JPH10212260A - Production of fluorovinyl ethers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject compounds useful as a monomer for producing a fluorine-containing polymer according to an industrially practicable method by reacting an alkoxide with a fluoroethylene in an ethereal solvent. SOLUTION: An alkoxide represented by the formula R<1> R<2> R<3> COX<1> (R<1> is H, a 1-18C alkyl, etc.; R<2> and R<3> are each H, a 1-4C alkyl, etc.; X<1> is Na or K) at a concentration within the range of 0.2-4.0mol/L is reacted with a fluoroethylene represented by the formula CF2 =CFX<2> (X<2> is F, Cl or H) in an ethereal solvent represented by the formula R<4> OR<5> (R<4> is a >=1C alkyl; R<5> is a >=3C alkyl), e.g. tert-butyl ether to afford fluorovinyl ethers represented by the formula R<1> R<2> R<3> COCF=CFX<2> . The reaction is usually carried out at ambient temperature to 80 deg.C reactional temperature under 0.1-30kg/cm<2> reactional pressure for 1-48hr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing fluorovinyl ethers useful as a monomer for producing a fluoropolymer.

[0002]

2. Description of the Related Art Methods for producing fluorovinyl ethers include (1) a method of reacting sodium methoxide with tetrafluoroethylene to produce methyl trifluorovinyl ether (J. Org. Chem., 33, 81).
6 (1968)), (2) a method of reacting a fluoroalkoxide derived from a fluoroalcohol with fluoroethylene (USP 5,260,492, USP
5,326,917, USP 5,350,821, US
P5, 350, 497) are known.

[0003]

However, these methods use diethyl ether, tetrahydrofuran or 1,4-dioxane as a reaction solvent.

[0004] Diethyl ether is classified as a Class 4 dangerously flammable substance under the Fire Service Law. Its flash point is as low as -45 ° C and its explosion range is as wide as 1.8 to 36%, making it extremely flammable. Similarly, tetrahydrofuran has a flash point of -17 [deg.] C. and an explosion range of 1.8 to 12%, and has a property of easily igniting. In addition, both of these solvents are prone to vapors that mix well with air to form explosive gas mixtures,
It also has a property that a violently explosive peroxide is easily generated.

[0005] 1,4-dioxane is also a designated chemical substance under the Chemical Substances Control Law, in addition to its property that steam mixes well with air to form an explosive mixture, and becomes unstable due to an increase in temperature and pressure. It has properties such as high toxicity.

[0006] As described above, the method of synthesizing fluorovinyl ethers using a large amount of these organic solvents has a disadvantage that it is dangerous as an industrial production method.

Further, if the amount of the above-mentioned reaction solvent, particularly diethyl ether and tetrahydrofuran, is reduced for the purpose of omitting the unreacted base treatment step, the yield of the target vinyl ether cannot be sufficiently secured.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to overcome the above-mentioned drawbacks of the conventional method, and as a result, have found an industrially feasible method for producing fluoroalkyl vinyl ethers. Was.

That is, the present invention comprises reacting an alkoxide represented by the general formula (1) with fluoroethylene represented by the general formula (2) in an ether solvent represented by the general formula (3). Which is a method for producing fluorovinyl ethers represented by the general formula (4).

[0010]

Embedded image R ¹ R ² R ³ COX ¹ (1) CF ₂ ＣＦCFX ² (2) R ⁴ OR ⁵ (3) R ¹ R ² R ³ COCF = CFX ² (4)

In the general formulas (1) to (4), R ¹ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, and a carbon atom having 6 to 18 carbon atoms.
And an aryl group or an alkenyl group having 3 to 18 carbon atoms, wherein a part or all of the hydrogen atoms of R ¹ other than a hydrogen atom may be substituted by a fluorine atom, a chlorine atom or a bromine atom. R ² and R ^{3 each} independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and a part or all of the hydrogen atoms in the alkyl group may be substituted by a fluorine atom, a chlorine atom or a bromine atom. R ⁴ represents an alkyl group having 1 or more carbon atoms, and R ⁵ represents an alkyl group having 3 or more carbon atoms. X ¹ represents a sodium atom or a potassium atom, and X ² represents a fluorine atom, a chlorine atom or a hydrogen atom.

