JP2796612B2 - Fluorinated ether compound and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorine-containing ether compound and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, cleaning agents, heat transfer media, fire extinguishers,
Chlorofluorocarbons (CFCs) have been widely used as a power circulation working fluid, a reaction solvent, a desiccant (a draining agent), and the like. However, it was pointed out that these CFCs destroy the stratospheric ozone layer and have a serious adverse effect on the earth's ecosystem including human beings, and their production was banned by an international treaty at the end of 1995. Hydrochlorofluorocarbons (HCFCs) are compounds that have less of an effect of depleting the ozone layer than CFCs. However, as the use amount increases, the possibility of destruction of the ozone layer increases. It has been decided that production will be progressively restricted. To respond to such problems, cleaning agents, heat transfer media, fire extinguisher, power circulation working fluid, reaction solvent, which do not destroy the ozone layer even if released to the atmosphere
CFCs and HC that can be used as a desiccant (draining agent)
There is a need for alternative compounds to FCs. As an alternative compound, there is a movement to shift to an organic solvent system or an aqueous solution system in part. However, most of the organic solvents are contained in dangerous substances such as flammable substances, so that they often need to be handled with care and require a large amount of equipment for collection and reuse.
Further, the aqueous solution system still has problems such as a problem in performance, and a large cost for equipment costs such as recovery and reuse.

[0003] Fluorine-containing ethers are considered to be promising compounds as substitutes for these CFCs and HCFCs. Conventionally, methods for producing a fluorinated ether can be broadly classified into a method of fluorinating an ether compound and a method of synthesizing an ether compound using a compound containing a fluorine atom as a building block. The former method includes the following method. 1) Direct fluorination of ether compounds with fluorine gas A. Sekiya et al., Chem. Letter, 1990, 609 .; or
RJ Ragow et al., J. Org.Chem., 53, 78 (1988) .2) Indirect fluorination of ether compounds with metal fluorides and the like.M. Brandwood et al., J. Fluorine Chem., 5,521 (197
5). 3) Electrofluorination of ether compounds T. Abe et al., J. Fluorine Chem., 15,353 (1980). In the latter, 4) Addition reaction of alcohols to fluorinated olefins RDChambers et al., Adv. Fluorine Chem., 4,50 (19
65). 5) Reaction of alcohol with alkyl halide JA Young et al., J. Am. Chem. Soc., 72, 1860 (1950). 6) Reaction of fluorinated alcohol with sulfonic acid ester UK Patent Specification No. 813,493 7) Reaction of acid fluoride with sulfonic acid ester German Patent Specification No. 1,294,949

On the other hand, in the latter method, hexafluoropropene oxide (hereinafter HFPO) is used as a starting material.
Has been known for a long time (US Pat. No. 3,114,778). This method uses HFPO
The main reaction is to react with acid fluoride to produce perfluoro-2-alkoxypropionyl fluoride. However, this HFPO is highly reactive and easily undergoes oligomerization, and the product is HFPO.
PO is often a perfluoropolyether having a dimerized or higher-ordered multimeric structure. There is also a method of converting the produced perfluoro-2-alkoxypropionyl fluoride into a carboxylic acid or a vinyl ether (US Pat. Nos. 3,250,808 and 3,321,53).
No. 2, etc.), the compound obtained by this method is a perfluoro compound, which does not destroy the ozone layer, but has a large coefficient that contributes to global warming and has a bad influence on the global environment. And there is no example of using this perfluoro-2-alkoxypropionyl fluoride as a raw material to synthesize a fluorinated ether containing no chlorine atom and containing a hydrogen atom in the molecule.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fluorine-containing ether compound which contains fluorine and hydrogen, does not contain chlorine atoms, does not destroy the ozone layer, and has little influence on global warming. Is the subject.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention,

Embedded image (Wherein, R ¹ represents a lower alkyl group and R ² represents a trifluoromethyl group or a partially fluorinated ethyl group).
Further, according to the present invention, the following general formula (1)

