JP2903109B2 - Method for producing mono- or tetrafluoroethyl trifluoromethyl ether - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing mono- or tetrafluoroethyl trifluoromethyl ether.

[0002]

2. Description of the Related Art Perfluoroethyl methyl ether (ie, CF ₃ OCF 2 CF ₂ CF ₃ ) is a refrigerant (see, for example, US Pat. No. 3,362,180;
94, 878) and suction anesthetics (Bagna
11, et al. , J. et al. Fluorine Che
m. , 1979, 13, 123;). As a conventional method for producing perfluoroethyl methyl ether, a method by electrolytic fluorination of ethylene glycols or 1,4-dioxane (Berenblit, et al.)
al. , 1974, 10, 2031; Zh. HPri
kl. Khim. , 1975, 48, 2206; or Zh. Prikl. Khim. , 1980, 53,
858), and a method of reacting dioxygen difluoride (O ₂ F ₂ ) with tetrafluoroethylene (Holzmann, et al. I.
norg. Chem. , 1962, 1, 972). However, this method has a problem that the yield of perfluoroethyl methyl ether is extremely low, about 1%. Further, in the above method, the yield of perfluoroethyl methyl ether is unknown because it is not described in the article, but in addition to the ether, seven types of by-products are generated, and the selectivity is extremely low. There are problems such as. That is, the conventional method for synthesizing perfluoroethyl methyl ether is not practical at all in terms of yield and selectivity. A method for producing perfluoroethyl methyl ether using fluorine gas has not been known until now. In the method for producing perfluoroethyl methyl ether, tetrafluoroethyl trifluoromethyl ether (CF ₃ ) which can be used as a raw material compound (or an intermediate raw material compound) is used.
The following methods are known as conventional methods for producing OCHFCF ₃ and CF ₃ OCF ₂ CHF ₂ ). (A) Electrolytic fluorination of β-methoxypropionic esters to obtain CF ₃ OCHFCF ₃ and CF ₃ OCF ₂ CHF
_Of obtaining a mixture of the _two (Berenblit, et a
l. , Zh. Org. Khim. , 1976, 12, 7
67), (b) a method of obtaining CF ₃ OCHFCF ₃ by reacting trifluoromethoxytrifluoroethylene with hydrogen fluoride in the presence of potassium fluoride (Gubanov,
et al. , Zh. Obschch. Khim. , 1
964, 34, 2802), (c) perfluoro- (β
Method for obtaining a thermal cracking process (170 ° C.) by CF ₃ OCF ₂ CHF ₂ of over methoxypropionate sodium salt) (Gubanov, etal., Zh.Obschc
h. Khim. , 1964, 34, 2802), (d)
By the electrolytic decarboxylation of perfluoro- (sodium salt of β-methoxypropionic acid), CF ₃ OCF ₂ CHF ₂
(Berenblit, et al., Nov.)
esti Elektrokhim. Org. Soed
in. Tezsiy Dokl. Vses. Loves
hch Elekutorokhim. , Org. Si
edin. 8th. 1973, 31), (e) A method of obtaining CF ₃ OCHFCF ₃ by a thermal decomposition reaction of perfluoro- (2-methoxypropyl peroxide) (Kom
endantov, et al. , Zh. Vses. K
him. O-va. , 1984, 29, 113). However, since these are all electrolytic reactions or thermal decomposition reactions, the yield is low (however, the yield is not described in the above-mentioned article (c)), and there are many by-products and the selectivity is remarkable. There are drawbacks such as low. (F) CF ₃ OF
On the reaction of olefins with olefins (Johri, eta)
l. , J. et al. Org. Chem. , 1983, 48, 24
Although there is 2), the reaction between CF ₃ OF and trifluoroethylene is not shown. CF ₃ OCH ₂ C, one of the starting compounds of the perfluoroethyl methyl ether of the present invention
The following is a conventional method for producing H ₂ F.
(G) CF ₃ OCH ₂ CH ₂ OC in the presence of hydrogen fluoride
By the reaction of OF and sulfur tetrafluoride, CF ₃ OCH ₂ CH
How to obtain _{2 F (Aldrich, et al.} , J.
Org. Chem. , 1964, 29, 11), (h).
A method of obtaining CF ₃ OCH ₂ CH ₂ CH ₂ F by reacting ethylene with CF ₃ OF under irradiation of ultraviolet rays (Alliso
n, et al. , J. et al. Am. Chem. Soc. , 1
959, 81, 1089). The above method (g) is not practical as an industrial production method because the raw material compound is complicated and hardly available, and the yield of CF ₃ OCH ₂ CH ₂ F is not so high as about 18%. There is a problem.
On the other hand, the above method (h) uses ultraviolet light and is disadvantageous as an industrial production method. Although the yield is not described in the article of (h), it is generally known that radiation reactions such as ultraviolet irradiation generally have low yield and selectivity. In any case, conventionally, ethylene and CF ₃ OF in a state where ultraviolet irradiation is not used or in the absence of a catalyst are used.
The reaction was unknown. Further, the reaction of CF ₃ OF with ethylene is not known in the above report (f).
Since CF ₃ OF normally causes a runaway reaction with hydrocarbon compounds, it was not clear whether the reaction with ethylene consisting of carbon and hydrogen proceeds.

[0003]

The present invention has been made in view of the above circumstances. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to obtain a mono- or tetra-form which has been conventionally obtained only in a low yield and a low selectivity by using a material which is relatively easily available or relatively easy to synthesize. Fluoroethyl trifluoromethyl ether (CF ₃ OCH ₂ CH ₂ F, C
It is an object of the present invention to provide a method for producing F ₃ OCHFCF ₃ and CF ₃ OCF ₂ CHF ₂ ) with high yield and high selectivity.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result of intensive studies on practically advantageous production methods. Fluoroethyltrifluoromethyl ether or a mixture of CF ₃ OCHFCF ₃ and CF ₃ OCF ₂ CHF ₂ can be mixed with ethylene or trifluoroethylene and trifluoromethyl hypofluorite (CF ₃ OF) without using ultraviolet rays or a catalyst. It has been found that the above reaction allows easy production with high yield and high selectivity, and the present invention has been completed.

That is, ethylene or trifluoroethylene or a mixture thereof is mixed with trifluoromethyl hypofluorite (CF ₃ O) without using ultraviolet rays or a catalyst.
The present invention provides a method for producing mono- or tetrafluoroethyltrifluoromethyl ether, characterized by reacting F).

[0006]

DETAILED DESCRIPTION OF THE INVENTION In the method of the present invention, ethylene or trifluoroethylene is reacted with trifluoromethyl hypofluorite (CF ₃ OF) to give 2-fluoroethyl trifluoromethyl ether or 1,2 A mixture of 2,2-tetrafluoroethyltrifluoromethyl ether is synthesized. The mixture of the above mono- and tetrafluoroethyl trifluoromethyl ethers can be obtained by reacting a mixture of ethylene and trifluoroethylene at an arbitrary ratio with trifluoromethyl hypofluorite.

The reaction raw materials used in this reaction may be appropriately diluted with an inert gas or an inert solvent, if necessary, and may contain other components within a range not to impair the object of the present invention. May be. For example, the ethylene and / or trifluoroethylene can be used as a mixture with other fluoroethylenes. The reaction temperature is usually -150 to 200C, preferably -100 to 20C.
It is appropriate to set within the range. If the reaction temperature is too low, a sufficient reaction rate may not be obtained. On the other hand, if the reaction temperature is too high, the decomposition reaction may increase and the selectivity may decrease. It is desirable that the reaction temperature is appropriately adjusted according to the degree of progress of the reaction. The reaction can be performed in various temperature modes such as a constant temperature.
For example, the temperature gradually increases from low temperature with the progress of the reaction,
Thereafter, a method of maintaining the temperature at an appropriate temperature can also be suitably adopted. In the method of the present invention, the reaction is carried out without irradiation with ultraviolet light and without using a catalyst. In general,
In a so-called non-catalytic thermal reaction, for example, it is known that the vessel walls and intermediates of the reaction vessel exert a catalytic action in a broad sense. Should not be interpreted as meaning.

As described above, 2-fluoroethyl trifluoromethyl ether, 1,2,2,2-tetrafluoroethyl trifluoromethyl ether,
1,2,2-tetrafluoroethyl trifluoromethyl ether or a mixture thereof in high yield (for example,
(High yield of 75% or more) and high selectivity. The obtained mono- or tetra-trifluoroethyl trifluoromethyl ether or a mixture thereof is purified to a desired purity as it is or according to an ordinary method, and is used as a raw material or various materials in a method for producing perfluoroethyl methyl ether. It can be suitably used in the field of use. As described above, by combining the method of the present invention with the production of perfluoroethyl methyl ether, olefins containing inexpensive ethylene or trifluoroethylene or a mixture thereof or at least one of them as an industrial raw material can be obtained. From such mixed raw materials, industrially useful perfluoroethyl methyl ether can be produced more advantageously.

In producing perfluoroethyl methyl ether containing the target product obtained in the present invention as a raw material, a general formula CF ₃ OCH _m F _n CH _j F _k (I) (where m and n are , 0, 1 or 2; j and k
Represents 0, 1, 2 or 3, respectively, but m +
n = 2, j + k = 3, and m + j is not zero. ) Is used. Examples of the compound represented by the general formula (I) include ethyl trifluoromethyl ether (CF ₃ OCH ₂ CH ₃ ), 2-fluoroethyl trifluoromethyl ether (CF ₃ OCH ₂ CH ₂ F),
1-fluoroethyl trifluoromethyl ether (CF
₃ OCHFCH ₃ ), 1,1 difluoroethyl trifluoromethyl ether (CF ₃ OCF ₂ CH ₃ ), 1,2 difluoroethyl trifluoromethyl ether (CF ₃
OCHFCH ₂ F), 2,2 difluoroethyl trifluoromethyl ether (CF ₃ OCH ₂ CHF ₂ ), 1,
1,2-trifluoroethyl trifluoromethyl ether (CF ₃ OCF ₂ CH ₂ F), 1,2,2-trifluoroethyl trifluoromethyl ether (CF ₃ OCHF
CHF ₂ ), 2,2,2-trifluoroethyl trifluoromethyl ether (CF ₃ OCH ₂ CF ₃ ), 1,1,
2,2-tetrafluoroethyl trifluoromethyl ether (CF ₃ OCF ₂ CHF ₂ ) and 1,2,2,2-tetrafluoroethyl trifluoromethyl ether (CF
₃ OCHFCF ₃ ). Among them, CF ₃ OCH ₂ CH ₃ , CF ₃ OCH ₂ CH ₂ F, CF ₃
OCH ₂ CF ₃ , CF ₃ OCF ₂ CHF ₂ , CF ₃ OCHFC
Such as F ₃ is preferable. These may be used singly or two or more of them may be used in combination as a mixture or the like, and may be subjected to a reaction as a mixture with other components as long as the object of the present invention is not impaired. Is also good. Also, CF ₃
A mixture of OCF ₂ CHF ₂ and CF ₃ OCHFCF ₃ and C
F ₃ OCH ₂ CH ₂ F is particularly preferred because it can be efficiently produced from inexpensive ethylene or trifluoroethylene by the method of the present invention. That is, if desired, a method for producing perfluoromethyl ethyl ether and the method of the present invention may be combined to produce perfluoroethyl methyl ether by a stepwise reaction or a one-step reaction from trifluoroethylene or ethylene and trifluoromethyl hypofluorite. It is possible to produce ethers.

In this production method, the fluorine gas used for the reaction with the compound represented by the general formula may be undiluted or diluted with an inert gas. These can also be used in combination. The inert gas is not particularly limited as long as it does not hinder the purpose of the production method. Usually, argon, helium, nitrogen or the like or a mixed gas thereof is suitably used. Although the dilution ratio of the fluorine gas is not particularly limited, usually, when using a fluorine gas, one containing 5 to 95% by volume of the fluorine gas is preferably used. The fluorine gas or the fluorine gas diluted with the inert gas may be used as a mixture with another component as needed, as long as the object of the present invention is not impaired. In this production method, perfluoroethyl methyl ether is produced from the reaction between the compound represented by the above general formula and fluorine gas. The proportion of fluorine gas used in this reaction is usually 1 equivalent or more, preferably 1 to 1.5 equivalents, based on the hydrogen atoms of the substrate (the whole of the compound represented by the general formula (I) used). It is preferable to set within the range. If this ratio is out of the above range, one of the reaction raw materials becomes stoichiometrically excessively large, and the amount of unreacted raw materials increases, which may lower the efficiency in the process. In particular, if the reaction is carried out in less than 1 equivalent, a large amount of unreacted substrate or partially fluorinated ethyl trifluoromethyl ether remains in the reaction mixture, which may lower the reaction efficiency or complicate the separation and purification of the target product. . The method for mixing the fluorine gas and the substrate is not particularly limited, and a predetermined total amount may be mixed at the same time or may be mixed in a stepwise manner as appropriate. In particular, it is represented by the general formula (I). For a substrate that reacts violently with fluorine gas during the fluorination of a compound, a method is known in which the amount of fluorine gas used is supplied to the reaction system in several appropriate portions in consideration of the intensity and progress of the reaction. The side reaction is further controlled by this method, and the yield of the target perfluoroethyl methyl ether can be further improved.

The reaction temperature is usually from -150 to 200 ° C,
Preferably, the temperature is set in the range of -100 to 20 ° C. If the reaction temperature is too high, a sufficient reaction temperature may not be obtained. On the other hand, if the reaction temperature is too high, side reactions such as a decomposition reaction may increase and selectivity may decrease. It is desirable that the reaction temperature is appropriately adjusted according to the intensity of the reaction, the degree of progress of the reaction, and the like. The reaction can be carried out in various temperature modes such as a constant temperature. For example, a method in which the temperature is gradually raised from a low temperature with the progress of the reaction and then maintained at an appropriate temperature can be suitably employed. In the above reaction, for example, the following formula: CF ₃ OCH ₂ CH ₂ F + 4F ₂ = CF ₃ OCF ₂ C
Hydrogen fluoride is generated as in F ₃ + 4HF. The reaction may be performed in the presence or absence of a hydrogen fluoride absorbent. By using the hydrogen fluoride absorbent, hydrogen fluoride generated (or contained in the raw material) can be absorbed, and the reaction and the separation of the product can be performed more efficiently. There are various types of the hydrogen fluoride absorbent, and specific examples include sodium fluoride and potassium fluoride. The reaction between the compound represented by the above general formula and fluorine gas can be usually suitably performed without a catalyst, but an appropriate catalyst may be used as desired. As described above, perfluoroethyl methyl ether can be efficiently synthesized with a high yield (for example, a high yield of 85% or more) and a high selectivity. The obtained perfluoroethyl methyl ether is separated and purified from the reaction mixture according to a conventional method, and can be used as a product having a desired purity. In addition, other components such as unreacted raw materials and partially fluorinated fluoroethyl trifluoromethyl ethers can be reused as the components for the above reaction, if necessary. The perfluoroethyl methyl ether produced as described above can be used as a chemical for various uses including a refrigerant and a suction anesthetic.

[0012]

According to the method of the present invention, mono- or tetrafluoroethyl triethyl useful as a reaction raw material for perfluoroethyl methyl ether can be produced from inexpensive ethylene or trifluoroethylene as an industrial raw material without using ultraviolet rays or a catalyst. Fluoromethyl ether can be efficiently produced with high yield and high selectivity. Further, perfluoroethyl methyl ether can be advantageously produced from industrially inexpensive ethylene or trifluoroethylene.

[0013]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 5 mmol of ethylene and 5 mmol of CF ₃ OF were charged into a reactor cooled to −194 ° C. This reaction vessel is -1
It was cooled to 53 ° C. and gradually heated to room temperature over 20 hours. The reaction mixture was separated and purified by changing the trap temperature to obtain CF ₃ OCH ₂ CH ₂ F (trap temperature −96
C) was obtained in an amount of 4.15 mmol (89% yield). In addition, the infrared absorption spectrum of the obtained product was obtained from a known document (J. Am. Chem. Soc., 1959, 81,
1089) was consistent with the infrared absorption spectrum of CF ₃ OCH ₂ CH ₂ F.

[0014] When instead the Example 2 ingredients ethylene, in addition to a trifluoroethylene was carried out in the same manner as in Example 1, CF ₃
A mixture of OCHFCF ₃ and CF ₃ OCF ₂ CHF ₂ (mixing ratio 67:33, mixing ratio determined by ¹⁹ F-nuclear magnetic resonance spectrum) was obtained in a yield of 75%. For the following reasons, the products were CF ₃ OCHFCF ₃ and CF ₃ OCF ₂
CHF ₂ was determined. The infrared absorption spectrum of the obtained product shows absorption of CH, CO, CF bond (300
0, 1430, 1300, 121250 to 1190, 1
170, 1130, and 1110 cm ^{- 1} ), and the measured molecular weights were almost the same (analytical value: 185.4, calculated value: 186.0). The ¹⁹ F nuclear magnetic resonance spectrum is
As shown below, φ (CFCI ₃ standard): CF ₃ OCHF at 55.5, 60.5, 83.5 ppm
CF ₃ and CF ₃ chemical shifts trifluoromethyl group OCF ₂ CHF ₃ is observed, other chemical shift was also supported the structure of the CF ₃ 0CHFCF ₃ and CF ₃ OCF ₂ CHF _3. ¹⁹ -nuclear magnetic resonance spectrum, φ (CFCI
₃ ): 55.5 (m, 3F, CF ₃ OCF ₂ CHF ₂ ), 60.5 (s, 3F, CF ₃ OCHFCF ₃ ), 83.5 (s, 3F, CF ₃ OCHFCF ₃ ), 90.0 _{(m, 2F, CF 3 OCF} 2 CHF 2), 136.0 (dd, 2F, J H-Fgem. = 65H Z J H-Fvic. = 4H Z, CF 3 OCF 2 CHF 2), 145.0 ( _{dd, 1F, J H-Fgem} . = 64H Z, J H-Fvic. = 4H Z, CF 3 OCHFCF 3)

Reference Example 1 A poly (chlorotrifluoroethylene) reaction vessel containing sodium fluoride (10 mmol) was cooled to -194 ° C., and 1 mmol of CF ₃ OCH ₂ CF ₃ and 2.2 mmol of fluorine gas were placed in the vessel. , And the reaction vessel
And gradually heated to room temperature over 20 hours.
After exhausting an excessive amount of fluorine gas, the obtained reaction mixture was separated and purified by changing the trap temperature to obtain 0.94 mmol of perfluoroethyl methyl ether (yield
R> 94%, trap temperature-155 ° C.). The product was identified as perfluoroethyl methyl ether by the following analysis. In the infrared absorption spectrum of the obtained product, no absorption in the CH region was observed.
-F bond absorption (1145, 1310 to 1200, 12
20, 1170, and 1110 cm ^-1 ), and the measured molecular weight was 202.9, which almost coincided with the molecular weight of perfluoroethyl methyl ether (204.0). The results are shown in Table 1.

Reference Example 2 A reaction was carried out in the same manner as in Reference Example 1, except that the amount of sodium fluoride used was changed to 20 mmol. The results are shown in Table-1.

Reference Example 3 A reaction was carried out in the same manner as in Reference Example 1, except that sodium fluoride was not used. The results are shown in Table-1.

Reference Example 4 CF ₃ OCHFCF was used instead of CF ₃ OCH ₂ CF ₃ as a substrate.
₃ and a mixture of CF ₃ OCF ₂ CHF ₂ (mixing ratio 67:33)
The reaction was carried out in the same manner as in Reference Example 1 except that The results are shown in Table-1.

Reference Example 5 A stainless steel container containing sodium fluoride (10 mmol) was cooled to -194 ° C., and CF ₃ OCH ₂ was added to the container.
CH ₂ F 1 mmol, fluorine gas 0.85 mmol
l was charged. The reaction vessel was cooled to −111 ° C. and heated to room temperature over 20 hours. Thereafter, the reaction vessel was again cooled to −194 ° C., and 0.86 mm of fluorine gas was introduced into the vessel.
ol was added and the temperature was raised to room temperature under the same reaction conditions as above. By repeating the above operation, the fluorine gas was changed to 5.6 in total.
9 mmol was charged. After exhausting an excessive amount of fluorine gas, the obtained reaction mixture was changed in trap temperature,
When separated and purified, CF ₃ OCF ₂ CF ₃ is 0.86 mmol
1 (85% yield, trap temperature-153 ° C.).
The results are shown in Table 1.

[0020] Instead of Reference Example 6 substrates _{CF 3 OCH 2 CH 2 F CF} 3 OCH 2 CH
A mixture of F ₂ and CF ₃ OCHFCH ₂ F (mixing ratio 90: 1)
The reaction was carried out in the same manner as in Reference Example 5, except that 0) was used.
The results are shown in Table-1.

Reference Example 7 1 mmol of CF ₃ OCH ₂ CF ₃ was charged into a reaction vessel cooled to -194 ° C. without using sodium fluoride. The reaction vessel was cooled to -70 ° C and 5 mmol of diluted 60
% Fluorine gas (F23 mmol / N22 mmol) and gradually warmed to room temperature over 20 hours.
Left at room temperature for days. After exhausting excess fluorine gas,
The reaction mixture was separated and purified by changing the trap temperature to obtain CF ₃ OCF ₂ CF ₃ (trap temperature-153 ° C.) with a yield of 58%. The results are shown in Table 1.

[0022]

[Table 1]

Claims (1)

(57) [Claims] 1. Mono- or tetrafluoroethyl trifluoromethyl characterized by reacting ethylene or trifluoroethylene or a mixture thereof with trifluoromethyl hypofluorite (CF ₃ OF) without using ultraviolet rays or a catalyst. Method for producing ether.