The alkoxide represented by the general formula (1) is obtained from an alcohol represented by the general formula (5) R ¹ R ² R ³ COH. General formulas (1), (4) and (5)
R ¹ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or 3 to 18 carbon atoms.
And a part or all of the hydrogen atoms of R ¹ other than the hydrogen atom may be substituted by a fluorine atom, a chlorine atom or a bromine atom.

As the alkyl group, the aryl group and the alkenyl group, a chain, branched or cyclic group is used. If the number of carbon atoms is too large, the heat resistance of the obtained fluoropolymer is reduced. Therefore, preferred R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. More preferred R
¹ is an alkyl group having 1 to 12 carbon atoms in which some or all of the hydrogen atoms have been replaced by fluorine atoms, chlorine atoms or bromine atoms.

R ² in the general formulas (1), (4) and (5) may be a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the alkyl group may be a linear, branched or cyclic alkyl group. Things are used. Desirable R ² is a hydrogen atom, a methyl group, an ethyl group or a part or all of the hydrogen atoms of an alkyl group having 1 or 2 carbon atoms is a fluorine atom,
It is substituted by a chlorine atom or a bromine atom.

R ³ in the general formulas (1), (4) and (5) may be a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the alkyl group may be a linear, branched or cyclic alkyl group. Things are used. Desirable R ³ is a hydrogen atom, a methyl group, or a methyl group in which some or all of the hydrogen atoms have been replaced by a fluorine atom, a chlorine atom or a bromine atom.

Preferred examples of the general formulas (1), (4) and (5) are the general formulas RfCH ₂ OX ¹ and RfCH, respectively.
₂ OCF = CFX ² and RfCH ₂ OH, wherein X ¹ and X ² are the same as described above, and Rf has 1 carbon atom.
To 13 polyfluoroalkyl groups.

The term "polyfluoroalkyl group" means a group in which two or more hydrogen atoms of an alkyl group are substituted by fluorine atoms, a perfluoroalkyl group in which all hydrogen atoms of an alkyl group are substituted by fluorine atoms, And a group in which two or more of the hydrogen atoms of the alkyl group are substituted with a fluorine atom and one or more of the hydrogen atoms of the alkyl group are substituted with a halogen atom other than a fluorine atom. As a halogen atom other than a fluorine atom, a chlorine atom is preferable.

As the polyfluoroalkyl group, a group in which 60% or more of the total number of hydrogen atoms of the alkyl group is substituted with a fluorine atom is preferable, and more preferably 80% or more.
Further preferred polyfluoroalkyl groups are perfluoroalkyl groups.

Specific examples of the alcohol represented by the general formula (5) include, but are not limited to, the following fluorinated alcohols and fluorinated chlorinated alcohols.

2,2,2-trifluoroethanol,
2,2-difluoroethanol, 2-monofluoroethanol, 2,2,3,3-tetrafluoropropanol, 2,2,3,3,3-pentafluoropropanol, 1,1,1,3,3,3 -Hexafluoro-2-propanol, 3,3,4,4,4-pentafluorobutanol, 2,2,3,3,4,4,4-heptafluorobutanol, 3,3,4,4-tetrafluoro -2-butanol, 3,3,4,4-tetrafluoro-2-methyl-2-butanol, 2,2,3,3,4,4,5,5
-Octafluoropentanol, 2,2,3,3,4
4,5,5,5-nonafluoropentanol.

3,3,4,4,5,5,6,6-octafluoro-2-hexanol, 3,3,4,4,5
5,6,6-octafluoro-2-methyl-2-hexanol, 3,3,4,4,5,6,6,6-octafluoro-5-trifluoromethylhexanol, 3,3
4,4,5,5,6,6,6-nonafluorohexanol, 2,2,3,3,4,4,5,6,6,6-undecafluorohexanol, 2,2,3 , 3,4
4,5,5,6,6,7,7-dodecafluoroheptanol, 3,3,4,4,5,5,6,6,7,7,8,
8-Dodecafluoro-2-octanol.

