JP2009102294A - Method for purification of trifluoromethanesulfonyl fluoride - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily producing trifluoromethanesulfonyl fluoride having high purity with a simple and short process on a commercial scale. <P>SOLUTION: Trifluoromethanesulfonyl fluoride is produced by reacting trifluoromethanesulfonyl fluoride with a metal hydroxide, treating with an acid to obtain trifluoromethanesulfonic acid, reacting the trifluoromethanesulfonic acid with a dehydration agent to obtain trifluoromethanesulfonic anhydride and reacting the trifluoromethanesulfonic anhydride with a fluorinating agent. High purity trifluoromethanesulfonyl fluoride can be produced in high selectivity and efficiency through 3 steps from trifluoromethanesulfonyl fluoride produced by an electrolytic fluorination method. The method is an extremely excellent method for the production of the compound on a commercial scale since the object compound is repeatedly producible by the method. <P>COPYRIGHT: (C)2009,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 document 7, after making trifluoromethanesulfonic acid and phosphorus pentoxide react, the produced | generated trifluoromethanesulfonic acid (trifluoromethanesulfonic anhydride) was distilled, phosphorus pentoxide was further added to this distillate, and it recirculate | refluxed. In addition, a method for purifying trifluoromethanesulfonic anhydride by distillation or vacuum distillation is disclosed. In Patent Document 8, a method of reacting trifluoromethanesulfonic acid with phosphorus pentoxide to obtain trifluoromethanesulfonic anhydride in a fluorine-based solvent is disclosed in Patent Document 9-10. A method for producing trifluoromethanesulfonic anhydride using phosphorus chloride and chlorine 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 2002-088050 A JP-A-9-227498 Japanese Patent Laid-Open No. 11-236365 Japanese Patent Laid-Open No. 11-236366

  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 manufacturing facility (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. .

  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] to [Invention 14] 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 a dehydrating agent to obtain trifluoromethanesulfonic anhydride ((CF ₃ SO ₂ ) ₂ O).
Third step: A step of obtaining trifluoromethanesulfonyl fluoride by reacting the trifluoromethanesulfonic anhydride obtained in the second step with a fluorinating agent.
[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 a dehydrating agent to obtain trifluoromethanesulfonic anhydride (second step), the dehydrating agent is phosphorus pentoxide (P ₂ O ₅ ) or pentachloride. The method according to invention 1 or 2, which is phosphorus (PCl ₅ ).
[Invention 4]
The trifluoromethanesulfonic acid anhydride obtained in the second step is reacted with any of the following steps when the fluorinating agent is reacted (third step). the method of.
Third step (a): A step of reacting trifluoromethanesulfonic anhydride with hydrogen fluoride in the presence of an organic base to obtain trifluoromethanesulfonyl fluoride.
Third step (b): a step of reacting a metal fluoride with trifluoromethanesulfonic anhydride to obtain trifluoromethanesulfonyl fluoride.
[Invention 5]
When trifluoromethanesulfonic anhydride is reacted with hydrogen fluoride in the presence of an organic base (third step (a)), trifluoromethanesulfonic anhydride and hydrogen fluoride are first allowed to coexist, followed by organic base. The method according to invention 4, wherein the method is carried out by adding
[Invention 6]
When trifluoromethanesulfonic anhydride is reacted with hydrogen fluoride in the presence of an organic base (third step (a)), the organic base and hydrogen fluoride are first allowed to coexist, followed by trifluoromethanesulfonic anhydride. The method according to invention 4, wherein the method is carried out by adding
[Invention 7]
When hydrogen fluoride is reacted with trifluoromethanesulfonic anhydride in the presence of an organic base (third step (a)), the amount of the organic base is 0.1 to 100 mol with respect to 1 mol of trifluoromethanesulfonic anhydride. The method according to any one of inventions 4 to 6, characterized in that:
[Invention 8]
When hydrogen fluoride is reacted with trifluoromethanesulfonic anhydride in the presence of an organic base (third step (a)), the amount of the fluorinating agent is 0.1 to 100 with respect to 1 mol of trifluoromethanesulfonic anhydride. The method according to any one of Inventions 4 to 7, wherein the method is a mole.
[Invention 9]
The invention is characterized in that when trifluoromethanesulfonic acid anhydride is reacted with hydrogen fluoride in the presence of an organic base (third step (a)), the temperature during the reaction is -30 ° C to 90 ° C. The method according to any one of 4 to 8.
[Invention 10]
When the metal fluoride is reacted with trifluoromethanesulfonic anhydride (third step (b)), the metal fluoride is lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), The method of the invention 4 which is rubidium fluoride (RbF) or cesium fluoride (CsF).
[Invention 11]
The method according to any one of inventions 4 to 10, characterized in that, when trifluoromethanesulfonic anhydride is reacted with a metal fluoride (third step (b)), water is used as a solvent. .
[Invention 12]
Any of the inventions 4 to 11, characterized in that when the metal fluoride is reacted with trifluoromethanesulfonic anhydride (third step (b)), the temperature at the time of reaction is -5 to 90 ° C. The method of crab.
[Invention 13]
When the metal fluoride is reacted with the trifluoromethanesulfonic anhydride (third step (b)), the amount of the metal fluoride is 0.1 to 100 mol with respect to 1 mol of the trifluoromethanesulfonic anhydride. A method according to any one of inventions 4 to 12, characterized by:
[Invention 14]
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 13.

  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.

  Among the three steps, particularly in the third step (fluorination step), the reaction proceeds well and the target product is obtained in a high yield, which is extremely useful for manufacturing on an industrial scale. Obtained.

