JP2002308828A - Method for producing fluorine-containing compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To synthesize CF3 OCF2 CF2 COORf (wherein a substituent Rf is a 1-5C group) becoming a starting substance in the synthesis of a copolymerizable monomer being a production raw material of a fluororubber or the like in an industrially practical yield by fluorination reaction. SOLUTION: A fluorine-containing compound CH3 OCF2 CF2 OOR (wherein, R is a 1-5C alkyl group) is perfectly fluorinated by fluorine gas in chlorofluorocarbon to synthesize CF3 OCF2 CF2 COORf (wherein a substituent Rf is a 1-5C group). In order to obtain this compound in a pure form in a high yield by synthesis, high purity cooled fluorine gas is introduced into a reactor in the presence of a hydrogen fluoride capturing agent while stepwise increasing the concentration of the hydrogen gas and fluorination is performed while raising reaction temperature stepwise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a fluorine-containing compound. More specifically, the present invention relates to CF ₃ OCF ₂ CF ₂ CF ₂ O which is a copolymer monomer for producing fluororubber and the like.
The present invention relates to a method for producing CF ₃ OCF ₂ CF ₂ COORf (the fluorine substituent Rf represents a group having 1 to 5 carbon atoms) as a starting material for the synthesis of CF = CF ₂ .

[0002]

TECHNICAL BACKGROUND OF THE INVENTION CF ₃ OCF ₂ CF ₂ COORf (fluorine substituent Rf
Represents a group having 1 to 5 carbon atoms) is a copolymer monomers to be subjected to the production of such superior fluororubber cold resistance CF ₃ OCF ₂ C
F ₂ CF ₂ OCF = Starting material for synthesizing CF ₂ . A hydrogen-containing compound, CH ₃ OCH ₂ CH ₂ COOR, corresponding to this compound is commercially available. The CF ₃ OCF ₂ C
To produce F ₂ COORf, all its hydrogen must be replaced by fluorine.

[0003] The perfluorination method capable of producing a derivative in which all hydrogen atoms are replaced by fluorine atoms is a useful technique for providing various fluoro compounds in the field of fluorine-based materials, and has been developed in the past. Have been. The fluorination reaction in this complete fluorination technique is a common concept meaning that a hydrocarbon compound or the like is fluorinated with fluorine gas without destroying the skeleton structure. In reality, when a compound having a certain structure is completely fluorinated, unexpected reactions such as decomposition and polymerization may occur. In that case, it is difficult to synthesize a completely fluorinated product in which all hydrogen atoms have been replaced by fluorine atoms in a yield that can be substantially isolated. For example, incomplete fluorinated compounds having an ether bond (all hydrogen atoms are not replaced by fluorine atoms) are easily decomposed, and it is not easy to increase the yield of fully fluorinated compounds while keeping the skeleton structure of the starting material. .

[0004] As a complete fluorination technology, Japanese Patent No.
Japanese Patent Application Laid-Open Publication No. H11-139,086 discloses a method of completely fluorinating a hydrogen-containing compound with a fluorine gas in a chlorofluorocarbon medium or the like. However, this publication does not disclose a method for completely fluorinating a carboxylic acid ester containing an ether bond. Further, Japanese Patent No. 3042703 discloses a method of completely fluorinating a polyether hydrocarbon compound containing both an ether bond and an ester bond with a fluorine gas in a chlorofluorocarbon medium or the like. Even in this case, there is no description of the perfluorination of a compound having a methyl group close to an ether bond and activated by an ester bond.

In general, in a polyether hydrocarbon compound containing an ester bond in addition to an ether bond, fluorination is promoted in a chain by the ester bond, and thus, it is not easy to remove the heat of reaction. In addition, since incomplete fluorinated compounds having an ether bond are easily decomposed, it is difficult for a perfluoro-substituted product (perfluorinated compound) of the above compound to keep the original form of the starting material and increase the yield. . The reason is as follows. The portion of the methylene group adjacent to the ether bond is susceptible to fluorination.
In addition, the methyl group is less likely to be fluorinated by fluorine gas than the methylene group, -CH _2-, and therefore, the unstable CH ₃ -O-CF ₂
-It is easy to form bonds, and as a result of the decomposition of such incomplete fluorinated compounds, the yield is reduced.