3,3,4,4,5,5,6,6,7,
7,8,8-dodecafluoro-2-methyl-2-octanol, 3,3,4,4,5,5,6,6,7,8,
8,8-dodecafluoro-7-trifluoromethyloctanol, 2,2,3,3,4,4,5,5,6,6
7,7,8,8,9,9-hexadecafluorononanol, 3,3,4,4,5,5,6,6,7,7,8,
8,9,10,10,10-hexadecafluoro-9-
Trifluoromethyldecanol, 3,3,4,4,5
5,6,6,7,7,8,8,9,9,10,10,1
0-Heptadecafluorodecanol.

2,2,3,3,4,4,5,5,6
6,7,7,8,8,9,9,10,10,11,11
-Eicosafluoroundecanol, 3,3,4,4
5,5,6,6,7,7,8,8,9,9,10,1
0,11,11,12,12,12-Henicosafluorododecanol, 2,2,3,3,4,4,5,5
6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11,
11,12,12,13,13-tetracosafluorotridecanol, 3,3,4,4,5,5,6,6,7,
7, 8, 8, 9, 9, 10, 10, 11, 11, 12,
12,13,13,14,14,14-pentacosafluorotetradecanol and the like.

1,3-dichloro-1,1,3,3-tetrafluoro-2-propanol, 2,4-dichloro-
2,3,3,4,4-pentafluorobutanol, 2,
3-dichloro-2,2,3,4,4-pentafluorobutanol and the like.

Various methods can be used for synthesizing the alcohol represented by the general formula (5). In particular,
(1) A method for reducing the corresponding acid fluoride R ¹ R ² R ³ COF (USP 5,260,492, USP 5,32
6,917, USP5,350,821, USP5,3
50,497), (2) CF ₂ ＣＦCFX in the presence of an alcohol such as methyl alcohol, ethyl alcohol and isopropyl alcohol [X represents a fluorine atom, a chlorine atom or a hydrogen atom. And (3) CF ₃ CF ₂ (CF ₂ CF ₂ ) _n CH ₂ CH
Of ₂ I Hydrolysis (where, n is an integer) can be obtained by a method such as the reduction of (4) hexafluoroacetone.

A reaction for obtaining an alkoxide represented by the general formula (1) R ¹ R ² R ³ COX ¹ (where X ¹ represents a sodium atom or a potassium atom) from an alcohol represented by the general formula (5) (hereinafter referred to as a reaction) The first stage reaction) is not particularly limited, but a method based on a reaction with a sodium-containing base or a potassium-containing base is preferable. For example, sodium hydride, a method by reaction with a base such as potassium hydride, sodium methoxide, sodium alkoxide such as sodium ethoxide, alkoxide exchange reaction with a base such as potassium alkoxide such as potassium methoxide, and the like, The reaction with a sodium-containing base, especially sodium hydride, is preferred because of its low cost.

The supply ratio of the base to the alcohol is not particularly limited, but is usually from 0.9 to 2.0 mol of the base to 1 mol of the alcohol. Since the process of unreacted base treatment accompanied by heat generation after the reaction is facilitated, the base is added in an amount of 1.0 to 1.2 per mole of alcohol.
Molar proportions are preferred. The reaction temperature and reaction time of the first-stage reaction are not particularly limited, either.
It is preferably used in the range of 0 ° C. for 1 to 20 hours.

The alkoxide obtained by the first-stage reaction is reacted with fluoroethylene represented by the general formula (2) CF ₂ ＣＦCFX ² to obtain a compound represented by the general formula (4) R ¹ R ² R ³ COC
A fluorovinyl ether represented by F = CFX ² can be produced (hereinafter referred to as a second-stage reaction).

X ² in the above fluoroethylene is a fluorine atom, a chlorine atom or a hydrogen atom, and is preferably a fluorine atom.

In the second stage reaction, an ether solvent represented by the general formula (3) R ⁴ OR ⁵ is used as a solvent. In the general formula, R ⁴ is an alkyl group having 1 or more carbon atoms, R ⁵ is an alkyl group having 3 or more carbon atoms, and the alkyl group is selected from a chain, a branched or a cyclic one. Preferred R ⁴ is an alkyl group having 1 to ⁴ carbon atoms, and preferred R ⁵ is an alkyl group having 3 carbon atoms.
Or 4 alkyl groups. A particularly preferred ether solvent is methyl tert-butyl ether (tC ₄ H ₉ O).
CH ₃ ).

The solvent in the first-stage reaction is also preferably the ether solvent in the second-stage reaction.

Methyl tert-butyl ether has a flash point of -28 ° C., an explosion range of 1.6 to 8.4%, and is stable to acids and bases and hardly generates peroxide. doing. Compared to diethyl ether and tetrahydrofuran, the flash point is lower than tetrahydrofuran but higher than diethyl ether, the explosion range is narrower than either diethyl ether or tetrahydrofuran, and the point of explosive peroxide formation is higher than either diethyl ether or tetrahydrofuran. Stable, 1,4
It is a solvent with a far lower toxicity compared to dioxane.

[0033] Solvents such as diethyl ether and tetrahydrofuran are not preferable when a chlorine- or bromine-containing fluoroalcohol is used as a raw material because a large amount of reaction by-products is produced. Methyl tert-butyl ether is a particularly preferable solvent for industrial production of fluorovinyl ether from the viewpoint of safety and health, the economic efficiency of being an industrially produced inexpensive solvent, and the small number of by-products.

The reaction pressure in the second stage is usually 0.1 to 30 k
g / cm ² G is used. However, if the pressure is too high, it is necessary to use a reactor with high pressure resistance, and if tetrafluoroethylene is used as fluoroethylene, there is a risk of explosion, which is not preferable. . Preferably 1.0 to
25 kg / cm ² G is used, and the higher the pressure, the higher the selectivity of the reaction tends to be. Particularly preferably 2.0 to
The pressure is 20 kg / cm ² G.

The method for supplying fluoroethylene into the second-stage reaction system is not particularly limited, but examples include batch supply, continuous supply, or a combination of both. When fluoroethylene is easily polymerized such as tetrafluoroethylene, it is preferable that a polymerization inhibitor such as α-pinene, which suppresses the polymerization, is present in the second-stage reaction system.

In the second stage reaction, an inert gas may be present in the system. Examples of the inert gas include nitrogen and rare gases, and nitrogen or helium is preferable from the viewpoint of ease of handling and availability.

The reaction temperature in the second stage is usually from room temperature to about 80 ° C. so as to satisfy the above pressure range.
Particularly, 40 to 60 ° C is preferable. The reaction time depends on the reaction temperature, but usually 1 to 48 hours is appropriate. If the time is too short, the conversion may decrease. If the time is long, the productivity may decrease. ~ 36
Time is preferred.

The concentration of the raw material alkoxide in the second-stage reaction is usually 0.2 to 4.0 mol / l. However, if the concentration is too low, the productivity is low, while if the concentration is too high, side reactions such as the reaction of a plurality of alkoxide molecules to one molecule of fluoroethylene and the reaction between alkoxide molecules are difficult, and it is difficult to control the reaction by a rapid reaction. 0.4 to 2.
0 mol / l is preferred.

The method for purifying the fluorovinyl ethers obtained by the second-stage reaction is not particularly limited. For example, purification by normal pressure or reduced pressure distillation is possible.

Specific examples of the fluorovinyl ethers obtained by the present invention include the following fluorinated vinyl ethers and fluorinated chlorinated vinyl ethers.
It is not limited to these.

1,1-dihydro-2,2,2-trifluoroethyl trifluorovinyl ether, 1,1-dihydro-2,2-difluoroethyl trifluorovinyl ether, 1,1-dihydro-2-monofluoroethyl trifluorovinyl ether Fluorovinyl ether, 1,1-dihydro-
2,2,3,3,3-pentafluoropropyl trifluorovinyl ether, 1,1,3-trihydro-2,
2,3,3-tetrafluoropropyl trifluorovinyl ether, 1,1,1,3,3,3-hexafluoro-2-hydro-2-propyl trifluorovinyl ether.

1,1-dihydro-2,2,3,3,4
4,4-heptafluorobutyl trifluorovinyl ether, 1,1,5-trihydro-2,2,3,3
4,4,5,5-octafluoropentyl trifluorovinyl ether, 1,1-dihydro-2,2,3
3,4,4,5,5,5-nonafluoropentyl trifluorovinyl ether, 1,1,2,2-tetrahydro-3,3,4,4,5,5,6,6,6-nonafluorohexyl Trifluorovinyl ether, 1,1,7
-Trihydro-2,2,3,3,4,4,5,5,6
6,7,7-dodecafluoroheptyl trifluorovinyl ether.

1,1,9-trihydro-2,2,3
3,4,4,5,5,6,6,7,7,8,8,9,9
-Hexadecafluorononyl trifluorovinyl ether, 1,1,2,2-tetrahydro-3,3,4
4,5,5,6,6,7,7,8,8,9,9,10,
10,10-heptadecafluorodecyl trifluorovinyl ether, 1,1,11-trihydro-2,2,
3,3,4,4,5,5,6,6,7,7,8,8,
9,9,10,10,11,11-Eicosafluoroundecyl trifluorovinyl ether, 1,1,13
-Trihydro-2,2,3,3,4,4,5,5,6
6,7,7,8,8,9,9,10,10,11,1
1,12,12,13,13-tetracosafluorotridecyl trifluorovinyl ether, 1,1,2,2
-Tetrahydro-3,3,4,4,5,5,6,6
7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 1
2,12,13,13,14,14,14-pentacosafluorotetradecyl trifluorovinyl ether.

1,1-dihydro-2,2,2-trifluoroethyl 2-hydrodifluorovinyl ether,
1,1-dihydro-2,2-difluoroethyl 2-hydrodifluorovinyl ether, 1,1-dihydro-2
-Monofluoroethyl 2-hydrodifluorovinyl ether, 1,1-dihydro-2,2,3,3,3-pentafluoropropyl 2-hydrodifluorovinyl ether, 1,1,3-trihydro-2,2.3,3 -Tetrafluoropropyl 2-hydrodifluorovinyl ether, 1,1,1,3,3,3-hexafluoro-2-
Hydro-2-propyl 2-hydrodifluorovinyl ether.

1,1-dihydro-2,2,3,3,4
4,4-heptafluorobutyl 2-hydrodifluorovinyl ether, 1,1,5-trihydro-2,2
3,3,4,4,5,5-octafluoropentyl 2
-Hydrodifluorovinyl ether, 1,1-dihydro-2,2,3,3,4,4,5,5,5-nonafluoropentyl 2-hydrodifluorovinyl ether, 1,
1,2,2-tetrahydro-3,3,4,4,5,5
6,6,6-nonafluorohexyl 2-hydrodifluorovinyl ether, 1,1,7-trihydro-2,
2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl 2-hydrodifluorovinyl ether.

1,1,9-trihydro-2,2,3
3,4,4,5,5,6,6,7,7,8,8,9,9
-Hexadecafluorononyl 2-hydrodifluorovinyl ether, 1,1,2,2-tetrahydro-3,
3,4,4,5,5,6,6,7,7,8,8,9,
9,10,10,10-heptadecafluorodecyl 2
-Hydrodifluorovinyl ether, 1,1,11-trihydro-2,2,3,3,4,4,5,5,6,6
7,7,8,8,9,9,10,10,11,11-eicosafluoroundecyl 2-hydrodifluorovinyl ether, 1,1,13-trihydro-2,2,3
3,4,4,5,5,6,6,7,7,8,8,9,
9,10,10,11,11,12,12,13,13
-Tetracosafluorotridecyl 2-hydrodifluorovinyl ether, 1,1,2,2-tetrahydro-
3,3,4,4,5,5,6,6,7,7,8,8,
9, 9, 10, 10, 11, 11, 12, 12, 13,
13,14,14,14-pentacosafluorotetradecyl 2-hydrodifluorovinyl ether and the like.

1,1-dihydro-2,4-dichloro-
2,3,3,4,4-pentafluorobutyl trifluorovinyl ether, 1,1-dihydro-2,3-dichloro-2,2,3,4,4-pentafluorobutyl trifluorovinyl ether, 1,1- Dihydro-2,
2,2-trifluoroethyl 2-chlorodifluorovinyl ether, 1,1-dihydro-2,2-difluoroethyl 2-chlorodifluorovinyl ether, 1,1
-Dihydro-2-monofluoroethyl 2-chlorodifluorovinyl ether, 1,1-dihydro-2,2,
3,3,3-pentafluoropropyl 2-chlorodifluorovinyl ether, 1,1,3-trihydro-2,
2,3,3-tetrafluoropropyl 2-chlorodifluorovinyl ether, 1,1,1,3,3,3-hexafluoro-2-hydro-2-propyl 2-chlorodifluorovinyl ether.

1,1-dihydro-2,2,3,3,4
4,4-heptafluorobutyl 2-chlorodifluorovinyl ether, 1,1-dihydro-2,4-dichloro-2,3,3,4,4-pentafluorobutyl 2-chlorodifluorovinyl ether, 2,3-dichloro-
2,2,3,4,4-pentafluorobutyl 2-chlorodifluorovinyl ether, 1,1,5-trihydro-2,2,3,3,4,4,5,5-octafluoropentyl 2-chlorodifluoro Vinyl ether, 1,1
-Dihydro-2,2,3,3,4,4,5,5,5-nonafluoropentyl 2-chlorodifluorovinyl ether, 1,1,2,2-tetrahydro-3,3,4,
4,5,5,6,6,6-nonafluorohexyl 2-
Chlorodifluorovinyl ether, 1,1,7-trihydro-2,2,3,3,4,4,5,5,6,6,7,
7-dodecafluoroheptyl 2-chlorodifluorovinyl ether.

1,1,9-trihydro-2,2,3
3,4,4,5,5,6,6,7,7,8,8,9,9
-Hexadecafluorononyl 2-chlorodifluorovinyl ether, 1,1,2,2-tetrahydro-3,
3,4,4,5,5,6,6,7,7,8,8,9,
9,10,10,10-heptadecafluorodecyl 2
-Chlorodifluorovinyl ether, 1,1,11-trihydro-2,2,3,3,4,4,5,5,6,6
7,7,8,8,9,9,10,10,11,11-eicosafluoroundecyl 2-chlorodifluorovinyl ether, 1,1,13-trihydro-2,2,3,
3,4,4,5,5,6,6,7,7,8,8,9,
9,10,10,11,11,12,12,13,13
-Tetracosafluorotridecyl 2-chlorodifluorovinyl ether, 1,1,2,2-tetrahydro-
3,3,4,4,5,5,6,6,7,7,8,8,
9, 9, 10, 10, 11, 11, 12, 12, 13,
13,14,14,14-pentacosafluorotetradecyl 2-chlorodifluorovinyl ether, 1,1-
Dihydro-2,4-dichloro-2,3,3,4,4-pentafluorobutyl 2-hydrodifluorovinyl ether, 1,1-dihydro-2,3-dichloro-2,2
3,4,4-pentafluorobutyl 2-hydrodifluorovinyl ether and the like.

The fluorovinyl ether of the present invention is a compound useful as a raw material of a fluorine-containing polymer, a functional material intermediate, a lubricating oil intermediate, and a pharmaceutical and agricultural chemical intermediate.

[0051]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited thereto.

Example 1 (Example) "1,1-dihydro-2,4-dichloro-2,3,3,3"
Synthesis of 4,4-pentafluorobutyl trifluorovinyl ether "Methyl tert-butyl ether 240
13.2 g of a 60% by weight solution of sodium hydride in an organic solvent was added little by little to a 500 ml flask containing 500 ml, thereby preparing a suspension. While cooling the system to 0 ° C., 55.2 g of 2,4-dichloro-2,3,3,4,4-pentafluorobutanol was slowly added dropwise thereto over 1 hour.

After completion of the dropwise addition, the system was returned to room temperature and stirred for 6 hours. The reaction mixture was transferred to a 500 ml autoclave, and α-pinene 80 mg / methyl tert-butyl ether solution 10 ml was added. The system was replaced with nitrogen, after applying a nitrogen pressure of 2.0 kg / cm ² G, is pressurized by tetrafluoroethylene to 14.5kg / cm ² G.

The temperature of the system was raised to 55 ° C. (at this time, the pressure was 19.
4 kg / cm ² G) and allowed to react for 20 hours. After purging unreacted tetrafluoroethylene, the reaction mixture was added little by little to 100 ml of methanol and cooled,
Subsequently, after 500 ml of water was added and liquid separation was performed, the aqueous layer was extracted twice with 250 ml of dichloromethane. The combined organic layers were washed three times with water and then dried over anhydrous magnesium sulfate.

The solvent was distilled off to obtain 65.0 g of a crude product. As a result of analyzing the crude product by gas chromatography, the conversion of the starting alcohol was 91.7%, and the selectivity for the target vinyl ether was 55.8%.

Example 2 (Example) "1,1-dihydro-2,4-dichloro-2,3,3,3"
Synthesis of 4,4-pentafluorobutyl trifluorovinyl ether "In Example 1, the autoclave was heated to 55 ° C.
And then apply a nitrogen pressure of 1.0 kg / cm ² G,
The pressure was increased to 9.0 kg / cm ² G with tetrafluoroethylene. The pressure was maintained at 8.5 to 9.0 kg / cm ² G for 9 hours, followed by a reaction for 11 hours. Otherwise, the same reaction as in Example 1 was carried out to obtain 60.6 g of a crude product. As a result of analyzing the crude product by gas chromatography, the conversion of the starting alcohol was 90.5% and the selectivity for the target vinyl ether was 41.7%.

Example 3 (Example) "1,1-dihydro-2,4-dichloro-2,3,3,3"
Synthesis of 4,4-pentafluorobutyl trifluorovinyl ether "In Example 2, 60
The reaction was carried out by reducing the weight-% organic solvent solution to 9.48 g, and the same reaction as in Example 2 was carried out except that the operation of cooling the reaction mixture with methanol was omitted in the post-reaction treatment, to obtain 63.7 g of a crude product. . As a result of analyzing the crude product by gas chromatography, the conversion of the starting alcohol was 8
The selectivity of the target vinyl ether was 9.5%.

Example 4 (Comparative Example) "1,1-dihydro-2,4-dichloro-2,3,3,3"
Synthesis of 4,4-pentafluorobutyl trifluorovinyl ether "
The reaction was carried out in the same manner as in Example 1 except that tetrahydrofuran was used instead of butyl ether, to obtain 60.2 g. As a result of analyzing the crude product by gas chromatography, the conversion of the starting alcohol was 90.1% and the selectivity for the target vinyl ether was 4.0%. The main product was 1,1-dihydro-2,4-dichloro-2,3,3,4,4-pentafluorobutyl 2-hydrotetrafluoroethyl ether, with a selectivity of 65%.

Example 5 (Comparative Example) "1,1-dihydro-2,4-dichloro-2,3,3,3"
Synthesis of 4,4-pentafluorobutyl trifluorovinyl ether "
The reaction was carried out in the same manner as in Example 1 except that diethyl ether was used instead of butyl ether. As a result of analyzing the crude product by gas chromatography, the conversion of the starting alcohol was 37% and the selectivity for the target vinyl ether was 0.0%.

Example 6 (Example) "1,1-dihydro-2,3-dichloro-2,2,3,
Synthesis of 4,4-pentafluorobutyl trifluorovinyl ether ", 2,4-dichloro-2,3,3
2,3- instead of 4,4-pentafluorobutanol
The reaction was carried out in the same manner as in Example 1 except that 47.7 g of dichloro-2,2,3,4,4-pentafluorobutanol was used, to obtain 70.6 g of a crude product. As a result of analyzing the crude product by gas chromatography, the conversion of the starting alcohol was 92.2% and the selectivity of the target product vinyl ether was 69.7.
%Met.

Example 7 (Example) "Synthesis of 2,2,3,3,3-pentafluoropropyl trifluorovinyl ether" 2,4-dichloro-2,3,3,4,4-pentafluoro of Example 1 The reaction was carried out in the same manner as in Example 1 except that 40.0 g of 2,2,3,3,3-pentafluoropropanol was used instead of butanol,
56.4 g of crude product were obtained. As a result of analyzing the crude product by gas chromatography, the conversion of the starting alcohol was 9
5.0%, and the selectivity of the target vinyl ether was 75.2%.

[0062]

Since methyl tert-butyl ether is used as the reaction solvent, the danger of flammability, explosion and toxicity is reduced as compared with conventional solvent systems, and it is economically advantageous and industrially advantageous. Mass production becomes possible.

Even if the amount of the base is reduced, the yield of the target vinyl ether can be sufficiently ensured, so that the step of unreacted base treatment involving heat generation after the reaction can be omitted.

Particularly when tetrafluoroethylene is used as a raw material, the reaction proceeds at a conversion rate equivalent to that of the high-pressure reaction even at a low pressure, thereby reducing the risk of the reaction and reducing the amount of unreacted tetrafluoroethylene after the reaction. Can be suppressed.

Claims (2)

[Claims] An alkoxide represented by the general formula (1):
A process for producing fluorovinyl ethers represented by the general formula (4), characterized by reacting fluoroethylene represented by the general formula (2) in an ether solvent represented by the general formula (3). . Embedded image R ¹ R ² R ³ COX ¹ (1) CF ₂ ＣＦCFX ² (2) R ⁴ OR ⁵ (3) R ¹ R ² R ³ COCF = CFX ² (4) [General formula (1) to In (4), R ¹ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms or an alkenyl group having 3 to 18 carbon atoms, and a part of R ¹ other than a hydrogen atom or All hydrogen atoms may be replaced by fluorine, chlorine or bromine atoms. R ² and R ³ independently represent a hydrogen atom or a carbon atom
And 4 to 4 alkyl groups, and some or all of the hydrogen atoms of the alkyl group may be substituted with a fluorine atom, a chlorine atom or a bromine atom. R ⁴ represents an alkyl group having 1 or more carbon atoms, and R ⁵ represents an alkyl group having 3 or more carbon atoms. X ¹ represents a sodium atom or a potassium atom,
X ² represents a fluorine atom, a chlorine atom or a hydrogen atom. ] 2. The method according to claim 1, wherein the alkoxide represented by the general formula (1) is obtained by reacting an alcohol represented by the following general formula (5) with a sodium-containing base or a potassium-containing base. Embedded image R ¹ R ² R ³ COH (5) [In the general formula (5), R ¹ is a hydrogen atom and has 1 to 1 carbon atoms.
An alkyl group having 18 carbon atoms, an aryl group having 6 to 18 carbon atoms or an alkenyl group having 3 to 18 carbon atoms, wherein a part or all of the hydrogen atoms of R ¹ other than a hydrogen atom are substituted by a fluorine atom, a chlorine atom or a bromine atom It may be. R
² and R ^{3 each} independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and a part or all of the hydrogen atoms of this alkyl group may be substituted by a fluorine atom, a chlorine atom or a bromine atom. ]