  In particular, when hydrogen fluoride is used as the fluorinating agent in the third step (a), when only trifluoromethanesulfonic anhydride and hydrogen fluoride are reacted, the reaction does not proceed at all (comparison described later). We have found that the reaction proceeds satisfactorily by reacting hydrogen fluoride in the presence of an organic base in the reaction system, and the target product can be obtained with high purity.

  On the other hand, in the third step (b), the reaction proceeds satisfactorily by using water as a solvent, and the target product is obtained in a high yield, which is extremely useful for production on an industrial scale. It was. When the present inventors use water as a solvent, trifluoromethanesulfonic anhydride as a raw material reacts with water instead of metal fluoride, causing hydrolysis, and it is difficult to obtain the target product. I originally expected that. However, it has been found that the target product can be obtained satisfactorily by reacting preferentially with metal fluoride without actually causing hydrolysis.

  The applicant has already filed applications for the contents of the third step (a) and the third step (b) of the third step in the present invention (Japanese Patent Application No. 2007-129454, Japanese Patent Application No. 2007-). 129455). In the present invention, by combining these steps, it is possible to easily produce trifluoromethanesulfonyl fluoride obtained by fluorination by an electrolytic method without performing a purification operation. Gas equipment) can be simplified. In addition, since trifluoromethanesulfonyl fluoride can be produced repeatedly through three steps, it is no longer necessary to handle a flammable gas (hydrogen gas) that has been a concern in conventional electrolytic fluorination methods.

  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. To obtain a trifluoromethanesulfonic anhydride (second step), and reacting the trifluoromethanesulfonic anhydride obtained in the second step with a fluorinating agent to give trifluoromethanesulfonyl fluoride. (3rd step).

  The following is summarized as Scheme 1.

  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 Produced by fluorinating methanesulfonyl chloride with metal fluoride and fluorinating the obtained methanesulfonyl fluoride in anhydrous hydrogen fluoride by electrolysis (this step is also referred to as “step A” in this specification) (See scheme 2 below).

  However, a mixed gas of about 20 vol% trifluoromethanesulfonyl fluoride and about 80 vol% hydrogen is generated from the electrolytic cell in the reaction solution during production. 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 manufacturing facility (high-pressure gas facility) is required, which is dangerous.

  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 is preferably performed under reduced pressure distillation 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 the trifluoromethanesulfonic acid obtained in the first step with a dehydrating agent to obtain trifluoromethanesulfonic anhydride (see Scheme 4).

  As the dehydrating agent used in this step, phosphorus pentoxide or phosphorus pentachloride is preferable. Other known substances used for dehydration, such as formic acid, acetic anhydride, thionyl chloride, dicyclohexylcarbodiimide (DCC), cyanuric chloride, titanium (IV) chloride or benzenesulfonyl chloride, are also known. It can also be used as an agent. However, phosphorus pentoxide or phosphorus pentachloride is industrially inexpensive and easy to handle and is preferably used.

Next, reaction conditions when phosphorus pentoxide and phosphorus pentachloride are used as the dehydrating agent will be described in detail below.
i) When phosphorus pentoxide (P ₂ O ₅ ) is used When phosphorus pentoxide is used, the amount used is usually 0.1 to 10 moles per mole of trifluoromethanesulfonic acid, and 2 to 6 It is preferably a mole, more preferably 2 to 4 mole. When the amount is less than 0.1 mol, the recovery rate is lowered, which is not preferable. On the other hand, when the amount is more than 10 mol, it is not preferable from the economical viewpoint that the inside of the reaction system is solidified and it is difficult to stir, and that an unnecessary amount of phosphorus pentoxide is used.

  In addition, when phosphorus pentoxide is reacted here, if a large amount is added to trifluoromethanesulfonic acid from the beginning, it cannot be solidified and stirred in the reaction system, and the recovery rate when distilled is reduced. Sometimes. Therefore, adding phosphorus pentoxide continuously or sequentially is one of the preferred embodiments because consolidation in the reaction system 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 Perfluoroalkylamines represented by N (n = 2 to 6), perfluoropolyethers, and the like. Among them, fluoroalkylsulfonic acid anhydrides (for example, trifluoromethanesulfonic acid) are preferred from the viewpoint of recovery of the product after the dehydration reaction. Anhydride) is particularly preferred. One type or a plurality of solvents may be combined.

The reaction temperature can usually be carried out at -20 ° C to 100 ° C. If it is lower than −20 ° C., the reaction rate becomes slow and the viscosity becomes high. Moreover, when it exceeds 100 degreeC, a decomposition reaction will accelerate | stimulate and a reaction liquid will solidify. Excessive heating is not energy efficient and is not preferable from the viewpoint of economy. The reaction time is preferably about 1 to 6 hours.
ii) When phosphorus pentachloride (PCl ₅ ) is used When phosphorus pentachloride is used, it can be used usually in an amount of 1 mol or less, preferably 1 mol or less, based on 1 mol of trifluoromethanesulfonic acid. 0.2 to 0.6 mol, and more preferably 0.2 to 0.5 mol. When the amount is more than 1 mol, trifluoromethanesulfonic acid chloride is produced as a by-product, and the yield of trifluoromethanesulfonic anhydride, which is the target product of this step, may be reduced.

