JPH07179385A - Production of trifluoromethoxyfluoroethanes - Google Patents

Abstract

PURPOSE:To synthesize a trifluoromethoxyfluoroethane compound in high efficiency. CONSTITUTION:This trifluoromethoxyfluoroethane compound expressed by the formula CF3O-R<1> is produced by reacting fluorophosgene expressed by the formula COF2 with a sulfonic acid ester compound of the formula R<1>-OSO2-R<2> (R<1> is a fluorine-containing 2C alkyl; R<2> is an alkyl or a fluorine-containing alkyl) in an aprotic polar solvent or without using a solvent in the presence of an alkali metal fluoride or an alkaline earth metal fluoride.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing trifluoromethoxyfluoroethanes which does not destroy ozone in the ozone layer because it does not contain chlorine atoms.

[0002]

2. Description of the Related Art Conventionally, chlorofluorocarbon (hereinafter abbreviated as CFC) has been most well known as a refrigerant, a foaming agent and a solvent. CFCs are widely used in various industrial fields due to their low toxicity, nonflammability, and chemical and thermal stability.

However, C having such excellent characteristics
It has been pointed out that FC, when released into the atmosphere, destroys the ozone layer in the stratosphere, and thus has a serious adverse effect on the earth's ecosystem including humans.

In order to deal with such global environmental problems,
There is a demand for compounds that can substitute for CFCs that can be used as refrigerants, foaming agents, and solvents that have little or no effect on the global environment even when they are released into the atmosphere. It is known that trifluoromethoxyfluoroethanes are useful compounds (US Pat. No. 3,409,555, US Pat. No. 3,362,180) that can be used similarly to chlorofluorocarbon (CFC) used as a refrigerant.

On the other hand, fluorine-containing ethers are considered as alternative compounds for CFC. As a method for producing the trifluoromethoxyfluoroalkanes, a fluoroformate derived from fluoroalcohol and fluorophosgene is fluorinated with sulfur tetrafluoride [US Pat.
80, J. Org. Chem. , Vol. 29, P1
1-15 (1964)], chlorination reaction of corresponding methyl ethers, and then fluorination with antimony trifluoride [J. Fluorine Chem. , Vol. 1
1, P93-107 (1978), ibid. , Vo
l. 13, P123-140 (1979)], addition reaction of trifluoromethyl hypofluoride with a fluorine-containing olefin compound [J. Org. Chem. , Vol. Four
8, P242-250 (1983)], and the reaction of diethylsulfate with fluorophosgene in the presence of potassium fluoride (US Pat. No. 3,505,410). Among these conventional production methods, SF ₄ used as a raw material is a compound that is extremely difficult to use industrially, and the reaction by-product is also a sulfur-containing compound, so there is a problem in post-treatment from the viewpoint of the environment. . In the chlorination reaction of, a plurality of isomers of chlorinated products are produced and it is difficult to separate them. Also in the above, two kinds of products are obtained due to the orientation of the addition reaction, and a separation operation is required. However, since a single product is obtained, the range of application is narrow in order to produce a similar compound because the raw materials are limited.

[0006]

An object of the present invention is to provide a production method for efficiently synthesizing trifluoromethoxyfluoroethanes.

[0007]

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, fluorinated ethers, particularly trifluoromethoxyfluoroethanes, have proved to be effective substitutes for CFCs. We have found that

[Chemical formula 5] COF ₂ (I) and general formula

Embedded image R ¹ —OSO ₂ —R ² (II) (R ¹ represents a fluorine-containing alkyl group having 2 carbon atoms, R ² represents an alkyl group or a fluorine-containing alkyl group) It was found that by reacting an ester compound with an aprotic polar solvent or in the absence of a solvent in the presence of an alkali metal fluoride or an alkaline earth metal fluoride, it is possible to synthesize with relatively good conversion and highly selective. The present invention has been completed.

Specific examples of the sulfonic acid ester compound represented by the general formula (II) used as a raw material in the present invention include, for example, 2,2,2-trifluoroethyltrifluoromethanesulfonate and 2,2-difluoro. Examples thereof include fluorine-containing ethyl trifluoromethane sulfonates such as ethyl trifluoromethane sulfonate.

In the present invention, fluorophosgene (I)
The reaction between the sulfonic acid ester compound represented by the general formula (II) and the sulfonic acid ester compound is carried out in an aprotic polar solvent or without solvent. Examples of the aprotic polar solvents, for example monoglyme [CH ₃ OCH ₂ CH ₂ OCH _3], diglyme _{[CH 3 O (CH 2 CH 2} O) 2 CH 3 ], triglyme _{[CH 3 O (CH 2 CH 2} O) ₃ CH ₃ ], tetraglyme [CH ₃ O (CH ₂ CH ₂ O) ₄ CH ₃ ], ethers such as dibutyl ether and dioxane; nitriles such as acetonitrile; amides such as dimethylformamide and dimethylacetamide. However, it goes without saying that the present invention is not limited to this.

In the present invention, an alkali metal fluoride or an alkaline earth metal fluoride is used as a catalyst. As the alkali metal fluoride, for example, sodium fluoride, potassium fluoride, cesium fluoride or the like is used, and as the alkaline earth metal fluoride, for example, calcium fluoride or the like is used. Alkali metal fluorides are preferred from the viewpoint of yield.

The amount of the alkali metal fluoride or the alkaline earth metal fluoride used is not particularly limited, and is 0.1 to 4.0 times the molar amount of fluorophosgene (I),
It is preferable to select from the range of 1.0 to 1.5 times mol.

In the reaction of the present invention, the charging ratio of fluorophosgene (I) and the sulfonic acid ester compound represented by the general formula (II) is not particularly limited, and the reaction can be carried out at any ratio. However, in order to improve the conversion rate of fluorophosgene (I), it is preferable to carry out the reaction with an excess of the sulfonate compound represented by the general formula (II).

The pressure in the reaction of the present invention is not particularly limited, and the reaction proceeds at any pressure from reduced pressure to increased pressure. When the reaction is carried out under pressure, the pressure is not particularly limited, but 50 kg / cm due to operability and the like.
It is preferably ² G or less.

The reaction temperature in the reaction of the present invention varies depending on the reaction time, the reaction pressure, the amount of catalyst, etc., but is usually 0 to 20.
It is selected from the range of 0 ° C, preferably 20 to 100 ° C.

The reaction time in the reaction of the present invention varies depending on the reaction temperature, the reaction pressure, the amount of the catalyst and the like, but the reaction is almost completed within several hours to several tens of hours.

[0016]

EXAMPLES Hereinafter, production examples of trifluoromethoxyfluoroethanes of the present invention will be described with reference to Examples. The general formula given here

Embedded image The sulfonic acid ester compound represented by R ¹ —OSO ₂ —R ² (II) is a reaction of a corresponding commercially available fluorine-containing alcohol with trifluoromethanesulfonic anhydride [Tetrahedron, vol. Four
4, P5375-5387 (1988), J. Or
g. Chem. , Vol. 49, P2258-2273
(1984)], or reaction with trifluoromethanesulfonic acid fluoride [J. Org. Chem. , Vol.
30, P4322-4324 (1965), Tetr
ahedron, vol. 21, P1-4 (196
5)] can be easily manufactured. Of course, the present invention is not limited to the following examples.

Example 1 In a 1000 ml reactor made of stainless steel equipped with a stirrer, a pressure gauge, a thermometer, a gas introduction pipe and a gas discharge pipe, 2,2,2-
Trifluoroethyl trifluoromethanesulfonate 2
37 g (1.02 mol), 59 g (1.02 mol) of spray-dried potassium fluoride, and 296 ml of dried diethylene glycol dimethyl ether were introduced and degassed, and then 67 g of fluorophosgene (1.02 mol) was introduced from the gas introduction tube.
(mol) was added and the mixture was sealed. The temperature rises gradually and the reaction temperature is about 7
Hold at 0 ° C. for 90 hours. Then, another stainless steel container was connected to the reactor, and the reaction product was transferred to this container under reduced pressure. This was washed with a dilute aqueous potassium hydroxide solution, dried with concentrated sulfuric acid, and then distilled to obtain 94.7 g (yield 56%) of a colorless transparent liquid having a boiling point of 6.2 ° C.

From ¹ H-NMR and ¹⁹ F-NMR spectra, it was found to be 1-trifluoromethoxy-2,2,2-trifluoroethane.

The ¹ H-NMR and ¹⁹ F-NMR spectrum data are shown below. In addition, ¹ H-NMR and ¹⁹ F-NM
For the measurement of the R spectrum, deuterated chloroform was used as a solvent, and tetramethylsilane and trichlorofluoromethane were used as internal standard substances, respectively.

¹ H-NMR (CDCl ₃ ) δ4.26
_{(2H, q, J HF =} 7.9Hz, - CH 2 CF 3).

¹⁹ F-NMR (CDCl ₃ ) δ-62.
_{6 (3F, s, CF 3} O -), - 75.3 (3F, t,
J _FH = 8.4 Hz, -CH ₂ CF ₃ ).

EXAMPLE 2 2,2-difluoroethyltrifluoromethanesulfonate 168. was added to a 1000 ml stainless steel reactor equipped with a stirrer, a pressure gauge, a thermometer, a gas inlet tube and a gas outlet tube.
0 g (0.785 mol), spray-dried potassium fluoride 45.6 g (0.785 mol) and 230 ml of dried diethylene glycol dimethyl ether were added and degassed, and then 51.8 g (0.78) of fluorophosgene was introduced from the gas inlet tube.
(785 mol) was added and the mixture was sealed. The temperature was gradually raised and the reaction temperature was kept at about 70 ° C. for 63 hours. Then, another stainless steel container was connected to the reactor, and the reaction product was transferred to this container under reduced pressure. This was washed with ice water, diluted potassium hydroxide aqueous solution and saturated saline solution in this order, dried over anhydrous magnesium sulfate, and then distilled to give 68.6 g of a colorless transparent liquid having a boiling point of 26 ° C.
(Yield 58%) was obtained.

From ¹ H-NMR and ¹⁹ F-NMR spectra, it was found to be 1-trifluoromethoxy-2,2-difluoroethane.

The ¹ H-NMR and ¹⁹ F-NMR spectral data are shown below. In addition, ¹ H-NMR and ¹⁹ F-NM
For the measurement of the R spectrum, deuterated chloroform was used as a solvent, and tetramethylsilane and trichlorofluoromethane were used as internal standard substances, respectively.

¹ H-NMR (CDCl ₃ ) δ 4.13
(2H, t, J _HF = 12.5 Hz, d, J _HH = 4.3
_{Hz, - CH 2 CHF 2)} , 5.97 (1H, t, J HF
= 54.6 Hz, t, J _HH = 4.3 Hz, -CH ₂ CH
F ₂ ).

¹⁹ F-NMR (CDCl ₃ ) δ-62.
_{1 (3F, s, CF 3} O -), - 126.7 (2F,
d, J _FH = 54.1 Hz, t, J _FH = 12.3 Hz,
-CH ₂ CHF _2).

[0027]

As the trifluoromethoxyfluoroethanes produced by the present invention, for example, 1-trifluoromethoxy-2,2,2-trifluoroethane and 1-trifluoromethoxy-2,2-difluoroethane have boiling points of respectively. Conventional CFC at 6.2 ° C and 26 ° C
It can be used for refrigerants, solvents, foaming agents, etc.
It is extremely useful as a substitute for C. Moreover, since it contains hydrogen atoms, it has high reactivity with hydroxyl radicals in the atmosphere and is easily decomposed in the troposphere, so it is a compound with a small greenhouse effect. Since it does not contain chlorine atoms, it is a compound that does not destroy the ozone layer and has little effect on the global environment.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000157119 Kanto Denka Kogyo Co., Ltd. 1-2-1, Marunouchi, Chiyoda-ku, Tokyo (71) Applicant 000002004 1-13-9 Shiba-Daimon, Minato-ku, Tokyo (71) Applicant 000000044 Asahi Glass Co., Ltd. 2-1-2 Marunouchi, Chiyoda-ku, Tokyo (71) Applicant 000174851 Mitsui DuPont Fluorochemical Co., Ltd. 1-5-18 Sarugakucho, Chiyoda-ku, Tokyo (71) Applicant 000003300 Tosoh Co., Ltd. 4560 Kaisei-cho, Shinnanyo-shi, Yamaguchi Prefecture (74) Attorney of the above 7 Patent Attorney Eiji Tomomatsu (1 outside) (72) Inventor Yoshihiko Goto 2-40-17 Hongo, Bunkyo-ku, Tokyo Hongo-Wakai Building, 6th floor, Institute for Global Environmental Technology, New Generation Refrigerant Project Room (72) Inventor Shiro Yamashita Hongo Wakai Building, 2-40-17 Hongo, Tokyo 6th floor, Hongo Wakai Building, New Generation Refrigerant Project, Institute for Global Environmental Technology (72) Inventor Haruaki Ito 2-40-17 Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6th floor, Research Institute for Global Environmental Industrial Technology, New Generation Refrigerant Project Room (72) Inventor Atsushi Suga 2-40-17 Hongo Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6th floor, Japan Institute for Global Environmental Technology Research Refrigerant Project Room (72) Inventor Yuji Mochizuki 2-40-17 Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6F New Generation Refrigerant Project Room, Institute for Global Environmental Technology (72) Inventor Noritaka Nagasaki Tokyo Metropolitan Government Hongo-Wakai Building, 6th floor, Hongo 2-chome, 2-chome, Bunkyo-ku, Japan (72) Inventor, Akira Sekiya, 1-1, Higashi, Tsukuba, Ibaraki, Japan Manabu Industrial Technology Research Institute in

Claims (2)

[Claims] 1. A fluorophosgene represented by the chemical formula: COF ₂ ... (I) and a general formula: R ¹ -OSO ₂ -R ² ... (II) (R ¹ has 2 carbon atoms. And a sulfonic acid ester compound represented by R ² represents an alkyl group or a fluorine-containing alkyl group) in an aprotic polar solvent or in the absence of a solvent, an alkali metal fluoride or an alkaline earth metal. Trifluoromethoxyfluoroethane represented by the general formula: CF ₃ O—R ¹ (III) (wherein R ¹ is the same as the above), characterized by reacting in the presence of a fluoride. Manufacturing method. 2. A sulfonic acid ester of the general formula (II), wherein R ¹ is CH _X F _3-X CH _2- (wherein x is an integer of 0 to 3). The method for producing trifluoromethoxyfluoroethanes according to claim 1.