Embedded image Wherein R ¹ represents a lower alkyl group and R ² represents a trifluoromethyl group or a partially fluorinated ethyl group. R ² COX (3) wherein R ² represents a trifluoromethyl group or a partially fluorinated ethyl group, and X represents chlorine or fluorine. An acid halide is reacted in the presence of at least one metal fluoride selected from an alkali metal fluoride and an alkaline earth metal fluoride to obtain a compound represented by the following general formula (4):

Embedded image (Wherein R ² has the same meaning as described above)
-Fluoroalkoxy-perfluoropropenyl fluoride, and this compound is treated with an alkylating agent having a lower alkyl group R ¹ in an aprotic polar organic solvent in an alkali metal fluoride and an alkaline earth metal fluoride. Wherein the reaction is carried out in the presence of at least one metal fluoride selected from the group consisting of: Further, according to the present invention, the following general formula (1)

Embedded image (Wherein, R ¹ represents a lower alkyl group and R ² represents a trifluoromethyl group or a partially fluorinated ethyl group). (4)

Embedded image Wherein R ² represents a trifluoromethyl group or a partially fluorinated ethyl group, and an alkylating agent having a lower alkyl group R ¹ in 2-fluoroalkoxy-perfluoropropionyl fluoride represented by the formula: Is reacted in an aprotic polar solvent in the presence of at least one metal fluoride selected from among alkali metal fluorides and alkaline earth metal fluorides. .

[0007]

DETAILED DESCRIPTION OF THE INVENTION Hexafluoropropene oxide (HFPO) used in the present invention has the formula

Embedded image It is a compound represented by these. On the other hand, the acid halide represented by the general formula (3) used in the present invention is a completely or partially fluorinated acid halide, for example,
Trifluoroacetyl chloride, trifluoroacetyl fluoride, 3H-tetrafluoropropionyl chloride and the like. As the alkylating agent having a lower alkyl group R ¹ used in the present invention, lower dialkyl sulfate, organic sulfonic acid lower alkyl ester, and lower alkyl halide are used. The carbon number of the lower alkyl group R ¹ is 1-6, preferably 1-3.
Examples of the lower dialkyl sulfate include dimethyl sulfate, diethyl sulfate, dinormal propyl sulfate, diisopropyl sulfate and the like. Organic sulfonic acid lower alkyl esters include methyl methanesulfonate, ethyl methanesulfonate, normal propyl methanesulfonate, isopropyl methanesulfonate, methyl paratoluenesulfonate, ethyl paratoluenesulfonate, normal propyl paratoluenesulfonate, para Examples include isopropyl toluenesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, normal propyl trifluoromethanesulfonate, and isopropyl trifluoromethanesulfonate. Examples of the lower alkyl halide include methyl bromide, methyl iodide, ethyl bromide, ethyl iodide, normal propyl bromide, normal propyl iodide, isopropyl bromide, and isopropyl iodide.

The metal fluoride used in the present invention is selected from alkali metal fluorides and alkaline earth metal fluorides. Examples of the alkali metal fluoride include potassium fluoride, sodium fluoride and cesium fluoride. As the alkaline earth metal fluoride, calcium fluoride is preferably used.

The aprotic polar organic solvent used in the present invention is not particularly limited as long as it is an aprotic polar organic solvent. For example, monoglyme, diglyme,
Ethers such as triglyme, tetraglyme, diethyl ether, dibutyl ether, diisopropyl ether, dioxane and tetrahydrofuran; nitriles such as acetonitrile and propionitrile; chain amides such as dimethylformamide and dimethylacetamide; or 1,3-dimethyl And cyclic amides such as -2 imidazolidinone and N-methyl-2-pyrrolidone.

The fluorine-containing ether compound represented by the general formula (1) of the present invention is produced by combining the following two reactions. That is, reaction (a): a reaction in which a fluoroalkoxide generated from an acid halide and a metal fluoride is added to HFPO to form 2-fluoroalkoxy-perfluoropropionyl fluoride, and a reaction (b): This is a reaction in which an alkylating agent is reacted with fluoroalkoxy-perfluoropropionyl fluoride in the presence of a metal fluoride to form a fluorine-containing ether compound of the general formula (1). The reaction formula of the reaction (a) is as follows.

Embedded image The reaction formula of the reaction (b) is as follows.

Embedded image In the above formula, R ² and X have the same meaning as described above. R ¹ Y
Represents an alkylating agent having a lower alkyl group R ¹ . In this case, Y is a residue obtained by removing one lower alkyl group from a lower dialkyl sulfate (—OSO ₃ R ³ , R ³ : lower alkyl group) or a lower alkyl group from an organic sulfonic acid lower alkyl ester. Residues (-OSO ₂ R ⁴ , R
⁴ : an organic group) and a residue (-X, X: halogen atom) obtained by removing a lower alkyl group from a halogenated lower alkyl.
MF indicates metal fluoride.

In these two reactions, the 2-fluoroalkoxy-perfluoropropionyl fluoride formed in the reaction (a) is separated, and the separated 2-fluoroalkoxy-perfluoropropionyl fluoride is placed in another reactor and reacted with an alkylating agent. The reaction (b) can be carried out, but the reaction (a) and the reaction (b) can be carried out continuously in one reactor.

When carrying out the reaction (a), the alkali metal fluoride or the alkaline earth metal fluoride is HFP
A catalytic amount for O may be used. Usually, 0.05 to 0.7 times mol, preferably 0.1 to 1 mol per mol of HFPO.
It is preferable to select from the range of 0.4 times mol. However, when the acid halide is an acid chloride, its amount is usually selected from the range of 1.05 to 1.7 times mol, preferably 1.1 to 1.4 times mol of HFPO. Is preferred. If the amount is extremely large, oligomerization of HFPO is caused, and the yield is reduced. The acid halide is usually added in an amount of 1.0 to 1 mol of HFPO.
It is desirably selected from the range of 2.0 to 2.0 times, preferably 1.1 to 1.7 times. The use of a reaction solvent is not essential, and can be performed without a solvent. However, in this case, oligomerization of HFPO is likely to occur, and the reaction must be performed at a low temperature equal to or lower than the boiling point of the acid halide, so that the reaction rate decreases. Therefore, reaction (a)
Is preferably carried out in the presence of a reaction solvent. As the reaction solvent, the above-mentioned aprotic polar solvent is used. The presence of water in the reaction solvent is not preferred, and the amount of water is 0.1%.
005% by weight or less. When moisture is present,
Acid halides and HFPO react with water, leading to lower yields. The amount of the reaction solvent used is 0.2 to 3 times by weight, preferably 0.5 to 3 times the charged weight of all the reaction substrates (total amount of HFPO, acid halide and metal fluoride).
It is desirable to select from the range of up to twice the weight. The pressure in this reaction is not particularly limited, and the reaction proceeds under reduced pressure to normal pressure or any pressure of a pressurized system.
It is preferably 20 kg / cm ² G or less from the viewpoint of operability and the like. The temperature in this reaction varies depending on the type of the reaction solvent and the like, but is usually −50 to 80 ° C., preferably −
It is selected from the range of 20 to 30 ° C. At a high temperature, the desired reaction of adding a fluoroalkoxide anion to HFPO and the side reaction of HFPO oligomerization using fluorinated ion as a catalyst proceed competitively, and the yield decreases.

When the reaction (b) is carried out, if the alkylating agent is 2-alkylalkoxy-perfluoropropionyl fluoride, a dialkyl sulfate or an alkyl sulfonate is usually used in an amount of from 0.7 to 2.0. 5
The molar ratio is preferably selected from a molar range of preferably 1.0 to 2.0 times, and if it is an alkyl halide, it is usually 2.1 to 4.0 times, preferably 2.5 to 2.0 times.
It is desirable to select from a range of 3.0 moles. Alkali metal fluoride or alkaline earth metal fluoride is usually 1.0 to 4.0 times mol, preferably 1.1 to 2.0 times mol, of 2-fluoroalkoxy-perfluoropropionyl fluoride. It is desirable to select from the range. It is preferable to use a sufficiently dehydrated reaction solvent. If a large amount of water is present, 2-
Fluoroalkoxy-perfluoropropionyl fluoride decomposes, reducing the yield. The amount of the reaction solvent used is
0.2 to 3 times the weight of the charged weight of all reaction substrates,
Preferably, it is desirable to select from the range of 0.5 to 2 times the weight. The pressure in this reaction is not particularly limited, and the reaction proceeds at any pressure from a normal pressure to a pressurized system, but is preferably 20 kg / cm ² G or less from the viewpoint of operability and the like. The temperature in this reaction depends on the type of the reaction solvent and the like, but is usually selected from the range of 0 to 120 ° C, preferably 50 to 100 ° C.

[0014]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

Example 1 7.0 g (0.1 g) of spray-dried potassium fluoride was placed in a 500 ml stainless steel autoclave reactor equipped with a pressure gauge, a thermometer, a stirrer, a gas inlet tube and a gas outlet tube.
2 g) and 91 g of diglyme sufficiently dehydrated with molecular sieve were added as a reaction solvent, and the inside of the reactor was sufficiently replaced with dry nitrogen gas. The reaction vessel was cooled to -70% using dry ice-methanol as a coolant.
After cooling to ℃, 70 g (0.60 mol) of trifluoroacetyl fluoride was introduced into the vessel while liquefying. The temperature of the reaction vessel was raised to −20 ° C. and maintained at that temperature for 2 hours. When the pressure in the container reaches a steady state, 82.0 g of hexafluoropropene oxide (HFPO)
(0.5 mol) was slowly blown into the reaction vessel. At this time, the temperature in the vessel was raised, but the temperature was kept at -10 ° C. After introducing all HFPO,
It was kept at 10 ° C. and reacted for 5 hours. The contents were distilled off under reduced pressure at room temperature to obtain a colorless liquid having a boiling point of 30 ° C., 117 ppm of perfluoro-2-ethoxypropionyl fluoride.
g (0.41 mol, yield based on HFPO = 83% mol) was obtained. In addition, a colorless liquid which is considered to have trifluoroacetyl fluoride added to a dimer of HFPO from the boiling point is 1
3 g were obtained.

Next, a newly prepared pressure gauge, thermometer,
A spray-dried potassium fluoride (24.5 g, 0.42 mol), dimethyl sulfate (53 g, 0.42 mol) and a reaction solvent were placed in a 500 ml stainless steel autoclave reactor equipped with a stirrer, gas inlet tube and gas outlet tube. 120 g of diglyme sufficiently dehydrated with molecular sieve
After the addition, the inside of the reactor was sufficiently replaced with dry nitrogen gas. The reactor was cooled to 0 ° C., and to this was added 81 g (0.28 mol) of perfluoro-2-ethoxypropionyl fluoride synthesized in the above reaction. The reactor was warmed up slowly and kept at 80-90 ° C. Reaction temperature is 65 ° C
The pressure inside the reactor began to decrease around the time when the temperature exceeded, and the pressure reached a steady state within 5 hours from the start of the temperature rise. The reaction vessel was cooled and distilled off at 40 ° C. under reduced pressure to obtain 98 g of a colorless liquid. This was determined by gas chromatography analysis to be methyl = 2.
-Pentafluoroethoxy-1,1,2,3,3,3-
Hexafluoropropyl was a liquid containing 63% ether (area ratio by TCD detector). This liquid is distilled to obtain methyl 2-pentafluoroethoxy-1,1,1,
2,3,3,3-hexafluoropropyl ether 5
1 g (purity 99% or more, area ratio by TCD detector) was obtained. According to the ¹ H-NMR and ¹⁹ F-NMR spectra and mass spectrum, this compound is represented by the following formula: methyl = 2-pentafluoroethoxy-1,1,2,3,3
It was confirmed that 3,3-hexafluoropropyl was an ether.

