JP2001288138A - Method for producing fluorine-containing α, β-unsaturated carboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing industrially useful fluorine-containing α, β-unsaturated carboxylic acids inexpensively, easily and efficiently without using specially expensive additives. . SOLUTION: In a method for producing a fluorine-containing α, β-unsaturated carboxylic acid by reacting a fluorine-containing halogenated alkene with carbon dioxide in a solvent in the presence of zinc, at least one of the following A or B 0 in the presence of the compound
The reaction is performed in a temperature range of 60 ° C., and the use ratio of the zinc and the fluorinated halogenated alkene is set to 0.1 to 10 equivalents of the zinc based on the fluorinated halogenated alkene. A: 0.001 to 0.1 equivalent of hydrogen halide and / or halogen molecule to the above zinc B: 100 to 1000 ppm of water to the above solvent

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a fluorine-containing α, β-unsaturated carboxylic acid which is a substance useful as an intermediate raw material for various fluorine-containing compounds such as pharmaceuticals and agricultural chemicals.

[0002]

2. Description of the Related Art Various methods have been proposed for producing a fluorine-containing α, β-unsaturated carboxylic acid using a fluorine-containing halogenated alkene as a starting material.
For example, the following methods are known. A method of reacting 1-halo-1-perfluoroalkylethylene with carbon monoxide and water in a solvent in the presence of triethylamine and a palladium catalyst to synthesize α-perfluoroalkylacrylic acid (JP-A-60-94933) See). A method of synthesizing α-perfluoroalkylacrylic acid by reacting carbon dioxide with a mixture of 1-halo-1-perfluoroalkylethylene and metallic magnesium in a solvent and subjecting the mixture to an acid treatment (Japanese Patent Application Laid-Open No. 62-1274).
No. 1). In a solvent, a cation selected from an alkali metal ion, an alkaline earth metal ion or an ammonium ion is allowed to coexist and a fluorinated alkene is reacted with carbon dioxide in the presence of zinc, and hydrolyzed to obtain a fluorinated α. , Β-unsaturated carboxylic acid synthesis method
-72156).

[0003]

However, the above methods (1) to (5) have the following problems, and none of these methods can be said to be industrially useful. In the above method, a palladium catalyst to be used is expensive, and carbon monoxide, which has many safety problems, must be used. In the above-mentioned method, since water passes through a Grignard reagent which is unstable to water as a reaction intermediate, water management in the reaction system becomes complicated. In the above method, it is necessary to add an expensive reaction aid such as lithium chloride, and the fluorine-containing α,
A plurality of polymers formed by polymerization of β-unsaturated carboxylic acids and intermediates are by-produced.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional methods and to obtain an industrially useful fluorine-containing α,
An object of the present invention is to provide an inexpensive and simple method for producing β-unsaturated carboxylic acid.

[0005]

SUMMARY OF THE INVENTION The present invention provides a process for producing a fluorine-containing α, β-unsaturated carboxylic acid by reacting a fluorine-containing halogenated alkene with carbon dioxide in a solvent in the presence of zinc. In the above, at least one compound of the following A or B is co-existed and reacted in a temperature range of 0 to 60 ° C., the use ratio of the zinc and the fluorinated halogenated alkene is based on the fluorinated halogenated alkene The object has been attained by providing a method for producing a fluorine-containing α, β-unsaturated carboxylic acid, wherein the amount of zinc is 0.1 to 10 equivalents. A: 0.001 to 0.1 equivalent of hydrogen halide and / or halogen molecule to the above zinc B: 100 to 1000 ppm of water to the above solvent

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the fluorine-containing α, β-
The method for producing an unsaturated carboxylic acid will be described in detail. Specifically, the process for producing a fluorine-containing α, β-unsaturated carboxylic acid of the present invention is carried out by reacting a fluorine-containing halogenated alkene represented by the following general formula (I) in a solvent with the “hydrogen halide and And / or a halogen molecule ”or“ water ”of the above B is allowed to coexist in the reaction system and reacted with carbon dioxide in the presence of zinc, and then the reaction product is hydrolyzed with an inorganic acid. The resulting general formula (I
This is a method for producing the fluorine-containing α, β-unsaturated carboxylic acid represented by I).