For example, when complete fluorination is performed with fluorine gas using methyl 3-methoxypropionate CH ₃ OCH ₂ CH ₂ COOCH ₃ as a starting material, a side reaction represented by the following formula occurs, and finally It is highly likely that the yield of the fluoro-substituted product (perfluorinated product) will be extremely low.

[0007]

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In the case of CH ₃ CH ₂ O—CH ₂ CH ₂ COO—,

[0009]

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It is presumed to give a relatively stable intermediate / partial fluoride as described above. CH ₃ OCH ₂ CH ₂ COOCH ₃
By electrolytic fluorination CF ₃ OCF ₂ CF ₂ COOCF ₃ , CF ₃ OCF ₂ CF ₂ COF
The synthesis example of J. Appl. Chem. USSR (Engl. Transl), 48,
742-744 (1975), but the yield is at most 1
This is 4%, which is not a very industrially practical method.

From the above, industrially available CH ₃ OCH
₂ Complete fluorination of CH ₂ COOR with fluorine gas is due to the existence of a presumed preferential position for fluorination, as well as CH ₃ -O-
Until now, the electrophilic attack of CF ₂ CH ₂ can cause an acid decomposition reaction of a weak bond, so that it has not been a practical method so far. If a method capable of producing a fully fluorinated product of such a substance in a high yield is realized, the copolymer monomer CF ₃ OCF ₂ CF ₂ CF ₂ OCF = C
Significant reduction in the manufacturing cost of the F ₂ becomes possible, and is awaited shall further also lead to the development of novel fluorine-containing compound.

[0012] In view of such a situation, the present inventors have taken the present invention into consideration.
After a keen research, CH_ThreeOCF _TwoCH_TwoCOOCH_Three-CF_TwoCH
_Two-Making the F of the moiety more non-ionic, specifically -CF
_TwoCF_Two-Introducing groups into the starting materials can be particularly problematic
Came up with the idea of preventing the chemical fluorination reaction.
Thus, the present invention has been completed.

[0013]

An object of the present invention is to provide a complete fluorination reaction using fluorine gas with an industrially practical yield.
CF ₃ OCF ₂ CF ₂ COORf (fluorine substituents Rf represents a group having 1 to 5 carbon atoms), is to synthesize CF ₃ OCF ₂ CF ₂ COF.

[0014]

SUMMARY OF THE INVENTION The process for producing a fluorine-containing compound according to the present invention comprises the step of completely fluorinating CH ₃ OCF ₂ CF ₂ COOR (R represents an alkyl group having 1 to 5 carbon atoms) in a chlorofluorocarbon with fluorine gas. This is characterized in that CF ₃ OCF ₂ CF ₂ COORf (the fluorine substituent Rf represents a group having 1 to 5 carbon atoms) is synthesized.

It is particularly preferable when the above-mentioned group R is CH ₃ and the above-mentioned fluorine substituent Rf is CF ₃ . The method for producing a fluorine-containing compound according to the present invention is characterized in that the method is performed using a high-purity fluorine gas substantially free of oxygen and oxygen compounds as the fluorine gas.

It is preferable that the fluorine gas is cooled to a temperature in the range of -50 ° C. to 0 ° C., and is introduced into the reaction system for complete fluorination to carry out the reaction. Further, it is desirable that the fluorine gas be diluted to 5 to 50 vol% with an inert gas and introduced into the reaction system for the complete fluorination. Further, it is characterized in that the fluorine gas is introduced into the complete fluorination reaction system while gradually increasing its concentration from 5 vol% to 50 vol%.

The method for producing a fluorine-containing compound according to the present invention is characterized in that the complete fluorination is carried out while gradually raising the temperature of the reaction system from -50 ° C to 20 ° C. Further, the fluorination is performed in the presence of a hydrogen fluoride scavenger. The hydrogen fluoride scavenger is preferably an alkali metal fluoride.

In the method for producing a fluorine-containing compound according to the present invention, the completely fluorinated compound may be made of copper,
Consisting of a container and a joint made of one or more metals selected from the group consisting of silver and nickel or their alloys or fluororesin, and a seal part made of fluororesin, perfluoroelastomer, fluorine grease or fluorine oil It is characterized in that it is carried out in a reactor formed.

According to the production method of the present invention, a carboxylic acid ester containing an ether bond which is liable to cause unstable incomplete fluoride during fluorination can be completely fluorinated in a practical yield. Become.

[0020]

DETAILED DESCRIPTION OF THE INVENTION The process for producing a fluorine-containing compound according to the present invention comprises the steps of converting CH ₃ OCF ₂ CF ₂ COOR (R represents an alkyl group having 1 to 5 carbon atoms) into This is a method of synthesizing CF ₃ OCF ₂ CF ₂ COORf (the fluorine substituent Rf represents a group having 1 to 5 carbon atoms).

Hereinafter, the present invention will be described in detail in the order of starting materials, solvent, complete fluorination reaction, reaction temperature, hydrogen fluoride scavenger, and reactor. In addition, in this specification, "perfluorination completely" means replacing all the hydrogen atoms of a hydrogen containing compound with a fluorine atom. On the other hand, fluorination in which substitution by a fluorine atom is limited to a part of hydrogen atoms is called "partial fluorination".

The "perfluorinated product" refers to a compound in which all hydrogen atoms have been replaced by fluorine atoms, and is also referred to as a "perfluoro-substituted product". Further, the “incomplete fluorinated compound” refers to a compound in which all hydrogen atoms are not replaced with fluorine atoms, and is also referred to as “partially fluorinated compound”.
When synthesizing CF ₃ OCF ₂ CF ₂ COORf (the fluorine substituent Rf represents a group having 1 to 5 carbon atoms), for example, industrially available CH ₃ OCH ₂
When complete fluorination is carried out using CH ₂ COOCH ₃ as a starting material, side reactions due to the generation of weak bonds to electrophilic attack such as CH ₃ -O-CF ₂ CH ₂ due to the progress of fluorination may occur. The resulting, ultimately perfluorinated, or perfluorosubstituted, is likely to result in a significant loss in yield.

As a solution for preventing the decomposing partial fluorination reaction which causes such a decrease in yield, CH ₃ O
It is conceivable to make F in the -CF ₂ CH ₂ -moiety of CF ₂ CH ₂ COOCH ₃ more non-ionic. Specifically, in the production method according to the present invention, a compound having a —CF ₂ CF ₂ — group is used as a starting material, and a complete fluorination substitution reaction with fluorine gas is performed under mild conditions. For example, methyl 3-methoxy-2,2,3,
In the case of 3-tetrafluoropropionate (MMTFP), perfluoro (methyl 3-methoxypropionate) (PFMMP) can be obtained in almost pure form and in high yield.

[0024]

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On the other hand, for the purpose of obtaining specific or special perfluorinated compounds, various additional means have been proposed to overcome various problems in the direct fluorination reaction. They (or a part thereof) can be appropriately adopted as long as the object of the present invention is not impaired. For example, dilution of fluorine gas with inert gas, low temperature adoption, efficient removal of heat of reaction, low concentration, partial fluoridation, use of HF scavenger, etc. U.S. Pat.No. 4,523,039,
Adcock et al., J. Am. Chem. Soc., 103 , 6937 (1981). For the significance and details of these proposals, besides the above documents, reference should be made to Japanese Patent No. 2945693, Japanese Patent No. 3042703, and the like. Production raw materials・ Alkyl 3-methoxy-2,2,3,3-tetrafluoropropionate (CH ₃ OCF ₂ CF ₂ COOR) R in the formula CH ₃ OCF ₂ CF ₂ COOR is an alkyl group having 1 to 5 carbon atoms Represents For example, methyl, ethyl, propyl, butyl, pentyl groups are included, and these groups may be linear or branched. For example, CH ₃ OCF ₂ where the group R is a methyl group
CF ₂ COOCH ₃ is composed of industrial raw materials CF ₂ = CF ₂ and (CH ₃ O) ₂ C = O
Is a compound synthesized in high yield by
2988537). Starting from CF ₂ = CF ₂ and (CH ₃ O) ₂ C = O, which can be mass-produced industrially, is much more cost-effective than using expensive fluorine gas. In fact, the main cost of the product is directly linked to the amount of fluorine gas used in the fluorination reaction. The method of manufacturing a-fluorine gas (F ₂₎ present invention, fluorine gas is preferably used a high-purity fluorine gas containing no oxygen and oxygen compounds substantially. The reason is that oxygen mixed in fluorine gas generates an oxidizing agent such as F ₂ O, and this oxidizing agent is CH ₃
This is because it induces an oxidative decomposition reaction of OCF ₂ CF ₂ COOR.
In order to prevent this undesired oxidative decomposition reaction, it is necessary to increase the purity of the fluorine gas (F ₂ ), and it is desirable to use a fluorine gas that is highly purified to the extent that no fluorocarbonyl compound is present.

The impurities in F ₂ can be controlled by monitoring the —COF compound generated by the reaction between the F ₂ and carbon of the electrode by IR. Fluorine gas is 5 to 50 vol% by inert gas for fluorination, preferably 10 to 25 v
It is desirable to use one diluted to a concentration range of ol%. This is particularly important when using a solvent for fluorine substitution such as 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). This is because it is required to keep the fluorine concentration lower so as not to generate a combustible mixture in the solvent and the fluorine. In addition, the use of fluorine gas diluted with an inert gas may be advantageous from the standpoint of better controlling the fluorination reaction and facilitating removal of by-product hydrogen fluoride from the reactor.

As the inert gas therefor, for example, nitrogen, helium, argon, CF ₄ or SF ₆ are suitable. Pure fluorine gas can also be used, but in view of the safety and the high cost of fluorine gas itself, as described above, no particular advantage is found. Reaction Medium In the process of the present invention, a suitable liquid for use as an inert reaction medium serves as a solvent or dispersant for the starting materials and, at the reaction temperature according to the process of the present invention, provides And inert media are preferred. Examples of the medium for this purpose include liquids completely substituted with halogens such as chlorofluorocarbon, perfluoroalkane, perfluoroether, perfluorotrialkylamine, and perfluoroalkanesulfonyl fluoride. Among them, chlorofluorocarbon is particularly preferred because it has an excellent action of dissolving or dispersing the raw material and is easily separated from the reaction product.

The chlorofluorocarbon solvent is preferably a saturated chlorofluorocarbon solvent having 2 to 8 carbon atoms. The solvent may be cyclic, linear or branched, may contain an ether bond, and contains no hydrogen or chlorine. Is also good. For example, tetrafluoroethane, dichloropentafluoropropane, 1,
2-dichlorotetrafluoroethane, 1,2-dichlorohexafluoropropane, 1,1,2-trichlorotrifluoroethane, 1,2-dichlorotrifluoroethyl trifluoromethyl ether, 1,2-dichlorotrifluorofluoropentafluoro Ethyl ether, n- or iso-heptafluoropropyl-
1,2-dichlorotrifluoroethyl ether, tetrafluoroethylheptafluoropropyl ether, pentafluoroethylheptafluoropropyl ether, perfluorocyclobutene, perfluoro (methylcyclopropene), chlorotrifluoroethylene oligomer oil, perfluoropolyether Oil or the like is used. However, it is not limited only to these. These media may be used alone or in combination of two or more. Among them, in the present invention, 1,1,2-trichloro-1,2,2-trifluoroethane, which is a solvent useful for most reactions, is particularly suitable. Complete fluorination reaction The complete fluorination method of the present invention is to be carried out by a "batch type" method in a reactor equipped with a cooling device (cooling jacket, internal cooling coil), a gas supply line, a stirring blade, and a reflux condenser. Can be. Alternatively, a “semi-continuous” method can be implemented by designing a reactor and peripheral devices for the method. In each case, the raw material CH ₃ OCF
₂ CF ₂ COOR may be introduced simultaneously with the fluorine gas during the reaction so as to fluorinate the hydrocarbon compound. However, since the reactivity to fluorine gas is more preferably lower than that of the hydrocarbon compound, CH ₃ OCF ₂ CF ₂ COOR, which is a raw material, is initially charged together with a solvent, and a method of introducing fluorine gas is used to obtain a high yield. The product is obtained. At that time, CH ₃ OCF
The concentration of ₂ CF ₂ COOR can be arbitrarily selected. From the viewpoint of yield and batch efficiency, CH ₃ OCF ₂ CF ₂ CO
The concentration of OR is preferably in the range of about 10% to 50% by weight, more preferably about 10% to 20% by weight, based on the total amount of starting materials.

In the production method of the present invention, in order to obtain a perfluoro-substituted product in a substantially pure form and in a high yield, a high-purity cooled fluorine gas is gradually increased in the presence of a hydrogen fluoride scavenger. It was established as a method of performing fluorination while introducing the reactor into the reactor while raising the temperature and gradually increasing the reaction temperature. Fluorine gas (F ₂ ) is added to the reactor in a stoichiometric excess necessary to replace all of the hydrogen atoms of the hydrogen-containing compound, for example, in excess of about 15 mol% to 40 mol% or more, to the reactor. It is preferable to introduce the foam by continuously whipping it through a capillary or the like. The fluorine gas concentration at that time starts from 5 vol% to 15 vol% at the beginning of the reaction, and is increased to 15 vol% to 30 vol% with the progress of fluorination, and then complete fluorination is performed at 30 vol% It is desirable to carry out at ~ 50 vol%. Introducing such a stepwise increase in the concentration of fluorine gas, together with diluting the fluorine gas with an inert gas as described above, allows the fluorination substitution reaction to proceed under as mild a condition as possible. This is significant for the purpose of suppressing the occurrence of side reactions.

The fluorination reaction by fluorine gas is a heterogeneous gas-liquid reaction, and is sometimes a solid-gas-liquid phase reaction in the presence of NaF or KF. From this point of view, it is more advantageous to make the bubbles small and sufficiently dispersed by vigorous stirring, and to make them small bubbles with a microcapillary or the like for the reaction. The liquid temperature is usually defined as the reaction temperature, but the actual reaction field was found to be in a fluorine gas bubble, and the temperature was found to be much higher than in the liquid phase. For that purpose, it is effective to sufficiently cool the fluorine gas to be introduced in advance and react it from the viewpoint of suppressing undesired decomposition of CH ₃ OCF ₂ CF ₂ COOR which is a reaction raw material. For this reason, it is desirable that the fluorination reaction is carried out by cooling to preferably -50 ° C to 0 ° C, more preferably -30 ° C to -10 ° C before introducing the fluorine gas, and then introducing the gas into the reactor.

The above reaction can be conveniently carried out under atmospheric pressure. F ₂ such as O ₂ and H ₂ O in fluorine gas
React with oxy fluorite, if there is a material such as to produce a -OF, F ₂ not only performs a fluorinated oxyflu
Orination is performed, which is thought to involve an unexpected introduction of a carbonyl group and a decomposition reaction as shown in the following formula.

[0032]

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From the same viewpoint, the reaction system is replaced with an inert gas.
It has been found that dehydration and water prohibition are the key to the reaction yield. The removal of O ₂ and F ₂ O in the F ₂ gas also contributes to the improvement of the yield for the same reason. The replacement of the reaction system with an inert gas is carried out with the aim of avoiding oxygen contamination in the fluorine gas used.Before the start of the reaction, the reaction system including the reactor is generally purged with an inert gas, for example, nitrogen gas. It may be done by flushing for about a minute and expelling the air. The dehydration and the prohibition of water should be performed with respect to the hydrogen-containing compound to be replaced with fluorine, a fluorine-substituted medium, fluorine gas, a hydrogen fluoride collector, and the like. Reaction temperature The reaction temperature of the fluorination reaction is high enough to cause a fluorine substitution reaction, but low enough to prevent the splitting of the hydrogen-containing compound and the occurrence of side reactions. It is desired to properly adjust the vessel temperature. In particular, it has been considered that the skeleton of a hydrogen-containing compound containing an ether bond and an ester bond in the molecule is not always stable to complete fluorination, and only a low yield can be expected. For this reason, when performing the substitution reaction for complete fluorination, it is essential to control the temperature to maintain the temperature in a relatively low temperature range.

For this purpose, the fluorination reaction for producing CF ₃ OCF ₂ CF ₂ COORf (substituent Rf represents a group having 1 to 5 carbon atoms) is carried out at a reaction temperature of -50 ° C. to 20 ° C. It is considered necessary to carry out the reaction while gradually raising the temperature of the reaction system. For example, start from -50 ° C to -20 ° C at the beginning of the reaction, gradually raise the reaction temperature to 0 ° C to 10 ° C while charging sufficiently cooled fluorine gas, and then complete fluorination Is carried out at 10 ° C. to 20 ° C., preferably while the temperature of the reaction system is raised stepwise. The time interval of the temperature rise depends on the reaction system and reaction conditions, etc., but is set to an optimum setting in consideration of the yield and efficiency. Specifically, it may be desirable to raise the temperature at a rate of, for example, 0.5 ° C. to 1.5 ° C./hour, although it depends on the total reaction time.

The temperature during the reaction is controlled by a cooling jacket,
This is achieved by the use of a cooling system such as a cooling coil, vigorous stirring, and dissipation of heat by a sufficient amount of liquid medium. Hydrogen Fluoride (HF) Scavenger The above-mentioned complete fluorination is desirably performed in the presence of a substance that traps by-product hydrogen fluoride (HF). Hydrogen fluoride must be removed from the reaction system more quickly from the standpoint of preventing backbone fragmentation or rearrangement of the compound, which results in reduced yield. More specifically, for the starting compound of the present invention, the fluorinated intermediate, including its virtual radical intermediate, exhibits abnormal instability during the fluorination reaction. For this reason, the method used for direct fluorination using fluorine gas, which is commonly used, such as an HF scavenger, or a method for removing acidic substances (HF), such as removing HF out of the system by putting it in a diluent gas stream, is used. Doing so can be said to be effective in improving the yield. In the production method according to the present invention, since the reaction is performed in the low temperature range as described above, rapid removal by volatilization of hydrogen fluoride itself cannot be expected. Therefore, in the present production method, it is preferable to charge a hydrogen fluoride (HF) scavenger to the reaction medium together with the raw material.

As the HF scavenger, for example, alkali metal fluoride, LiF, NaF, KF, CsF, RbF and the like can be used, but a finely powdered one is particularly preferable. Alkali metal fluoride becomes acidic alkali metal fluoride and is substantially
Does not show HF function. Therefore, alkali metal fluoride is suitable as the HF scavenger. The addition amount of the hydrogen fluoride scavenger is from 1.0 times the molar amount of the replaceable hydrogen.
A 1.5-fold molar amount is appropriate. Reactor The material of the reactor and the joint for performing the fluorination is preferably copper, silver, nickel, copper alloy, silver alloy,
Nickel alloy, copper plated with silver, nickel plated with silver, etc. can also be used, and PTFE, FEP, PFA, EFA, M
Fluororesins such as FA can also be used. In addition, it is preferable to use a fluorine resin, a fluorine grease, or a fluorine oil for the seal portion in an auxiliary manner.

The reactor is preferably equipped with a cooling jacket for temperature control, an internal cooling coil, a microcapillary for introducing fluorine gas, and a stirrer for dispersing fluorine gas. More desirably, it has a baffle plate for improving dispersion, and has a condenser and a receiver for collecting volatiles, a reaction medium, a reactant, and a raw material, and a transfer line for returning the same to the reactor in some cases. Is more preferable.

The reactor, stirrer, condenser, cooling pipe, etc.
It is preferable to be made of a metal such as copper, silver, nickel or the like. In particular, copper and silver are more preferable because they have good thermal conductivity and can quickly remove reaction heat. Copper and nickel are cost-effective. Further, the above three metals are effective not only in terms of corrosion resistance and heat conduction, but also in promoting a controlled (ie, mild) fluorination reaction by the action of fluoride and perfluoride on the surface.

[0039]

Next, the present invention will be described more specifically with reference to examples. The present invention is not limited by these. In the following examples, unless otherwise specified,%
Indicates% by weight.

[0040]

Example 1 For the purpose of synthesizing CF ₃ OCF ₂ CF ₂ COOCF ₃ , the 1,1,2 dehydrated water was fed into a full-copper reactor (300 ml) equipped with a cooling jacket, an internal cooling coil, a stirring blade, and a reflux condenser.
-Trichloro-1,2,2-trifluoroethane (CFC-113) 200
g, CH ₃ OCF ₂ CF ₂ COOCH ₃ 50 g (0.26 mol) and dried and ground NaF 78 g were charged.

The above-mentioned copper reactor in which the contents were vigorously stirred was cooled to -30 ° C, and passed through a cooling coil at -10 ° C.
, Cooled mixed gas of F ₂ / N ₂ was introduced. Mixing the diluent gas, the F ₂ gas 20 ml / min, the N ₂ gas at a flow rate of 180 ml / min, was introduced into the reactor through micro-capillaries after adjusted so F ₂ concentration of 10 vol%. afterwards,
The reaction temperature was increased at a rate of 5 ° C. every 5 hours, and F ₂ / N ₂
From the introduction point of the mixed and diluted gas after 20 hours, F the flow rate of ₂ gas with increased to 40 ml / min N ₂ gas flow rate of 160 ml / min
And the reaction was carried out by increasing the F ₂ concentration in the mixed gas to 20 vol%.

Forty hours later, F_TwoStop introducing gas and N_TwoGas
F left behind_Two, And HF was discharged out of the system. The product is
N to avoid hydrolysis by contact with air_TwoBridge with gas pressure
Filter using a filter and remove the component adsorbed on NaF to CFC-1
13 Collected by washing twice with 30 ml. Distilling the filtrate
Of the mixture separated from the reaction medium CFC-113 by 58.9 g
(Target product: hydrogen-containing material = 92: 8) with copper reflux condenser
Into a reactor (100 ml) equipped with Intense contents
Heat the stirred copper reactor to 20 ° C._Two/ N_TwoMixing
Dilution gas was introduced into the reactor. Mixed dilution gas is F_Twogas
20ml / min, N_TwoGas flow rate of 30 ml / min and F_TwoConcentration 40vo
l%, introduced through the microcapillary and left
The C—H bond in question was completely fluorinated. 2 hours later, F_Two
Stop introducing N _TwoF left only after flowing_Two, HF out of the system
Discharged. The final compound obtained weighs 58.2 g.
CF with a purity of 99% or more_ThreeOCF_TwoCF_TwoCOOCF_ThreeSo
(74.2% yield).

[0043]

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[0044]

Example 2 150 g of diglyme and 1.0 g of KF were placed in a glass reactor (300 ml) equipped with a stirrer, the internal temperature was kept at 50 ° C., and 50 g of the reaction product obtained in Example 1 was gradually dropped. Bubbling was observed with the progress of the reaction, and reflux was observed in the reflux condenser. Analysis revealed that the reflux was a mixture of unreacted raw materials and the desired product, CF ₃ OCF ₂ CF ₂ COF. As the reaction proceeded, the proportion of unreacted raw materials in the reflux decreased. When the unreacted raw materials disappeared, the reaction was terminated, and the refluxed product and the target product in the solvent were recovered.
The recovered reactants were then purified by distillation. The final compound obtained weighed 24.6 g and was analyzed by CF ₃ OCF ₂
It was found to be CF ₂ COF (yield 63.2%).

[0045]

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[0046]

Comparative Example 1 (Synthesis example using CH ₃ OCH ₂ CH ₂ COOCH ₃ ) As a starting material, instead of CH ₃ OCF ₂ CF ₂ COOCH ₃ in Example 1, 20 g of CH ₃ OCH ₂ CH ₂ COOCH ₃ (0.17 mol) ), Dehydrated 1,1,
180 g of 2-trichloro-1,2,2-trifluoroethane (CFC-113)
And 85.7 g of dried and ground NaF was charged to the reactor. The reaction was carried out in the same manner as in Example 1, but the desired product was not obtained due to decomposition or side reactions.

[0047]

Comparative Example 2 Using the reactor of Example 1, 200 g
Of CFC-113 and 42.7 g of NaF were charged in advance, and 10 g (0.085 mol) of CH ₃ OCH ₂ C was added to these with vigorous stirring.
A mixture of H ₂ COOCH ₃ diluted with 40 g of CFC-113 at 2 g / h
was added at r speed of, at the same time F ₂ is 15 ml / min, N ₂ is 60m
A mixed dilution gas having a flow rate of 1 / min was introduced through the microcapillary. During the reaction, set the reaction temperature to -30 ° C
Kept. After the introduction of the raw materials, the reaction was carried out at a reaction temperature of 20 ° C., at a flow rate of 20 ml / min for F _{2 and} 30 ml / min for N ₂ for complete fluorination for 5 hours. CFC-113 was separated by distillation to obtain 8.1 g of a target product having a purity of 99% or more. The yield was 32%.

[0048]

Example 3 except that was introduced into the reaction system remains room temperature without cooling the mixed and diluted gas F ₂ / N ₂ at (MTFPM Synthesis of Starting materials a F ₂ introducing without cooling) Example 1, Example Reaction was carried out in the same procedure as in Example 1. The obtained compound is 51.0 g,
The yield was 65.0%.

[0049]

Example 4 (Synthesis example using a stainless steel reactor) A fluorination reaction was carried out in the same manner as in Example 1 except that a stainless steel reactor was used instead of the copper reactor used in Example 1. . The obtained compound was 54.2 g and the yield was 69.2%.

[0050]

As can be seen from Example 1, the partially fluorinated CH ₃ OCF ₂ C is obtained based on the production method of the present invention.
When F ₂ COOCH ₃ is used as a starting material and is subjected to fluorine substitution,
CF ₃ OCF ₂ CF ₂ COOC is the desired high purity perfluorinated compound
F ₃ could be obtained in 74% yield. On the contrary,
As shown in Comparative Example 1, when CH ₃ OCH ₂ CH ₂ COOCH ₃ , which is a hydrogen-containing compound without partial fluorination, is used as a starting material, skeleton fragmentation and fragmentation due to a fluorination partial reaction are caused. Could not be obtained. However, when the raw material is added little by little to the reaction system simultaneously with the introduction of the fluorine gas, as shown in Comparative Example 2, the reactivity between the raw material and the fluorine gas is low, and the side reaction tends to be suppressed. there were.

To summarize the above, a carboxylic acid ester containing an ether bond, for example, CH ₃ OCF ₂ CF ₂ COOR (R represents an alkyl group having 1 to 5 carbon atoms) as a raw material by the production method of the present invention By fluorinating with a fluorine gas in a solvent such as 113, side reactions and decomposition of the raw material can be suppressed. As a result, the fully fluorinated CF ₃ OCF ₂ CF ₂ COORf (the fluorine substituent Rf represents a group having 1 to 5 carbon atoms) was obtained at an industrially practical yield and efficiency per batch. Can be obtained in pure form.

According to the production method of the present invention, perfluoro substituents such as perfluoro (methyl 3-methoxypropionate) (PFMMP), CF ₃ OCF ₂ CF ₂ COORf (the fluorine substituent Rf has 1 to (Representing group 5)) can be obtained by efficient use of fluorine gas and simple operation, and the production cost can be significantly reduced. In particular, PFMMP is a comonomer CF ₃ OCF ₂ CF ₂ CF
_Since it is a synthetic starting material of ₂ OCF = CF ₂ , its ripple effect on cost reduction is considered to be extremely large.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G075 AA14 AA62 AA63 BA10 BD13 CA02 CA03 CA57 DA18 EB01 EC26 FB02 FB11 FB12 FC09 FC11 4H006 AA02 AC30 BA92 BB12 BB61 BC10 BD10 BD21 BD83 BE53 BM10 BM71 BP10 BT12

Claims (10)

[Claims] (1) CH ₃ OCF ₂ CF ₂ COOR (R represents an alkyl group having 1 to 5 carbon atoms) is completely fluorinated with fluorinated gas in chlorofluorocarbon to obtain CF ₃ OCF ₂ CF ₂ COORf.
(Wherein the fluorine substituent Rf represents a group having 1 to 5 carbon atoms). 2. The method according to claim 1, wherein said R is CH ₃ and said fluorine substituent Rf is
Characterized in that it is a CF _3, process for producing a fluorine-containing compound according to claim 1. 3. The method for producing a fluorine-containing compound according to claim 1, wherein said fluorine gas is a high-purity fluorine gas substantially free of oxygen and oxygen compounds. 4. The fluorine-containing compound according to claim 1, wherein the fluorine gas is cooled to a temperature in the range of -50 ° C. to 0 ° C., and is introduced into the complete fluorination reaction system to carry out the reaction. Manufacturing method. 5. The method according to claim 5, wherein the fluorine gas is supplied with an inert gas for 5 to 50 v.
3. The process for producing a fluorine-containing compound according to claim 1, wherein the solution is diluted to ol% and introduced into the reaction system for complete fluorination. 6. The process for producing a fluorine-containing compound according to claim 1, wherein said fluorine gas is introduced into said complete fluorination reaction system while gradually increasing its concentration from 5 vol% to 50 vol%. . 7. The process for producing a fluorine-containing compound according to claim 1, wherein the complete fluorination is carried out while gradually raising the temperature of the reaction system from -50 ° C. to 20 ° C. 8. The method for producing a fluorine-containing compound according to claim 1, wherein said complete fluorination is carried out in the presence of a hydrogen fluoride scavenger. 9. The method according to claim 8, wherein the hydrogen fluoride scavenger is an alkali metal fluoride. 10. The complete fluorination includes a container and a joint made of at least one metal selected from the group consisting of copper, silver and nickel or alloys thereof or a fluororesin; The method for producing a fluorine-containing compound according to claim 1, wherein the method is carried out in a reactor comprising a sealing portion using an elastomer, fluorine grease or fluorine oil.