Embedded image

¹ H-NMR (CDCl ₃ ) (270 MHz) δ = 3.7 (s, 3H
^{of CH3O-), ppm. 19 F} -NMR (CDCl 3) (254MHz) δ = -80.9 (tq, J = 9.2Hz,
2.8Hz, 3F),-86.4 (m, 2F),-87.4 (s, 3F),-88.6 (m, J
= 9.2Hz, 2F),-144.9 (broad t, 1F), ppm.MS m / z (rel.intensity,%) CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCH ₃ (C ₆ H ₃ F ₁₁ O _{2, FW = 316) 297 (} M-19, 33.0), 181 (CF (CF 3) CF 2 OCH 3, 83.4), 16
9 (13.6), 150 (3.8), 147 (CF ₃ CF ₂ OC, 29.9), 131 (9
7.7), 119 (CF ₃ CF ₂ , base peak), 81 (CH ₃ OCF ₂ , 100.
0), 69 (41.7), 31 (3.7).

Methyl 2-pentafluoroethoxy-
As a result of measuring the physical property values of 1,1,2,3,3,3-hexafluoropropyl = ether, the following results were obtained. (Physical property value of CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCH ₃ ) Density (23 ° C.) (g / ml): 1.539 Surface tension (23 ° C.) (dyn / cm): 13.30 Boiling point (101.325 kPa) (° C.) ): 79.04 Kinematic viscosity (23 ° C) (cSt): 0.566 Specific heat (kJ / (kg · K)): 1.152 Thermal conductivity λ (w / m · K): 0.0700 Solubility in water (g / 100g water): 0.004 Relative permittivity (23 ° C) ε ': 5.59 Latent heat of vaporization (calculated value by vapor pressure curve: 25 ° C) (kJ / k
g): 116.0 Solubility parameter (25 ° C.) δ (cal / cm ³ ) ^1/2 : 6.3
1 The physical properties were measured by the following methods. Density: Pycnometer method Surface tension: Precision electric balance Ring method using Cahn 2000 Boiling point: Isoteniscope method Latent heat of evaporation: Isoteniscope method Viscosity: Capillary tube viscosity method Specific heat: DSC method Thermal conductivity: Comparative stationary method of concentric cylinder type Liquid thermal conductivity measurement method by water solubility: GC-FID method Relative permittivity: transformer bridge method

Comparative Example 1 CFC ₁₁₃ (1,1,1) having excellent properties as a detergent
Physical properties of 2-trichloro-1,2,2-trifluoroethane) are shown below. (Organic Synthetic Chemistry Association New Edition Solvent Pocket Book, Japan Refrigeration Association New Edition Refrigeration and Air Conditioning Handbook No. 4
(Characteristics of CFC ₁₁₃ ) Density (25 ° C) (g / ml): 1.561 Surface tension (20 ° C) (dyn / cm): 19 Boiling point (101.325 kPa) (° C): 47.57 Specific heat (Liquid) (kJ / (kg · K)): 0.912 Thermal conductivity λ (w / m · K): 0.0804 Solubility in water (25 ° C) (g / 100g water): 0.017 Latent heat of vaporization (0 ° C) (kJ / kg): 160.5 Solubility parameter (25 ° C) δ (cal / cm ³ ) ^1/2 : 7.2

Comparative Example 2 HCFC _225ca ( _1,1) having excellent properties as a detergent
1,1,2,2-pentafluorodichloropropane),
HCFC _225cb , 1,2,2,3-pentafluoro-
Physical properties of (1,3-dichloropropane) are shown below.
(Physical property value of HCFC _225ca ) Density (20 ° C) (g / ml): 1.55 Surface tension (25 ° C) (dyn / cm): 15.8 Boiling point (101.325 kPa) (° C): 51.1 Specific heat ( 25 ° C, liquid) (kJ / (kg · K)): 1.03 Thermal conductivity λ (w / m · K): 0.053 Latent heat of vaporization (kJ / kg): 168.1 Solubility parameter δ (cal / cm ³ ) ^1/2 : 6.76 (physical property value of HCFC _225cb ) Density (25 ° C) (g / ml): 1.56 Surface tension (25 ° C) (dyn / cm): 16.7 Boiling point (101.325 kPa) (° C): 56.1 Specific heat (25 ° C, liquid ) (KJ / (kg · K): 1.08 Thermal conductivity λ (w / m · K): 0.053 Latent heat of vaporization (kJ / kg): 171.6

C used in these cleaning agents and the like
For FC and HCFC, methyl 2-pentafluoroethoxy-1,1,2,3 produced in the present invention is used.
3,3-hexafluoropropyl ether has a boiling point,
It is considered that physical properties such as surface tension are close and can be applied to similar applications.

Example 2 The procedure of Example 1 was repeated, except that 3H-tetrafluoropropionyl chloride (CHF ₂ CF ₂ COCl) was used instead of trifluoroacetyl fluoride.
A fluorine-containing ether compound represented by the following formula can be obtained.

Embedded image

[0023]

The fluorinated ether compound of the present invention can be used for cleaning, heat transfer medium, fire extinguisher, power circulating working fluid, reaction solvent, desiccant (draining agent), etc., like conventional CFCs. , Is very useful as a substitute for CFC. Moreover, in the case of the fluorinated ether compound of the present invention,
Since it contains a hydrogen atom, it has high reactivity with hydroxyl radicals in the atmosphere and is easily decomposed in the troposphere, and thus has a small greenhouse effect. In addition, since it does not contain chlorine atoms, it is a compound that does not destroy ozone in the ozone layer and has little effect on the global environment.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Mochizuki 2-40-17 Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6F 6F, New Refrigerant etc. Project Office, Institute for Global Environmental Technology Research Institute (72) Inventor Naotaka Takada 6th floor, Hongo Wakai Building, 2-40-17 Hongo, Bunkyo-ku, Tokyo Inside the New Refrigerants Project Office of the National Institute for Environmental Science and Technology (72) Inventor Akira Sekiya 1-1-1 Higashi, Tsukuba, Ibaraki Industrial Technology Toshiro Fujimori, Examiner, National Institute of Materials Science and Technology (56) References JP-A-61-1658 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C07C 43/12 C07C 41 / 02 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] [Claim 1] The following general formula: (Wherein, R ¹ represents a lower alkyl group, and R ² represents a trifluoromethyl group or a partially fluorinated ethyl group). 2. The formula: A fluorine-containing ether compound represented by the formula: 3. The following general formula (1): Wherein R ¹ represents a lower alkyl group and R ² represents a trifluoromethyl group or a partially fluorinated ethyl group. R ² COX (3) wherein R ² represents a trifluoromethyl group or a partially fluorinated ethyl group, and X represents chlorine or fluorine. The acid halide is reacted in the presence of at least one metal fluoride selected from alkali metal fluorides and alkaline earth metal fluorides to obtain the following general formula (4): (Wherein R ² has the same meaning as described above)
-Fluoroalkoxy-perfluoropropenyl fluoride, and this compound is treated with an alkylating agent having a lower alkyl group R ¹ in an aprotic polar organic solvent in an alkali metal fluoride and an alkaline earth metal fluoride. Wherein the reaction is carried out in the presence of at least one metal fluoride selected from the group consisting of: 4. The following general formula (1): (Wherein, R ¹ represents a lower alkyl group and R ² represents a trifluoromethyl group or a partially fluorinated ethyl group). (4) Wherein R ² represents a trifluoromethyl group or a partially fluorinated ethyl group, and an alkylating agent having a lower alkyl group R ¹ in 2-fluoroalkoxy-perfluoropropionyl fluoride represented by the formula: In an aprotic polar solvent in the presence of at least one metal fluoride selected from alkali metal fluorides and alkaline earth metal fluorides.