General formula (I): R ¹ (R ² ) CＣC (R ³ ) X (I) (wherein R ¹ , R ² and R ³ are a hydrogen atom, a fluorine atom, Any of an alkyl group and a fluorine-containing alkyl group, and at least one of them represents a fluorine atom or a fluorine-containing alkyl group, and X represents any one of a chlorine atom, a bromine atom and an iodine atom.)

General formula (II): R ¹ (R ² ) CＣC (R ³ ) CO ₂ H (II) (wherein R ¹ , R ² and R ³ represent general formula (I) Is the same as in.)

[0009] The fluorine-containing α is an object of the present invention, beta-unsaturated carboxylic acids, fluorinated α represented by the above formula (II), a beta-unsaturated carboxylic acids, for example, F ₂ C
ＣC (F) COOH, F ₂ C = C (H) COOH, F
(H) C = C (F) COOH, F (H) C = C (H) C
OOH, H ₂ C = C (F) COOH, F ₂ C = C (R)
COOH, F ₂ C = C (Rf) COOH, F (R) C =
C (F) COOH, F (R) C = C (R) COOH, F
(R) C = C (Rf) COOH, F (R) C = C (H)
COOH, F (Rf) C = C (F) COOH, F (R
f) C = C (R) COOH, F (Rf) C = C (Rf)
COOH, F (Rf) C = C (H) COOH, F (H)
C = C (R) COOH, F (H) C = C (Rf) COO
H, R ₂ C = C (F) COOH, R ₂ C = C (Rf) C
OOH, R (Rf) = C (F) COOH, R (Rf) =
C (R) COOH, R (Rf) = C (Rf) COOH,
R (Rf) = C (H) COOH, Rf ₂ C = C (F) C
OOH, Rf ₂ C = C (R) COOH, Rf ₂ C = C
(Rf) COOH, Rf ₂ C = C (H) COOH, H ₂
C = C (Rf) COOH, H (R) = C (F) COO
H, H (R) = C (Rf) COOH, H (Rf) = C
(F) COOH, H (Rf) = C (R) COOH, H
(Rf) = C (Rf) COOH, H (Rf) = C (H)
It is a fluorine-containing α, β-unsaturated carboxylic acid represented by COOH, H ₂ C ＝ C (Rf) COOH and the like. In the formula, R represents an alkyl group, Rf represents a fluorinated alkyl group, and X represents any one of a chlorine atom, a bromine atom and an iodine atom.

In the present invention, various fluorine-containing halogenated alkenes represented by the above general formula (I) can be used, but considering the reactivity between the halogenated alkene and zinc, the above general formula (I) can be used. R ¹ and R in (I)
^At least one of ² and R ³ must be a fluorine atom or a fluorine-containing alkyl group. Such fluorinated halogenated alkenes include, for example, F ₂ C = C
(F) X, F ₂ C = C (H) X, F (H) C = C (F)
X, F (H) C ＝ C (H) X, H ₂ C ＝ C (F) X (wherein X represents any one of a chlorine atom, a bromine atom and an iodine atom) Halogen compounds, or F ₂ C = C (R) X, F ₂ C = C (Rf) X, F
(R) C = C (F) X, F (R) C = C (R) X, F
(R) C = C (Rf) X, F (R) C = C (H) X, F
(Rf) C = C (F) X, F (Rf) C = C (R) X,
F (Rf) C = C (Rf) X, F (Rf) C = C (H)
X, F (H) C = C (R) X, F (H) C = C (Rf)
X, R ₂ C = C (F) X, R ₂ C = C (Rf) X, R
(Rf) = C (F) X, R (Rf) = C (R) X, R
(Rf) = C (Rf) X, R (Rf) = C (H) X, R
f ₂ C = C (F) X, Rf ₂ C = C (R) X, Rf ₂ C
= C (Rf) X, Rf 2 C = C (H) X, H 2 C = C
(Rf) X, H (R) = C (F) X, H (R) = C (R
f) X, H (Rf) = C (F) X, H (Rf) = C
(R) X, H (Rf) = C (Rf) X, H (Rf) = C
(H) X, H ₂ C ＝ C (Rf) X (wherein, R represents an alkyl group, Rf represents a fluorine-containing alkyl group, and X represents any one of a chlorine atom, a bromine atom and an iodine atom. )) Can be used. However, in consideration of the solubility and reactivity of the fluorinated halogenated alkene compound in a solvent, the alkyl group or the fluorinated alkyl group preferably has 10 or less carbon atoms. Further, the fluorinated alkyl group can be used as long as it has a substituent effect similarly to the trifluoromethyl group, and is particularly a perfluoro or polyfluoro or monofluoro aliphatic group having a linear or branched chain. Is preferred.

As the zinc used in the reaction of the present invention, commercially available zinc powder can be used as it is, but the amount of zinc can be reduced by previously treating the surface of the zinc particles with an inorganic acid. The average particle size of the zinc is preferably in the range of 1 to 50 μm. If the particle size of the zinc is less than 1 μm, the operation of filtering solids in the post-treatment step becomes complicated. On the other hand, when the particle size of zinc is more than 50 μm, the surface area of the zinc particles is reduced, so that the reaction yield is reduced. Therefore, in consideration of the reaction yield and the operability, it is particularly preferable that the zinc has an average particle size of 1 to 20 μm.

The ratio of the above zinc and the fluorinated halogenated alkene used in the reaction is preferably 0.1 to 10 equivalents of zinc to the fluorinated halogenated alkene for effective use of the zinc and the raw material. Preferably, the reaction is allowed to proceed at about normal temperature, and it is more preferable to use the compound in a range of 1 to 5 equivalents.

The solvent used in the reaction of the present invention is preferably an aprotic polar solvent such as N, N-dimethylformamide, dimethyl sulfoxide, N, N-dimethylacetamide, but is not limited thereto. is not.

In the present invention, the "halogenation"
Hydrogen and / or halogen molecules ”or“ water ”in B above.
The reaction is carried out by coexisting at least one compound in the reaction system.
It is essential to do. Hydrogen halide and
And / or coexistence of halogen molecules, the reaction rate and yield
Is significantly improved. Halogenation used in the reaction of the present invention
Examples of hydrogen include HF, HCl, HBr, and HI.
Is easy to handle and work up,
HCl and HBr are preferred from the viewpoint of advancing ability. In addition,
The halogen molecules used in the light reaction include F_Two, Cl
_Two, Br_Two, I_TwoEtc., but handling and after
Cl in terms of ease of treatment and ability to promote the reaction_Two, B
r _TwoIs preferred. The above hydrogen halide or the above halo
The amount of the gene molecule used is 0.001 to 0.
It is in the range of 1 equivalent, preferably 0.005 to 0.1 equivalent.
Range of quantity. The above hydrogen halide or the above halo
If the amount of the gen molecule used is less than 0.001 equivalent, the yield is low.
Even if used in excess of 0.1 equivalents, in terms of yield or economy,
It is not possible to obtain an effect that is commensurate with the amount used.

When water is allowed to coexist in the reaction system, the formation of by-products due to the reaction can be prevented, and the selectivity is improved. The amount of the water used is 100 to 1000 pp with respect to the solvent.
m, preferably in the range of 300 to 800 ppm. If the amount of water used is less than 100 ppm, a polymer is formed as a by-product and the effect of addition cannot be obtained. If the amount exceeds 1000 ppm, the selectivity decreases.

The above reaction can be carried out in a wide temperature range, but is preferably carried out in a temperature range of 0 to 60 ° C., particularly preferably in a temperature range of 0 to 30 ° C. If the reaction temperature is lower than 0 ° C., stirring becomes difficult because the viscosity of the reaction solution increases, and the reaction time becomes long to increase the reaction yield, which is not practical. The reaction temperature is 60 ° C.
If it exceeds, the polymerization reaction of the fluorinated halogenated alkene or the produced fluorinated α, β-unsaturated carboxylic acid proceeds, so that the yield is significantly reduced.

