JP7523365B2 - Method for producing fluorine-containing vinyl sulfonic acid fluoride - Google Patents

Description

The present invention relates to a method for producing fluorine-containing vinyl sulfonic acid fluoride.

（ｐは０～６の整数、ｑは１～６の整数）
一般式（５）で表されるフッ素系高分子電解質は、下記一般式（６）で表される含フッ素ビニルスルホン酸フルオリド（６）とテトラフルオロエチレン（ＴＦＥ）との共重合体をケン化反応及び酸処理を施すことによって製造できることが知られている。

（ｐは０～６の整数、ｑは１～６の整数）
上記一般式（６）で表される含フッ素ビニルスルホン酸フルオリド（６）の製造方法として、
下記一般式（１）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸無水物（１）と、
フッ化水素、金属フッ化物、４級アンモニウムフルオリド、及び４級ホスホニウムフルオリドからなる群より選択される１種以上であるフッ素化剤とを、
接触・混合させることにより、下記一般式（４）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸フルオリド（４）を製造方法が開示されている（特許文献１）。 Conventionally, a fluoropolymer electrolyte (5) represented by the following general formula (5) has been mainly used as a main component of a membrane for a fuel cell, a catalyst binder polymer for a fuel cell, a membrane for salt electrolysis, and the like.

(p is an integer from 0 to 6, and q is an integer from 1 to 6)
It is known that a fluorine-containing polymer electrolyte represented by the general formula (5) can be produced by subjecting a copolymer of fluorine-containing vinylsulfonic acid fluoride (6) represented by the following general formula (6) and tetrafluoroethylene (TFE) to a saponification reaction and an acid treatment.

(p is an integer from 0 to 6, and q is an integer from 1 to 6)
The method for producing the fluorine-containing vinyl sulfonic acid fluoride (6) represented by the above general formula (6) includes the following steps:
The following general formula (1):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula:
a fluorinating agent which is at least one selected from the group consisting of hydrogen fluoride, a metal fluoride, a quaternary ammonium fluoride, and a quaternary phosphonium fluoride;
By contacting and mixing, a compound represented by the following general formula (4):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
A method for producing a fluorine-containing vinyl sulfonic acid fluoride (4) represented by the following formula (JP-A-2003-133633) is disclosed.

International Publication No. 2020/012913

Patent Document 1 discloses a method for producing fluorine-containing vinyl sulfonic acid fluoride (4) where m = 0 and n = 2 by reacting fluorine-containing vinyl sulfonic acid anhydride (1) where m = 0 and n = 2 with sodium fluoride or potassium fluoride in the presence of acetonitrile, but a higher yield is required.

As a result of intensive research aimed at solving the above-mentioned problems, the present inventors discovered that the above-mentioned object can be achieved by reacting a fluorine-containing vinyl sulfonic anhydride (1) (hereinafter also referred to as "compound (1)") with an alkali metal fluoride (2) (hereinafter also referred to as "compound (2)") in the presence of a fluorine-containing nitrile compound (3) (hereinafter also referred to as "compound (3)"), and thus completed the present invention.

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸フルオリド（４）の製造方法であり、
下記一般式（１）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸無水物（１）と、
下記一般式（２）：
ＭＦ （２）
（式中、Ｍは、Ｌｉ、Ｎａ、Ｋ、Ｒｂ、又はＣｓである。）
で表されるアルカリ金属フッ化物（２）とを、
下記一般式（３）：
Ｒ^ｆＣＮ （３）
（式中、Ｒ^ｆは、少なくとも１つのフッ素原子で置換されている脂肪族炭化水素基、又は芳香族炭化水素基であり、炭素数は１～２０である。）
で表される含フッ素ニトリル化合物（３）の存在下で反応させる
ことを特徴とする、製造方法。
［２］
前記含フッ素ニトリル化合物（３）において、置換されているフッ素原子の数が、１～５個である、［１］に記載の製造方法。
［３］
前記含フッ素ニトリル化合物（３）において、Ｒ^ｆは、少なくとも１つのフッ素原子で置換されている芳香族炭化水素基である、［１］又は［２］に記載の製造方法。
［４］
前記含フッ素ニトリル化合物（３）が、ｍ－フルオロベンゾニトリル、２，３－ジフルオロベンゾニトリル、２，３，４－トリフルオロベンゾニトリル、２，３，６－トリフルオロベンゾニトリル、２－フルオロ－３－（トリフルオロメチル）ベンゾニトリル、２－フルオロ－４－（トリフルオロメチル）ベンゾニトリル、２－フルオロ－５－（トリフルオロメチル）ベンゾニトリル、３－フルオロ－５－（トリフルオロメチル）ベンゾニトリル、２，３，４，５－テトラフルオロベンゾニトリル、フルオロアセトニトリル、ジフルオロアセトニトリル、２－フルオロベンゾニトリル、２，４，５－トリフルオロベンゾニトリル、ｏ－（トリフルオロメチル）ベンゾニトリル、ペンタフルオロベンゾニトリルからなる群より選ばれる少なくとも１種である、［１］～［３］のいずれかに記載の製造方法。 That is, the present invention is as follows.
[1]
The following general formula (4):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
The present invention relates to a method for producing a fluorinated vinyl sulfonic acid fluoride (4) represented by the following formula:
The following general formula (1):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula:
The following general formula (2):
Midfielder (2)
(In the formula, M is Li, Na, K, Rb, or Cs.)
and an alkali metal fluoride (2) represented by
The following general formula (3):
^RfCN (3)
(In the formula, ^Rf is an aliphatic hydrocarbon group substituted with at least one fluorine atom or an aromatic hydrocarbon group having 1 to 20 carbon atoms.)
The production method according to claim 1, characterized in that the reaction is carried out in the presence of a fluorine-containing nitrile compound (3) represented by the following formula:
[2]
The method according to [1], wherein the number of fluorine atoms substituted in the fluorine-containing nitrile compound (3) is 1 to 5.
[3]
The process according to [1] or [2], wherein in the fluorine-containing nitrile compound (3), R ^f is an aromatic hydrocarbon group substituted with at least one fluorine atom.
[4]
The process according to any one of [1] to [3], wherein the fluorine-containing nitrile compound (3) is at least one selected from the group consisting of m-fluorobenzonitrile, 2,3-difluorobenzonitrile, 2,3,4-trifluorobenzonitrile, 2,3,6-trifluorobenzonitrile, 2-fluoro-3-(trifluoromethyl)benzonitrile, 2-fluoro-4-(trifluoromethyl)benzonitrile, 2-fluoro-5-(trifluoromethyl)benzonitrile, 3-fluoro-5-(trifluoromethyl)benzonitrile, 2,3,4,5-tetrafluorobenzonitrile, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile.

According to the present invention, fluorine-containing vinyl sulfonic acid fluoride (4) can be produced in good yield.

The following describes in detail the form for carrying out the present invention (hereinafter, referred to as the "present embodiment"). However, the present invention is not limited to the present embodiment below, and can be carried out in various modifications within the scope of the gist of the present invention.

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸フルオリド（４）の製造方法であり、
下記一般式（１）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸無水物（１）と、
下記一般式（２）：
ＭＦ （２）
（式中、Ｍは、Ｌｉ、Ｎａ、Ｋ、Ｒｂ、又はＣｓである。）
で表されるアルカリ金属フッ化物（２）とを、
下記一般式（３）：
Ｒ^ｆＣＮ （３）
（式中、Ｒ^ｆは、少なくとも１つのフッ素原子で置換されている脂肪族炭化水素基、又は芳香族炭化水素基であり、炭素数は１～２０である。）
で表される含フッ素ニトリル化合物（３）の存在下で反応させる
ことを特徴とする。 The manufacturing method of this embodiment is as follows:
The following general formula (4):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
The present invention relates to a method for producing a fluorinated vinyl sulfonic acid fluoride (4) represented by the following formula:
The following general formula (1):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula:
The following general formula (2):
Midfielder (2)
(In the formula, M is Li, Na, K, Rb, or Cs.)
and an alkali metal fluoride (2) represented by
The following general formula (3):
^RfCN (3)
(In the formula, ^Rf is an aliphatic hydrocarbon group substituted with at least one fluorine atom or an aromatic hydrocarbon group having 1 to 20 carbon atoms.)
The reaction is carried out in the presence of a fluorine-containing nitrile compound (3) represented by the following formula:

The following provides details about compounds (1), (2), and (3), as well as the reaction conditions for producing compound (4) from compound (1).

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される。
含フッ素ビニルスルホン酸無水物（１）は、１種単独であっても、複数種を組み合わせて用いてもよい。 <Fluorine-containing vinyl sulfonic anhydride (1) (compound (1))>
The fluorine-containing vinyl sulfonic anhydride (1) is represented by the following general formula (1):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
It is expressed as:
The fluorine-containing vinyl sulfonic anhydride (1) may be used alone or in combination of two or more kinds.

As m, 0 to 1 is preferable, and 0 is more preferable, since it is easily available or produced and tends to be economical.
As n, it is preferable that n is 1 to 4, more preferably 2 to 4, and even more preferably 2, because n is easily available or produced and tends to be economical.
A particularly preferred combination of m and n is m=0 and n=2.

The method for producing the fluorine-containing vinyl sulfonic anhydride (1) is not particularly limited, and it can be produced by a conventionally known method. For example, it can be produced by the method described in WO 2020/012913.

<Alkali Metal Fluoride (2) (Compound 2)>
The alkali metal fluoride (2) is represented by the following general formula (2):
Midfielder (2)
(In the formula, M is Li, Na, K, Rb, or Cs.)
It is expressed as:
The alkali metal fluoride (2) may be used alone or in combination of two or more kinds.

M is preferably K, Rb, or Cs, since the reactivity of the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2) tends to be increased, and the yield of fluorine-containing vinyl sulfonic acid fluoride tends to be increased. K or Cs is more preferred, since they tend to be easily available and economically advantageous, and K is even more preferred from the same viewpoint.

Compound (2) having a reduced water content can also be used, if necessary.
The method for reducing the water content of compound (2) is not particularly limited as long as it is a commonly available method, and examples of the method include a method of heating, a method of heating under vacuum, and a method of heating under a dry gas flow.
The heating temperature is not particularly limited as long as it is a temperature that can reduce the water content of compound (2), but since there is a tendency to suppress decomposition of compound (2), it is preferably 600° C. or less. Since excessive heating is suppressed and there is a tendency to be more economical, it is more preferably 300° C. or less, and from the same viewpoint, it is even more preferably 250° C. or less, and particularly preferably 200° C. or less. In addition, since there is a tendency to promote reduction of the water content, it is preferably 100° C. or more, more preferably 120° C. or more, and even more preferably 150° C. or more.
The dry gas is not particularly limited as long as it is a commonly used dry gas, and examples of the dry gas include dry air and dry nitrogen.

<Fluorine-containing nitrile compound (3) (compound (3))>
The fluorine-containing nitrile compound (3) is represented by the following general formula (3):
^RfCN (3)
(In the formula, ^Rf is an aliphatic hydrocarbon group substituted with at least one fluorine atom or an aromatic hydrocarbon group having 1 to 20 carbon atoms.)
It is expressed as:
The fluorine-containing nitrile compound (3) may be used alone or in combination of two or more kinds.

^Rf of the fluorine-containing nitrile compound (3) is substituted with at least one fluorine atom. The number of substituted fluorine atoms (the number of hydrogen atoms in the hydrocarbon group substituted with fluorine atoms) is not particularly limited as long as it is the number of fluorine atoms possessed by a generally available fluorine-containing nitrile compound (3), but is preferably 1 to 20. Since it is easily available and tends to be economically excellent, the number of fluorine atoms is more preferably 1 to 10, and from the same viewpoint, it is even more preferably 1 to 5. Since the reactivity of the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2) tends to increase and the yield of the fluorine-containing vinyl sulfonic acid fluoride tends to increase, the number of fluorine atoms is preferably 3 to 5, and from the same viewpoint, it is particularly preferably 5.

^Rf of the fluorine-containing nitrile compound (3) is an aliphatic hydrocarbon group substituted with at least one fluorine atom, or an aromatic hydrocarbon group. It is more preferably an aromatic hydrocarbon group substituted with at least one fluorine atom, since the reactivity of the fluorine-containing vinylsulfonic anhydride (1) with the alkali metal fluoride (2) tends to be increased and the yield of the fluorine-containing vinylsulfonic acid fluoride tends to be increased.
R ^f of the fluorine-containing nitrile compound (3) may have a substituent other than a fluorine atom. The substituent other than a fluorine atom is not particularly limited as long as it is a commonly used substituent, and examples thereof include a halogen atom other than a fluorine atom, such as a chlorine atom or a bromine atom, a nitrile group (-CN), an ether group (-O-), a carbonate group (-OCO ₂ -), an ester group (-CO ₂ -), a carbonyl group (-CO-), a sulfide group (-S-), a sulfoxide group (-SO-), a sulfone group (-SO ₂ -), and a urethane group (-NHCO ₂ -).

The number of carbon atoms in ^Rf of the fluorine-containing nitrile compound (3) is not particularly limited as long as it is a commonly used carbon number, but is preferably 1 to 20. Since it tends to be easily available and economically superior, the number of carbon atoms is more preferably 1 to 10. Since the reactivity of the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2) tends to be increased and the yield of the fluorine-containing vinyl sulfonic acid fluoride tends to be increased, the number of carbon atoms is further preferably 6 to 10, and particularly preferably 6 or 7.

Examples of the fluorine-containing nitrile compound (3) include p-fluorobenzonitrile, 2,4-difluorobenzonitrile, 2,5-difluorobenzonitrile, 2,6-difluorobenzonitrile, 2,4,6-trifluorobenzonitrile, 2,3,5,6-tetrafluorobenzonitrile, 3-(trifluoromethyl)benzonitrile, p-(trifluoromethyl)benzonitrile, 2,4-bis(trifluoromethyl)benzonitrile, 3,5-bis(trifluoromethyl)benzonitrile, 3-fluoro-4-methylbenzonitrile, 5-fluoro-2-methylbenzonitrile, 2-fluoro-6-(trifluoromethyl)benzonitrile, 3-fluoro-4-(trifluoromethyl)benzonitrile, 4-fluoro-2-(trifluoromethyl)benzonitrile, 4-fluoro-3-(trifluoromethyl)benzonitrile, 5-fluoro-2-(trifluoromethyl)benzonitrile, trifluoro Acetonitrile, pentafluoropropionitrile, heptafluorobutyronitrile, nonafluorovaleronitrile, undecafluorohexanenitrile, tridecafluoroheptanenitrile, pentadecafluorooctanenitrile, heptadecafluorononanenitrile, nonadecafluorodecanenitrile, tetrafluoroisophthalonitrile, tetrafluorophthalonitrile, tetrafluoroterephthalonitrile, 2-fluoro-4-methylbenzonitrile, 4-fluoro-3-methylbenzonitrile, 2,3-difluoro-4-hydroxybenzonitrile, 2,4-difluoro-3-methylbenzonitrile, 2,6-difluoro-3-nitrobenzonitrile, 2-chloro-5-cyanobenzonitrile, 3-chloro-4-cyanobenzonitrile, 2-chloro-5-(trifluoromethyl)benzonitrile, 4-chloro-2,6-difluorobenzonitrile, 2,6-dichloro-4-(trifluoromethyl)benzonitrile, benzonitrile, 4-bromo-2,6-difluorobenzonitrile, 2-bromo-5-(trifluoromethyl)benzonitrile, 2-amino-5-cyanobenzonitrile, 5-amino-2-cyanobenzotrifluoride, 4-amino-2,5-difluorobenzonitrile, 4-cyano-3-nitrobenzonitrile, 4-cyano-3-(trifluoromethyl)acetanilide, (2-cyano-4-(trifluoromethyl)phenyl)boronic acid, (3-cyano-5 -(trifluoromethyl)phenyl)boronic acid, (4-cyano-3-(trifluoromethyl)phenyl)boronic acid, (3-cyano-2,4-difluorophenyl)boronic acid, 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-4-(trifluoromethyl)benzonitrile, 2-(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)-6-(trifluoromethyl)benzonitrile, 2-methoxy-5-(trifluoromethyl)phenyl)boronic acid, (4-cyano-3-(trifluoromethyl)phenyl)boronic acid, (3-cyano-2,4-difluorophenyl)boronic acid, 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-4-(trifluoromethyl)benzonitrile, (fluoromethyl)benzonitrile, 4-methoxy-3-(trifluoromethyl)benzonitrile, 4-hydroxy-2-(trifluoromethyl)benzonitrile, 4-hydroxy-3-(trifluoromethyl)benzonitrile, m-fluorobenzonitrile, 2,3-difluorobenzonitrile, 2,3,4-trifluorobenzonitrile, 2,3,6-trifluorobenzonitrile, 2-fluoro-3-(trifluoromethyl)benzonitrile, 2-fluoro-4-(trifluoromethyl)benzonitrile, 2-fluoro-5-(trifluoromethyl)benzonitrile, 3-fluoro-5-(trifluoromethyl)benzonitrile, 2,3,4,5-tetrafluorobenzonitrile, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile.

Because they are easily available and tend to be economical, m-fluorobenzonitrile, 2,3-difluorobenzonitrile, 2,3,4-trifluorobenzonitrile, 2,3,6-trifluorobenzonitrile, 2-fluoro-3-(trifluoromethyl)benzonitrile, 2-fluoro-4-(trifluoromethyl)benzonitrile, 2-fluoro-5-(trifluoromethyl)benzonitrile, 3-fluoro-5-(trifluoromethyl)benzonitrile, 2,3,4,5-tetrafluorobenzonitrile, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile are preferred. Since the reactivity of the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2) tends to increase and the yield of the fluorine-containing vinyl sulfonic acid fluoride tends to increase, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile are more preferred, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile are even more preferred, and pentafluorobenzonitrile is particularly preferred.

Compound (3) having a reduced water content can also be used, if necessary.
Compound (3) having a low water content can be purchased, or a method for reducing the water content of compound (3) can be used. The method for reducing the water content of compound (3) is not particularly limited as long as it is a commonly available method, and examples thereof include a method using a dehydrating agent, a distillation method, and the like.
The dehydrating agent is not particularly limited as long as it is a commonly used dehydrating agent, and examples thereof include sodium hydride, magnesium sulfate, sodium sulfate, calcium sulfate, calcium chloride, zinc chloride, calcium oxide, magnesium oxide, diphosphorus pentoxide, activated alumina, silica gel, molecular sieves, etc. When a dehydrating agent is used, a compound (3) containing a dehydrating agent may be used as long as it does not affect the reaction between compound (1) and compound (2), or a compound (3) that is free of a dehydrating agent by filtration or the like may be used.

When reacting the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2) in the presence of the fluorine-containing nitrile compound (3), additives such as ether compounds, nitrile compounds, amide compounds, sulfo compounds, saturated hydrocarbon compounds, aromatic hydrocarbon compounds, halogenated hydrocarbon compounds, alcohol compounds, ketone compounds, ester compounds, and water can be used as necessary.

The additive is not particularly limited as long as it is a commonly used compound, but specific examples include tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, cyclopentyl methyl ether, diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, methyl tert-butyl ether, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol dibutyl ether, 1,2-dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, and triethylene glycol dimethyl ether. ether compounds such as glycol butyl methyl ether, tetraethylene glycol dimethyl ether, and dipropylene glycol dimethyl ether; nitrile compounds such as acetonitrile, propionitrile, butyronitrile, isobutyronitrile, 2-methylbutyronitrile, cyclohexanecarbonitrile, benzonitrile, and adiponitrile; amide compounds such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone, tetramethylurea, and 1,3-dimethyl-2-imidazolidinone; sulfo compounds such as dimethyl sulfoxide, dibutyl sulfoxide, ethyl methyl sulfone, ethyl isopropyl sulfone, sulfolane, and 3-methylsulfolane; saturated hydrocarbon compounds such as n-octane, isooctane, n-nonane, n-decane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; aromatic hydrocarbon compounds such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, naphthalene, tetralin, and biphenyl; halogenated hydrocarbon compounds such as methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, trichloroethane, tetrachloroethane, pentachloroethane, hexachloroethane, dichloroethylene, trichloroethylene, tetrachloroethylene, dichloropropane, trichloropropane, isopropyl chloride, butyl chloride, hexyl chloride, chlorobenzene, dichlorobenzene, trichlorobenzene, chlorotoluene, and chloronaphthalene; methanol, ethanol, propanol, isopropanol, butadiene, butyl chloride ... alcohol compounds such as n-butanol, isobutanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, cyclohexanol, and benzyl alcohol; ketone compounds such as acetone, methylacetone, ethylmethylketone, methylpropylketone, methylbutylketone, methylisobutylketone, methylhexylketone, diethylketone, ethylbutylketone, dipropylketone, diisobutylketone, and cyclohexanone; and ester compounds such as ethylacetate, propylacetate, butylacetate, isobutylacetate, pentylacetate, hexylacetate, octylacetate, cyclohexylacetate, methylpropionate, ethylpropionate, butylpropionate, methylbenzoate, ethylbenzoate, propylbenzoate, butylbenzoate, and benzylbenzoate.

The additives may have a reduced water content, if necessary.
Additives with low water content can be purchased, or a method for reducing the water content of the additive can be used. The method for reducing the water content of the additive is not particularly limited as long as it is a generally available method, and examples thereof include a method using a dehydrating agent, a distillation method, and the like.
The dehydrating agent is not particularly limited as long as it is a commonly used dehydrating agent, and examples thereof include sodium hydride, magnesium sulfate, sodium sulfate, calcium sulfate, calcium chloride, zinc chloride, calcium oxide, magnesium oxide, diphosphorus pentoxide, activated alumina, silica gel, molecular sieve, etc. When a dehydrating agent is used, an additive containing a dehydrating agent may be used as long as it does not affect the reaction between compound (1) and compound (2), or an additive that does not contain a dehydrating agent after filtration or the like may be used.

<Ratio (β/α) of the amount of substance (β) of compound (2) to the amount of substance (α) of compound (1)>
The ratio (β/α) of the amount of substance (β) of compound (2) to the amount of substance (α) of compound (1) is preferably 0.5 or more, more preferably 0.8 or more, since the yield of compound (4) tends to increase and the economic efficiency of the method for producing compound (4) tends to be excellent, and further preferably 1 or more, since the amount of unreacted compound (1) tends to be suppressed.

The upper limit of the ratio (β/α) of the amount of substance (β) of compound (2) to the amount of substance (α) of compound (1) is not particularly limited, but since the amount of compound (2) used is reduced and the method for producing compound (4) tends to be more economical, it is preferable that β/α is 10 or less, and from the same viewpoint, it is more preferable that β/α is 7 or less, and even more preferable that β/α is 5 or less.

<Ratio (δ/γ) of the mass (δ) of compound (3) to the mass (γ) of compound (1)>
The ratio (δ/γ) of the mass (δ) of compound (3) to the mass (γ) of compound (1) is preferably 0.5 or more since the reactivity between compound (1) and compound (2) tends to increase, and from the same viewpoint, δ/γ is more preferably 1 or more, and further preferably δ/γ is 1.5 or more. The lower limit of the ratio (δ/γ) may be set to 1.8 or more, 2.0 or more, 2.2 or more, or 2.4 or more.

The upper limit of the ratio (δ/γ) of the mass (δ) of compound (3) to the mass (γ) of compound (1) is not particularly limited, but since the amount of compound (3) used is reduced and the method for producing compound (4) tends to be more economical, it is preferable that δ/γ is 20 or less, and from the same viewpoint, it is more preferable that δ/γ is 15 or less, and further more preferable that δ/γ is 10 or less. The upper limit of the above ratio (δ/γ) may be set to 8 or less, 6 or less, or 4 or less.

<Reaction of Compound (1) and Compound (2)>
The reaction temperature of compound (1) and compound (2) is not particularly limited as long as it is a reaction temperature that is generally used, but since the reactivity of compound (1) and compound (2) tends to be increased, the temperature is preferably −40° C. or higher, and more preferably −20° C. or higher. From the same viewpoint and since the temperature tends to be economically advantageous when adjusting the temperature industrially, the temperature is further preferably 0° C. or higher, and particularly preferably 10° C. or higher.

The upper limit of the reaction temperature between compound (1) and compound (2) is not particularly limited, but is preferably 150° C. or lower, more preferably 100° C. or lower, since this tends to suppress volatilization of compound (3). It is further preferably 80° C. or lower, particularly preferably 60° C. or lower, since this tends to suppress a side reaction between compound (1) and compound (2) and increase the yield of compound (4).
The reaction temperature of the compound (1) and the compound (2) does not need to be constant so long as it is within the above range, and may be changed during the reaction.

The reaction time between compound (1) and compound (2) is not particularly limited as long as it is within a commonly used range, but is preferably 0.5 hours or more, and more preferably 1 hour or more, because this increases the stability of the yield of compound (4). Avoiding an excessive reaction time tends to result in a more economical production method, so it is preferably 100 hours or less, and from the same viewpoint, it is more preferably 50 hours or less, and even more preferably 20 hours or less.

The reaction pressure of compound (1) and compound (2) is not particularly limited as long as it is within the range of normal use, and the reaction is usually carried out under atmospheric pressure. However, depending on the type of compound (3), the vapor pressure at standard conditions is high, so if compound (3) is liquefied and not reused, pressurization at atmospheric pressure or higher is an effective means. If compound (3) is liquefied and reused, reduced pressure below atmospheric pressure may be used.
The pressure for the reaction of compound (1) and compound (2) does not need to be constant so long as it is within the above range, and may be changed during the reaction.

The atmosphere for the reaction of compound (1) and compound (2) is not particularly limited as long as it is a commonly used atmosphere, and usually, air atmosphere, nitrogen atmosphere, argon atmosphere, etc. are used. Among these, nitrogen atmosphere and argon atmosphere are preferred because they tend to produce compound (4) more safely. In addition, nitrogen atmosphere is more preferred because they tend to be a more economical production method.
The reaction atmosphere may be used alone or in combination of a plurality of reaction atmospheres.

The order of adding compounds (1), (2), and (3) is not particularly limited, but the reaction between compound (1) and compound (2) is an exothermic reaction, and since side reactions tend to be suppressed, particularly when the amounts of compounds (1), (2), and (3) used are large, the following methods are preferred: a method of gradually adding a mixture of compounds (1) and (3) to compound (2), a method of gradually adding compound (2) to a mixture of compounds (1) and (3), a method of gradually adding a mixture of compounds (2) and (3) to compound (1), and a method of gradually adding compound (1) to a mixture of compounds (2) and (3). Among these, the method of gradually adding a mixture of compounds (2) and (3) to compound (1) and the method of gradually adding compound (1) to a mixture of compounds (2) and (3) are more preferred, since they tend to suppress local exothermic reactions and side reactions.

As described above, the present invention can produce fluorine-containing vinyl sulfonic acid fluoride (4) in a higher yield than conventional methods, which is useful as a raw material for fluorine-based polymer electrolytes, which are a main component of membranes for fuel cells, catalyst binder polymers for fuel cells, membranes for salt electrolysis, etc.

The following are examples that specifically explain this embodiment. The present invention is not limited to the following examples as long as they do not exceed the gist of the invention.

The analytical methods used in the examples and comparative examples are as follows:

<Nuclear Magnetic Resonance Analysis (NMR): Molecular Structure Analysis by ¹⁹ F-NMR>
The products obtained in the examples and comparative examples were subjected to molecular structure analysis using ¹⁹ F-NMR under the following measurement conditions.
[Measurement condition]
Measurement device: JNM-ECZ400S nuclear magnetic resonance device (manufactured by JEOL Ltd.)
Observed nucleus: ^19F
Solvent: deuterated chloroform Standard substance: tetramethylsilane (0.00 ppm)
Observation frequency: 400MHz ( ^1H )
Pulse width: 6.5 μsec Waiting time: 2 sec Number of integrations: 16

The raw materials used in the examples and comparative examples are listed below.

[Production Example 1]
(Fluorine-containing vinyl sulfonic anhydride (1) (compound (1))
According to JP 2019/156782 A, compound (7) represented by the following formula (7) was produced.
CF ₂ =CFOCF ₂ CF ₂ SO ₃ Na (7)
Using the obtained compound of formula (7) above, a compound (8) represented by the following formula (8) was produced according to WO 2020/012913.
(CF ₂ = CFOCF ₂ CF ₂ SO ₂ ) ₂ O (8)
The obtained compound (8) had a purity of 96% by weight and contained 4% by weight of compound (9) represented by the following formula (9).
_{CF2 = CFOCF2CF2SO3H} ( ₉ )

(Alkali Metal Fluoride (2) (Compound (2))
・Lithium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent)
- Sodium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent)
・Potassium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent)
Rubidium fluoride (Aldrich, purity 99.8%)
・Cesium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent)

(Fluorine-containing nitrile compound (3) (compound (3))
Fluoroacetonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter also referred to as "FAN"). The water content was adjusted by adding dried molecular sieve 4A 1/16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), dehydrating, and removing the molecular sieve 4A 1/16.)
Difluoroacetonitrile (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., hereinafter also referred to as "DFAN"). The water content was adjusted by adding dried molecular sieve 4A 1/16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), dehydrating, and removing the molecular sieve 4A 1/16.)
2-Fluorobenzonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter also referred to as "2FBN"). The water content was adjusted by adding dried molecular sieve 4A 1/16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), dehydrating, and removing the molecular sieve 4A 1/16.)
2,4,5-trifluorobenzonitrile (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.; hereinafter also referred to as "TFBN"). The water content was adjusted by adding dried molecular sieve 4A 1/16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), dehydrating, and removing the molecular sieve 4A 1/16.)
o-(trifluoromethyl)benzonitrile (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.; hereinafter also referred to as "TFMBN"). The water content was adjusted by adding dried molecular sieve 4A 1/16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), dehydrating, and removing the molecular sieve 4A 1/16.)
Pentafluorobenzonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter also referred to as "PFBN". The water content was adjusted by adding dried molecular sieve 4A 1/16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), dehydrating, and removing the molecular sieve 4A 1/16.)

(others)
2,2,2-trifluoroethanol (Tokyo Chemical Industry Co., Ltd.)
・1,2-dimethoxyethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent)

[Example 1]
A stirrer and potassium fluoride (0.17 g, 2.89 mmol) were placed in a test tube (Radley Discovery Technologies, RP98059, RP98062), placed in a heating/cooling stirrer (Tokyo Rikakikai Co., Ltd., PPM-5512 type, cooling water was circulated from the outside when cooling), dried under vacuum at 150° C. for 5 hours, returned to room temperature, and placed in a nitrogen atmosphere. The heating/cooling stirrer was set to 40° C., and fluoroacetonitrile (1.93 g) was added to the test tube and stirred. Subsequently, compound (8) (1.00 g, consisting of 0.96 g (1.78 mmol) of compound (8) and 0.04 g (0.14 mmol) of compound (9)) produced in Production Example 1 was added. After stirring for another hour, the temperature was returned to room temperature. For the analysis, 1,2-dimethoxyethane (2.00 g) and 2,2,2-trifluoroethanol (0.10 g) were added and stirred. The obtained reaction mixture was filtered, and the filtrate was analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinyl sulfonic acid fluoride (10) represented by the following general formula (10) was produced (production amount: 0.36 g, product mass: 1.29 mmol, production rate: 72.2%). In the analysis, the production amount of fluorine-containing vinyl sulfonic acid fluoride (10) was calculated from the mass of 2,2,2-trifluoroethanol, the integral value of _CF3 of 2,2,2-trifluoroethanol, and the integral value of _CF2 of fluorine-containing vinyl sulfonic acid fluoride (10). In addition, the production rate of fluorine-containing vinyl sulfonic acid fluoride (10) was calculated by the following formula (1).
Production rate (%) of fluorine-containing vinyl sulfonic acid fluoride (10)=amount of substance of fluorine-containing vinyl sulfonic acid fluoride (10)/amount of substance of compound (8)×100 (1)
For example, the production rate (%) of the fluorine-containing vinylsulfonic acid fluoride (10) in this example is 1.29 (mmol)/1.78 (mmol)×100=72.2.
In this embodiment, β/α was 1.6, and δ/γ was 1.9.
CF ₂ =CFOCF ₂ CF ₂ SO ₂ F (10)
¹⁹ F-NMR: δ (ppm) 42.31 (1F), -86.42 (2F), -114.36 (2F), -116.60 (1F), -123.87 (1F), -139.00 (1F)

[Example 2]
Except for using difluoroacetonitrile (1.99 g) instead of fluoroacetonitrile , fluorinated vinylsulfonic acid fluoride (10) was produced in the same manner as in Example 1. Analysis revealed that fluorinated vinylsulfonic acid fluoride (10) was produced (amount produced: 0.37 g, product mass: 1.31 mmol, production rate: 73.5%).
In this embodiment, β/α was 1.6, and δ/γ was 2.0.

[Example 3]
Except for using 2-fluorobenzonitrile (2.03 g) instead of fluoroacetonitrile, fluorinated vinylsulfonic acid fluoride (10) was produced in the same manner as in Example 1. Analysis revealed that fluorinated vinylsulfonic acid fluoride (10) was produced (amount produced: 0.41 g, product mass: 1.47 mmol, production rate: 82.5%).
In this embodiment, β/α was 1.6, and δ/γ was 2.0.

[Example 4]
Except for using 2,4,5-trifluorobenzonitrile (2.45 g) instead of fluoroacetonitrile, fluorinated vinylsulfonic acid fluoride (10) was produced in the same manner as in Example 1. Analysis revealed that fluorinated vinylsulfonic acid fluoride (10) was produced (amount produced: 0.43 g, product mass: 1.54 mmol, production rate: 86.5%).
In this embodiment, β/α was 1.6, and δ/γ was 2.4.

[Example 5]
Except for using o-(trifluoromethyl)benzonitrile (2.30 g) instead of fluoroacetonitrile, fluorinated vinylsulfonic acid fluoride (10) was produced in the same manner as in Example 1. Analysis revealed that fluorinated vinylsulfonic acid fluoride (10) was produced (amount produced: 0.44 g, product mass: 1.55 mmol, production rate: 87.1%).
In this embodiment, β/α was 1.6, and δ/γ was 2.3.

[Example 6]
Except for using pentafluorobenzonitrile (2.80 g) instead of fluoroacetonitrile, fluorinated vinylsulfonic acid fluoride (10) was produced in the same manner as in Example 1. Analysis revealed that fluorinated vinylsulfonic acid fluoride (10) was produced (amount produced: 0.46 g, product mass: 1.65 mmol, production rate: 92.3%).
In this embodiment, β/α was 1.6, and δ/γ was 2.8.

[Example 7]
Except for using lithium fluoride (0.08 g, 2.89 mmol) instead of potassium fluoride, fluorinated vinyl sulfonic acid fluoride (10) was produced in the same manner as in Example 6. Analysis revealed that fluorinated vinyl sulfonic acid fluoride (10) was produced (amount produced: 0.41 g, product mass: 1.45 mmol, production rate: 81.3%).
In this embodiment, β/α was 1.6, and δ/γ was 2.8.

[Example 8]
Except for using sodium fluoride (0.12 g, 2.89 mmol) instead of potassium fluoride, fluorinated vinyl sulfonic acid fluoride (10) was produced in the same manner as in Example 6. Analysis revealed that fluorinated vinyl sulfonic acid fluoride (10) was produced (amount produced: 0.42 g, product mass: 1.49 mmol, production rate: 83.6%).
In this embodiment, β/α was 1.6, and δ/γ was 2.8.

[Example 9]
Except for using rubidium fluoride (0.30 g, 2.89 mmol) instead of potassium fluoride, fluorinated vinyl sulfonic acid fluoride (10) was produced in the same manner as in Example 6. Analysis revealed that fluorinated vinyl sulfonic acid fluoride (10) was produced (amount produced: 0.47 g, product mass: 1.67 mmol, production rate: 93.5%).
In this embodiment, β/α was 1.6, and δ/γ was 2.8.

[Example 10]
Except for using cesium fluoride (0.44 g, 2.89 mmol) instead of potassium fluoride, fluorinated vinyl sulfonic acid fluoride (10) was produced in the same manner as in Example 6. Analysis revealed that fluorinated vinyl sulfonic acid fluoride (10) was produced (amount produced: 0.47 g, product mass: 1.68 mmol, production rate: 94.1%).
In this embodiment, β/α was 1.6, and δ/γ was 2.8.

[Example 11]
Except for changing the amount of potassium fluoride used to 0.11 g (1.93 mmol), fluorinated vinyl sulfonic acid fluoride (10) was produced in the same manner as in Example 6. As a result of analysis, it was found that fluorinated vinyl sulfonic acid fluoride (10) was produced (amount produced: 0.45 g, product mass: 1.61 mmol, production rate: 90.1%).
In this embodiment, β/α was 1.1, and δ/γ was 2.8.

[Example 12]
Except for changing the amount of potassium fluoride used to 0.50 g (8.67 mmol), fluorinated vinyl sulfonic acid fluoride (10) was produced in the same manner as in Example 6. As a result of analysis, it was found that fluorinated vinyl sulfonic acid fluoride (10) was produced (amount produced: 0.47 g, product mass: 1.66 mmol, production rate: 93.2%).
In this embodiment, β/α was 4.9, and δ/γ was 2.8.

[Example 13]
Fluorine-containing vinylsulfonic acid fluoride (10) was produced in the same manner as in Example 6, except that the amount of pentafluorobenzonitrile used was 9.33 g and the heating/cooling stirrer was set to 60° C. As a result of analysis, it was found that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 0.46 g, product mass: 1.64 mmol, production rate: 91.8%).
In this embodiment, β/α was 1.6, and δ/γ was 9.3.

[Example 14]
A stirrer and potassium fluoride (0.50 g, 8.67 mmol) were placed in a test tube (Radley Discovery Technologies, RP98059, RP98062), placed in a heating/cooling stirrer (Tokyo Rikakikai Co., Ltd., PPM-5512 type, cooling water was circulated from the outside when cooling), dried under vacuum at 150° C. for 5 hours, returned to room temperature, and placed in a nitrogen atmosphere. The heating/cooling stirrer was set to 10° C., and pentafluorobenzonitrile (2.80 g) was added to the test tube and stirred. Subsequently, compound (8) (1.00 g, consisting of 0.96 g (1.78 mmol) of compound (8) and 0.04 g (0.14 mmol) of compound (9)) produced in Production Example 1 was added. After stirring for another 4 hours, the temperature was returned to room temperature. For analysis, 1,2-dimethoxyethane (2.00 g) and 2,2,2-trifluoroethanol (0.10 g) were added and stirred. The resulting reaction mixture was filtered, and the filtrate was analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinyl sulfonic acid fluoride (10) represented by the following general formula (10) was produced (production amount: 0.47 g, product mass: 1.67 mmol, production rate: 93.7%).
In this embodiment, β/α was 4.9, and δ/γ was 2.8.

[Comparative Example 1]
As a comparative example, Example 5 of International Publication No. 2020/012913 is shown. In this example, the production rate of fluorine-containing vinyl sulfonic acid fluoride (10) was 60.2%. In addition, β/α was 1.6, and δ/γ was 4.2.

[Comparative Example 2]
As a comparative example, Example 6 of WO 2020/012913 is shown. In this example, the production rate of fluorine-containing vinyl sulfonic acid fluoride (10) was 64.1%. In addition, β/α was 1.5, and δ/γ was 4.2.

The production method of the present invention allows the production of fluorine-containing vinyl sulfonic acid fluoride (4) in a higher yield than conventional methods, and can therefore be suitably used in the production of raw materials for various fluorine-containing compounds, ion exchange resins, ion exchange membranes, salt electrolysis membranes, fuel cell membranes, membranes for redox flow batteries, membranes for water electrolysis, etc.

Claims (4)

The following general formula (4):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
The present invention relates to a method for producing a fluorinated vinyl sulfonic acid fluoride (4) represented by the following formula:
The following general formula (1):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula:
The following general formula (2):
Midfielder (2)
(In the formula, M is Li, Na, K, Rb, or Cs.)
and an alkali metal fluoride (2) represented by
The following general formula (3):
^RfCN (3)
(In the formula, ^Rf is an aliphatic hydrocarbon group substituted with at least one fluorine atom or an aromatic hydrocarbon group having 1 to 20 carbon atoms.)
The production method according to claim 1, characterized in that the reaction is carried out in the presence of a fluorine-containing nitrile compound (3) represented by the following formula: The method according to claim 1, wherein the number of fluorine atoms substituted in the fluorine-containing nitrile compound (3) is 1 to 5. 3. The process according to claim 1 or 2, wherein in the fluorine-containing nitrile compound (3), ^Rf is an aromatic hydrocarbon group substituted with at least one fluorine atom. The method according to any one of claims 1 to 3, wherein the fluorine-containing nitrile compound (3) is at least one selected from the group consisting of m-fluorobenzonitrile, 2,3-difluorobenzonitrile, 2,3,4-trifluorobenzonitrile, 2,3,6-trifluorobenzonitrile, 2-fluoro-3-(trifluoromethyl)benzonitrile, 2-fluoro-4-(trifluoromethyl)benzonitrile, 2-fluoro-5-(trifluoromethyl)benzonitrile, 3-fluoro-5-(trifluoromethyl)benzonitrile, 2,3,4,5-tetrafluorobenzonitrile, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile.