, the yield of the fluorinated monomer represented by the above general formula (II) with p=0 having a short chain structure becomes extremely low.

For example, as shown in the scheme below, when q=2, only the cyclization reaction proceeds, and it is difficult to obtain a fluorinated monomer with p=0 and q=2 in the above general formula (II). (For example, see Non-Patent Document 1).

A sulfonic acid group-containing monomer (CF ₂ =CFO(CF ₂ ) ₂ SO ₃ Na) that does not cause such a cyclization reaction has also been developed, and its production method is CF ₃ CF (COF) O (CF ₂ ). ₂ SO ₂ F is neutralized with an aqueous sodium hydroxide solution to obtain powdered CF ₃ CF(CO ₂ Na)O(CF ₂ ) ₂ SO ₃ Na, and then heated and decarboxylated to form CF ₂ =CFO. A method for obtaining (CF ₂ ) ₂ SO ₃ Na is disclosed. (For example, see Patent Document 1)
However, in the method described in Patent Document 1, before heating and decarboxylating CF ₃ CF(CO ₂ Na)O(CF ₂ ) ₂ SO ₃ Na, moisture is removed through a two-step drying process with different drying temperatures. Since a removal step is required, the reaction operation becomes complicated.

If water is not removed sufficiently in the method described in Patent Document 1, or if other hydrogen sources are present, the hydrogen-containing compound CF ₃ -CHFO(CF ₂ ) ₂ SO ₃ Na is removed in the heating/decarboxylation reaction. is known to be generated (for example, see Non-Patent Document 2).

（式（ＩＩＩ）中、ＡはＦ又はＣＦ_３であり、ｄは１～６の整数であり、ｄが２以上の場合、各々のＣＦＡは同じでも異なっていてもよい。）

（式（ＩＶ）中、ｄ及びＡのそれぞれは、上記一般式（ＩＩＩ）のｄ及びＡと同一であり、Ｇは水素原子、アルカリ金属、アルカリ土類金属又はＲ^ａ１Ｒ^ａ２Ｒ^ａ３Ｓｉである。（Ｒ^ａ１～Ｒ^ａ３は各々独立に、置換されていてもよい炭素数１～１０個の一価の炭化水素基又はＯＭ（Ｍはアルカリ金属又はアルカリ土類金属を表す。）である。）） On the other hand, a method for producing a sulfonic acid group-containing monomer ((IV)) represented by the following general formula (IV) from a cyclic compound represented by the following general formula (III) is disclosed, but in this method, It is also known that the hydrogen-containing compound CF ₃ -CHFO(CF ₂ ) ₂ SO ₃ Na is produced when water is not removed sufficiently when reacting cyclic compounds, or when other hydrogen sources are present. (For example, see Patent Document 2).

(In formula (III), A is F or _CF3 , d is an integer from 1 to 6, and when d is 2 or more, each CFA may be the same or different.)

(In formula (IV), each of d and A is the same as d and A in the above general formula (III), and G is a hydrogen atom, an alkali metal, an alkaline earth metal, or R ^a1 R ^a2 R ^a3 Si. (R ^a1 to R ^a3 are each independently an optionally substituted monovalent hydrocarbon group having 1 to 10 carbon atoms or OM (M represents an alkali metal or an alkaline earth metal). .))

Japanese Patent Application Publication No. 2004-18454 International Application Publication Patent No. 2019/176425

Japan Society for the Promotion of Science, 155th Committee on Fluorine Chemistry, “Introduction to Fluorine Chemistry 2010: The Frontiers of Fundamentals and Applications,” p. 353-355 Journal of FLUORINE CHEMISTRY 129 (2008) 535-540

CF ₃ -CHFO(CF ₂ ) ₂ SO ₃ Na produced in the presence of moisture or other hydrogen sources as described above is similar to CF ₂ =CFO(CF ₂ ) ₂ SO ₃ Na, which is an intermediate of the target product. It has the reactivity of Therefore, in the production of vinylsulfonyl fluoride, a by-product CF ₃ --CHFO(CF ₂ ) ₂ SO ₂ F is produced. In order to suppress the production of such by-products, a complicated water removal process is required.

The object of the present invention is to provide a method for producing vinyl sulfonyl fluoride, that is, a sulfonic acid group-containing monomer, in consideration of the above-mentioned current situation, which does not require a complicated water removal step and converts the generated hydrogen-containing compound into a cyclic compound. It is an object of the present invention to provide a method for producing vinylsulfonyl fluoride by converting, recovering and reusing it.

As a result of intensive studies to solve the above problems, the present inventors discovered a method of recovering a cyclic compound by contacting and mixing a hydrogen-containing compound with a base, and completed the present invention.

That is, the present invention is as follows.
[1] The present invention is a method for producing vinylsulfonyl fluoride represented by the following general formula (1),
(In formula (1), X ¹ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ¹ is 1 or 2.)
A separation step of separating the hydrogen-containing compound (2) represented by the following general formula (2) from a mixture (1) containing the hydrogen-containing compound (2) and the vinylsulfonyl fluoride;
(In formula (2), X ² is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ² is 1 or 2.)
A cyclic compound (3) represented by the following general formula (3) is obtained by contacting and mixing the basic compound (a) with the hydrogen-containing compound (2).
(In formula (3), X ³ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ³ is 1 or 2.)
a cyclization step to prepare
a reaction mixture generation step of generating the mixture (1) from the cyclic compound (3);
This is a method for producing vinylsulfonyl fluoride containing.

[2] In this embodiment, the basic compound (a) is preferably a combination of a dialkyl lithium amide or a hydrocarbon lithium compound and a coordinating nitrogen compound.

[3] In the present embodiment, the reaction mixture generation step includes the cyclic compound (3) and the silanol compound (4) represented by the following general formula (4).
(In formula (4), M ^a is an alkali metal or an alkaline earth metal, and R ¹ to R ³ are each independently a hydrogen atom, an optionally substituted monovalent group having 1 to 10 carbon atoms, a hydrocarbon group, or ^OMb ( ^Mb is an alkali metal or alkaline earth metal), and when two or more ^Mb 's are present, they may be the same or different.)
By mixing and stirring, a (vinyl)sulfonic acid compound (5) represented by the following general formula (5) is obtained.
(In formula (5), W ⁵ is CF ₂ =CF- or CF ₃ -CHF-, X ⁵ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ⁵ is 1 or 2. , Y is a hydrogen atom, M ^a or R ¹ R ² R ³ Si-. However, M ^a and R ¹ to R ³ have the same meaning as M ^a and R ¹ to R ³ in the general formula (4). Yes. - represents a bond.)
It is preferable to include a step (I) of preparing a mixture (2) containing the following.

[4] In the present embodiment, the reaction mixture generation step includes contacting and mixing the mixture (2) with a derivatizing agent to produce a (vinyl)sulfonic acid derivative represented by the following general formula (6) ( 6)
(In formula (6), W ⁶ is CF ₂ =CF- or CF ₃ -CHF-, X ⁶ is a fluorine atom or a fluoroalkyl having 1 to 3 carbon atoms, n ⁶ is 1 or 2, Z is CF ₂ =CFO(CF ₂ ) _m ^a CFX ^a SO ₂ - or CF ₃ -CHFO(CF ₂ ) _m ^b CFX ^b SO ₂ - or Cl, and X ^a and X ^b are each independently fluorine It is an atom or a fluoroalkyl having 1 to 3 carbon atoms, m ^a and m ^b are each independently 1 or 2, and - represents a bond.)
The method for producing vinyl sulfonyl fluoride according to claims 1 to 3, further comprising a step (II) of preparing a mixture (3) containing.

[5] In the present embodiment, the reaction mixture generation step may further include a step (III) of preparing the mixture (1) by contacting and mixing the mixture (3) and a fluorinating agent. preferable.

[6] In this embodiment, M ^a in the general formula (4) is preferably an alkali metal.

[7] In this embodiment, the silanol compound (4) is lithium trimethylsilanolate, lithium triethylsilanolate, lithium triisopropylsilanolate, lithium (tert-butyl)dimethylsilanolate, lithium triphenylsilanolate, dilithium Dimethylsilanediolate, dilithium diethylsilanediolate, dilithium diphenylsilanediolate, sodium trimethylsilanolate, sodium triethylsilanolate, sodium triisopropylsilanolate, sodium (tert-butyl)dimethylsilanolate, sodium triphenylsilanolate , disodium dimethylsilanediolate, disodium diethylsilanediolate, and disodium diphenylsilanediolate.

[8] In this embodiment, the derivatizing agent is phosphorus pentoxide, phosphorus pentachloride, acetic anhydride, trifluoroacetic anhydride, methanesulfonic anhydride, trifluoromethanesulfonic anhydride, p-toluenesulfonic acid. Preferably, the compound is one or more compounds selected from the group consisting of anhydride, thionyl chloride, dicyclohexylcarbodiimide, cyanuric acid chloride, titanium tetrachloride, and benzenesulfonyl chloride.

[9] In this embodiment, the fluorinating agent is one or more compounds selected from the group consisting of hydrogen fluoride, metal fluoride, quaternary ammonium fluoride, and quaternary phosphonium fluoride. It is preferable that there be.

According to the present invention, the hydrogen-containing compound produced by the contained moisture is converted into a cyclic compound, which is an intermediate in the production of vinyl sulfonyl fluoride, and is recovered and reused, without requiring a complicated water removal process. Sulfonyl fluoride can be produced.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "this embodiment") will be described in detail.

The method for producing vinylsulfonyl fluoride according to the present invention includes a separation step of separating a hydrogen-containing compound (2), which is a by-product of the vinylsulfonyl fluoride, from a reaction mixture (=mixture (1)); The method includes a cyclization step of cyclizing the compound (2), and a reaction mixture production step of producing the mixture (1) from the cyclic compound (3) obtained by cyclizing the hydrogen-containing compound (2).

In other words, in the method for producing vinylsulfonyl fluoride in this embodiment, after converting the byproduct (hydrogen-containing compound (2)) produced when the vinylsulfonyl fluoride is produced into a cyclic compound (3), , if necessary, the vinylsulfonyl fluoride and the by-product (hydrogen-containing compound (2)) are synthesized from the cyclic compound (3) into a precursor of the vinylsulfonyl fluoride and the hydrogen-containing compound (2). , the step of producing from the precursor or the cyclic compound (3) is a repeatable reaction cycle. Each step will be explained below.

"Separation process"
The present invention provides vinylsulfonyl fluoride represented by the following general formula (1),
(In formula (1), X ¹ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ¹ is 1 or 2.)
A hydrogen-containing compound (2) represented by the following general formula (2),
(In formula (2), X ² is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ² is 1 or 2.)
The hydrogen-containing compound (2) is separated from the mixture (1) containing the hydrogen-containing compound (2).

In this embodiment, vinylsulfonyl fluoride represented by general formula (1), which is the final target product, is recovered from the mixture (1), which is a reactant. At that time, the hydrogen-containing compound (2) represented by the general formula (2) is separated from the mixture (1) before or after recovering the vinylsulfonyl fluoride, or in conjunction with the recovery of the vinylsulfonyl fluoride. be able to.
Therefore, the method for producing vinylsulfonyl fluoride in this embodiment may include a recovery step of recovering vinylsulfonylfluoride represented by the above formula (1) from the mixture (1).

In the above separation step, the hydrogen-containing compound (2) can be separated from the vinylsulfonyl fluoride-containing mixture (1) by a known method such as distillation or column chromatography.
For example, in the separation step by distillation, either simple distillation or rectification can be carried out, but rectification is preferable from the viewpoint of obtaining a highly pure target product and a high distillation yield. As for the rectification conditions, the number of theoretical plates in the rectification column is preferably 2 or more and 20 or less, and the reflux ratio is preferably 0.1 or more and 20 or less.
Further, in the separation step using column chromatography, silver ion chromatography, etc., in which separation is performed depending on the number of double bonds in the compound molecule to be separated, etc. is preferable.

In the above general formula (1), X ¹ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, preferably F or CF ₃ .

In the above general formula (2), X ² is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, preferably F or CF ₃ .

Further, the recovery step of recovering the target product, vinylsulfonyl fluoride represented by general formula (1), can be performed by a known method such as distillation or column chromatography, similar to the above separation step.

"Cyclization process"
The present invention produces a cyclic compound (3) represented by the following formula (3) by contacting and mixing a basic compound (a) with the hydrogen-containing compound (2) represented by the above formula (2).
(In formula (3), X ³ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ³ is 1 or 2.)
It has a cyclization step to prepare.

In the above formula (3), X ³ is preferably F or CF ₃ .

The mechanism of the cyclization reaction from the hydrogen-containing compound (2) to the cyclic compound (3) is estimated as follows. Hydrogen is extracted from the hydrogen-containing compound (2) by the action of the basic compound (a), and the produced carbanion attacks the sulfur atom in the molecule and cyclizes, thereby producing the cyclic compound (3).

The basic compound (a) in the present invention may be any basic compound that can extract hydrogen from the hydrogen-containing compound (2). From the viewpoint of reactivity, the basic compound (a) is preferably, for example, a dialkyl lithium amide or a combination of a hydrocarbon lithium compound and a coordinating nitrogen compound.
Examples of the dialkyllithium amide include lithium diisopropylamide, lithium-2,2,6,6-tetramethylpiperidide, and the like. Further, the dialkyllithium amide can be synthesized by mixing a basic substance (b) such as n-butyllithium with a secondary amine compound such as dialkylamine. Further, the basic compound (a) synthesized in advance may be reacted with the hydrogen-containing compound (2), or when reacting with the hydrogen-containing compound (2), the basic substance (b) and a secondary amine compound (e.g. , dialkylamine) may be added at the same time.
Examples of the basic substance (b) include methyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, and phenyllithium. Examples of the secondary amine compound include di-n-propylamine, diisopropylamine, di-n-butylamine, di-tert-butylamine, dicyclohexylamine, piperidine, pyrrolidine, 2,6-dimethylpiperidine, or 2,2,6,6 - dialkylamines such as tetramethylpiperidine; or aromatic amines such as diphenylamine and dibenzylamine; or hydrocarbon compounds containing these.

The combination of the hydrocarbon-based lithium compound and the coordinating nitrogen compound may be any combination as long as the coordinating nitrogen compound is capable of coordinating with the hydrocarbon-based lithium compound (for example, alkyl lithium). For example, the hydrocarbon-based lithium compound includes alkyllithium such as methyllithium, n-butyllithium, sec-butyllithium, or tert-butyllithium, and aromatic lithium such as phenyllithium. In addition, the coordinating nitrogen compounds include N,N,N',N'-tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane, N,N'-dimethylpropylene urea, hexamethyl Examples include phosphoric acid triamide.

From the viewpoint of operability, the basic compound (a) in the present invention is preferably used after being diluted with a solvent. The solvent need only be inert during the reaction, and various aprotic solvents can be used, such as aliphatic hydrocarbon solvents such as hexane, heptane, and cyclohexane, aromatic solvents such as toluene, xylene, and ethylbenzene. Hydrocarbon solvent, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,4-dioxane, cyclopentyl methyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 4- Examples include various ether group-containing solvents such as methyltetrahydropyran, nitrile group-containing solvents such as acetonitrile, and sulfone group-containing solvents such as sulfolane.

In the production method of the present embodiment, the amount of the solvent used is preferably 10 to 2000 parts by mass, more preferably 10 to 2000 parts by mass, based on 100 parts by mass of the hydrogen-containing compound (2) from the viewpoint of ease of stirring and solvent removal. is 50 to 1000 parts by mass.

In the production method of the present embodiment, the amount of the basic compound (a) used is preferably 0.5 to 6 times the molar equivalent of the hydrogen-containing compound (2) from the viewpoint of reaction results. It is more preferable to use 1 to 3 times the molar equivalent of (2).
In this embodiment, the temperature at which the basic compound (a) and the solvent are mixed and stirred is preferably -100°C to 100°C, more preferably -80°C to 50°C from the viewpoint of reaction results.

In this embodiment, the time for mixing and stirring the basic compound (a) and the solvent is preferably 0.01 to 50 hours, more preferably 0.1 to 10 hours, from the viewpoint of productivity.

"Reaction mixture generation process"
The present invention includes a reaction mixture production step of producing the mixture (1) from the cyclic compound (3). In the reaction mixture generation step, the cyclic compound (3) is ring-opened, and vinylsulfonyl fluoride represented by the above general formula (1) and the hydrogen-containing compound (2) represented by the above general formula (2) are prepared. Any synthetic route that can prepare the mixture (1) containing the following may be used. A preferred embodiment of the synthesis route, which is the reaction mixture production step in this embodiment, will be described below.

In this embodiment, the reaction mixture generation step preferably includes a step (I) of preparing a mixture (2) by reacting a cyclic compound (3) with a silanol compound (4) described below. Furthermore, in the present embodiment, the reaction mixture generation step includes contacting and mixing the mixture (2) with a derivatizing agent described below to form a mixture (vinyl)sulfonic acid derivative (6) as described below. It is preferable to further include step (II) of preparing step 3).
In the present embodiment, the reaction mixture generation step preferably further includes a step (III) of preparing the mixture (1) by contacting and mixing the mixture (3) with a fluorinating agent.

In this embodiment, a particularly preferred embodiment of the reaction mixture production step is an embodiment including the above step (I), the above step (II), and the above step (III). Below, the above steps (I) to (III) will be explained in detail.

<Step (I): Reaction between cyclic compound (3) and silanol compound (4)>
In this embodiment, the reaction mixture generation step includes the cyclic compound (3) and the silanol compound (4) represented by the following general formula (4).
(In formula (4), M ^a is an alkali metal or an alkaline earth metal, and R ¹ to R ³ are each independently a hydrogen atom, an optionally substituted monovalent group having 1 to 10 carbon atoms, a hydrocarbon group, or ^OMb ( ^Mb is an alkali metal or alkaline earth metal), and when two or more ^Mb 's are present, they may be the same or different.)
By mixing and stirring, a (vinyl)sulfonic acid compound (5) represented by the following general formula (5) is obtained.
(In formula (5), W ⁵ is CF ₂ =CF- or CF ₃ -CHF-, X ⁵ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ⁵ is 1 or 2. , Y is a hydrogen atom, M ^a or R ¹ R ² R ³ Si-, provided that M ^a and R ¹ to R ³ have the same meaning as M ^a and R ¹ to R ³ in the above general formula (4). (In addition, - represents a bond.)
It is preferable to include a step (I) of preparing a mixture (2) containing the following.

In the above general formula (4), M ^a is an alkali metal or an alkaline earth metal, but from the viewpoint of availability and ease of synthesis of the silanol compound (4), M ^a is preferably an alkali metal. The alkali metal is preferably lithium, sodium, or potassium.

In the above general formula (4), R ¹ to R ³ are preferably each independently a hydrogen atom or an optionally substituted monovalent hydrocarbon group having 1 to 10 carbon atoms.
Examples of the "monovalent hydrocarbon group" in the above general formula (4) include an aliphatic hydrocarbon group and an aromatic hydrocarbon group such as a phenyl group. In addition, "may be substituted" means that some or all of the hydrogen atoms in the monovalent hydrocarbon group are substituted with a substituent such as a halogen atom (fluorine atom or chlorine atom) or a functional group described below. It means something that can be done. Therefore, "optionally substituted monovalent hydrocarbon group" refers to, for example, an aliphatic hydrocarbon group, an aromatic hydrocarbon group such as a phenyl group, and a hydrocarbon group in which all hydrogen atoms are replaced by fluorine atoms. Examples include substituted fluorine-substituted hydrocarbon groups such as trifluoromethyl groups. Further, the monovalent hydrocarbon group is preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

In the above general formula (5), X ⁵ is preferably F or CF ₃ . Moreover, (vinyl) means that it may have a vinyl group. Therefore, for example, the (vinyl)sulfonic acid compound (5) refers to a sulfonic acid compound that may contain one or more vinyl groups.

In addition, the said hydrocarbon group may have a functional group as needed. Examples of the functional group include halogen atoms such as fluorine atom, chlorine atom, and bromine atom, nitrile group (-CN), ether group (-O-), carbonate group (-OCO ₂ -), and ester group (-CO ₂ -), carbonyl group (-CO-), sulfide group (-S-), sulfoxide group (-SO-), sulfone group (-SO ₂ -), urethane group (-NHCO ₂ -), and the like.

The silanol compound (4) in this embodiment includes lithium trimethylsilanolate, lithium triethylsilanolate, lithium triisopropylsilanolate, lithium (tert-butyl)dimethylsilanolate, lithium triphenylsilanolate, and dilithium dimethylsilanediolate. , dilithium diethylsilanediolate, dilithium diphenylsilanediolate, sodium trimethylsilanolate, sodium triethylsilanolate, sodium triisopropylsilanolate, sodium (tert-butyl)dimethylsilanolate, sodium triphenylsilanolate, disodium dimethyl Examples include silanediolate, disodium diethylsilanediolate, and disodium diphenylsilanediolate.

The silanol compound (4) may be a commercially available product, or may be synthesized from available compounds such as halogenated silanes, silanols, and siloxanes.

In the manufacturing method of this embodiment, it is preferable to use a solvent when mixing and stirring the cyclic compound (3) and the silanol compound (4).

The above-mentioned solvent only needs to be inert during the reaction, and various aprotic solvents can be used, such as aliphatic hydrocarbon solvents such as hexane, heptane, and cyclohexane, and aromatic solvents such as toluene, xylene, and ethylbenzene. Hydrocarbon solvent, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,4-dioxane, cyclopentyl methyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 4- Examples include various ether group-containing solvents such as methyltetrahydropyran, nitrile group-containing solvents such as acetonitrile, and sulfone group-containing solvents such as sulfolane. Among these, in order to obtain the (vinyl)sulfonic acid compound (5) in a good yield, it is preferable to use an ether group-containing solvent such as tetrahydrofuran, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, or 4-methyltetrahydropyran.

In the production method of the present embodiment, the amount of the solvent used is preferably 10 to 1000 parts by mass, more preferably 10 to 1000 parts by mass, based on 100 parts by mass of the cyclic compound (3), from the viewpoint of ease of stirring and solvent removal. is 50 to 500 parts by mass.

In the production method of the present embodiment, the amount of silanol compound (4) used is preferably 0.95 to 4 times the molar equivalent of cyclic compound (3) from the viewpoint of reaction results.

In this embodiment, the temperature at which the cyclic compound (3) and the silanol compound (4) are mixed and stirred is preferably -100°C to 200°C from the viewpoint of reaction results.

In this embodiment, the time for mixing and stirring the cyclic compound (3) and the silanol compound (4) is preferably 0.01 to 100 hours from the viewpoint of productivity.

（式（５－１）中、Ｗ^５、Ｘ^５、ｎ^５及びＹは、上記一般式（５）中のＷ^５、Ｘ^５、ｎ^５及びＹと同義である。）
下記式（５－２）で表わされるスルホン酸化合物（５－２）と、

（式（５－２）中、Ｗ^５、Ｘ^５、ｎ^５及びＹは、上記一般式（５）中のＷ^５、Ｘ^５、ｎ^５及びＹと同義である。）
を含有することが好ましい。 The mixture (2) obtained by step (I) in this embodiment includes a vinyl sulfonic acid compound (5-1) represented by the following general formula (5-1),

(In formula (5-1), W ⁵ , X ⁵ , n ⁵ and Y have the same meanings as W ⁵ , X ⁵ , n ⁵ and Y in the above general formula (5).)
A sulfonic acid compound (5-2) represented by the following formula (5-2),

(In formula (5-2), W ⁵ , X ⁵ , n ⁵ and Y have the same meanings as W ⁵ , X ⁵ , n ⁵ and Y in the above general formula (5).)
It is preferable to contain.

The vinyl sulfonic acid compound (5-1) corresponds to the precursor of vinyl sulfonyl fluoride, and the sulfonic acid compound (5-2) corresponds to the precursor of the hydrogen-containing compound (2).

In a preferred aspect of this embodiment, the vinyl sulfonic acid compound (5-1) can be converted to the target object, vinyl sulfonyl fluoride, via the vinyl sulfonic acid derivative (6-1) described below. On the other hand, the sulfonic acid compound (5-2) can be converted to the hydrogen-containing compound (2) via the sulfonic acid derivative (6-2) described below.

As a result, vinylsulfonyl fluoride can be produced by converting the hydrogen-containing compound (2), which is a by-product, into a cyclic compound (3), which is an intermediate for producing vinylsulfonyl fluoride, and recovering and reusing it.

<Step (II): Reaction of mixture (2) and derivatizing agent>
In this embodiment, the reaction mixture generation step includes contacting and mixing the mixture (2) with a derivatizing agent to produce a (vinyl)sulfonic acid derivative (6) represented by the following general formula (6).
(In formula (6), W ⁶ is CF ₂ =CF- or CF ₃ -CHF-, X ⁶ is a fluorine atom or a fluoroalkyl having 1 to 3 carbon atoms, n ⁶ is 1 or 2, Z is CF ₂ =CFO(CF ₂ ) _m ^a CFX ^a SO ₂ -, CF ₃ -CHFO(CF ₂ ) _m ^b CFX ^b SO ₂ -, Cl, or OH group, and X ^a and X ^b are each independent is a fluorine atom or a fluoroalkyl having 1 to 3 carbon atoms, m ^a and m ^b are each independently 1 or 2, and - represents a bond.)
It is preferable to further include a step (II) of preparing a mixture (3) containing the following.

In the above general formula (6), it is preferable that X ⁶ , X ^a and X ^b are each independently F or CF ₃ .

Examples of the derivatizing agent include phosphorus pentoxide, acetic anhydride, trifluoroacetic anhydride, methanesulfonic anhydride, trifluoromethanesulfonic anhydride, p-toluenesulfonic anhydride, thionyl chloride, dicyclohexylcarbodiimide, Examples include cyanuric acid chloride, titanium tetrachloride, benzenesulfonyl chloride, oxalyl chloride, phosphorus trichloride, phosphorus pentachloride, sulfuryl chloride, etc. However, from the viewpoint of availability and ease of reaction operation, phosphorus pentoxide, trifluoro Preferred are acetic anhydride, trifluoromethanesulfonic anhydride, and thionyl chloride. The above derivatizing agents may be used alone or in combination of two or more.

In the manufacturing method of this embodiment, the reaction may be carried out using a solvent or without a solvent. When a solvent is used, it is preferably a solvent that is inert to the raw materials and reaction products.

The reaction temperature between the mixture (2) and the derivatizing agent is usually -40°C to 300°C, but from the viewpoint of thermal stability and reactivity of the raw materials and reaction products, the reaction temperature is -20°C to 280°C. The temperature is preferably 0°C to 250°C, more preferably 10°C to 200°C.

The reaction time between the mixture (2) and the derivatizing agent is usually 0.01 to 200 hours, preferably 0.1 to 180 hours.

In step (II) of the present embodiment, the contacting/mixing method may be a commonly used method, regardless of whether the reaction is carried out without a solvent or using a solvent. Not limited. For example, methods using stirring blades (e.g., fans, propellers, crosses, butterflies, dragonflies, turbines, disc turbines, dispers, paddles, inclined paddles, screws, etc.), crushers (jaw crushers, gyratory crushers, impact crushers, cone crushers, etc.), methods using resonance phenomena (e.g., resonance (acoustic mixer), etc. These methods may be used alone or in combination. In addition, since contact and mixing may be performed more efficiently, it is also possible to use grinding media commonly used in bead mills, such as alumina beads, glass beads, zirconia beads, zircon beads, steel beads, etc. (see above). Beads can also be used as balls). These grinding media may be used alone or in combination.

（式（６－１）中、Ｘ^６ _、ｎ^６及びＺは、上記一般式（６）中のＸ^６ _、ｎ^６及びＺと同義である。）
下記式（６－２）で表される（ビニル）スルホン酸誘導体（６－２）と、

（式（６－２）中、Ｘ^６ _、ｎ^６及びＺは、上記一般式（６）中のＸ^６ _、ｎ^６及びＺと同義である。）
を含有することが好ましい。 The mixture (3) obtained by step (II) in this embodiment includes a vinyl sulfonic acid derivative (6-1) represented by the following general formula (6-1),

(In formula (6-1), X ⁶ _, n ⁶ and Z have the same meanings as X ⁶ _, n ⁶ and Z in general formula (6) above.)
(vinyl)sulfonic acid derivative (6-2) represented by the following formula (6-2),

(In formula (6-2), X ⁶ _, n ⁶ and Z have the same meanings as X ⁶ _, n ⁶ and Z in general formula (6) above.)
It is preferable to contain.

（上記化合物（６－１．１）～（６－２．３）中の記号は、一般式（６）と同様である。）
で表される化合物群が少なくとも混在されていると推定している。現状のＮＭＲ測定では、上記化合物群中、（６－１．１）～（６－１．２）及び（６－２．１）～（６－２．２）のグループと、（６－１．３）及び（６－２．３）のグループとは判別できる。また、ＣＦ_２＝ＣＦＯ－又はＣＦ_３－ＣＨＦＯ－も判別は可能である。しかし、（６－１．１）～（６－１．２）及び（６－２．１）～（６－２．２）の各化合物の存在比を特定することが困難である。そのため、本明細書では、（６－１．１）～（６－１．２）及び（６－２．１）～（６－２．２）のグループを、便宜上、（６－１．１）で表される化合物と、（６－２．２）で表される化合物との２つに分けて存在比を確認した。
また、化合物（６－１．１）～（６－２．３）のうち、（６－２．２）及び（６－２．３）で表される化合物は、水素含有化合物（２）の前駆体になり、それ以外は、ビニルスルホニルフルオリドの前駆体になると考えられる。 The vinyl sulfonic acid derivative (6-1) is a precursor of vinyl sulfonyl fluoride. Among the (vinyl)sulfonic acid derivatives (6-2), sulfonic acid derivatives that do not have vinyl groups at both ends are precursors of the hydrogen-containing compound (2). More specifically, the mixture (3) contains the following compounds (6-1.1) to (6-2.3):

(Symbols in the above compounds (6-1.1) to (6-2.3) are the same as in general formula (6).)
It is estimated that at least the compound group represented by is mixed. In the current NMR measurement, among the above compound groups, the groups (6-1.1) to (6-1.2) and (6-2.1) to (6-2.2) and (6-1 It can be distinguished from the groups .3) and (6-2.3). Further, CF ₂ =CFO- or CF ₃ -CHFO- can also be determined. However, it is difficult to specify the abundance ratio of each compound (6-1.1) to (6-1.2) and (6-2.1) to (6-2.2). Therefore, in this specification, the groups (6-1.1) to (6-1.2) and (6-2.1) to (6-2.2) are referred to as (6-1.1) for convenience. ) and the compound represented by (6-2.2), and the abundance ratio was confirmed.
Furthermore, among the compounds (6-1.1) to (6-2.3), the compounds represented by (6-2.2) and (6-2.3) are the hydrogen-containing compound (2). It is thought that it becomes a precursor, and the others become precursors of vinylsulfonyl fluoride.

<Step (III): Reaction of mixture (3) and fluorinating agent>
In this embodiment, in the reaction mixture generation step, the mixture (1) is preferably prepared by contacting and mixing the mixture (3) and a fluorinating agent.

Examples of the fluorinating agent in this embodiment include hydrogen fluoride, metal fluoride, quaternary ammonium fluoride, quaternary phosphonium fluoride, etc. At least one type of phosphonium fluoride may be selected.

When using hydrogen fluoride as the fluorinating agent in this embodiment, examples include a method of reacting hydrogen fluoride alone, or reacting hydrogen fluoride in the presence of an organic base. When using an organic base, the following primary amines, secondary amines, tertiary amines, or nitrogen-containing aromatic heterocyclic compounds may be mentioned.
・Primary amines: methylamine, ethylamine, isopropylamine, butylamine, etc. ・Secondary amines: dimethylamine, diethylamine, diisopropylamine, morpholine, etc. ・Tertiary amines: trimethylamine, triethylamine, diisopropylethylamine, etc. ・Nitrogen-containing aromatic heterocyclic compounds :Pyridine, 2,6-lutidine, imidazole, quinoline These organic bases can be used alone or in combination of two or more organic bases.

When a metal fluoride is used as the fluorinating agent in this embodiment, examples of the metal include alkali metals (Li, Na, K, Rb, Cs), alkaline earth metals (Mg, Ca), and Ag. Specific examples include LiF, NaF, KF, RbF, CsF, MgF ₂ , CaF ₂ , AgF, etc., but from the viewpoint of reactivity, the group consisting of LiF, NaF, KF, RbF, CsF, and AgF At least one metal fluoride selected from the following is more preferred, and NaF or KF is particularly preferred.

When quaternary ammonium fluoride is used as the fluorinating agent, specific examples include tetramethylammonium fluoride, tetraethylammonium fluoride, and tetrabutylammonium fluoride.

When quaternary phosphonium fluoride is used as the fluorinating agent, specific examples include tetramethylphosphonium fluoride, tetraethylphosphonium fluoride, and tetrabutylphosphonium fluoride.

The above fluorinating agents can be used alone or in combination of two or more. The amount of fluorinating agent used is usually 0.95 to 20 mol per 1 mol of (vinyl)sulfonic acid derivative (6), but if unused fluorinating agent remains, separation becomes complicated. The amount is preferably 0.98 to 10 mol. In step (III) of the present embodiment, the reaction may be carried out using a solvent or without a solvent. When a solvent is used, it is preferably a solvent that is inert to the raw materials and reaction products.

In this embodiment, the reaction temperature between the mixture (3) and the fluorinating agent is usually -40°C to 300°C, but from the viewpoint of thermal stability and reactivity of the raw materials and reaction products, - The temperature is preferably 20°C to 280°C, more preferably 0°C to 250°C, and particularly preferably 10°C to 200°C.

In this embodiment, the reaction time between the mixture (3) and the fluorinating agent is usually 0.01 to 40 hours, preferably 0.1 to 20 hours.

As described above, the present invention provides vinylsulfonyl fluoride, that is, sulfone, which can be used as a raw material for various fluoropolymer electrolytes such as highly heat-resistant membranes for fuel cells, catalyst binder polymers for fuel cells, and membranes for salt electrolysis. Acid group-containing monomers can be produced with good yield.

Hereinafter, the present invention will be explained in more detail using Examples, but the present invention is not limited to these Examples. The analytical methods used in the Examples and Comparative Examples are as follows.

Nuclear magnetic resonance analysis (NMR): Quantification was performed using molecular structure analysis by ¹ H-NMR and ¹⁹ F-NMR.
Measuring device: JNM-ECZ400S type nuclear magnetic resonance device (manufactured by JEOL Ltd.)
Solvent: Deuterated chloroform or heavy water Standard substance: _CFCl3 (0ppm)
Gas chromatography (GC): Quantification of compounds Measuring device: GC-2010Plus (Shimadzu Corporation)
Column: Rtx-200 (manufactured by RESTEK), length 60 m, inner diameter 0.25 mm, film thickness 1 μm
Detector: FID
Temperature increase profile: After being held at 40°C for 10 minutes, the temperature was raised to 280°C at 20°C/min and held for 20 minutes.

及び４－メチルテトラヒドロピラン２８０．０ｇを加え、０℃に冷却した。次に、４－メチルテトラヒドロピラン３００．０ｇにナトリウムトリメチルシラノラート（シグマアルドリッチ社製、１１２．１ｇ、１．００ｍｏｌ）を溶解させた溶液をこのフラスコの中へ１時間かけて滴下した後、さらに室温で２時間攪拌した。得られた反応混合物を減圧濃縮すると固体状の残渣（１７１．９ｇ）が得られた。この固体状の残渣は^１９Ｆ－ＮＭＲ（内部標準：トリフルオロエタノール）より、ＣＦ_２＝ＣＦＯＣＦ_２ＣＦ_２ＳＯ_３Ｎａが７９．２質量％（収率９１％）、ＣＦ_３－ＣＨＦＯＣＦ_２ＣＦ_２ＳＯ_３Ｎａが８．６質量％（収率９％）含まれていることがわかった。 [Example 1]
<Step (I): Reaction between cyclic compound (3) and silanol compound (4)>
Under a nitrogen atmosphere, a cyclic compound (3) represented by the following formula (3-a) (140.0 g, 0.50 mol) was placed in a 1 L 4-necked flask.

and 280.0 g of 4-methyltetrahydropyran were added, and the mixture was cooled to 0°C. Next, a solution of sodium trimethylsilanolate (manufactured by Sigma-Aldrich, 112.1 g, 1.00 mol) dissolved in 300.0 g of 4-methyltetrahydropyran was added dropwise into the flask over 1 hour. Stirred at room temperature for 2 hours. The resulting reaction mixture was concentrated under reduced pressure to obtain a solid residue (171.9 g). According to ¹⁹ F-NMR (internal standard: trifluoroethanol), this solid residue contains 79.2% by mass (yield 91%) of CF ₂ =CFOCF ₂ CF ₂ SO ₃ Na, CF ₃ -CHFOCF ₂ CF ₂ It was found that 8.6% by mass (9% yield) of SO ₃ Na was contained.

In a 500 mL four-necked flask, CF ₂ =CFOCF ₂ CF ₂ SO ₃ Na (129.4 g, 0.43 mol) obtained above and CF ₃ -CHFOCF ₂ CF ₂ SO ₃ Na (14.0 g, 0.4 mol) were placed in a 500 mL four-necked flask. After adding a mixture of 0.044 mol) and sulfuric acid (163.0 g, 1.7 mol), the inside of the flask was set to 30 kPa and stirred at 70° C., and after a while they were uniformly dissolved. Next, the inside of the flask was set to 0.33 kPa and the temperature of this flask was gradually raised to 145° C., and a liquid was distilled out (obtained amount: 127.6 g). According to ¹⁹ F-NMR, this liquid has the following properties: CF ₂ =CFOCF ₂ CF ₂ SO ₃ H (0.41 mol, yield 96%), CF ₃ -CHFOCF ₂ CF ₂ SO ₃ H (0.042 mol, yield 96%) It was found to be a mixture (2) of

<Step (II): Reaction of (vinyl)sulfonic acid compound (5) and derivatizing agent>
After adding phosphorus pentoxide (P ₂ O ₅ ) (129.4 g, 0.91 mol) to a 500 mL four-necked flask in a glove box under a dry air atmosphere, the flask was equipped with a Liebig condenser and a dropping funnel. , heated to 50° C. under a nitrogen stream. Next, from the dropping funnel, CF ₂ =CFOCF ₂ CF ₂ SO ₃ H (115.1 g, 0.41 mol) and CF ₃ -CHFOCF ₂ CF ₂ SO ₃ H (12.5 g, 0.042 mol) obtained above were added. After dropping the mixture, the temperature of the flask was raised to 140° C., and the pressure inside the flask was raised from normal pressure to 60 kPa. When the temperature was further raised to 160° C. and the pressure inside the flask was reduced to 20 kPa, a liquid was distilled out (182.1 g). According to ¹⁹ F-NMR, this liquid contains 85% by mass (0.15 mol, yield 74%) of (CF ₂ =CFOCF ₂ CF ₂ SO ₂ ) ₂ O and 10% by mass of CF ₂ =CFOCF ₂ CF ₂ SO ₃ H. % (0.033 mol), (CF ₃ -CHFOCF ₂ CF ₂ SO ₂ ) ₂ O is 9 mass % (0.016 mol, yield 74%), and CF ₃ -CHFOCF ₂ CF ₂ SO ₃ H is 1 mass % (0.003 mol) was found to be mixture (3).

<Step (III): Reaction of (vinyl)sulfonic acid derivative (6) and fluorinating agent>
After weighing NaF (10.6 g, 0.25 mol) into a 300 mL three-necked flask, it was dried under vacuum at 150° C. for 1 hour, and then returned to room temperature under normal pressure. This flask was equipped with a Liebig condenser and a dropping funnel, and the above-obtained (CF ₂ = CFOCF ₂ CF ₂ SO ₂ ) ₂ O, CF ₂ = CFOCF ₂ CF ₂ SO ₃ was added from the dropping funnel at room temperature under a nitrogen stream. After dropping a mixture (182.1 g) of H, (CF ₃ -CHFOCF ₂ CF ₂ SO ₂ ) ₂ O, CF ₃ -CHFOCF ₂ CF ₂ SO ₃ H, the mixture was heated to 190° C. under reduced pressure (95 kPa). A liquid distilled out (46.6g). According to ¹⁹ F-NMR, this liquid was a mixture (1) containing CF ₂ =CFOCF ₂ CF ₂ SO ₂ F (0.15 mol) and CF ₃ -CHFOCF ₂ CF ₂ SO ₂ F (0.015 mol). It turned out to be.

<Separation step and recovery step: separation of hydrogen-containing compound (2), recovery of vinylsulfonyl fluoride>
46.6 g of the mixture (1) of CF ₂ =CFOCF ₂ CF ₂ SO ₂ F (0.15 mol) and CF ₃ -CHFOCF ₂ CF ₂ SO ₂ F (0.015 mol) obtained above was purchased from Sulzer Chemtech Co., Ltd. When distilled and separated under atmospheric pressure using a distillation apparatus equipped with a packed column (inner diameter 25 mm, packing height 1200 mm) packed with EX packing made by Manufacturer Co., Ltd., 36.6 g of a liquid mainly containing CF ₂ =CFOCF ₂ CF ₂ SO ₂ F was obtained ( 0.13 mol, GC purity 99.9%) and 3.9 g (0.013 mol, GC purity 99.0%) of a liquid mainly containing CF ₃ -CHFOCF ₂ CF ₂ SO ₂ F were obtained. This produced vinylsulfonyl fluoride and separated the hydrogen-containing compound (2) from the mixture (1).

<Cyclization step: Reaction between hydrogen-containing compound (2) and basic compound (a)>
Under a nitrogen atmosphere, 1.0 g (3.3 mmol) of the CF ₃ -CHFOCF ₂ CF ₂ SO ₂ F obtained above and 4.0 g of tetrahydrofuran were added to a 50 mL flask, and the mixture was cooled to -80°C. Next, 4.0 mL (4.0 mmol) of a solution of lithium diisopropylamide in n-hexane-tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., 1M) was added, and the mixture was stirred at -80°C for 2 hours. Thereafter, the reaction solution was analyzed and it was found that a cyclic compound (3) represented by the following formula (3-a) was produced. (1.8 mmol, yield 54%)

回収した式（３－ａ）の環状化合物（３）を用い下記に示す製造工程に従ってビニルスルホニルフルオリドを得た。

Using the recovered cyclic compound (3) of formula (3-a), vinylsulfonyl fluoride was obtained according to the production process shown below.

<Second step (I): Reaction between cyclic compound (3) and silanol compound (4) 5.0 g of 4-methyltetrahydropyran and water are added to the liquid containing the cyclic compound (3) obtained in the above reaction (4). After adding 5.0 g and shaking, the oil layer was collected. After further adding 5.0 g of water and shaking, the oil layer was collected, and Molecular Sieves 3A1/8 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 1.0 g) was added to remove water, and the cyclic compound (3) 1. 4.50 g of a liquid containing 8 mmol was obtained.

The above liquid was placed in a 50 mL three-necked flask under a nitrogen atmosphere and cooled to 0°C. Next, a solution of sodium trimethylsilanolate (manufactured by Sigma-Aldrich, 0.40 g, 3.6 mmol) dissolved in 2.0 g of 4-methyltetrahydropyran was added dropwise into the flask over 1 hour, and then Stirred at room temperature for 2 hours. The resulting reaction mixture was concentrated under reduced pressure to obtain a solid residue (0.62 g). According to ¹⁹ F-NMR (internal standard: trifluoroethanol), this solid residue contains 80.3% by mass (yield 92%) of CF ₂ =CFOCF ₂ CF ₂ SO ₃ Na, CF ₃ -CHFOCF ₂ CF ₂ It was found that 7.5% by mass (yield: 8%) of SO ₃ Na was contained.

3.0 g of cyclopentyl methyl ether and 1.0 g (3.1 mmol) of 30% sulfuric acid were added to the mixture of CF ₂ =CFOCF ₂ CF ₂ SO ₃ Na and CF ₃ -CHFOCF ₂ CF ₂ SO ₃ Na obtained above. After shaking and mixing, the oil layer was collected and concentrated under reduced pressure to obtain 0.53 g of liquid. From ¹⁹ F-NMR, this liquid showed CF ₂ =CFOCF ₂ CF ₂ SO ₃ H (1.6 mmol, yield 96%), and CF ₃ -CHFOCF ₂ CF ₂ SO ₃ H (0.14 mmol, yield 96%). %) was found to be mixture (2).

<Second step (II): Reaction of (vinyl)sulfonic acid compound (5) and derivatizing agent>
Phosphorous pentoxide (P ₂ O ₅ ) (0.78 g, 5.53 mmol), CF ₂ =CFOCF ₂ CF ₂ SO ₃ H obtained above, was added to a 25 mL test tube flask in a glove box under a dry air atmosphere. After adding a mixture of CF 3 -CHFOCF ₂ CF ₂ SO ₃ H (0.44 g, 1.59 mmol) and CF ₃ -CHFOCF 2 CF 2 SO 3 H (0.04 g, 0.14 mmol), the flask was heated to 140° C. under a nitrogen stream. After 30 minutes, the flask was returned to room temperature, 4.0 g of hexafluorobenzene was added and mixed, and the phosphorus pentoxide residue was separated by filtration to obtain a liquid. According to ¹⁹ F-NMR, this liquid has the following properties: (CF ₂ = CFOCF ₂ CF ₂ SO ₂ ) ₂ O (0.60 mmol, yield 75%), CF ₂ = CFOCF ₂ CF ₂ SO ₃ H (0.10 mmol), ( The mixture (3) contained CF ₃ -CHFOCF ₂ CF ₂ SO ₂ ) ₂ O (0.05 mmol, yield 75%) and CF ₃ -CHFOCF ₂ CF ₂ SO ₃ H (0.01 mmol). Understood.

<Second step (III): Reaction of (vinyl)sulfonic acid derivative (6) and fluorinating agent>
NaF (0.04 g, 0.97 mmol) was weighed into a 25 mL test tube flask, dried at 150° C. for 1 hour under vacuum, and then returned to room temperature under normal pressure. Under a nitrogen stream, (CF ₂ =CFOCF ₂ CF ₂ SO ₂ ) ₂ O, CF ₂ =CFOCF ₂ CF ₂ SO ₃ H, (CF ₃ -CHFOCF ₂ CF ₂ SO ₂ ) ₂ O, CF ₃ obtained above After adding 0.36 g of a mixture of -CHFOCF ₂ CF ₂ SO ₃ H, the mixture was heated to 190° C. and the pressure was gradually reduced to 50 kPa over 30 minutes, and a liquid was distilled out (0.15 g). From ^19F -NMR, this liquid was found to be a mixture (1) of CF ₂ =CFOCF ₂ CF ₂ SO ₂ F (0.51 mmol, yield 87%) and CF ₃ -CHFOCF ₂ CF ₂ SO ₂ F (0.04 mmol). It turned out to be. As a result, the final product CF ₂ =CFOCF ₂ CF ₂ SO ₂ F (0.51 mol, yield 87%) was obtained from the cyclic compound (3) of formula (3-a) produced in the above cyclization step. Manufactured.
Furthermore, it is confirmed that the reaction cycle of Example 1 does not require a water removal step because the cyclic compound (3) is used.

[Example 2]
The steps other than the cyclization step "reaction of hydrogen-containing compound (2) and basic compound (a)" in Example 1 above were performed in the same manner as in Example 1. The cyclization step performed in Example 2 is as follows.
Under a nitrogen atmosphere, 1.0 g (3.3 mmol) of the CF ₃ -CHFOCF ₂ CF ₂ SO ₂ F obtained above and 8.0 g of tetrahydrofuran were added to a 50 mL flask, and the mixture was cooled to -80°C. Next, lithium-2,2,6,6-tetramethylpiperidide (manufactured by Sigma-Aldrich, 0.74 g, 5.0 mmol) was added, and the mixture was stirred at -80°C for 2 hours. Thereafter, the reaction solution was analyzed and it was found that a cyclic compound (3) was produced. (1.5 mmol, yield 45%)

[Example 3]
The steps other than the cyclization step "reaction of hydrogen-containing compound (2) and basic compound (a)" in Example 1 above were performed in the same manner as in Example 1. The cyclization step performed in Example 3 is as follows.
Under a nitrogen atmosphere, 1.0 g (3.3 mmol) of the CF ₃ -CHFOCF ₂ CF ₂ SO ₂ F obtained above and 4.0 g of tetrahydrofuran were added to a 50 mL flask, and the mixture was cooled to -80°C. Next, tetramethylethylenediamine (manufactured by Tokyo Kasei, 0.74 g, 6.4 mmol) was added, followed by 4.0 mL (6.4 mmol) of an n-hexane solution of n-butyllithium (manufactured by Tokyo Kasei, 1.6 M). was added and stirred at -80°C for 2 hours. Thereafter, the reaction solution was analyzed and it was found that a cyclic compound (3) was produced. (1.0 mmol, yield 30%)

The present invention has produced vinylsulfonyl fluoride, a sulfonic acid group-containing monomer that can be used as a raw material for various fluoropolymer electrolytes such as highly heat-resistant membranes for fuel cells, catalyst binder polymers for fuel cells, and membranes for salt electrolysis. It can be produced with good yield.

Claims (8)

A method for producing vinylsulfonyl fluoride represented by the following general formula (1), comprising:
(In formula (1), X ¹ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ¹ is 1 or 2.)
A separation step of separating the hydrogen-containing compound (2) represented by the following general formula (2) from a mixture (1) containing the hydrogen-containing compound (2) and the vinylsulfonyl fluoride;
(In formula (2), X ² is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ² is 1 or 2.)
A cyclic compound (3) represented by the following general formula (3) is obtained by contacting and mixing the basic compound (a) with the hydrogen-containing compound (2).
(In formula (3), X ³ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ³ is 1 or 2.)
a cyclization step to prepare
a reaction mixture generation step of generating the mixture (1) from the cyclic compound (3);
including;
A method for producing vinylsulfonyl fluoride, wherein the basic compound (a) is a dialkyl lithium amide or a combination of a hydrocarbon lithium compound and a coordinating nitrogen compound . The hydrocarbon lithium compound is methyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, or phenyllithium, and the coordinating nitrogen compound is N, N, N', N Production of vinylsulfonyl fluoride according to claim 1, which is '-tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane, N,N'-dimethylpropylene urea, or hexamethylphosphoric triamide. Method. The reaction mixture generation step includes the cyclic compound (3), the silanol compound (4) represented by the following general formula (4),
(In formula (4), M ^a is an alkali metal or an alkaline earth metal, and R ¹ to R ³ are each independently a hydrogen atom, an optionally substituted monovalent group having 1 to 10 carbon atoms, a hydrocarbon group, or ^OMb ( ^Mb is an alkali metal or alkaline earth metal), and when two or more ^Mb 's are present, they may be the same or different.)
By mixing and stirring, a (vinyl)sulfonic acid compound (5) represented by the following general formula (5) is obtained.
(In formula (5), W ⁵ is CF ₂ =CF- or CF ₃ -CHF-, X ⁵ is a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and n ⁵ is 1 or 2. , Y is a hydrogen atom, M ^a or R ¹ R ² R ³ Si-. However, M ^a and R ¹ to R ³ have the same meanings as M ^a and R ¹ to R ³ in formula (4) above. .- represents a bond.)
The method for producing vinylsulfonyl fluoride according to claim 1 or 2, comprising the step (I) of preparing a mixture (2) containing. In the reaction mixture generation step, a (vinyl)sulfonic acid derivative (6) represented by the following formula (6) is produced by contacting and mixing the mixture (2) with a derivatizing agent.
(In formula (6), W ⁶ is CF ₂ =CF- or CF ₃ -CHF-, X ⁶ is a fluorine atom or a fluoroalkyl having 1 to 3 carbon atoms, n ⁶ is 1 or 2, Z is CF ₂ =CFO(CF ₂ ) _m ^a CFX ^a SO ₂ - or CF ₃ -CHFO(CF ₂ ) _m ^b CFX ^b SO ₂ -, Cl or OH group, and X ^a and X ^b are each independently is a fluorine atom or a fluoroalkyl having 1 to 3 carbon atoms, m ^a and m ^b are each independently 1 or 2, and - represents a bond.)
further comprising a step (II) of preparing a mixture (3) containing
The derivatizing agent is phosphorus pentoxide, phosphorus pentachloride, acetic anhydride, trifluoroacetic anhydride, methanesulfonic anhydride, trifluoromethanesulfonic anhydride, p-toluenesulfonic anhydride, thionyl chloride, dicyclo The method for producing vinylsulfonyl fluoride according to claims 1 to 3 , which is one or more compounds selected from the group consisting of xylcarbodiimide, cyanuric acid chloride, titanium tetrachloride, and benzenesulfonyl chloride . The vinyl according to claim 1, wherein the reaction mixture generation step further includes a step (III) of preparing the mixture (1) by contacting and mixing the mixture (3) with a fluorinating agent. Method for producing sulfonyl fluoride. The method for producing vinylsulfonyl fluoride according to any one of claims 3 to 5, wherein M ^a in the formula (4) is an alkali metal. The silanol compound (4) is lithium trimethylsilanolate, lithium triethylsilanolate, lithium triisopropylsilanolate, lithium (tert-butyl)dimethylsilanolate, lithium triphenylsilanolate, dilithium dimethylsilanediolate, dilithium diethyl Silanediolate, dilithium diphenylsilanediolate, sodium trimethylsilanolate, sodium triethylsilanolate, sodium triisopropylsilanolate, sodium (tert-butyl)dimethylsilanolate, sodium triphenylsilanolate, disodium dimethylsilanediolate, The vinyl sulfonyl fluoride according to any one of claims 3 to 6, which is one or more compounds selected from the group consisting of disodium diethylsilanediolate and disodium diphenylsilanediolate. Production method. Claims 5 to 7 , wherein the fluorinating agent is one or more compounds selected from the group consisting of hydrogen fluoride, metal fluoride, quaternary ammonium fluoride, and quaternary phosphonium fluoride. A method for producing vinylsulfonyl fluoride according to any one of the items.