The method of supplying carbon dioxide used in the present invention includes, for example, a method of supplying carbon dioxide under atmospheric pressure and a method of supplying it by forcibly dissolving it in a reaction solvent under carbon dioxide pressure. Although any method can be used, the composition and yield of the product are almost the same. The supply time of the carbon dioxide may be freely set, but in consideration of production efficiency, 5 hours to 24 hours.
Time is particularly preferred. The supply amount of the carbon dioxide may be freely set with respect to the fluorinated halogenated alkene which is a raw material, but it is preferable to supply 1.1 to 1.3 equivalents in consideration of economic aspects. preferable.

After the reaction, the desired fluorine-containing α, β-unsaturated carboxylic acid can be obtained by adding an inorganic acid such as hydrochloric acid to the reaction solution and subjecting it to a hydrolysis treatment. In order to purify the fluorinated α, β-unsaturated carboxylic acid obtained by the above production method, the fluorinated α, β-unsaturated carboxylic acid in the obtained solution is extracted with a non-aqueous organic solvent. A reverse extraction operation of extracting the non-aqueous organic solvent and the fluorine-containing α, β-unsaturated carboxylic acid by extracting the non-aqueous organic solvent from the aqueous layer again under an acidic condition with an aqueous solution under an acidic condition. Can be used.

Examples of the non-aqueous organic solvent for the extraction solvent used in the present invention include ethers such as diethyl ether and diisopropyl ether; halogens such as methylene chloride and chloroform; aromatics such as benzene and toluene; Esters such as ethyl and ketones such as methyl ethyl ketone are preferable, but not limited thereto.

[0020]

EXAMPLES Examples of the present invention will be described below together with comparative examples, but the present invention is not limited to these examples.

Example 1 90 ml of DMF (N, N-dimethylformamide) and commercially available zinc powder were placed in a reactor.
2 g, and with stirring, 0.2 g of bromine (0.0 g with respect to zinc).
(07 equivalents) and stirred at room temperature for 30 minutes, after which the reaction was cooled to 10 ° C. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution, and then carbon dioxide gas was blown in at a supply rate of 0.3 L / hr while cooling to 20 ° C. or lower. 24 hours later,
After the solid was filtered off, the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treated liquid with diisopropyl ether, the extract was analyzed by gas chromatography. As a result, it was found that 7.1 g (89% yield) of α- (trifluoromethyl) acrylic acid was obtained.

Example 2 90 ml of DMF and 11.2 g of commercially available zinc powder were placed in a reactor, and 0.2 g of bromine was added with stirring. After stirring at room temperature for 30 minutes, the reaction solution was cooled to 10 ° C. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly added dropwise to the reaction solution.
While cooling below, the carbon dioxide gas was reduced to 0.3 L / hr.
It was blown at the supply speed. After 5 hours, the solid was filtered off, and the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. The target substance was extracted from the treated liquid with diisopropyl ether, impurities were removed by a back extraction operation, and the extract was concentrated. As a result, 6.9 g (86% yield) of α- (trifluoromethyl) acrylic acid was obtained with a purity of 99%.

Example 3 A reaction was carried out under the same conditions as in Example 2 except that 10 g of 2-bromo-1,1-difluoroethylene was used as the starting fluorinated halogenated alkene. As a result, β, β-difluoroacrylic acid was obtained in a yield of 80% (6.0 g).

Example 4 Example 2 was repeated except that hydrogen chloride (0.007 equivalents to zinc) was used instead of bromine.
The reaction was carried out under the same conditions as described above to obtain α- (trifluoromethyl) acrylic acid in a yield of 81% (6.5 g).

Example 5 Instead of DMF, DMSO
The reaction was carried out under the same conditions as in Example 2 except that (dimethyl sulfoxide) was used, and α- (trifluoromethyl)
Acrylic acid was obtained in a yield of 78% (6.2 g).