It is also possible to use phosphorus trichloride (PCl ₃ ) and chlorine (Cl ₂ ) instead of phosphorus pentachloride and use it as phosphorus pentachloride in the reaction system (PCl ₃ + Cl ₂ → PCl ₅ ). In this case, the addition amount of phosphorus trichloride and chlorine may be usually 1 mol or less with respect to 1 mol of trifluoromethanesulfonic acid.

  When phosphorus pentachloride is added, since it generates heat, the reaction temperature at the time of addition is preferably 40 ° C. or lower, more preferably 0 ° C. to 20 ° C. Although the reaction temperature after the addition is preferably about 20 to 80 ° C, it is more preferably 40 to 80 ° C in order to promote the reaction. The reaction time is preferably about 1 to 6 hours.

When phosphorus pentachloride is used, a solvent can be used. However, even when trifluoromethanesulfonic anhydride, phosphoryl chloride (POCl ₃ ), and trifluoromethanesulfonyl chloride are produced in the reaction system by the reaction, these include trifluoromethanesulfonic acid that is an unreacted raw material, It is liquid and does not require a solvent. Moreover, it can isolate | separate and refine | purify easily by distilling after completion | finish of reaction. Therefore, in the present invention, the target product, trifluoromethanesulfonic anhydride, can be obtained very easily and efficiently.

  Moreover, although said i) and ii) can be performed under normal pressure or under pressure, since the pressure does not affect the reaction, the reaction proceeds sufficiently even under normal pressure. Specifically, it is performed at 0.0001 to 1.0 MPa (absolute pressure reference, hereinafter the same in the specification), preferably 0.001 to 0.5 MPa, particularly preferably 0.01 to 0.2 MPa. it can.

  The reactor used in this step is not particularly limited in material, and a reactor in which tetrafluoroethylene resin, chlorotrifluoroethylene resin, vinylidene fluoride resin, PFA resin, glass or the like is lined, or a glass container is used. Can be used.

  After completion of the reaction, trifluoromethanesulfonic anhydride can be obtained by ordinary means such as filtration, extraction, distillation, recrystallization and the like.

  Next, the third step will be described. The third step is a step of obtaining trifluoromethanesulfonyl fluoride by reacting the trifluoromethanesulfonic anhydride obtained in the second step with a fluorinating agent.

Examples of the fluorinating agent used in this step include hydrogen fluoride or metal fluoride. Moreover, as a concrete aspect of this process, the following two processes,
Third step (a): A step of reacting trifluoromethanesulfonic anhydride with hydrogen fluoride in the presence of an organic base to obtain trifluoromethanesulfonyl fluoride.
Third step (b): a step of reacting a metal fluoride with trifluoromethanesulfonic anhydride to obtain trifluoromethanesulfonyl fluoride.
It goes by going through either.

First, the third step (a) will be described. This step is a step for producing trifluoromethanesulfonyl fluoride by reacting trifluoromethanesulfonic anhydride ((CF ₃ SO ₂ ) ₂ O) with hydrogen fluoride (HF) in the presence of an organic base.

  Although there is no special restriction | limiting as an organic base used at this process, The basic substance which has the intensity | strength that pH becomes 8 or more is preferable.

Preferred organic bases used in the reaction of this step are (a) primary amine, (b) secondary amine, (c) tertiary amine, (d) nitrogen-containing aromatic heterocyclic compound, (e) Imine skeleton -C = N-C-
It is an organic base selected from the group consisting of organic bases having “(imine bases)”.

  The “nitrogen-containing aromatic heterocyclic compound” includes a ring assembly compound and a condensed ring compound in addition to a monocyclic compound. The number of atoms constituting the aromatic ring is usually from 5 to 30, and preferably from 5 to 18, and those having 6 to 10 atoms are particularly preferred because they are readily available and have excellent performance. On the rings of these monocyclic compounds, ring assembly compounds, and condensed ring compounds, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, halogen (F, Cl, Br, I), A halogen-substituted alkyl group or the like may be further substituted.

Specific examples of these organic bases are as follows.
(A) Primary amine: methylamine, ethylamine, isopropylamine, n-butylamine, N, N-dimethylaniline, N, N-diethylaniline, guanidine and the like.
(B) Secondary amine: dimethylamine, diethylamine, di-n-butylamine, dibutylamine, diisopropylamine, piperidine, pyrrolidine, morpholine and the like.
(C) Tertiary amine: trimethylamine, triethylamine, N-ethyldiisopropylamine, di-isopropylethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, trioctylamine, tridecylamine, triphenylamine , Tribenzylamine, tris (2-ethylhexyl) amine, N, N-dimethyldecylamine, N-benzyldimethylamine, N-butyldimethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N-dimethylaniline, N, N-diethylaniline, 1,4-diazabicyclo [2.2.2] octane, N-methylpyrrolidine, N-methylpiperidine, N-methylmorpholine, N-ethylmorpholine, N, N -Dimethylpiperazine, N-methylpipecholine, N-methylpyrrolidone, N-vinyl-pyrrolidone, bis (2-dimethylamino-ethyl) ether, N, N, N, N ', N''-pentamethyl-diethylenetriamine, tri Ethanolamine, tripropanolamine, dimethylethanolamine, dimethylaminoethoxyethanol, N, N-dimethylaminopropylamine, N, N, N ′, N ′, N ″ -pentamethyldipropylenetriamine, tris (3-dimethyl) Aminopropyl) amine, tetramethylimino-bis (propylamine), N-diethyl-ethanolamine and the like.
(D) Nitrogen-containing aromatic heterocyclic compounds: pyridine, 2-methylpyridine, 2,4,6-trimethylpyridine, 4-dimethylaminopyridine, 2,6-lutidine, pyrimidine, pyridazine, pyrazine, oxazole, isoxazole , Thiazole, isothiazole, imidazole, 1,2-dimethylimidazole, 3- (dimethylamino) propylimidazole, pyrazole, furazane, pyrazine, quinoline, isoquinoline, purine, 1H-indazole, quinazoline, cinnoline, quinoxaline, phthalazine, pteridine, Phenanthridine, 2,6-di-t-butylpyridine, 2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridyl, 4,4′-dimethyl-2,2′-bipyridyl, 5,5′-dimethyl-2,2′-bipyridyl, 6,6 ′ t-butyl-2,2′-dipyridyl, 4,4′-diphenyl-2,2′-bipyridyl, 1,10-phenanthroline, 2,7-dimethyl-1,10-phenanthroline, 5,6-dimethyl-1 , 10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline and the like.
(E) Imine base: 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5-diazabicyclo [4.3.0] non-5-ene and the like.
Of the organic base.

  Among these organic bases, in order to particularly increase the yield of the target trifluoromethanesulfonyl fluoride, it is preferable to use the organic bases (a) to (e). Among the organic bases, methylamine, Ethylamine, isopropylamine, dimethylamine, diethylamine, di-n-butylamine, dibutylamine, trimethylamine, triethylamine, N-ethyldiisopropylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethylbenzylamine, pyridine, piperidine, pyrrolidine, morpholine, 4-methylpyridine, 1,4-diazabicyclo [2.2.2] Ok An organic base selected from 1,8-diazabicyclo [5.4.0] undec-7-ene is preferred, and among these, diethylamine, di-n-butylamine, triethylamine, pyridine are preferred because of economy and ease of handling. 4-methylpyridine is particularly preferred.

  These organic bases may be used alone or in combination of two or more organic bases.

  Although there is no special restriction | limiting in the quantity of the organic base used for this process, It is 0.1-100 mol normally with respect to 1 mol of trifluoromethanesulfonic anhydride, It is preferable that it is 0.1-50 mol, More preferably, it is 0.1-10 mol. The fact that the organic base is less than 0.1 mol does not have a great effect on the selectivity, but the reaction conversion rate is low, leading to a decrease in yield. Conversely, if the organic base is more than 100 mol, it is economical. It is disadvantageous to both, so neither is preferable.

  Although there is no special restriction | limiting in the quantity of the hydrogen fluoride used for this process, It is 0.1-100 mol normally with respect to 1 mol of trifluoromethanesulfonic anhydride, It is preferable that it is 0.1-50 mol. More preferably, it is 0.1-10 mol. Less than 0.1 mol of hydrogen fluoride 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 there is more than 100 mol of hydrogen fluoride, Neither is desirable because it is economically disadvantageous.

  Although there is no special restriction | limiting in the mixing ratio of an organic base and hydrogen fluoride, It is preferable to carry out by adding more than an equivalent amount of either hydrogen fluoride or an organic base.

  In this step, the reaction can also be carried out using “a salt or complex comprising an organic base and hydrogen fluoride”. At that time, there is no particular limitation on the molar ratio of the organic base and hydrogen fluoride in the “salt or complex comprising an organic base and hydrogen fluoride”, but usually a range of 100: 1 to 1: 100 is used. It is preferably 50: 1 to 1:50, and more preferably 25: 1 to 1:25. Although there is no restriction | limiting in particular as a preparation method of "the salt or complex which consists of an organic base and hydrogen fluoride", Usually, what is necessary is just to mix an organic base and hydrogen fluoride in arbitrary ratios under cooling. It is also convenient to use a “complex comprising 1 mol of triethylamine and 3 mol of hydrogen fluoride” commercially available from Aldrich (2003-2004 General Catalog).

The amount of the “salt or complex comprising an organic base and hydrogen fluoride” is not particularly limited, but usually 1 mol or more of fluorine anion (F ⁻ ) is used per 1 mol of trifluoromethanesulfonic anhydride. What is necessary is just 1-30 mol, and especially 1-15 mol is more preferable.

  Moreover, this process can also react by making an organic solvent coexist separately. Here, the organic solvent refers to an inert organic compound that does not directly participate in the reaction of this step. Specific examples of the reaction solvent include aliphatic hydrocarbons such as n-hexane, cyclohexane and n-heptane, aromatic hydrocarbons such as benzene, toluene and xylene, methylene chloride, chloroform, 1,2-dichloroethane and the like. Halogenated hydrocarbons, ethers such as diethyl ether, tetrahydrofuran and tert-butyl methyl ether, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and n-butyl acetate, N, N-dimethylformamide, N, Examples thereof include amides such as N-dimethylacetamide and N-methylpyrrolidone, nitriles such as acetonitrile and propionitrile, and dimethyl sulfoxide. Among these, n-heptane, toluene, methylene chloride, tetrahydrofuran, acetone, ethyl acetate, N, N-dimethylformamide, acetonitrile and dimethyl sulfoxide are preferable, and toluene, methylene chloride, tetrahydrofuran, N, N-dimethylformamide and acetonitrile are more preferable. preferable. These reaction solvents can be used alone or in combination.

  The amount of the solvent can be optimized by those skilled in the art so that the reagent dissolves sufficiently and the reaction proceeds smoothly. The amount of the solvent is usually 0.5 to 1 g per trifluoromethanesulfonic anhydride. 5 g, preferably 0.8-3 g, more preferably 1-2 g.

  In addition, when the above-mentioned “organic base” is a liquid, these organic bases (for example, triethylamine and the like) also serve as a solvent (see Examples described later). You can also

  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.

  The reaction temperature in this step is usually −30 ° C. to 90 ° C., preferably −20 ° C. to 70 ° C., and −5 ° C. to 50 ° C. does not take a cooling load and is easy to control the temperature. Therefore, it is a more preferable temperature range.

There are no particular restrictions on the method of charging the raw material trifluoromethanesulfonic anhydride and the reaction reagent, but usually trifluoromethanesulfonic anhydride ((CF ₃ SO ₂ ) ₂ O) is added in the presence of an organic base in the presence of an organic base. Can be reacted.

  In addition, the present inventors have also obtained knowledge that the target product can be obtained in a higher yield by appropriately changing the order in which reagents are added to the reaction system.

For example, in the embodiment:
i) Add trifluoromethanesulfonic anhydride and hydrogen fluoride first, then add organic base
ii) After coexisting the organic base and hydrogen fluoride first, add trifluoromethanesulfonic anhydride.
iii) Add trifluoromethanesulfonic anhydride and organic base first, then add hydrogen fluoride
iv) trifluoromethanesulfonic anhydride is charged first, followed by hydrogen fluoride and organic base at once, or sequentially or continuously
v) An organic base is charged first, and then trifluoromethanesulfonic anhydride and hydrogen fluoride are added at once, or sequentially or continuously.

  In any of the operations i) to v), the target product can be suitably obtained. Of these, the present inventors have found that the preparation methods i) and ii) are more selective and highly pure. The knowledge to obtain the target was obtained.

  For example, in this example, trifluoromethanesulfonic anhydride is added to the reactor, hydrogen fluoride is added first while stirring, and then an organic base is dropped (Example 2-5), It is one of the particularly preferred embodiments in the present invention that an organic base is put into a reactor, and hydrogen fluoride is first allowed to coexist with stirring, followed by dropwise addition of trifluoromethanesulfonic anhydride (Example 1). One.

  Next, the third step (b) will be described. This step is a step of obtaining trifluoromethanesulfonyl fluoride by reacting trifluoromethanesulfonic anhydride with metal fluoride (MF).

  Regarding the metal fluoride used in this step, the metal referred to here is an alkali metal, and examples of the alkali metal include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs ).

  Specific compounds of metal fluorides are lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, and cesium fluoride. Among these, sodium fluoride is relatively easy to obtain. Potassium fluoride is preferably used. These fluorides can be used alone or in admixture of two or more.

  The amount of the metal fluoride is usually 0.1 to 100 mol, preferably 1 to 50 mol, more preferably 1 to 25 mol, relative to 1 mol of trifluoromethanesulfonic anhydride. If it is less than 1 mol, the reaction yield will be reduced. Further, there is no problem with the progress of the reaction even when an amount of metal fluoride exceeding 10 mol is used, but there is no particular advantage in terms of reaction rate and yield.

  Moreover, this process can also react by making a solvent coexist in a reaction system. Here, the solvent means an inert substance that does not directly participate in the reaction of this step. Specific solvents include aliphatic hydrocarbons such as n-hexane, cyclohexane and n-heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and halogens such as methylene chloride, chloroform and 1,2-dichloroethane. Hydrocarbons, ethers such as diethyl ether, tetrahydrofuran, tert-butyl methyl ether, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and n-butyl acetate, N, N-dimethylformamide, N, N Examples include amides such as dimethylacetamide and N-methylpyrrolidone, nitriles such as acetonitrile and propionitrile, alcohols such as methanol, ethanol, isopropanol, n-butanol and phenol, dimethyl sulfoxide, and water. Among these, n-heptane, toluene, methylene chloride, tetrahydrofuran, acetone, ethyl acetate, N, N-dimethylformamide, acetonitrile, water, methanol, ethanol, isopropanol, and dimethyl sulfoxide are preferable, and toluene, methylene chloride, tetrahydrofuran, N , N-dimethylformamide, acetonitrile, methanol, and ethanol are more preferred. These reaction solvents can be used alone or in combination.

  The amount of the solvent can be optimized by those skilled in the art so that a sufficient amount of the reagent dissolves and the reaction proceeds smoothly. However, the amount of the solvent is usually 0.1 g to 10 g with respect to 1 g of trifluoromethanesulfonic anhydride. Yes, preferably 0.8 to 8 g, more preferably 1 to 6 g.

  Moreover, in this process, the knowledge which obtains the said target object with high purity and a high yield was acquired by making water coexist as a solvent. For example, in Examples 6 and 7, it is a particularly preferred embodiment to obtain trifluoromethanesulfonyl fluoride with high purity (purity 99% or more) and high yield (88-91%) by using water as a solvent. One.

  Thus, when considering the industrial production method of this step, the reaction proceeds sufficiently even with a method using water as a solvent, and the desired product can be suitably obtained.

  When water is used as the reaction solvent in this step, the solubility varies depending on the type of metal fluoride, and 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 50%, preferably 20% to 40%, more preferably 25% to 35%. 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.

  The reaction temperature in this step can be in the range of −5 ° C. to 90 ° C., but −10 ° C. to 70 ° C. is preferable because the cooling load is not applied and temperature control is easy. Among these, performing the reaction in the range of 0 ° C. to 60 ° C. is a particularly preferable aspect of the present invention because it does not take a cooling load and is easy to control the temperature. When the temperature is lower than -20 ° C, the conversion rate of the reaction is lowered. For example, when water is used as a solvent, if a large amount of water is present in the reaction system, solidification may occur, which is not preferable. On the other hand, when the temperature exceeds 90 ° C., the raw material trifluoromethanesulfonic anhydride is liable to vaporize and does not react well with the metal fluoride.

  The reaction time in this step 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 has not progressed by a technique such as gas chromatography. Can be adjusted. Furthermore, when carrying out this reaction, it is preferable to stir in order to advance the reaction efficiently.

  Among the third steps, there is no particular limitation on the reaction pressure in any of the third step (a) and the third step (b), and the reaction is carried out under normal pressure (atmospheric pressure), pressurized or reduced pressure conditions. be able to. 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. For this reason, it is also possible to seal the reaction system using a pressure-resistant reaction vessel and to perform the reaction under pressurized conditions.

  In the third step, it is also possible to carry out the reaction under reduced pressure conditions. In the present invention, since the target product is generated as a gas as described above, 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. It is also possible to carry out the reaction under normal pressure (atmospheric pressure). In the present invention, the reaction is carried out while returning the generated gas (trifluoromethanesulfonyl fluoride) to the reactor while circulating it through a condenser (condenser, also referred to as a cooler) cooled below the boiling point of trifluoromethanesulfonyl fluoride (this At the same time as the operation is also referred to as reflux), when a certain pressure is reached, a part of the condenser is opened and a part of the gas circulated through the condenser is collected by the collector. The reaction can be carried out with almost no increase in pressure. Thus, the present invention can be sufficiently carried out even at normal pressure (atmospheric pressure).

  The reactor used in the third step can use a tetrafluoroethylene resin, a chlorotrifluoroethylene resin, a vinylidene fluoride resin, a PFA resin, or the like when the reaction is performed at normal pressure. 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.

  The object of the present invention, trifluoromethanesulfonyl fluoride, has a very low boiling point (boiling point -21 ° C.) and exists as a gas at room temperature. Therefore, the present inventors easily circulate the gas generated after the reaction through a condenser cooled to less than 0 ° C., specifically, −20 to −30 ° C., and then collect the gas to easily obtain high purity. It was also found that trifluoromethanesulfonyl fluoride can be obtained, and purification operation such as distillation is not required.

  For example, after adding trifluoromethanesulfonic anhydride, an organic base, and hydrogen fluoride, the generated gas is circulated through a condenser cooled to −30 ° C., and the reaction liquid is returned to the reaction vessel while returning the circulated gas to room temperature. Raise to reflux. 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 particularly preferable embodiments for carrying out 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.

  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 12% potassium hydroxide aqueous solution is supplied at 60 ° C. over 1 hour, and trifluoromethane is added. 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 trifluoromethanesulfonic anhydride 498 g (1.766 mol) of trifluoromethanesulfonic anhydride and 348 g (2.320 mol) of trifluoromethanesulfonic acid were placed in a glass 1000 ml flask and oxidized with stirring. 165 g (1.162 mol) of phosphorus (P ₂ O ₅ ) was added while keeping the internal temperature at 20 ° C. or lower. After the addition, the reactor was depressurized to 15.96 kPa, and the internal temperature was raised from 20 ° C. to 105 ° C. over 64 hours while allowing the reactant to flow into the receiver. (Stirring was carried out for about 20 hours and then stopped.) 701 g of crude effluent (purity 98.2%). After completion of the reaction, the crude product was distilled at 15.96 kPa under reduced pressure to obtain 635 g of trifluoromethanesulfonic anhydride (purity 99.9%).
[Third Step (a)] Production of Trifluoromethanesulfonyl Fluoride 55.8 g (2.790 mol) of anhydrous hydrofluoric acid was charged into a stainless steel reactor (500 ml) equipped with a stirrer, reflux tube and thermometer. Then, 94.2 g (0.931 mol) of triethylamine was added dropwise over 30 minutes while cooling to 10 ° C. or lower and stirring. Next, 114.3 g (0.405 mol) of trifluoromethanesulfonic anhydride was added dropwise over 10 minutes with stirring (while maintaining the internal temperature of the reaction solution at 5 to 15 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from a tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with liquid argon. The gas collection was stopped when the dropwise addition of trifluoromethanesulfonic anhydride was completed. In the stainless steel cylinder, 53.1 g of gas was collected. When the composition of this gas was analyzed by gas chromatography, the purity of trifluoromethanesulfonyl fluoride was 97.3% (0.349 mol) (86% isolated yield from trifluoromethanesulfonic anhydride). .

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonic anhydride obtained in the second step, the following third step was performed.
[Third step (a)] Production of trifluoromethanesulfonyl fluoride 169.0 g (0.599 mol) of trifluoromethanesulfonic anhydride was added to a stainless steel reactor (500 ml) equipped with a stirrer, a reflux tube and a thermometer. With stirring and stirring, 10.4 g (0.520 mol) of anhydrous hydrofluoric acid was added and cooled to 10 ° C. or lower. Next, with stirring, 13.2 g (0.130 mol) of triethylamine was added dropwise over 30 minutes (while maintaining the internal temperature of the reaction solution at 5 to 15 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from a tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with liquid argon. The gas collection was stopped when the dropwise addition of triethylamine was completed. 16.0 g of gas was collected in the stainless steel cylinder. When the composition of this gas was analyzed by gas chromatography (GC), the purity of trifluoromethanesulfonyl fluoride was 99.0% (0.105 mol) (isolated yield from trifluoromethanesulfonic anhydride) 81%).

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonic anhydride obtained in the second step, the following third step was performed.
[Third step (a)] Production of trifluoromethanesulfonyl fluoride A stainless steel reactor (500 ml) equipped with a stirrer, a reflux tube and a thermometer and a stainless steel cylinder (200 ml) are made of a tetrafluoroethylene resin tube. Then, the pressure in the system was reduced to 600 Pa, and 287.7 g (1.020 mol) of trifluoromethanesulfonic anhydride was sucked into the reactor, and then 26.6 g (1. 330 mol) was introduced by suction and cooled to 10 ° C. or lower. Next, 191.1 g (1.031 mol) of tributylamine was added dropwise over 30 minutes with stirring (while maintaining the internal temperature of the reaction solution at 8 to 44 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from the tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with an acetone-dry ice solution. The gas collection was stopped when the addition of tributylamine was completed. In the stainless steel cylinder, 135.8 g of gas was collected. When the composition of this gas was analyzed by gas chromatography, the purity of trifluoromethanesulfonyl fluoride was 99.9% (0.893 mol) (isolated yield from trifluoromethanesulfonic anhydride 88%). .

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonic anhydride obtained in the second step, the following third step was performed.
[Third step (a)] Production of trifluoromethanesulfonyl fluoride A stainless steel reactor (500 ml) equipped with a stirrer, a reflux tube and a thermometer and a stainless steel cylinder (200 ml) are made of a tetrafluoroethylene resin tube. Then, the pressure in the system was reduced to 600 Pa, and 285.3 g (1.011 mol) of trifluoromethanesulfonic anhydride was introduced into the reactor while being sucked, and then 12.4 g (0. 620 mol) was introduced by suction and cooled to 10 ° C. or lower. Next, while stirring, 74.4 g (1.017 mol) of diethylamine was added dropwise over 30 minutes (while maintaining the internal temperature of the reaction solution at 8-44 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from the tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with an acetone-dry ice solution. The gas collection was stopped when the dropwise addition of diethylamine was completed. 42.6 g of gas was collected in the stainless steel cylinder. When the composition of this gas was analyzed by gas chromatography, the purity of trifluoromethanesulfonyl fluoride was 100.0% (0.280 mol) (45% isolated yield from trifluoromethanesulfonic anhydride). .

The A step, the first step, and the second step were performed in the same manner as in Example 1. Using the trifluoromethanesulfonic anhydride obtained in the second step, the following third step was performed.
[Third step (a)] Production of trifluoromethanesulfonyl fluoride A stainless steel reactor (500 ml) equipped with a stirrer, a reflux tube and a thermometer and a stainless steel cylinder (200 ml) are made of a tetrafluoroethylene resin tube. Then, the pressure in the system was reduced to 600 Pa, and 283.6 g (1.005 mol) of trifluoromethanesulfonic anhydride was introduced into the reactor while being sucked, and then 10.3 g (0.003 mol) of anhydrous hydrofluoric acid with stirring. 515 mol) was introduced by suction and cooled to 10 ° C. or lower. Next, 83.1 g (1.051 mol) of pyridine was added dropwise over 30 minutes while stirring (while maintaining the internal temperature of the reaction solution at 12 to 34 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from the tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with an acetone-dry ice solution. Gas collection was stopped when the addition of pyridine was completed. 20.0 gas was collected in the stainless steel cylinder. When the composition of this gas was analyzed by gas chromatography, the purity of trifluoromethanesulfonyl fluoride was 99.6% (0.132 mol) (isolated yield from trifluoromethanesulfonic anhydride 26%). .
[Comparative Example 1]
In Comparative Example 1, the A step, the first step, and the second step were performed in the same manner as in Example 1. As the third step (a), 169 g (0.6 mol) of trifluoromethanesulfonic anhydride was used as a raw material, Operation and conditions are the same as in Example 1 except that 15.9 g (0.795 mol) of anhydrous hydrofluoric acid is added dropwise, the internal temperature of the reaction solution is maintained at 8 to 10 ° C., and no triethylamine is added to the reaction system. Went to. However, the reaction did not proceed at all, and trifluoromethanesulfonyl fluoride was not produced (conversion rate 0%, yield 0%).

The A step, the first step, and the second step were performed in the same manner as in Example 1, and the following third step was performed using the trifluoromethanesulfonic anhydride obtained in the second step.
[Third Step (b)] Production of Trifluoromethanesulfonyl Fluoride 37 g of potassium fluoride was added to a glass reactor (500 ml) equipped with a stirrer, a reflux tube and a thermometer while stirring. 2 g (0.640 mol) was added and cooled to 5 ° C. Next, 120.5 g (0.427 mol) of trifluoromethanesulfonic anhydride was added dropwise over 10 minutes with stirring (while maintaining the internal temperature of the reaction solution at 5 to 20 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from a tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with liquid argon. The gas collection was stopped when the dropwise addition of trifluoromethanesulfonic anhydride was completed. 59.1 g of gas was collected in the stainless steel cylinder. When the composition of this gas was analyzed by gas chromatography, the purity of trifluoromethanesulfonyl fluoride was 99.9% (0.389 mol) (isolation yield from trifluoromethanesulfonic anhydride 91%) .

The A step, the first step, and the second step were performed in the same manner as in Example 1, and the following third step was performed using the trifluoromethanesulfonic anhydride obtained in the second step.
[Third step (b)] Production of trifluoromethanesulfonyl fluoride A stainless steel reactor (500 ml) equipped with a stirrer, a reflux tube, and a thermometer and a stainless steel cylinder (200 ml) are made of a tetrafluoroethylene resin tube. Then, 50.2 g (0.864 mol) of potassium fluoride was added to the reactor, the pressure in the system was reduced to 600 Pa, and 102 g of water was sucked into the reactor and cooled to 5 ° C. Next, with stirring, 145.4 g (0.515 mol) of trifluoromethanesulfonic anhydride was added dropwise over 30 minutes (while maintaining the internal temperature of the reaction solution at 5 to 18 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from a tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with an acetone-dry ice solution. The gas collection was stopped when the dropwise addition of trifluoromethanesulfonic anhydride was completed. 69.0 g of gas was collected in the stainless steel cylinder. When the composition of this gas was analyzed by gas chromatography, the purity of trifluoromethanesulfonyl fluoride was 99.9% (0.454 mol) (isolated yield from trifluoromethanesulfonic anhydride 88%). .

The A step, the first step, and the second step were performed in the same manner as in Example 1, and the following third step was performed using the trifluoromethanesulfonic anhydride obtained in the second step.
[Third step (b)] Production of trifluoromethanesulfonyl fluoride A stainless steel reactor (500 ml) equipped with a stirrer, a reflux tube, and a thermometer and a stainless steel cylinder (200 ml) are made of a tetrafluoroethylene resin tube. Then, 29.1 g (0.501 mol) of potassium fluoride was added to the reactor, the pressure in the system was reduced to 600 Pa, and 144 g of acetonitrile was sucked into the reactor and cooled to 5 ° C. Next, with stirring, 139.2 g (0.493 mol) of trifluoromethanesulfonic anhydride was added dropwise over 30 minutes (while maintaining the internal temperature of the reaction solution at 5 to 18 ° C.). A gas was generated simultaneously with the dropping, and the gas was collected from a tip of the reflux tube into a stainless steel cylinder (200 ml) cooled with an acetone-dry ice solution. The gas collection was stopped when the dropwise addition of trifluoromethanesulfonic anhydride was completed. In the stainless steel cylinder, 43.6 g of gas was collected. When the composition of this gas was analyzed by gas chromatography, the purity of trifluoromethanesulfonyl fluoride was 99.8% (0.287 mol) (isolated yield from trifluoromethanesulfonic anhydride 58%). .

Claims (14)

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 a dehydrating agent to obtain trifluoromethanesulfonic anhydride ((CF ₃ SO ₂ ) ₂ O).
Third step: A step of obtaining trifluoromethanesulfonyl fluoride by reacting the trifluoromethanesulfonic anhydride obtained in the second step with a fluorinating agent. 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 a dehydrating agent to obtain trifluoromethanesulfonic anhydride (second step), the dehydrating agent is phosphorus pentoxide (P ₂ O ₅ ) or pentachloride. The method according to claim 1, wherein the method is phosphorus (PCl ₅ ). The trifluoromethanesulfonic anhydride obtained in the second step is reacted with any one of the following steps when the fluorinating agent is reacted (third step): The method described.
Third step (a): A step of reacting trifluoromethanesulfonic anhydride with hydrogen fluoride in the presence of an organic base to obtain trifluoromethanesulfonyl fluoride.
Third step (b): a step of reacting a metal fluoride with trifluoromethanesulfonic anhydride to obtain trifluoromethanesulfonyl fluoride. When trifluoromethanesulfonic anhydride is reacted with hydrogen fluoride in the presence of an organic base (third step (a)), trifluoromethanesulfonic anhydride and hydrogen fluoride are first allowed to coexist, followed by organic base. The method according to claim 4, wherein the method is performed by adding: When trifluoromethanesulfonic anhydride is reacted with hydrogen fluoride in the presence of an organic base (third step (a)), the organic base and hydrogen fluoride are first allowed to coexist, followed by trifluoromethanesulfonic anhydride. The method according to claim 4, wherein the method is performed by adding: When hydrogen fluoride is reacted with trifluoromethanesulfonic anhydride in the presence of an organic base (third step (a)), the amount of the organic base is 0.1 to 100 mol with respect to 1 mol of trifluoromethanesulfonic anhydride. A method according to any of claims 4 to 6, characterized in that When hydrogen fluoride is reacted with trifluoromethanesulfonic anhydride in the presence of an organic base (third step (a)), the amount of the fluorinating agent is 0.1 to 100 with respect to 1 mol of trifluoromethanesulfonic anhydride. The method according to claim 4, wherein the method is a mole. When the hydrogen fluoride is reacted with trifluoromethanesulfonic anhydride in the presence of an organic base (third step (a)), the temperature during the reaction is -30 ° C to 90 ° C, Item 9. The method according to any one of Items 4 to 8. When the metal fluoride is reacted with trifluoromethanesulfonic anhydride (third step (b)), the metal fluoride is lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), The method of Claim 4 which is a rubidium fluoride (RbF) or a cesium fluoride (CsF). The trifluoromethanesulfonic anhydride is reacted with water as a solvent when the metal fluoride is reacted (third step (b)), according to any one of claims 4 to 10, Method. The temperature at the time of performing the reaction when reacting the metal fluoride with trifluoromethanesulfonic anhydride (third step (b)) is -5 to 90 ° C, according to claim 4 to 11, The method in any one. When the metal fluoride is reacted with the trifluoromethanesulfonic anhydride (third step (b)), the amount of the metal fluoride is 0.1 to 100 mol with respect to 1 mol of the trifluoromethanesulfonic anhydride. A method according to any of claims 4 to 12, characterized in that 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 claim 1, wherein: