JP2010059071A - Method for purifying trifluoromethanesulfonyl fluoride - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent method for producing trifluoromethanesulfonyl fluoride in a commercial scale, whereby trifluoromethanesulfonyl fluoride produced by electrolytic fluorination can be produced with high selectivity and high purity and in a repeated manner by carrying out three steps. <P>SOLUTION: Trifluoromethanesulfonyl fluoride is produced by carrying out the following three steps of: reacting trifluoromethanesulfonyl fluoride with a metal hydroxide and subsequently treating the same with an acid so as to obtain trifluoromethanesulfonic acid; reacting trifluoromethanesulfonic acid with phosphorus trichloride (PCl<SB>3</SB>) and chlorine (Cl<SB>2</SB>) so as to obtain trifluoromethanesulfonyl chloride (CF<SB>3</SB>SO<SB>2</SB>Cl); and reacting trifluoromethanesulfonyl chloride with a metal fluoride in the presence of water and a halogenated quaternary salt. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method for purifying trifluoromethanesulfonyl fluoride (CF ₃ SO ₂ F) useful as a raw material for producing intermediates in the fields of organic synthesis, medical agrochemicals, and electronic materials, and as a fluorination reagent.

As a method for producing a fluorinated alkanesulfonyl fluoride such as trifluoromethanesulfonyl fluoride, an electrochemical fluorination method has been conventionally known. For example, Patent Document 1 discloses a method of producing methanesulfonyl chloride (CH ₃ SO ₂ Cl) by electrolytic fluorination in anhydrous hydrofluoric acid. In Patent Document 2, a reaction obtained by electrochemical fluorination of α, β-difluoroalkane-β-sultone and the corresponding α-halocarbonylfluoroalkanesulfonyl halide in the presence of anhydrous hydrogen fluoride. Is disclosed.

On the other hand, in recent years, as a method not using electrochemical fluorination, production has been carried out by the following methods. For example, in Patent Document 3, perfluoroolefin is used as a starting material, reacted with sulfuric anhydride, passed through perfluoroalkanesultone, and then hydrolyzed to monohydroperfluoroalkanesulfonyl fluoride (Rf—CHF—SO ₂ F). ), Followed by reaction with fluorine or a fluorine-containing gas, to produce perfluoroalkanesulfonyl fluoride (Rf—CF ₂ —SO ₂ F), and Patent Document 4 discloses alkanesulfonyl fluoride. A method for producing perfluoroalkanesulfonyl fluoride or hydrofluoroalkanesulfonyl fluoride by reacting with a gas containing fluorine is disclosed.

In addition, as a technical field related to the present invention, in Patent Document 5 and Patent Document 6, a method of obtaining fluorocarbon sulfonic acid by hydrolysis with fluorocarbon sulfonic acid fluoride and potassium hydroxide solution, further acid treatment and distillation, And in patent documents 7-9, the manufacturing method which makes phosphorus trichloride, chlorine, phosphorus oxychloride etc. act on trifluoromethanesulfonic acid and obtains the corresponding sulfonyl chloride is disclosed. Patent Document 10 discloses a method for producing a sulfonic acid fluoride by reacting a sulfonic acid halide with an inorganic fluoride in an organic-water phase, and carrying out the reaction in the presence of a catalytic amount of an amine or an onium salt. It is disclosed.
US Pat. No. 2,732,398 Japanese translation of Japanese translation of PCT publication No. 8-512095 International Publication No. 2004-096759 JP 2003-206272 A Japanese Patent Publication No. 30-4218 Japanese Patent Laid-Open No. 1-061452 JP 2000-191634 A JP 2000-191635 A JP 2000-264771 A JP 51-125322 A

  In the above-mentioned Patent Document 1 and Patent Document 2 (electrolytic fluorination), a mixed gas of about 20 vol% trifluoromethanesulfonyl fluoride and about 80 vol% hydrogen is generated from the electrolytic cell during the reaction. Combustible gas is used to separate and purify high-purity trifluoromethanesulfonyl fluoride from a solution containing hydrogen gas because it contains 0.1% to 0.2% oxidizing gas. Therefore, a large-scale production facility (combustible high-pressure gas facility) is required, which is dangerous.

  On the other hand, the method that does not use electrolytic fluorination, that is, the method of Patent Document 3, is a preferable production method because the desired product is obtained as 88%, but on the other hand, it requires a multi-step process. The method is cumbersome and somewhat difficult to manufacture industrially. Moreover, since the perfluoroalkanesulfonyl fluoride obtained by the method of patent document 4 is a very low yield, it is difficult to employ | adopt industrially.

  In addition to hydrogen gas, many by-products resulting from electrolytic fluorination are produced in the reaction system (monofluoromethanesulfonyl fluoride, difluoromethanesulfonyl fluoride), making separation and purification more difficult. In the field of electronic materials, it is very difficult to produce high-purity trifluoromethanesulfonyl fluoride because even if several ppm level of impurities are mixed, it has a great influence on electronic equipment. .

  On the other hand, in Patent Document 10, although it is a reaction in a two-layer system of an organic phase and an aqueous phase, in order to purify the corresponding sulfonic acid fluoride, sulfonic acid fluoride is mixed in two layers, so these These phases must be treated separately, and since water is present in the reaction system, it is easily hydrolyzed to produce sulfonic acid, which is somewhat difficult in terms of productivity.

  For these reasons, it has been desired to establish a method capable of easily producing high-purity trifluoromethanesulfonyl fluoride on an industrial scale in a simple and short process.

  In view of such problems, the present inventors have intensively studied a method for easily producing trifluoromethanesulfonyl fluoride industrially. As a result, a method for obtaining trifluoromethanesulfonyl fluoride which is a target product with a short process and high purity was found, and the present invention was completed.

That is, the present invention provides a method for purifying trifluoromethanesulfonyl fluoride described in [Invention 1]-[Invention 11] below.
[Invention 1]
A method for purifying trifluoromethanesulfonyl fluoride (CF ₃ SO ₂ F), comprising the following three steps.
First step: A step of reacting a metal hydroxide with trifluoromethanesulfonyl fluoride, followed by treatment with an acid to obtain trifluoromethanesulfonic acid (CF ₃ SO ₃ H).
Second step: A step of reacting the trifluoromethanesulfonic acid obtained in the first step with phosphorus trichloride (PCl ₃ ) and chlorine (Cl ₂ ) to obtain trifluoromethanesulfonyl chloride (CF ₃ SO ₂ Cl).
Third step: A step of reacting the trifluoromethanesulfonyl chloride obtained in the second step with metal fluoride in the presence of water and a halogenated quaternary salt to obtain trifluoromethanesulfonyl fluoride.
[Invention 2]
After reacting trifluoromethanesulfonyl fluoride with a metal hydroxide and subsequently treating with an acid to obtain trifluoromethanesulfonic acid (first step), the metal hydroxide is potassium hydroxide, sodium hydroxide, The method according to invention 1, which is at least one selected from the group consisting of lithium hydroxide, cesium hydroxide, magnesium hydroxide, and calcium hydroxide.
[Invention 3]
When the trifluoromethanesulfonic acid obtained in the first step is reacted with phosphorus trichloride and chlorine (PCl ₃ + Cl ₂ ) to obtain trifluoromethanesulfonyl chloride (CF ₃ SO ₂ Cl) (second step), the reaction system The method according to the invention 1 or 2, characterized in that it is carried out in the presence of phosphorus oxychloride (POCl ₃ ).
[Invention 4]
When the metal fluoride is reacted with trifluoromethanesulfonyl chloride obtained in the second step in the presence of water and a halogenated quaternary salt (third step), the metal fluoride is lithium fluoride (LiF), fluoride. The method according to any one of Inventions 1 to 3, wherein the method is at least one selected from the group consisting of sodium (NaF), potassium fluoride (KF), rubidium fluoride (RbF), and cesium fluoride (CsF).
[Invention 5]
When the trifluoromethanesulfonyl chloride obtained in the second step is reacted with a metal fluoride in the presence of water and a halogenated quaternary salt (third step), the halogenated quaternary salt is represented by the formula [1]. Ammonium halide salt

(Wherein R ¹ is the same or different linear or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 9 carbon atoms or the same or different aryl group (wherein some or all of the hydrogen atoms are halogen atoms) (Fluorine, chlorine, bromine, iodine), alkyl group, amino group, nitro group, acetyl group, cyano group or hydroxyl group may be substituted), X is halogen (fluorine, chlorine, bromine, iodine) Represents
Or a halogenated phosphonium salt represented by the formula [2]

(Wherein R ¹ and X are the same as those in formula [1])
The method according to any one of Inventions 1 to 4, wherein
[Invention 6]
The group in which the ammonium halide salt consists of tetrapropylammonium bromide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, methyltributylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, methyltrioctylammonium chloride The method according to invention 5, which is at least one selected from the group consisting of:
[Invention 7]
The method according to invention 5, wherein the phosphonium halide salt is at least one selected from the group consisting of tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetrabutylphosphonium chloride, and tetrabutylphosphonium bromide.
[Invention 8]
8. The method according to any one of inventions 5 to 7, wherein the amount of the halogenated quaternary salt is 0.005 to 1.0 mol per mol of trifluoromethanesulfonyl chloride.
[Invention 9]
The amount of metal fluoride is 1 mol of trifluoromethanesulfonyl chloride.
The method according to any one of Inventions 5 to 8, wherein the method is 1 to 10 mol.
[Invention 10]
10. The method according to any one of inventions 5 to 9, wherein the temperature during the reaction is -5 to 20 ° C.
[Invention 11]
The trifluoromethanesulfonyl fluoride used in the first step is obtained by fluorinating methanesulfonyl chloride with a metal fluoride and fluorinating the obtained methanesulfonyl fluoride in anhydrous hydrogen fluoride by an electrolytic method. The method according to any one of Inventions 1 to 10.

  In the present invention, the trifluoromethanesulfonyl fluoride obtained by fluorination by the electrolytic method is subjected to three steps (the first step to the third step) without performing a purification operation at this time, thereby obtaining high purity. The present inventors have obtained a practically advantageous finding that trifluoromethanesulfonyl fluoride can be easily and efficiently obtained.

  In addition, in the third step (fluorination step) among the three steps, the reaction proceeds well and the target product is obtained in a high yield, obtaining extremely useful knowledge for manufacturing on an industrial scale. It was.

The third step is characterized in that the metal fluoride is reacted in “in the presence of water and a halogenated quaternary salt”. So far, a reaction in which a substrate having no fluorine atom, that is, methanesulfonyl chloride and a metal fluoride are reacted in the presence of water to obtain a corresponding fluoride is known (CH ₃ SO ₂ Cl + KF → CH ₃ SO ₂ F + KCl) and Patent Document 5 are related methods. For example, in the method of Patent Document 5, even if trifluoromethanesulfonyl chloride, which is the starting material of the present invention, is used, the target fluorinated product is hardly obtained (see Comparative Example 1 described later).

  On the other hand, an example in which a phase transfer catalyst such as crown ether is used for a substrate having no trifluoromethyl group as in Patent Document 4 has been conventionally known, but the method is applied to trifluoromethanesulfonyl chloride. In this case, the corresponding trifluoromethanesulfonyl fluoride is obtained, but the yield is very low (see Comparative Example 2-3 described later).

  Moreover, as described in Patent Document 5 and Patent Document 10, it is known that methanesulfonyl chloride itself has hydrolyzability, and methanesulfonyl chloride is easily converted into a corresponding sulfonic acid.

  Here, trifluoromethanesulfonyl chloride which is a starting material of the present invention has a trifluoromethyl group. Due to the strong electron-attracting properties of fluorine atoms, the reactivity is significantly different from that of sulfonyl chlorides that do not have fluorine atoms, and hydrolysis proceeds easily in systems where water is present in the reaction system. It is thought that the formation of sulfonic acid, which is a minor side reaction, is likely to occur.

  From these facts, it was initially expected that it would be very difficult to efficiently fluorinate the substrate having a trifluoromethyl group used in the present invention to efficiently obtain the target product.

  However, the present inventors have reacted metal fluoride in the presence of water and a halogenated quaternary salt, so that practically no hydrolysis occurs and trifluoromethanesulfonyl chloride is a metal fluoride such as potassium fluoride. A surprising finding was obtained that the target product was satisfactorily obtained with a very high selectivity and yield (see Example 1-5 described below).

  As described above, the present invention can produce the target compound in a yield higher than that of the prior art under industrially feasible reaction conditions. Since no environmental load is applied and no refining operation is required, the target trifluoromethanesulfonyl fluoride can be produced with high productivity.

  In addition, the present applicant has already applied for the contents of the third step (Japanese Patent Application No. 2008-048591, International Application No. PCT / JP2008 / 53767). In the present invention, by combining the previous two steps and the third step, the trifluoromethanesulfonyl fluoride obtained by fluorination by the electrolytic method is obtained at this time without purifying the high purity fluoride. Became possible. It is possible to simplify large-scale production facilities (flammable high-pressure gas facilities), and because trifluoromethanesulfonyl fluoride can be produced repeatedly according to the present invention, combustible gases that have been a concern in conventional electrolytic fluorination methods. It is no longer necessary to handle (hydrogen gas).

  Thus, the present invention is an industrially and economically very advantageous method.

  According to the present invention, trifluoromethanesulfonyl fluoride produced by electrolytic fluorination can be efficiently produced with high selectivity and high purity by passing through three steps. In addition, it is possible to repeatedly produce the target product, which is a very excellent method for production on an industrial scale.

Hereinafter, the present invention will be described in more detail. In the present invention, trifluoromethanesulfonyl fluoride is reacted with a metal hydroxide and then treated with an acid to obtain trifluoromethanesulfonic acid (first step), and the trifluoromethanesulfonic acid obtained in the first step. And phosphorus trichloride (PCl ₃ ) and chlorine (Cl ₂ ) to obtain trifluoromethanesulfonyl chloride (CF ₃ SO ₂ Cl) (second step). The trifluoromethanesulfonyl chloride obtained in the second step In the presence of water and a halogenated quaternary salt, a metal fluoride is reacted to obtain trifluoromethanesulfonyl fluoride (third step) (see Scheme 1 below).

  In addition, about the trifluoromethanesulfonyl fluoride of the starting material of the 1st process, the method currently disclosed by patent documents 1 and 2, ie, the method of fluorinating trifluoromethanesulfonyl chloride in anhydrous hydrogen fluoride by an electrolysis method, or As shown in Scheme 2 below, methanesulfonyl chloride is fluorinated with a metal fluoride, and the obtained methanesulfonyl fluoride is fluorinated by anhydrous electrolysis in anhydrous hydrogen fluoride (this step is referred to as “ (Also referred to as “Step A”) (see Scheme 2 below).

  However, as described above, in order to separate and purify trifluoromethanesulfonyl fluoride, flammable gas is handled, so a large-scale manufacturing facility (flammable high-pressure gas facility) is required, which is dangerous. It will be.

  Therefore, as will be described in detail later, the trifluoromethanesulfonyl fluoride obtained by the above-described electrolytic fluorination is used as a starting material in the next first step without being subjected to separation operation such as purification at this point. By doing so, in the first step, it is possible to proceed well without impairing the yield, and the separation operation can be performed very simply. For example, in this example, the use of trifluoromethanesulfonyl fluoride containing a mixed gas that is difficult to separate by electrolytic fluorination as a starting material in the first step reduces the number of steps to the separation operation. This is one of the preferred embodiments in the present invention because the productivity is remarkably improved.

  First, the first step will be described. The first step is a step in which trifluoromethanesulfonyl fluoride is reacted with a metal hydroxide and then treated with an acid to obtain trifluoromethanesulfonic acid. Here, the chemical reaction formula of this step is described as follows (refer to Scheme 3 below).

The metal hydroxide to be used may be any metal hydroxide that allows the reaction to proceed efficiently. Potassium hydroxide (KOH), sodium hydroxide (NaOH), lithium hydroxide (LiOH), cesium hydroxide (CsOH) ), Magnesium hydroxide (Mg (OH) ₂ ), and calcium hydroxide (Ca (OH) ₂ ), at least one selected from the group consisting of potassium hydroxide, sodium hydroxide, hydroxide Lithium is preferable, and potassium hydroxide and sodium hydroxide are particularly preferable. The metal mentioned here is an alkali metal, and examples of the alkali metal include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs).

  The amount of the metal hydroxide used in this step is usually 2 to 10 mol, preferably 2 to 6 mol, and preferably 2 to 4 mol with respect to 1 mol of trifluoromethanesulfonyl fluoride. Further preferred. The fact that the base is less than 2 moles does not have a great effect on the selectivity, but the reaction conversion rate is low, leading to a decrease in yield, and conversely, if the base is more than 10 moles, Since it reacts with a by-product contained in the product gas, a large amount of inorganic substances are produced as a by-product, and purification becomes difficult.

  The amount of water used in this step is such that the concentration of the aqueous solution of metal hydroxide is usually 10% to 50%, preferably 15% to 40%, more preferably 20% to 30%. And good. Here, when the amount of water is large, it causes a decrease in the reaction rate, and when the amount of water is small, it is not preferable because the metal hydroxide precipitates without dissolving.

  The reaction temperature (temperature of the internal liquid) when adding the metal hydroxide can be in the range of 0 ° C. to 90 ° C., but 40 ° C. to 60 ° C. is not subjected to heating load, and temperature control is easy. This is preferable. Especially, it is one of the especially preferable aspects of this invention to perform reaction in the range of 40 to 50 degreeC.

  If it is less than 0 ° C., the water used is frozen, and the metal hydroxide is difficult to dissolve, which is not preferable. On the other hand, when it exceeds 90 ° C., by-products are likely to be generated, and excessive heating is not preferable from the viewpoint of economy because of poor energy efficiency. The reaction time is preferably 1 to 5 hours.

  In this step, when trifluoromethanesulfonyl fluoride containing a mixed gas that is difficult to separate by electrolytic fluorination is used as a starting material, hydrogen fluoride derived from electrolytic fluorination is included. Therefore, the product gas extracted from the electrolytic cell by electrolytic fluorination is passed through a condenser at 0 to −40 ° C. to liquefy the accompanying hydrofluoric acid and return to the electrolytic cell, leading to a SUS scrubber, and 10% Separation operation can be performed very simply by reacting with a 50% metal hydroxide solution (potassium hydroxide aqueous solution in this embodiment) in the range of 0 ° C to 90 ° C. In addition, the metal hydroxide can be reacted in two stages, which can be adjusted appropriately by those skilled in the art.

As shown in Scheme 3, after reacting with a metal hydroxide, the metal salt of trifluoromethanesulfonyl fluoride (CF ₃ SO ₃ M, where “M” is an alkali metal, Indicating a hydroxide-derived metal). Here, at the same time as CF ₃ SO ₃ M is obtained, metal fluoride is generated in the reaction system, but it can be easily separated from the metal fluoride by ordinary operations such as filtration and centrifugation. A person skilled in the art can appropriately adjust filtration, centrifugation, temperature, and the like.

  There is no restriction | limiting in particular about reaction pressure, Reaction can be performed on normal pressure (atmospheric pressure) and pressurization conditions.

  It is also possible to carry out the reaction under reduced pressure conditions. In the present invention, as described above, trifluoromethanesulfonyl fluoride, which is a raw material in this step, is generated as a gas at room temperature, so the pressure in the reaction system may increase. Therefore, it is possible to carry out the reaction in a state where the pressure is not so high by adding a reaction reagent after depressurizing the reaction system in advance using a pressure resistant reaction vessel.

Next, as shown in Scheme 3, by treating the obtained CF ₃ SO ₃ M with an acid, the corresponding trifluoromethanesulfonic acid can be obtained. The acid used in this step is not particularly limited as long as it is a Bronsted acid, but inorganic acids such as hydrochloric acid, sulfuric acid, fuming sulfuric acid, nitric acid, phosphoric acid, silicic acid, hydrobromic acid, boric acid, formic acid, acetic acid, propion Examples thereof include organic acids such as acid, butyric acid, valeric acid, pivalic acid, oxalic acid, succinic acid, adipic acid, crotonic acid, methanesulfonic acid, and trifluoromethanesulfonic acid. The amount of use varies depending on the valence of the acid used. For example, in the case of a monovalent acid, the amount of acid used is 1 mol or more, preferably 1 mol per 1 mol of CF ₃ SO ₃ M. ~ 5 moles. In the case of a divalent acid, the amount of acid used is 0.5 mol or more, preferably 0.5 to 2.5 mol, relative to 1 mol of CF ₃ SO ₃ M. Moreover, although there is no limitation in particular regarding the density | concentration of an acid, 10%-90% are preferable. When the hydrolysis is performed in the presence of an acid, the amount of water to be used is not particularly limited as long as it is 1 mol or more with respect to 1 mol of CF ₃ SO ₃ M as a substrate. Mol, more preferably 1 to 100 mol. Moreover, when water is contained in the acid mentioned above, you may use the water. The reaction temperature is usually −30 ° C. to 150 ° C., preferably −10 ° C. to 120 ° C., more preferably 0 ° C. to 100 ° C. The reaction time is preferably about 1 to 4 hours.

  From the acid-decomposed mixture, trifluoromethanesulfonic acid can be obtained by subjecting to ordinary means such as distillation. The distillation operation can be performed under normal pressure (atmospheric pressure) or reduced pressure conditions, but it is preferable to carry out distillation under reduced pressure because trifluoromethanesulfonic acid has a high boiling point (boiling point 162 ° C.). A person skilled in the art can appropriately adjust the vacuum distillation.

  The reactor used in this step is not particularly limited as long as it can withstand pressure, and is lined with tetrafluoroethylene resin, chlorotrifluoroethylene resin, vinylidene fluoride resin, PFA resin, glass, or the like. A reactor or a glass container can be used.

  Next, the second step will be described. The second step is a step of reacting phosphorus trichloride and chlorine with the trifluoromethanesulfonic acid obtained in the first step to obtain trifluoromethanesulfonyl chloride (see Scheme 4).

When using phosphorus trichloride and chlorine, the molar ratio of phosphorus trichloride to chlorine used is usually preferably 1: 1. The addition amount of phosphorus trichloride and chlorine in this step is preferably 2 mol or less, more preferably 0.5 to 2.0 mol, per 1 mol of trifluoromethanesulfonic acid. When the addition amount of phosphorus trichloride and chlorine exceeds 2 mol, the yield of the target product trifluoromethanesulfonyl chloride is hardly increased when the addition amount of phosphorus trichloride and chlorine exceeds 2 mol. Further, as the addition amount increases, a large amount of phosphorus trichloride as a raw material remains, which causes a load on the subsequent purification process, which is not preferable. In addition, when the molar ratio of phosphorus trichloride and chlorine to trifluoromethanesulfonic acid is small, the amount of trifluoromethanesulfonic anhydride [(CF ₃ SO ₂ ) ₂ O] that is a by-product increases accordingly. However, this is not preferable because the yield of the target product trifluoromethanesulfonyl chloride is reduced. In order to perform the reaction efficiently because the yield of the target product trifluoromethanesulfonyl chloride is 50% or less when the molar ratio of phosphorus trichloride and chlorine to trifluoromethanesulfonic acid is less than 0.5. The molar ratio of phosphorus trichloride and chlorine to trifluoromethanesulfonic acid is preferably 0.5 or more. For the above reasons, in order to carry out the reaction more efficiently, the amount is more preferably 0.8 to 1.2 mol.

  As a preparation method in the case of using phosphorus trichloride and chlorine, it is usually preferable to carry out the reaction by adding trifluoromethanesulfonic acid and phosphorus trichloride and then introducing chlorine. Since heat is generated when chlorine is introduced, the reaction temperature at the time of introduction is preferably 50 ° C. or less, more preferably 10 to 30 ° C.

  Moreover, although the reaction temperature after introduce | transducing chlorine is preferable to set it as 40-90 degreeC, in order to advance reaction more efficiently, 60-80 degreeC is more preferable. In order to make the reaction proceed more efficiently, it is preferably refluxed for about 2 to 4 hours, whereby the target product trifluoromethanesulfonyl chloride can be obtained with high selectivity and high yield.

  The reactor used in this step can perform the reaction at normal pressure or under pressure. When the reaction is performed under pressure, the material is not particularly limited as long as it can withstand the pressure, and a reaction in which tetrafluoroethylene resin, chlorotrifluoroethylene resin, vinylidene fluoride resin, PFA resin, glass, etc. are lined inside. A glass container or a glass container can be used. In the case of a reaction vessel having an inner wall made of stainless steel, iron, etc., the reaction itself proceeds. However, since the metal may cause corrosion by chlorine, it is preferable to use the aforementioned reaction vessel.

In this step, it is preferable that phosphorus oxychloride (POCl ₃ ) coexist in the reaction system. When chlorine is introduced without adding phosphorus oxychloride, the intermediate produced by the reaction of trifluoromethanesulfonic acid and phosphorus trichloride at the time of chlorine introduction precipitates as crystals. This crystal precipitation may cause insufficient stirring and blockage of the chlorine inlet tube, which may hinder the reaction.

  Therefore, by adding phosphorus oxychloride to dissolve the crystal, a reaction system is obtained in which the stirring is good and the blockage of the chlorine introduction tube can be avoided.

As the solvent used in the present invention, a solvent inert to the raw materials and reaction products is preferable, and among them, a fluorine-based solvent is preferably used. For example, the general formula _{(C n F 2n + 1 SO} 2) 2 O (n = 1~8) fluoroalkyl sulfonic anhydride represented by the general formula _{C n F 2n + 1 SO 2} · O n C n F 2n _{Fluoroalkylsulfonic} acid ester represented by ₊₁ (n = 1 to 8), perfluoroalkane represented by general formula C _n F _{2n + 2} (n = 4 to 20), general formula (C _n F _{2n + 1} ) ₃ Examples include perfluoroalkylamines represented by N (n = 2 to 6), perfluoropolyethers, and the like, and the solvents may be used alone or in combination.

  However, even when trifluoromethanesulfonic acid, the obtained trifluoromethanesulfonyl chloride, and phosphoryl chloride coexist in the reaction system, these are all liquids at room temperature and do not particularly require a solvent.

  As a specific embodiment of this step, for example, trifluoromethanesulfonic acid, phosphorus trichloride, and phosphorus oxychloride are charged, and then chlorine is introduced, and then the reaction can be performed under pressure.

  When the above reaction is performed, trifluoromethanesulfonyl chloride and phosphorus oxychloride are generated. Furthermore, although trifluoromethanesulfonic anhydride may be produced as a by-product, these include trifluoromethanesulfonic acid, which is an unreacted raw material, and phosphorus oxychloride added in advance before the reaction. Trifluoromethanesulfonyl chloride can be obtained by ordinary means such as extraction, distillation, recrystallization and the like.

  Next, the third step will be described. The third step is a step in which the trifluoromethanesulfonyl chloride obtained in the second step is reacted with a metal fluoride in the presence of water and a halogenated quaternary salt to obtain trifluoromethanesulfonyl fluoride.

  Specific compounds of metal fluoride used in this step include lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), rubidium fluoride (RbF), and cesium fluoride (CsF). Among these, at least one selected from the group consisting of sodium fluoride, potassium fluoride, and cesium fluoride is preferably used because they are relatively easily available. These fluorides can be used alone or in admixture of two or more.

  The amount of the metal fluoride is usually 1 to 10 mol, preferably 1 to 8 mol, more preferably 1.5 to 6 mol, relative to 1 mol of trifluoromethanesulfonyl chloride. If it is less than 1 mole, the reaction yield will be reduced. If the amount exceeds 10 moles, there is no problem with the progress of the reaction, but there is no particular merit in terms of reaction rate and yield, and it is not economically preferable.

  In the present invention, since the solubility varies depending on the type of metal fluoride, the amount of water varies greatly accordingly. When carrying out this reaction, those skilled in the art can appropriately adjust the amount of water to such an extent that the reaction proceeds efficiently.

  For example, when potassium fluoride is used as the metal fluoride, water is added so that the concentration of the aqueous solution is usually 15% to 60%, preferably 25% to 50%, more preferably 35% to 45%. good. Here, when the amount of water is large, the reaction rate is lowered, and when the amount of water is small, the metal fluoride is precipitated without dissolving, which is not preferable. In this case, the above-mentioned concentration can be achieved by adding water in an amount of 0.5 g to 10 g with respect to 1 g of potassium fluoride. In a present Example, it is one of the preferable aspects to add water in the range of 1-6g with respect to 1g of potassium fluoride.

  In the present invention, water is used as a solvent, but the reaction can be carried out in the presence of water and an organic solvent. Here, the organic solvent means an inert organic compound that does not directly participate in the reaction of the present invention. Specifically, benzene, toluene, xylene, pentane, hexane, heptane, acetonitrile, carbon tetrachloride, chloroform, methylene chloride, 1,2-dichloroethane, ethylbenzene, mesitylene, dioxane, dimethyl ether, diethyl ether, dibutyl ether, tetrahydrofuran, etc. It can be obtained as an organic solvent. These organic solvents can be used alone or in combination of two kinds.

  However, when considering the industrial production method of the present invention, the reaction proceeds sufficiently even with a method using water as a solvent, and the target product can be obtained with high yield and high selectivity (see Examples below). There is little merit of coexisting an organic solvent.

The most important feature of the present invention is that trifluoromethanesulfonyl chloride (CF ₃ SO ₂ Cl) is reacted with a metal fluoride in the presence of water and a halogenated quaternary salt. In the present invention, it is essential to use a halogenated quaternary salt as well as water. When the halogenated quaternary salt is not present, the target product is hardly formed, or the yield of the target product is low. Very low (see comparative example below). Examples of the halogenated quaternary salt include a halogenated quaternary ammonium salt represented by the formula [1] or a halogenated quaternary phosphonium salt represented by the formula [2]. 2], R ¹ is the same or different linear or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 9 carbon atoms or the same or different aryl group (wherein some or all of the hydrogen atoms are halogen atoms) (Fluorine, chlorine, bromine, iodine), alkyl group, amino group, nitro group, acetyl group, cyano group or hydroxyl group may be substituted), X is halogen (fluorine, chlorine, bromine, iodine) Things can be used. Among these, regarding the aliphatic hydrocarbon group, those having 1 to 7 carbon atoms are preferable, and those having 1 to 4 carbon atoms are particularly preferable.

  Among these, specific compounds of the halogenated quaternary ammonium salt include tetramethylammonium fluoride, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetraethylammonium fluoride, tetraethylammonium chloride, tetraethyl. Ammonium bromide, tetraethylammonium iodide, tetrapropylammonium fluoride, tetrapropylammonium chloride, tetrapropylammonium bromide, tetrapropylammonium iodide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide And benzyltriethylammonium fluoride Benzyltriethylammonium chloride, benzyltriethylammonium bromide, benzyltriethylammonium iodide, benzyltributylammonium fluoride, benzyltributylammonium chloride, benzyltributylammonium bromide, benzyltributylammonium iodide, methyltributylammonium fluoride, methyltributylammonium chloride, At least one selected from the group consisting of methyltributylammonium bromide, methyltributylammonium iodide, methyltrioctylammonium fluoride, methyltrioctylammonium chloride, methyltrioctylammonium bromide, methyltrioctylammonium iodide, Among these Trapropylammonium fluoride, tetrapropylammonium chloride, tetrapropylammonium bromide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, benzyltriethylammonium fluoride, benzyltriethylammonium chloride, benzyltriethylammonium bromide, benzyltributyl Ammonium fluoride, benzyltributylammonium chloride, benzyltributylammonium bromide, methyltributylammonium fluoride, methyltributylammonium chloride, methyltributylammonium bromide, methyltrioctylammonium fluoride, methyltrioctylammonium chloride, methyltrio Cutylammonium bromide is preferred and easily available. From the viewpoint of easy availability, tetrapropylammonium bromide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, methyltributylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, Alternatively, methyl trioctyl ammonium chloride is more preferably used.

  Specific compounds of the halogenated quaternary phosphonium salt include tetraphenylphosphonium fluoride, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, tetrabutylphosphonium fluoride, tetrabutylphosphonium chloride, tetra Butylphosphonium bromide, tetrabutylphosphonium iodide, butyltriphenylphosphonium fluoride, butyltriphenylphosphonium chloride, butyltriphenylphosphonium bromide, butyltriphenylphosphonium iodide, trioctylethylphosphonium fluoride, trioctylethylphosphonium chloride, tri Octylethylphosphonium bromide, trioctylethylphosphonium iodide Benzyltriphenylphosphonium fluoride, benzyltriphenylphosphonium chloride, benzyltriphenylphosphonium bromide, benzyltriphenylphosphonium iodide, ethyltriphenylphosphonium fluoride, ethyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide And at least one selected from the group consisting of tetraphenylphosphonium fluoride, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, tetrabutylphosphonium fluoride, tetrabutylphosphonium chloride. , Tetrabutylphosphonium bromide, tetrabutylphospho Umuyojido are preferred, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide is more preferably used.

  The amount of the halogenated quaternary salt used is usually 0.005 to 1.0 mol, preferably 0.01 to 0.5 mol, more preferably 0, relative to 1 mol of trifluoromethanesulfonyl chloride as a raw material. 0.03 to 0.3 mol. If the amount is less than 0.005 mol, the reaction yield decreases, and the reaction can be carried out even if the amount exceeds 1.0 mol. . A suitable amount used in this reaction varies depending on the reaction conditions, and can be appropriately adjusted by those skilled in the art within the above range.

  These halogenated quaternary salts may be used alone or in combination of two or more. On the other hand, the halogenated quaternary salt can actually be used as a hydrate in which any number of water molecules are hydrated, and can be appropriately adjusted by those skilled in the art.

  The reaction in the production method of the present invention can be performed by adding a metal fluoride and a halogenated quaternary salt in the presence of water, stirring and mixing, and then adding trifluoromethanesulfonyl chloride. In the present invention, the order of charging the reaction reagents is not particularly limited. However, in the present invention, it is preferable to add trifluoromethanesulfonyl chloride after adding water, metal fluoride, and halogenated quaternary salt. It is preferable because it is efficient.

  The temperature at the time of reaction is usually -5 ° C to 20 ° C, preferably 0 ° C to 15 ° C. If it is lower than −5 ° C., it is not preferable because water is solidified, metal fluoride or halogenated quaternary salt is precipitated, and the reaction rate is lowered. In addition, when the reaction is carried out at a temperature higher than 20 ° C., since trifluoromethanesulfonyl chloride (boiling point 25 ° C. to 35 ° C.) and water as starting materials are vaporized, the reaction system is sealed using a pressure-resistant reaction vessel and pressurized. The reaction can be carried out under conditions. However, since the reaction proceeds sufficiently even in the range of −5 ° C. to 20 ° C., the merit performed at a temperature higher than 20 ° C. is not particularly large.

  The reaction time is not particularly limited, but it is desirable that the reaction is completed after confirming that the consumption of the raw material has sufficiently progressed and the reaction no longer proceeds by a technique such as gas chromatography, and can be adjusted appropriately by those skilled in the art. be able to. Furthermore, when carrying out this reaction, it is preferable to stir in order to advance the reaction efficiently. When adding trifluoromethanesulfonyl chloride, the reaction proceeds even if trifluoromethanesulfonyl chloride is added to the reaction system all at once or continuously, and thus can be appropriately selected by those skilled in the art. Dropping trifluoromethanesulfonyl chloride is one of the preferred embodiments. Moreover, about the dripping time at the time of adding trifluoromethanesulfonyl chloride, it is preferable to complete dripping in about 1 to 4 hours.

  There is no restriction | limiting in particular about reaction pressure, Reaction can be performed under a normal pressure (atmospheric pressure) or pressurization. The boiling point of trifluoromethanesulfonyl fluoride which is the object of the present invention is very low (−23 ° C.) and exists as a gas at room temperature. When the present invention is carried out in the above-described temperature range in the reaction system, the target product is generated in the reaction system immediately after the reaction between trifluoromethanesulfonyl chloride and the metal fluoride. Although it is possible to seal the reaction system using a pressure-resistant reaction vessel and carry out the reaction under pressurized conditions, in the present invention, the generated gas (trifluoromethanesulfonyl fluoride) is converted into trifluoromethanesulfonyl fluoride. The reaction is carried out while returning to the reactor while flowing through a condenser (condenser, also called a condenser) cooled below the boiling point (this operation is also called reflux), and at the same time when the predetermined pressure is reached, By collecting part of the gas that has been partially opened and circulated through the condenser with a collector, the reaction can be carried out with almost no increase in the pressure of the entire reaction vessel. Thus, the present invention can be sufficiently carried out even at normal pressure (atmospheric pressure).

  The reactor used in the present invention is a reactor in which tetrafluoroethylene resin, chlorotrifluoroethylene resin, vinylidene fluoride resin, PFA resin, glass or the like is lined inside, or a glass container when the reaction is performed at normal pressure. Can be used. Further, when the reaction is performed under pressure, the material is not particularly limited as long as it can withstand the pressure, and a metal container such as stainless steel, hastelloy, monel, or the like can be used.

  Since trifluoromethanesulfonyl fluoride, which is the object of the present invention, exists as a gas at room temperature as described above, after the gas obtained after the reaction is circulated through a condenser, the gas is collected in a collection container. Thus, high-purity trifluoromethanesulfonyl fluoride can be obtained without requiring a purification operation such as distillation.

  For example, after adding water, potassium fluoride, a quaternary halide, trifluoromethanesulfonyl chloride, the generated gas is circulated through a condenser cooled to -30 ° C, and the reaction is performed while returning the circulated gas to the reaction vessel again. The solution is warmed to room temperature and refluxed. While performing the reflux operation, a part of the condenser is opened, and a part of the gas circulated through the condenser is collected by a collector. After completion of the reaction, the condenser temperature is raised to about −20 ° C., and all the remainder of the gas is collected in a collection container to obtain high-purity trifluoromethanesulfonyl fluoride without requiring a distillation operation. (See Examples below). Thus, it is one of the preferable features of the present invention that no distillation operation is required.

  In the present invention, it may be performed continuously, semi-continuously, or batchwise, and can be adjusted as appropriate by those skilled in the art.

  In this way, high-purity trifluoromethanesulfonyl fluoride can be obtained by a simple method without mixing water or trifluoromethanesulfonyl chloride.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by this Example. Here, “%” of the composition analysis value represents “area%” of the composition obtained by directly measuring the reaction mixture by gas chromatography (GC, unless otherwise specified, the detector is TCD).

[Step A]: Production of trifluoromethanesulfonyl fluoride (electrolytic fluorination)
363.0 kg of water was put into a tetrafluoroethylene resin equipped with a stirrer, a reflux pipe, and a thermometer, or a Hastelloy reactor, and 130.86 kg of sodium fluoride was added while stirring and cooled to 5 ° C. Thereto, 255.0 kg of methanesulfonyl chloride (CH ₃ SO ₂ Cl) was gradually added, and then the reaction solution was stirred at room temperature for 1 hour, and the stirred reaction solution was distilled at normal pressure, thereby methanesulfonyl fluoride. A mixed solution containing 384.8 kg of (CH ₃ SO ₂ F) and 176.9 kg of water was obtained. Next, after separating into two layers and removing water, electrolytic fluorination was performed using a part of this methanesulfonyl fluoride.

In an electrolytic fluorination tank equipped with a reflux condenser set at −34 ° C., 2.42 kg of methanesulfonyl fluoride and 10.0 kg of anhydrous hydrogen fluoride (HF) were introduced 4 times every 8 hours (total 32 hours). ), Electrolytic fluorination was performed at a bath temperature of 4 ° C., a voltage of 5.5 volts (V), and a current of 500 amperes (A).
As a result, a gas having the following composition was obtained.

The composition gas was used as a raw material for the first step.
[Step 1] Production of trifluoromethanesulfonic acid After the product gas produced in Step A is introduced to a water scrubber, 38.73 kg of a 12% aqueous potassium hydroxide solution is supplied at 60 ° C over 1 hour. Reacted with sulfonyl fluoride.

  Next, this hydrolyzate was heated with steam in a stainless steel evaporator, thereby evaporating water at the boiling point. After cooling to 30 ° C., crystals began to precipitate. Then, it was separated by filtration with a centrifugal separator and dried at 120 ° C. for 10 hours. As a result, 18.54 kg of crystals having the following composition were obtained.

Next, an acid treatment was performed using a part of 18.54 kg of crystals having the composition obtained in Table 2.
3 kg of crystals having the composition obtained in Table 2, 1.05 kg of 98% sulfuric acid and 1.9 kg of 26% fuming sulfuric acid were mixed and reacted at 120 ° C. for 1 hour with stirring. After 1 hour, stirring was stopped and the temperature was returned to room temperature, 5.33 kPa to 3.33 kPa, boiling point 130 ° C. to 110 ° C. under reduced pressure and simple distillation, trifluoromethanesulfonic acid (CF ₃ SO ₃ H) 2.32 kg Was obtained with a purity of 99% or more. Hereinafter, a part of trifluoromethanesulfonic acid was used as a raw material for the second step.
[Second Step] Production of Trifluoromethanesulfonyl Chloride 183.5 g (1.3 mol) of phosphorus trichloride was charged into 200.5 g (1.3 mol) of trifluoromethanesulfonic acid. Next, 202.9 g (1.3 mol) of phosphorus oxychloride was added under water cooling. Chlorine 95.0 (1.3 mol) was introduced at 22-32 ° C. After introducing chlorine, the mixture was heated to 75 ° C. and refluxed for 4 hours. After completion of the reaction, the reaction solution was distilled to obtain 201.1 g (yield 89.6%) of trifluoromethanesulfonyl chloride.
[Third step] Production of trifluoromethanesulfonyl fluoride- A 200 ml glass flask equipped with a condenser cooled to about 30 ° C was charged with 100 g of water, 51.7 g (0.890 mol) of potassium fluoride, tetrabutylammonium fluoride 3 4.9 g (0.016 mol) of hydrate ((C ₄ H ₉ ) ₄ NF · 3H ₂ O) was added and mixed well with stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and trifluoromethanesulfonyl chloride (50.0 g (0.297 mol)) was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 40.8 g of a collected product was obtained, and generation of trifluoromethanesulfonyl fluoride was confirmed by gas chromatogram (GC) analysis. The product was obtained in a purity of 99.4% and a yield of 89.3%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Third Step] Production of trifluoromethanesulfonyl fluoride— A 200 ml glass flask equipped with a condenser cooled to about 30 ° C., 67 g of water, 34.5 g (0.594 mol) of potassium fluoride, tetrabutylammonium fluoride 3 4.9 g (0.016 mol) of hydrate ((C ₄ H ₉ ) ₄ NF · 3H ₂ O) was added and mixed well with stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 50.0 g (0.297 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 40.3 g of a collected product was obtained, and generation of trifluoromethanesulfonyl fluoride was confirmed by gas chromatogram (GC) analysis. The product was obtained in a purity of 99.2% and a yield of 88.6%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Third Step] Production of trifluoromethanesulfonyl fluoride—In a 200 ml glass flask equipped with a condenser cooled to about 30 ° C., 100 g of water, 51.7 g (0.890 mol) of potassium fluoride, tetrabutylammonium chloride (( C ₄ H ₉ ) ₄ NCl) (4.1 g (0.016 mol)) was added and mixed well with stirring.

  The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 50.0 g (0.297 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 40.9 g of collected material was obtained, and gas chromatogram (GC) analysis confirmed the formation of trifluoromethanesulfonyl fluoride. The product was obtained in a purity of 99.0% and a yield of 89.1%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Third Step] Production of trifluoromethanesulfonyl fluoride- A 200 ml glass flask equipped with a condenser cooled to about 30 ° C was charged with 100 g of water, 51.7 g (0.890 mol) of potassium fluoride, tetrapropylammonium bromide (( 7.9 g (0.030 mol) of C ₃ H ₇ ) ₄ NBr) was added and mixed well by stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 50.0 g (0.297 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 36.4 g of a collected product was obtained, and gas chromatogram (GC) analysis confirmed the production of trifluoromethanesulfonyl fluoride. The product was obtained in a purity of 98.9% and a yield of 79.7%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Step 3] Production of trifluoromethanesulfonyl fluoride- A 200 ml glass flask equipped with a condenser cooled to about 30 ° C was charged with 100 g of water, 52.2 g (0.898 mol) of potassium fluoride, methyltributylammonium chloride (CH ₃ N (Cl) (C ₃ H ₇ ) ₃ ) was added in an amount of 3.5 g (0.015 mol) and mixed well with stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 25.2 g (0.150 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 18.1 g of a collected product was obtained, and generation of trifluoromethanesulfonyl fluoride was confirmed by gas chromatogram (GC) analysis. The product was obtained in a purity of 99.3% and a yield of 79.6%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Step 3] Production of trifluoromethanesulfonyl fluoride- A 200 ml glass flask equipped with a condenser cooled to about 30 ° C was charged with 50 g of water, 27.0 g (0.465 mol) of potassium fluoride, benzyltriethylammonium chloride (C 7.2 g (0.032 mol) of ₆ H ₅ CH ₂ N (Cl) (C ₂ H ₅ ) ₃ ) was added, and the mixture was stirred and mixed well. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 52.3 g (0.310 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 32.7 g of collected matter was obtained, and generation of trifluoromethanesulfonyl fluoride was confirmed by gas chromatogram (GC) analysis, and it was obtained with a purity of 98.5% and a yield of 69.4%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Third step] Production of trifluoromethanesulfonyl fluoride-In a 200 ml glass flask equipped with a condenser cooled to about 30 ° C, 50 g of water, 27.0 g (0.465 mol) of potassium fluoride, benzyltributylammonium chloride (C 9.7 g (0.031 mol) of ₆ H ₅ CH ₂ N (Cl) (C ₄ H ₉ ) ₃ ) was added and mixed well with stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 52.3 g (0.310 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 41.7 g of a collected product was obtained, and generation of trifluoromethanesulfonyl fluoride was confirmed by gas chromatogram (GC) analysis. The product was obtained in a purity of 99.6% and a yield of 88.5%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Third Step] Production of trifluoromethanesulfonyl fluoride— Into a 200 ml glass flask equipped with a condenser cooled to about 30 ° C., 50 g of water, 27.0 g (0.465 mol) of potassium fluoride, methyltrioctylammonium chloride ( 12.0 g (0.031 mol) of (C ₈ H ₁₇ ) ₃ N (Cl) CH ₃ ) was added and mixed well with stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 52.3 g (0.310 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 37.9 g of a collected product was obtained, and the production of trifluoromethanesulfonyl fluoride was confirmed by gas chromatogram (GC) analysis. The product was obtained in a purity of 95.1% and a yield of 80.4%.

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonyl chloride obtained in the second step, the following third step was performed.
[Third step] Production of trifluoromethanesulfonyl fluoride- A 200 ml glass flask equipped with a condenser cooled to about 30 ° C was charged with 100 g of water, 51.7 g (0.890 mol) of potassium fluoride, tetrabutylphosphonium bromide (( 10.4 g (0.030 mol) of C ₄ H ₉ ) ₄ PBr) was added and mixed well with stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 50.0 g (0.297 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 21.1 g of a collected product was obtained, and generation of trifluoromethanesulfonyl fluoride was confirmed by gas chromatogram (GC) analysis. The product was obtained in a purity of 90.6% and a yield of 42.3%.
[Comparative Example 1] Production of trifluoromethanesulfonyl fluoride Step A, Step 1 and Step 2 were carried out in the same manner as in Example 1. The following experiment was conducted using the trifluoromethanesulfonyl chloride obtained in the second step.

  100 g of water and 51.7 g (0.890 mol) of potassium fluoride were charged into a 200 ml glass flask equipped with a condenser cooled to about −30 ° C. and mixed well with stirring. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 50.0 g (0.297 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 5.3 g of a collected product was obtained, and gas chromatogram analysis confirmed the production of trifluoromethanesulfonyl fluoride. The product was obtained in a purity of 1.0% and a yield of 0.1%.

Thus, it can be seen that when the halogenated quaternary salt is not used, the reaction does not proceed, and the target trifluoromethanesulfonyl fluoride is hardly obtained.
[Comparative Example 2] Production of trifluoromethanesulfonyl fluoride Step A, Step 1 and Step 2 were carried out in the same manner as in Example 1. The following experiment was conducted using the trifluoromethanesulfonyl chloride obtained in the second step.
In a 200 ml glass flask equipped with a condenser cooled to about −30 ° C., 100 g of water, 51.7 g (0.890 mol) of potassium fluoride, and 7.8 g (0.030 mol) of crown ether (18-crown-6) ) The mixture was stirred and mixed well. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 50.0 g (0.297 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was refluxed with stirring at room temperature for 1 hour. After stirring, the condenser temperature was raised to about −20 ° C., and the gas produced by the reaction was collected by a collector cooled with liquid nitrogen. 23.6 g of a collected product was obtained, and gas chromatogram analysis confirmed the production of trifluoromethanesulfonyl fluoride. The product was obtained with a purity of 49.7% and a yield of 26.0%.
[Comparative Example 3] Production of trifluoromethanesulfonyl fluoride Step A, Step 1 and Step 2 were carried out in the same manner as in Example 1. The following experiment was conducted using the trifluoromethanesulfonyl chloride obtained in the second step.
100 g of water, 51.7 g (0.890 mol) of potassium fluoride, and 17.5 g (0.088 mol) of polyethylene glycol 200 (PEG200) were charged into a 200 ml glass flask equipped with a condenser cooled to about −30 ° C. and stirred. And mixed well. The liquid temperature was cooled to 10 ° C. under atmospheric pressure, and 50.0 g (0.297 mol) of trifluoromethanesulfonyl chloride was added dropwise over 1 hour. After completion of the dropping, the mixture was stirred at room temperature for 1 hour, and then the condenser temperature was raised to about −20 ° C., and the gas generated by the reaction was collected by a collector cooled with liquid nitrogen. 22.7 g of a collected product was obtained, and gas chromatogram analysis confirmed the production of trifluoromethanesulfonyl fluoride. The product was obtained in a purity of 52.3% and a yield of 26.3%.

  Thus, when crown ether or polyethylene glycol is used, trifluoromethanesulfonyl fluoride is obtained, but the yield is low compared to Example 1-9, and there is some difficulty in industrial production.

Claims (11)

A method for purifying trifluoromethanesulfonyl fluoride (CF ₃ SO ₂ F), comprising the following three steps.
First step: A step of reacting a metal hydroxide with trifluoromethanesulfonyl fluoride, followed by treatment with an acid to obtain trifluoromethanesulfonic acid (CF ₃ SO ₃ H).
Second step: A step of reacting the trifluoromethanesulfonic acid obtained in the first step with phosphorus trichloride (PCl ₃ ) and chlorine (Cl ₂ ) to obtain trifluoromethanesulfonyl chloride (CF ₃ SO ₂ Cl).
Third step: A step of reacting the trifluoromethanesulfonyl chloride obtained in the second step with metal fluoride in the presence of water and a halogenated quaternary salt to obtain trifluoromethanesulfonyl fluoride. After reacting trifluoromethanesulfonyl fluoride with a metal hydroxide and subsequently treating with an acid to obtain trifluoromethanesulfonic acid (first step), the metal hydroxide is potassium hydroxide, sodium hydroxide, The method according to claim 1, which is at least one selected from the group consisting of lithium hydroxide, cesium hydroxide, magnesium hydroxide, and calcium hydroxide. When the trifluoromethanesulfonic acid obtained in the first step is reacted with phosphorus trichloride and chlorine (PCl ₃ + Cl ₂ ) to obtain trifluoromethanesulfonyl chloride (CF ₃ SO ₂ Cl) (second step), the reaction system The method according to claim 1, wherein the method is carried out by allowing phosphorus oxychloride (POCl ₃ ) to coexist in the inside. When the metal fluoride is reacted with trifluoromethanesulfonyl chloride obtained in the second step in the presence of water and a halogenated quaternary salt (third step), the metal fluoride is lithium fluoride (LiF), fluoride. The method according to any one of claims 1 to 3, wherein the method is at least one selected from the group consisting of sodium (NaF), potassium fluoride (KF), rubidium fluoride (RbF), and cesium fluoride (CsF). When the trifluoromethanesulfonyl chloride obtained in the second step is reacted with a metal fluoride in the presence of water and a halogenated quaternary salt (third step), the halogenated quaternary salt is represented by the formula [1]. Ammonium halide salt
(Wherein R ¹ is the same or different linear or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 9 carbon atoms or the same or different aryl group (wherein some or all of the hydrogen atoms are halogen atoms) (Fluorine, chlorine, bromine, iodine), alkyl group, amino group, nitro group, acetyl group, cyano group or hydroxyl group may be substituted), X is halogen (fluorine, chlorine, bromine, iodine) Represents
Or a halogenated phosphonium salt represented by the formula [2]
(Wherein R ¹ and X are the same as those in formula [1])
The method according to claim 1, wherein: The group in which the ammonium halide salt consists of tetrapropylammonium bromide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, methyltributylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, methyltrioctylammonium chloride The method of Claim 5 which is at least 1 sort (s) chosen from. The method according to claim 5, wherein the phosphonium halide salt is at least one selected from the group consisting of tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetrabutylphosphonium chloride, and tetrabutylphosphonium bromide. The method according to any one of claims 5 to 7, wherein the amount of the halogenated quaternary salt is 0.005 to 1.0 mol with respect to 1 mol of trifluoromethanesulfonyl chloride. The amount of metal fluoride is 1 mol of trifluoromethanesulfonyl chloride.
The method according to claim 5, wherein the method is 1 to 10 mol. The method according to any one of claims 5 to 9, wherein the temperature during the reaction is -5 ° C to 20 ° C. The trifluoromethanesulfonyl fluoride used in the first step is obtained by fluorinating methanesulfonyl chloride with a metal fluoride and fluorinating the obtained methanesulfonyl fluoride in anhydrous hydrogen fluoride by an electrolytic method. A method according to any one of claims 1 to 10.