Example 6 7.5 g of zinc previously treated with acid
The reaction was carried out under the same conditions as in Example 2 except that
α- (trifluoromethyl) acrylic acid yield 85%
(6.8 g).

Comparative Example 1 90 ml of DMF and 11.2 g of commercially available zinc powder were added to a reactor, and the reaction solution was stirred at 10 ° C.
And cooled. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly added dropwise to the reaction solution.
While cooling to 0 ° C. or less, 0.3 L /
It was blown in at a feed rate of hr. After 24 hours, the solid was filtered off, and the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treatment liquid with diisopropyl ether, impurities were removed by a back extraction operation, and the extract was concentrated. As a result, the amount of the obtained α- (trifluoromethyl) acrylic acid was 4.4 g (55% yield).

Comparative Example 2 90 ml of DMF and 11.2 g of commercially available zinc powder were added to a reactor, 0.2 g of bromine was added with stirring, the mixture was stirred at room temperature for 30 minutes, and the reaction solution was cooled to 10 ° C. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution.
While heating to ° C, carbon dioxide gas was blown in at a supply rate of 0.3 L / hr. After 24 hours, the solid was filtered off, and the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the processing solution with diisopropyl ether,
After removing impurities by a reverse extraction operation, the extract was concentrated. As a result, the obtained α- (trifluoromethyl)
Acrylic acid was 1.6 g (20% yield).

Comparative Example 3 90 ml of DMF and 1.9 g (0.5 equivalent) of commercially available zinc powder were placed in a reactor, 0.2 g of bromine was added with stirring, and the mixture was stirred at room temperature for 30 minutes. Cooled to ° C. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution, and then carbon dioxide gas was blown in at a supply rate of 0.3 L / hr while cooling to 20 ° C. or lower. 24 hours later,
After the solid was filtered off, the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treatment liquid with diisopropyl ether, impurities were removed by a back extraction operation, and the extract was concentrated. As a result, 1.9 g (yield 24%) of the obtained α- (trifluoromethyl) acrylic acid was obtained.
Met.

Example 7 DMF (90 ml) was placed in a reactor, and water was added thereto to reduce the amount of water in the solvent to 500 ppm.
Then, 11.2 g of commercially available zinc powder was added, and the reaction solution was cooled to 10 ° C. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution, and then carbon dioxide gas was blown in at a supply rate of 0.3 L / hr while cooling to 20 ° C. or lower. 24 hours later,
After the solid was filtered off, the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treated liquid with diisopropyl ether, the extract was analyzed by gas chromatography. As a result, it was found that 7.2 g (yield 90%) of α- (trifluoromethyl) acrylic acid was obtained. Incidentally, no by-product of the polymer was confirmed.

Example 8 90 ml of DMF was placed in a reactor, and water was added thereto to reduce the amount of water in the solvent to 500 ppm.
Then, after adding 11.2 g of commercially available zinc powder and sealing, the reaction solution was cooled to 10 ° C. with stirring. Next,
After 10 g of 3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution, carbon dioxide gas was blown in at a supply rate of 0.3 L / hr while cooling to 20 ° C. or lower. After 5 hours, the solid was filtered off, and the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treatment liquid with diisopropyl ether, impurities were removed by a back extraction operation, and the extract was concentrated. as a result,
6.8 g (yield 85%) of α- (trifluoromethyl) acrylic acid was obtained at a purity of 99%. Incidentally, no by-product of the polymer was confirmed.

Example 9 A reaction was carried out under the same conditions as in Example 8 except that 10 g of 2-bromo-1,1-difluoroethylene was used as a starting material fluorine-containing halogenated alkene. As a result, β, β-difluoroacrylic acid was obtained in a yield of 82% (6.2 g). Incidentally, no by-product of the polymer was confirmed.

Example 10 Instead of DMF, DMSO was used.
The reaction was carried out under the same conditions as in Example 8 except that
80% yield of α- (trifluoromethyl) acrylic acid
(6.4 g). Incidentally, no by-product of the polymer was confirmed.

Example 11 Zinc 7.5 previously treated with acid
The reaction was carried out under the same conditions as in Example 8 except that g was used, to obtain α- (trifluoromethyl) acrylic acid in a yield of 90.
% (7.2 g). Incidentally, no by-product of the polymer was confirmed.

Comparative Example 4 90 ml of DMF having a water content of 30 ppm and 11.2 g of commercially available zinc powder were added to a reactor, and the reaction solution was cooled to 10 ° C. with stirring. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution, and then carbon dioxide gas was blown in at a supply rate of 0.3 L / hr while cooling to 20 ° C. or lower. 24
After an hour, the solid was filtered off, and the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treatment liquid with diisopropyl ether, impurities were removed by a back extraction operation, and the extract was concentrated. As a result, 4.0 g of α- (trifluoromethyl) acrylic acid was obtained (yield: 50%).
Obtained. At that time, 1 g of a red-brown polymer having an unidentified structure was obtained.

Comparative Example 5 90 ml of DMF was placed in a reactor, and water was added thereto to reduce the amount of water in the solvent to 5000 pp.
After adjusting to m, 11.2 g of commercially available zinc powder was added, and the reaction solution was cooled to 10 ° C. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution, and then carbon dioxide gas was blown in at a supply rate of 0.3 L / hr while cooling to 20 ° C. or lower. After 24 hours, the solid was filtered off, and the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treatment liquid with diisopropyl ether, impurities were removed by a back extraction operation, and the extract was concentrated. As a result, 3.1 g (yield 39%) of α- (trifluoromethyl) acrylic acid was obtained. Incidentally, no by-product of the polymer was confirmed.

Comparative Example 6 DMF (90 ml) was placed in a reactor, and water was added thereto to reduce the water content in the solvent to 500 ppm.
Then, 11.2 g of commercially available zinc powder was added, and the reaction solution was cooled to 10 ° C. Next, 10 g of 3,3,3-trifluoro-2-bromopropene was slowly dropped into the reaction solution, and then carbon dioxide gas was blown in at a supply rate of 0.3 L / hr while heating to 100 ° C. 24 hours later,
After the solid was filtered off, the filtrate was hydrolyzed by adding 9% diluted hydrochloric acid. After extracting the target substance from the treatment liquid with diisopropyl ether, impurities were removed by a back extraction operation, and the extract was concentrated. As a result, 2.1 g (yield 26%) of α- (trifluoromethyl) acrylic acid was obtained. At this time, 3 g of a red-brown polymer having an unidentified structure was obtained.

[0038]

According to the method of the present invention, an industrially useful fluorine-containing α, β-unsaturated carboxylic acid can be produced easily at low cost.

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Claims (3)

[Claims] 1. A method for producing a fluorine-containing α, β-unsaturated carboxylic acid by reacting a fluorine-containing halogenated alkene with carbon dioxide in a solvent in the presence of zinc, wherein at least one of the following A or B is 0
The reaction is performed in a temperature range of 範 囲 60 ° C., and the use ratio of the zinc and the fluorinated alkene is 0.1 to 10 equivalents to the fluorinated alkene. A method for producing a fluorine-containing α, β-unsaturated carboxylic acid. A: 0.001 to 0.1 equivalent of hydrogen halide and / or halogen molecule to the above zinc B: 100 to 1000 ppm of water to the above solvent 2. The method according to claim 1, wherein the hydrogen halide is HF, HCl, HBr.
2. The method according to claim 1, wherein the halogen molecule is at least one selected from the group consisting of F ₂ , Cl ₂ , Br ₂ and I ₂ . 3. Extraction of a fluorinated α, β-unsaturated carboxylic acid in the obtained solution with a non-aqueous organic solvent, extraction under an alkaline condition, and again from an aqueous layer under an acidic condition with a non-aqueous organic solvent. 3. The method according to claim 1, wherein the non-aqueous organic solvent and the fluorine-containing α, β-unsaturated carboxylic acid are separated by extraction.
The manufacturing method as described.