Tetrafluoroethylene production method and tfe composition

Abstract

Provided are a tetrafluoroethylene production method that uses a fluorocarbon as a raw material, and a composition containing tetrafluoroethylene.　The production method according to the present disclosure comprises a step in which tetrafluoroethylene is obtained by subjecting pentafluoroethane to a base treatment using a basic compound. The composition according to the present disclosure contains tetrafluoroethylene and pentafluoroethane. The tetrafluoroethylene production method according to the present disclosure makes it possible to obtain tetrafluoroethylene by means of a simple step at a mild temperature.

Description

Method for producing tetrafluoroethylene and TFE composition

[0001] The present invention relates to a method for producing tetrafluoroethylene and a TFE composition.

[0002] The development of a method for reusing fluorocarbons used as refrigerants and the like and using them as resin raw material monomers is important from the viewpoint of effective utilization of fluorocarbons. Among the monomers that serve as resin raw materials, tetrafluoroethylene (TFE) is a raw material for producing fluororesins such as PTFE, FEP, PFA, and ETFE, and is also an effective intermediate for synthesizing organic fluorine compounds, making it an important fluorine compound.

[0003] As a method for producing the above-mentioned TFE, for example, Patent Document 1 discloses a method for producing pentafluoroethane (CF ３ CF ２ H) in the presence of chlorine gas to obtain an intermediate, which is then treated with hydrogen in the presence of a catalyst to produce TFE.

[0004] U.S. Patent Publication No. 2004 / 0127757

[0005] The present disclosure aims to provide a method for producing tetrafluoroethylene in a single step using fluorocarbons as a raw material, and also aims to provide a composition containing tetrafluoroethylene that imposes a small burden on the purification step.

[0006] The present disclosure encompasses the following features. Item 1: A method for producing tetrafluoroethylene, comprising the step of treating pentafluoroethane with a basic compound to obtain tetrafluoroethylene. Item 2: The method for producing tetrafluoroethylene according to Item 1, wherein the basic compound is in a solid state under atmospheric pressure and in an atmosphere at 25°C. Item 3: The method for producing tetrafluoroethylene according to Item 1 or 2, wherein the basic compound has a conjugate acid having a pKa value of 13 or greater. Item 4: The method for producing tetrafluoroethylene according to any one of Items 1 to 3, wherein the basic compound is a compound containing a metal. Item 5: The method for producing tetrafluoroethylene according to any one of Items 1 to 4, wherein the treatment is carried out in the presence or absence of a phase transfer catalyst. Item 6: The method for producing tetrafluoroethylene according to any one of Items 1 to 5, wherein the treatment is carried out in the presence or absence of a solvent. Item 7: A composition comprising tetrafluoroethylene and pentafluoroethane. Item 8: The composition according to Item 7, wherein pentafluoroethane is contained in an amount of 52 mol% or less based on the total amount of tetrafluoroethylene and pentafluoroethane. Item 9. The composition according to Item 7, wherein pentafluoroethane is contained in an amount of 30 mol% or less, based on the total amount of tetrafluoroethylene and pentafluoroethane. Item 10. The composition according to Item 7, wherein pentafluoroethane is contained in an amount of 10 mol% or less, based on the total amount of tetrafluoroethylene and pentafluoroethane. Item 11. The composition according to any one of Items 7 to 10, wherein pentafluoroethane is contained in an amount of 0.1 mol% or more, based on the total amount of tetrafluoroethylene and pentafluoroethane.

[0007] According to the method for producing tetrafluoroethylene of the present disclosure, tetrafluoroethylene can be easily obtained in a single step even under mild conditions.

[0008] 1 is a schematic diagram illustrating the synthesis apparatus used in Example 1B, etc. (a) is the reaction scheme performed in Examples 16A to 16D, (b) is the reaction scheme performed in Examples 17A to 17C, (c) is the reaction scheme performed in Examples 18A to 18C, (d) is the reaction scheme performed in Examples 19A to 19D, and (e) is the reaction scheme performed in Example 20. This is a schematic diagram of the reaction apparatus used in the reaction performed in Example 21A. This is a schematic diagram of the reaction apparatus used in the reaction performed in Example 22A.

[0009] The present inventors have conducted extensive research to obtain tetrafluoroethylene simply and easily. First, the method disclosed in the aforementioned Patent Document 1 requires a step of obtaining an intermediate by chlorination, and therefore requires at least two steps to obtain tetrafluoroethylene. Furthermore, it requires high-temperature heating at 300°C or higher, which is a process with high energy consumption. Furthermore, although the yield is unclear, a high yield cannot be expected considering the complexity of the process.

[0010] The present disclosure has been made in view of the above, and aims to provide a production method by which tetrafluoroethylene can be obtained at a mild temperature in a single step. Specifically, the above object is achieved by a reaction using a basic compound.

[0011]

[0023] In the present specification, the terms "contain" and "comprise" include the concepts of "contain," "comprise," "consist essentially of," and "consist only of."

[0012] In the numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. In the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in an example or a value that can be unambiguously derived from an example. In addition, in this specification, a numerical value connected with "to" means a numerical range that includes the numbers before and after "to" as the lower and upper limits.

[0013] 1. Method for Producing Tetrafluoroethylene The method for producing tetrafluoroethylene of the present disclosure includes a step of treating pentafluoroethane with a basic compound to obtain tetrafluoroethylene. In other words, the production method of the present disclosure is a method for producing tetrafluoroethylene by reacting pentafluoroethane in the presence of a basic compound.

[0014] Hereinafter, the step of obtaining tetrafluoroethylene by treating pentafluoroethane with a basic compound will be referred to as "Step 1."

[0015] Pentafluoroethane (HFC-125) used in step 1 is used as a raw material for obtaining tetrafluoroethylene (TFE). Pentafluoroethane can be obtained, for example, by production using a known method, or it can also be obtained as a commercially available product. In addition, pentafluoroethane used in step 1 can also be obtained by recovery from air conditioners, refrigerators, and the like.

[0016] The basic compound used in step 1 is a compound that acts as a base in step 1. As the basic compound, for example, a basic compound that is in a solid state under atmospheric pressure and an atmosphere at 25°C can be used. That is, the basic compound used in step 1 is preferably solid at room temperature. In this case, the base treatment can be carried out easily, and it also becomes easy to carry out the treatment in step 1 in a gas phase, as described below.

[0017] When the basic compound is in the solid state, its form is not particularly limited, and examples thereof include powder, granules, and lumps.

[0018] The basic compound used in step 1 preferably has a conjugate acid having a pKa value of at least 13. In this case, the conversion rate of pentafluoroethane to tetrafluoroethylene is likely to be increased, the yield of tetrafluoroethylene is likely to be increased, and the reaction is likely to proceed more rapidly.

[0019] In order to facilitate the reaction of Step 1 at a milder temperature, the basic compound used in Step 1 preferably has a conjugate acid having a pKa value of 15 or more, more preferably 16 or more, even more preferably 17 or more, and particularly preferably 18 or more; and preferably 40 or less, more preferably 38 or less, even more preferably 35 or less, and particularly preferably 32 or less.

[0020] The pKa in the present disclosure refers to the acid dissociation constant in water or DMSO at 25° C. The pKa value can be referenced to values ​​described in publicly available information such as literature (for example, Chemistry Handbook Basic Edition (Maruzen Publishing), Graduate School Lectures on Organic Chemistry (Tokyo Kagaku Dojin), Bordwell's pKa Table (https: / / organicchemistrydata.org / hansreich / resources / pka / #pka_dmso_compilation), or Green Chem., 2015, 17, 945-949, etc.).

[0021] The basic compound used in step 1 is preferably a compound containing a metal or ammonium, and more preferably a compound containing a metal. In this case, the reaction in step 1 can be carried out at a milder temperature, and tetrafluoroethylene can be obtained in a higher yield. Even if the basic compound is a compound containing a metal or ammonium, it is preferable that the basic compound is in a solid state, and its conjugate acid is preferably in the above-mentioned range.

[0022] When the basic compound is a compound containing a metal, the metal contained in such a compound is referred to as "metal M." Examples of the metal M include alkali metals, alkaline earth metals, and various transition metals, and among these, alkali metals are preferred. Therefore, the metal M is preferably lithium, sodium, potassium, etc., and more preferably potassium.

[0023] On the other hand, when the basic compound is a compound containing ammonium, the ammonium contained in such a compound is referred to as "ammonium R ４ N＋ " Ammonium R ４ N ＋ Examples of the ammonium R include ammonium, quaternary alkyl ammonium, ammonium formed from all or part of the amine moieties of polyethyleneimine, and ammonium formed from all or part of the amine moieties of aminoethylated acrylic polymer. ４ N ＋ In the formula (I), it is preferable that at least some or all of the four R's are one or more selected from the group consisting of hydrogen and alkyl groups. All four R's may be the same, or some may be different. Two R's may be bonded together to form a cyclic structure. More preferably, R's are hydrogen or alkyl groups having 1 to 4 carbon atoms.

[0024] The basic compound used in step 1 preferably contains an amide anion, and more particularly, it is preferably an amide anion having the above-mentioned metal or ammonium as a counter cation. The amide anion refers to an anion formed by removing a proton from an amine skeleton.

[0025] That is, it is preferable that the basic compound used in step 1 has at least one of the counter cations and amide anions in one molecule. In this case, the numbers of counter cations and amide anions contained in one molecule are not particularly limited.

[0026] The molecular weight of the basic compound used in step 1 is not particularly limited, and for example, the basic compound used in step 1 may be a polymer.

[0027] Specific examples of the basic compound used in step 1 include silazide salts, amide salts, polyethyleneimine salts containing counter cations in which all or part of the amine moieties have become amide anions, aminoethylated acrylic polymer salts containing counter cations in which all or part of the amine moieties have become amide anions, polysilazane salts containing counter cations in which all or part of the amine moieties have become amide anions, alkyl metal compounds, metal salts of tetramethylpiperidide, metal alkoxides, metal hydrides, metal or ammonium hydroxides, and ammonium fluorides.

[0028] The type of metal or ammonium contained in each basic compound can be the same metal as the aforementioned metal M, or an ammonium form. The pKa of the conjugate acid of these basic compounds is 29.5 for the salt of hexamethyldisilazide, 35.7 for the salt of diisopropylamide, 40 to 53 for the alkyl metal compound, 37.3 for the salt of tetramethylpiperidide, 15.9 to 19.2 for the metal alkoxide, 35.0 for the metal hydride, 14.0 for the metal or ammonium hydroxide, and 15.0 for the ammonium fluoride (see Green Chem., 2015, 17, 945-949).

[0029] Among these, the basic compound preferably contains one or more selected from the group consisting of metal salts of disilazide, metal alkoxides, and salts containing counter cations in which all or part of the amine moieties of polysilazane are amide anions, and more preferably contains a metal salt of silazide, since this allows the reaction (base treatment) in step 1 to be carried out at a milder temperature and tetrafluoroethylene to be obtained in a higher yield. In particular, when the basic compound contains a metal salt of silazide, the reaction can be carried out at a milder temperature without using a phase transfer catalyst described below, and the yield of tetrafluoroethylene can be particularly increased. Moreover, when the basic compound contains a metal salt of silazide, it has high solubility in pentafluoroethane, which is the raw material, so that tetrafluoroethylene can be obtained efficiently even when the reaction in step 1 is carried out in the absence of a solvent.

[0030] Examples of the metal salt of silazide include lithium hexamethyldisilazide, sodium hexamethyldisilazide, and potassium hexamethyldisilazide. Of these, potassium hexamethyldisilazide is preferred. The pKa of the conjugate acid of these metal salts of hexamethyldisilazide is 29.5.

[0031] Examples of metal alkoxides include metal salts of methoxide, ethoxide, and tert-butoxide. Of these, metal salts of tert-butoxide are preferred, and specific examples include lithium tert-butoxide, sodium tert-butoxide, and potassium tert-butoxide. The pKa of the conjugate acid of these metal alkoxides is 19.2 (Graduate School Lectures on Organic Chemistry (Tokyo Kagaku Dojin)).

[0032] Examples of metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide, etc. The pKa of the conjugate acid of these metal hydroxides is 15.7 (Graduate School Lectures on Organic Chemistry (Tokyo Kagaku Dojin)).

[0033] When the basic compound is a polymer, examples of the basic compound include polyethyleneimine; aminoethylated acrylic polymers obtained by aminoethylating the carboxylic acid moieties of acrylic acid polymers; and compounds obtained by treating polysilazane with a metal- or ammonium-containing basic compound, and converting all or part of the amine moieties to amide anions.

[0034] A preferred form of the metal salt containing a counter cation in which all or part of the amine moieties of the polysilazane are amide anions is represented by the following formula (1): -(SiR １ R ２ ２ -NH-) m -r-(SiR １ R ２ ２ -NM-) ｎ - (1) (In formula (1), R １ is H or CH ３ , R ２ are the same or different and may be H, CH ３ , -CH=CH ２M is an alkali metal, an alkaline earth metal, or a transition metal.

[0035] In formula (1), the metal M is preferably an alkali metal, and therefore preferably lithium, sodium, potassium, or the like. In formula (1), m and n each independently represent an integer of 0 or more, and the sum of m and n is not particularly limited and is, for example, 2 to 4900, preferably 5 to 2500, and more preferably 10 to 490. In formula (1), -r- represents (SiR １ R ２ ２ —NH—) and (SiR １ R ２ ２ This means that repeating units of the formula (-NM-) are bonded in any order (i.e., randomly).

[0036] A preferred form of the ammonium having a counter cation in which all or part of the amine moieties of the polysilazane are amide anions is represented by the following formula (2): -(SiR ３ R ４ ２ -NH-) m -r-(SiR ３ R ４ ２ -N － (R ４ N ＋ )-) ｎ - (2) (In formula (2), R ３ is H or CH ３ , R ４ are the same or different and represent H, —CH ３ , -CH=CH ２ and the four R's are one or more selected from the group consisting of H and alkyl groups.) The four R's may be the same or different, and two R's or two or more R's may be bonded together to form a cyclic structure. In formula (2), m and n each independently represent an integer of 0 or greater, and the sum of m and n is not particularly limited and is, for example, 2 to 3200, preferably 5 to 1600, and more preferably 10 to 320. In formula (2), -r- represents (SiR ３ R ４２ —NH—) and (SiR ３ R ４ ２ -N － (R ４ N ＋ )-) repeating units are bonded in any order (i.e., randomly).

[0037] A preferred form of the metal salt containing a counter cation in which all or part of the amine moieties of polyethyleneimine are amide anions is represented by the following formula (3): —(CH ２ CH ２ -NH-) ｍ -r-(CH ２ CH ２ -NM-) ｎ - (3) In formula (3), M is an alkali metal, an alkaline earth metal, or a transition metal.

[0038] In formula (3), the metal M is preferably an alkali metal, and therefore preferably lithium, sodium, potassium, or the like. In formula (3), m and n each independently represent an integer of 0 or more, and the sum of m and n is not particularly limited and is, for example, 2 to 5600, preferably 5 to 2800, and more preferably 10 to 560. In formula (3), -r- represents (CH ２ CH ２ —NH—) and (CH ２ CH ２ This means that repeating units of the formula (-NM-) are bonded in any order (i.e., randomly).

[0039] A preferred form of the ammonium having a counter cation in which all or part of the amine moieties of polyethyleneimine are amide anions is represented by the following formula (4): —(CH ２ CH ２ -NH-) ｍ -r-(CH ２ CH ２ -N － (R ４ N ＋ )-) ｎ- (4) (in formula (4), the four R's are one or more selected from the group consisting of H and alkyl groups). The four R's may be the same or different, and two R's or two or more R's may be bonded together to form a cyclic structure. In formula (4), m and n each independently represent an integer of 0 or greater, and the sum of m and n is not particularly limited and is, for example, 2 to 3500, preferably 5 to 1800, and more preferably 10 to 350. In formula (4), -r- means (CH ２ CH ２ —NH—) and (CH ２ CH ２ -N － (R ４ N ＋ )-) repeating units are bonded in any order (i.e., randomly).

[0040] A preferred form of the metal salt containing a counter cation in which all or part of the amine moieties of the aminoethylated acrylic polymer have become amide anions is represented by the following formula (5): —(CH ２ CR (COOR) ｍ -r1-(CH ２ CR(COO-(CH ２ CH ２ -NH) ｎ -r2-(CH ２ CH ２ -NM) ｐ -H)) ｋ - (5) (wherein R is at least one selected from the group consisting of H and alkyl groups) In formula (5), M is an alkali metal, an alkaline earth metal, or a transition metal.

[0041] In formula (5), the metal M is preferably an alkali metal, and therefore preferably lithium, sodium, potassium, or the like. In formula (5), m, n, p, and k are each independently an integer of 0 or more, and the sum of m, n, p, and k is not particularly limited and can be appropriately set so that the molecular weight of the compound represented by formula (5) is 1,000 to 1,000,000 (preferably 5,000 to 500,000, more preferably 10,000 to 100,000). In formula (5), -r1- is a group selected from the group consisting of (CH ２ CR(COOR)) and (CH ２ CR(COO-(CH ２ CH ２ -NH) ｎ - (CH ２ CH ２ -NM) ｐ In formula (5), -r2- means that the repeating units of (CH ２ CH ２ —NH) and (CH ２ CH ２ This means that repeating units of the formula (N-NM) are bonded in any order (i.e., randomly).

[0042] A preferred form of the ammonium having a counter cation in which all or part of the amine moieties of the aminoethylated acrylic polymer have become amide anions is represented by the following formula (6): —(CH ２ CR (COOR) ｍ -r1-(CH ２ CR(COO-((CH ２ CH ２ -NH) ｎ -r2-(CH ２ CH ２ -N － (R ４ N ＋ )) ｐ -H) ｋ- (6) (In formula (6), R is one or more selected from the group consisting of H and alkyl groups). Two R or two or more R may be bonded together to form a cyclic structure. In formula (6), m, n, p, and k each independently represent an integer of 0 or more, and the sum of m, n, p, and k is not particularly limited and can be appropriately set so that the molecular weight of the compound represented by formula (6) is 1,000 to 1,000,000 (preferably 5,000 to 500,000, more preferably 10,000 to 100,000). In formula (6), -r1- means (CH ２ CR(COOR)) and (CH ２ CR(COO-((CH ２ CH ２ -NH) ｎ -r2-(CH ２ CH ２ -N － (R ４ N ＋ )) ｐ In formula (6), -r2- means that the repeating units of (CH ２ CH ２ —NH) and (CH ２ CH ２ -N － (R ４ N ＋ )) repeating units are bonded in any order (i.e., randomly).

[0043] Examples of basic compounds containing ammonium include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, tetramethylammonium fluoride, tetrabutylammonium fluoride, tetramethylammonium hexamethyldisilazide, etc. The pKa of the conjugate acid of these ammonium hydroxide bases is 15.7 (Graduate School Lectures on Organic Chemistry (Tokyo Kagaku Dojin)), the pKa of the conjugate acid of these ammonium fluoride bases is 15.0 (Bordwell pKa Table), and the pKa of the conjugate acid of hexamethyldisilazide base is 29.5.

[0044] In step 1, potassium hexamethyldisilazide, sodium hexamethyldisilazide, lithium hexamethyldisilazide, lithium diisopropylamide, potassium tert-butoxide, or the like can be preferably used as the basic compound.

[0045] In step 1, the treatment with pentafluoroethane can be carried out in a solvent, if necessary. That is, in step 1, the base treatment can be carried out in the presence or absence of a solvent.

[0046] When the treatment is carried out in the presence of a solvent, the type of solvent that can be used is not particularly limited, and a wide variety of organic solvents can be used. Examples of such organic solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; ketone solvents such as acetone, methyl ethyl ketone, and isophorone; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane; halogenated hydrocarbon solvents such as methylene chloride and chloroform; ether solvents such as 1,2-dimethoxyethane, tetrahydrofuran, 1,4-dioxane, and anisole; ester solvents such as ethyl acetate, propyl acetate, ethyl carbitol acetate, and butyl carbitol acetate; carbonate solvents such as dimethyl carbonate, diethyl carbonate, and propylene carbonate; alcohol solvents such as tert-butyl alcohol, benzyl alcohol, phenoxyethanol, and phenylpropylene glycol; and dimethyl sulfoxide. The solvent can be used alone or in a mixture of two or more solvents.

[0047] When the treatment is carried out in the presence of a solvent, it is preferable to use a solvent with low polarity. In this case, the reaction in step 1 can be carried out at a milder temperature, and the yield of tetrafluoroethylene is likely to be increased. Examples of solvents with low polarity include aromatic hydrocarbon solvents, aliphatic hydrocarbons, alicyclic hydrocarbons, and ether solvents. Of these, aromatic hydrocarbon solvents and aliphatic hydrocarbons are more preferred, and aromatic hydrocarbon solvents are even more preferred. From the above perspective, preferred examples of the solvent used in step 1 include benzene, toluene, xylene, n-hexane, n-heptane, 1,2-dimethoxyethane, tetrahydrofuran, 1,4-dioxane, and anisole.

[0048] When a solvent is used in step 1, there are no particular limitations on the ratio of the solvent to pentafluoroethane used. For example, the molar concentration of pentafluoroethane relative to the solvent can be in the range of 0.01 to 3 M.

[0049] The treatment in step 1 can also be carried out in the absence of a solvent. In particular, when a basic compound that is easily soluble in pentafluoroethane, such as a metal salt of hexamethyldisilazide, is used as the basic compound, the reaction proceeds rapidly even without the use of a solvent.

[0050] The treatment in step 1 can be carried out in the presence of a phase transfer catalyst, if necessary. That is, step 1 can be carried out in the presence or absence of a phase transfer catalyst. For example, when a solvent is used in the treatment in step 1, if the basic compound is poorly soluble in the solvent, it is preferable to carry out the base treatment in the presence of a phase transfer catalyst. In this case, the basic compound becomes more soluble in the solvent, and tetrafluoroethylene is more easily produced from pentafluoroethane. For example, when the basic compound is a metal alkoxide, the use of a phase transfer catalyst makes the reaction in step 1 more likely to proceed. When the basic compound is a metal salt of hexamethyldisilazide, the reaction easily proceeds even without the use of a phase transfer catalyst, and the reaction can be carried out at a milder temperature.

[0051] As the phase transfer catalyst, for example, a wide variety of known phase transfer catalysts can be used, and specific examples of the phase transfer catalyst include quaternary ammonium salts, phosphonium salts, amines, crown ethers, etc., and among these, quaternary ammonium salts are preferred.

[0052] Examples of quaternary ammonium salts include tetrabutylammonium salts such as tetrabutylammonium chloride, tetrabutylammonium bromide, and tetrabutylammonium iodide; as well as tetramethylammonium salts, tetraethylammonium salts, tetrapropylammonium salts, tetrahexylammonium salts, tetraoctylammonium salts, tetradecylammonium salts, hexadecyltriethylammonium salts, dodecyltrimethylammonium salts, trioctylmethylammonium salts, octyltriethylammonium salts, benzyltrimethylammonium salts, benzyltriethylammonium salts, benzyltributylammonium salts, benzyldimethyloctadecylammonium salts, and phenyltrimethylammonium salts.

[0053] In the step 1, when a phase transfer catalyst is used, the phase transfer catalyst may be used alone or in combination of two or more.

[0054] When a phase transfer catalyst is used in step 1, the ratio of pentafluoroethane to the phase transfer catalyst is not particularly limited and can be, for example, the same ratio as in reactions using known phase transfer catalysts. For example, the phase transfer catalyst can be used in the range of 0.05 to 2.0 moles per mole of pentafluoroethane.

[0055] The treatment in step 1, that is, the reaction for obtaining tetrafluoroethylene from pentafluoroethane, can be carried out in either a gas phase or a liquid phase.

[0056] When the reaction in step 1 is a gas phase reaction, for example, the treatment can be carried out by contacting gaseous pentafluoroethane with a basic compound. In this case, the basic compound is preferably in a solid state. That is, in the gas phase reaction, gaseous pentafluoroethane is contacted with a solid basic compound. The basic compound may be supported on a carrier.

[0057] When the base treatment in step 1 is a gas-phase reaction, the gas-phase reaction can be carried out, for example, by placing a basic compound in a reactor and flowing pentafluoroethane into the reactor to contact the basic compound. In this case, the number of reactors containing the basic compound may be one, or two or more. When two or more reactors containing the basic compound are used, the reactors can be connected in series, for example. The reactors can be connected to each other by a connecting pipe such as a tube. The product containing tetrafluoroethylene after the reaction can be collected, for example, from the outlet of the reactor. When the base treatment in step 1 is a gas-phase reaction, for example, the flow rate (also referred to as flow rate) of pentafluoroethane flowing into the reactor is not particularly limited.

[0058] In the gas phase reaction, the contact time, which is expressed as the ratio W / Fo of the amount of basic compound charged in the reactor W (g) to the flow rate Fo of pentafluoroethane introduced into the reactor, is not particularly limited.

[0059] In the gas-phase reaction, the ratio of pentafluoroethane to the basic compound is not particularly limited, and for example, 0.01 to 10.00 moles of the basic compound can be used per mole of pentafluoroethane. In the gas-phase reaction, the amount of the basic compound used per mole of pentafluoroethane is preferably 0.05 moles or more, more preferably 0.10 moles or more, even more preferably 0.30 moles or more, particularly preferably 0.50 moles or more, and preferably 4.50 moles or less, more preferably 4.00 moles or less, even more preferably 3.50 moles or less, still more preferably 3.00 moles or less, and particularly preferably 2.50 moles or less.

[0060] The gas phase reaction may be carried out in the presence of either an inert gas or air. The pressure during the gas phase reaction is not particularly limited, and the reaction may be carried out under any of reduced pressure, increased pressure, and atmospheric pressure. The gas phase reaction may be carried out in either a continuous or batch system.

[0061] On the other hand, when the treatment in step 1 is a liquid phase reaction, for example, the reaction can be carried out by contacting liquid pentafluoroethane with a basic compound in a reactor. Alternatively, in the liquid phase reaction, the reaction can be carried out by dissolving pentafluoroethane and a basic compound in the above-mentioned solvent. In this case, a phase transfer catalyst may be present in the solvent as necessary.

[0062] An example of a liquid-phase reaction is a method in which gaseous pentafluoroethane is introduced into a solution of a basic compound by bubbling or the like, and the pentafluoroethane and the basic compound are brought into contact with each other (see Figure 1, etc., described later). The flow time for bubbling pentafluoroethane is not particularly limited, but a longer flow time is preferable in that the yield of tetrafluoroethylene improves, and is preferably 1 minute or more, more preferably 3 minutes or more, and particularly preferably 5 minutes or more, 10 minutes or more, 15 minutes or more, 25 minutes or more, or 30 minutes or more. Alternatively, the flow time is preferably 120 minutes or less, more preferably 90 minutes or less, even more preferably 70 minutes or less, and particularly preferably 60 minutes or less.

[0063] In the liquid-phase reaction, the ratio of pentafluoroethane to the basic compound is not particularly limited, and for example, 0.70 to 4.00 moles of the basic compound can be used per mole of pentafluoroethane. In the liquid-phase reaction, the amount of the basic compound used per mole of pentafluoroethane is preferably 0.90 moles or more, more preferably 1.10 moles or more, even more preferably 1.30 moles or more, particularly preferably 1.50 moles or more, and preferably 20 moles or less, more preferably 10 moles or less, even more preferably 8 moles or less, still more preferably 6 moles or less, and particularly preferably 5 moles or less.

[0064] The liquid phase reaction may be carried out in the presence of either an inert gas or air. The pressure during the liquid phase reaction is not particularly limited, and the reaction may be carried out under any of reduced pressure, increased pressure, and atmospheric pressure. The liquid phase reaction may be carried out in either a continuous or batch system.

[0065] After completion of the liquid-phase reaction, the purity of the target product containing tetrafluoroethylene, particularly the purity of tetrafluoroethylene, can be improved by purifying the product by an appropriate method. The purification method is not particularly limited, and various methods such as distillation, filtration, separation, and centrifugation can be used.

[0066] In step 1, tetrafluoroethylene can be obtained in good yield even if the temperature for the base treatment, i.e., the reaction temperature for obtaining tetrafluoroethylene from pentafluoroethane, is in a low temperature range.

[0067] For example, when the treatment in step 1 is the gas phase reaction described above, the reaction temperature can be in the range of −40 to 150° C. The reaction time can be set within an appropriate range depending on the temperature, and can be, for example, in the range of 0.5 hours to 48 hours, preferably 1 hour to 10 hours.

[0068] On the other hand, when the treatment in step 1 is the liquid phase reaction described above, the reaction temperature can be in the range of −100° C. to 100° C., and is preferably −80° C. or higher, more preferably −70° C. or higher, even more preferably −60° C. or higher, particularly preferably −50° C. or higher, and preferably 80° C. or lower, more preferably 60° C. or lower, even more preferably 50° C. or lower, particularly preferably 40° C. or lower. The reaction time can be set within an appropriate range depending on the temperature, and can be, for example, in the range of 0.5 hours or higher and 48 hours or lower, preferably 1 hour or higher and 10 hours or lower.

[0069] Within the above-mentioned temperature range for the liquid phase reaction, a reaction temperature lower than room temperature is preferred in that tetrafluoroethylene can be easily obtained selectively.

[0070] Furthermore, when the liquid phase reaction is carried out in the absence of a solvent, the reaction temperature is preferably equal to or lower than the boiling point of pentafluoroethane, and more preferably equal to or lower than −50° C. When the reaction temperature is within this range, pentafluoroethane is liquefied and can be efficiently brought into contact with the basic compound.

[0071] When liquefaction can be achieved by adjusting the pressure, the preferred reaction temperature range is the same as that for the liquid-phase reaction described above, even when the liquid-phase reaction is carried out in the absence of a solvent. Therefore, when liquefaction can be achieved by adjusting the pressure, the reaction temperature can be in the range of −100° C. to 100° C., preferably −80° C. or higher, more preferably −70° C. or higher, even more preferably −60° C. or higher, particularly preferably −50° C. or higher, and preferably 80° C. or lower, more preferably 60° C. or lower, even more preferably 50° C. or lower, and particularly preferably 40° C. or lower.

[0072] Various reactors can be used in the treatment of step 1. For example, a tubular flow reactor, a pressure-resistant autoclave, or the like can be used as the reactor for the dehydrochlorination reaction. As the flow reactor, for example, an adiabatic reactor or a multi-tubular reactor cooled using a heat transfer medium can be used. The reactor is preferably made of a material resistant to corrosion, such as stainless steel (SUS), and is particularly preferably made of Hastelloy, Inconel, Monel, or the like.

[0073] The reactor may be provided with a jacket for adjusting the temperature inside the reactor, and a heat transfer medium or the like may be circulated inside the jacket, thereby adjusting the atmospheric temperature inside the reactor.

[0074] The product obtained by the treatment in step 1 contains the target product, tetrafluoroethylene. In addition to tetrafluoroethylene, the product also contains CF, a by-product obtained by reaction of a carbene intermediate. ３ Products derived from the anion, unreacted pentafluoroethane, etc. may be included.

[0075] In the product obtained by the treatment in step 1, the content of pentafluoroethane relative to the total amount of tetrafluoroethylene and pentafluoroethane is, for example, preferably 52 mol% or less, more preferably 30 mol% or less, and even more preferably 10 mol% or less. The lower limit of the content of pentafluoroethane relative to the total amount of tetrafluoroethylene and pentafluoroethane is not particularly limited, and may be, for example, 0.1 mol% or more.

[0076] The product obtained by the treatment in step 1 preferably contains 50 mol% or more of tetrafluoroethylene, more preferably 60 mol% or more, even more preferably 70 mol% or more, and particularly preferably 80 mol% or more. The product obtained by the base treatment in step 1 may contain 90 mol% or more of tetrafluoroethylene.

[0077] The manufacturing method of the present disclosure may include steps other than step 1, or may consist of step 1 only.

[0078] The other step can include, for example, a step of recovering and regenerating the basic compound used in step 1. The method for regenerating the basic compound is not particularly limited, and for example, a wide variety of known regeneration methods can be employed.

[0079] Furthermore, in the production method of the present disclosure, the basic compound regenerated as described above can be reused in the treatment of step 1. Furthermore, in the production method of the present disclosure, by-products may be generated due to the basic compound used in step 1, and these by-products can be reused as raw materials for other reactions. Such by-products are fluoride salts; for example, when the basic compound used in step 1 is a metal salt, they are metal fluorides; and when the basic compound used in step 1 is an ammonium salt, they are ammonium fluoride salts. More specifically, when a potassium-containing compound (e.g., potassium hexamethyldisilazide) is used as the basic compound, KF (potassium fluoride) may be generated as a by-product in step 1, and such KF can be used in other reactions. Specific reactions using fluoride salts will be described in detail in the section "3. Fluorination Reaction Using By-Product Fluoride Salt" below. The fluoride salt is preferably a metal fluoride. In this case, the metal is preferably lithium, sodium, or potassium, with potassium being more preferred.

[0080] In the production method of the present disclosure, tetrafluoroethylene is obtained by treating pentafluoroethane (HFC-125) with a base in step 1, and tetrafluoroethylene can be obtained from pentafluoroethane, which is easily available in large quantities. Conventionally, tetrafluoroethylene has been produced from raw materials through two or more reaction steps or processes, but in step 1, tetrafluoroethylene can be obtained in one step, making it a simpler method for obtaining tetrafluoroethylene.

[0081] Moreover, the production method of the present disclosure uses pentafluoroethane, which has a high GWP, as a raw material and converts it to obtain tetrafluoroethylene, which is highly useful, and is therefore an extremely useful production method from an environmental perspective.In other words, the production method of the present disclosure is expected to be developed into a technology for reusing fluorocarbon substances used as refrigerants and converting them into TFE, a resin raw material, and can contribute to the development of a technology for the effective use of fluorocarbon substances.

[0082] Furthermore, the production method of the present disclosure can obtain tetrafluoroethylene even under mild temperature conditions in both the gas phase and liquid phase reactions. The method disclosed in the aforementioned Patent Document 1 requires a step of obtaining an intermediate by chlorination, and therefore requires high-temperature heating of 300°C or higher to obtain tetrafluoroethylene, which is a process that consumes a lot of energy. However, the production method of the present disclosure can obtain tetrafluoroethylene under mild temperature conditions and can produce tetrafluoroethylene in a single step, which is advantageous from the perspective of reducing energy consumption. Furthermore, the method disclosed in the aforementioned Patent Document 1 generates hydrochloric acid, which makes post-treatment of the chlorine compound a problem, whereas the production method of the present disclosure is less likely to cause such problems.

[0083] The tetrafluoroethylene obtained by the production method of the present disclosure can be suitably used as a raw material for producing fluororesins such as PTFE, and can also be widely applied to various uses requiring tetrafluoroethylene.

[0084] 2. Composition The present disclosure encompasses a composition containing tetrafluoroethylene and pentafluoroethane (hereinafter referred to as the "composition of the present disclosure"). The composition of the present disclosure can be obtained, for example, by the production method of the present disclosure described above. That is, the product obtained in step 1 can be the composition of the present disclosure. Therefore, even when the composition of the present disclosure is purified by a purification step, the burden on the purification step is low. Furthermore, since the composition of the present disclosure is produced without going through chlorination, the chlorine content is low. From the viewpoints of stable storage of tetrafluoroethylene and reducing the number of separation and purification steps for chlorine and by-products derived from the reaction with chlorine, a low chlorine content is preferable. The lower limit of the chlorine content is not particularly limited, and the chlorine content per 100 parts by mass of the composition is, for example, 1% or less, preferably 0.1% or less, more preferably 0.01% or less, and even more preferably 0.001% or less.

[0085] In the composition of the present disclosure, pentafluoroethane is preferably contained in an amount of 52 mol% or less, more preferably 30 mol% or less, and even more preferably 10 mol% or less, based on the total amount of tetrafluoroethylene and pentafluoroethane. Furthermore, in the composition of the present disclosure, the lower limit of the pentafluoroethane content is not particularly limited, and is, for example, 0.1 mol% or more, based on the total amount of tetrafluoroethylene and pentafluoroethane. In these compositions, the tetrafluoroethylene can be easily purified, and the composition can be used for producing fluororesins and fluorine-containing intermediates that can be derived from tetrafluoroethylene without purification. Therefore, the lower the content of pentafluoroethane, the more preferable, and the more preferable the content of pentafluoroethane is 5 mol% or less.

[0086] 3. Fluorination Reaction Using By-Product Fluoride Salt As described above, in the production method of the present disclosure, by-products may be generated due to the basic compound used in step 1. Such by-products can be reused as raw materials for other reactions. That is, the present disclosure can include a method of reusing fluoride salts (by-product fluoride salts) generated as by-products in step 1. For example, when a potassium-containing compound is used as the basic compound, KF (potassium fluoride) may be generated as a by-product in step 1, and such KF can be used in other reactions. That is, the present disclosure can include a method of reusing KF generated as a by-product in step 1. A specific embodiment of the method of reusing KF will be described below as an example.

[0087] The type of reaction using the recycled KF is not particularly limited, and for example, a wide range of reactions using known KF can be mentioned. Examples of such reactions include: ａ -SO ２ Synthesis of F (sulfonyl fluoride) R using KF ｂ Synthesis of -COF (acyl fluoride) R using KF ｃ -CH ２ Synthesis of F Examples include a Halex reaction using KF and a deoxyfluorination reaction using KF.

[0088] R using KF ａ-SO ２ In the synthesis of sulfonyl fluoride (F), for example, R ａ is an aromatic ring which may have a substituent. Examples of the aromatic ring which may have a substituent include a monocyclic aromatic ring such as a benzene ring, and a polycyclic (for example, bicyclic or tricyclic) aromatic ring such as a naphthalene ring or an anthracene ring.

[0089] The aromatic ring may be a heteroaromatic ring. The heteroatom in the heteroaromatic ring may be, for example, nitrogen, oxygen, sulfur, or the like, and the number of heteroatoms in the heteroaromatic ring may be one or more. Specific examples of the heteroaromatic ring include thiophene, thiazole, pyridine, pyrazole, imidazole, and pyrrole.

[0090] In the aromatic ring which may have a substituent, the type of the substituent is not particularly limited, and examples thereof include a hydrocarbon group having 1 to 20 carbon atoms which may have an oxygen atom, R ｒ O-, R ｒ CO-, R ｒ SO ２ -, R ｒ Examples of the substituent include OCO-, halo, nitro, cyano, oxo, thioxo, sulfo, sulfamoyl, sulfinamoyl, and sulfenamoyl groups. ２ It is preferably bonded to F at the ortho position.

[0091] The hydrocarbon group having 1 to 20 carbon atoms may have a chain structure (acyclic structure), a cyclic structure, or a structure that is a combination of one or more of these. Examples of such "hydrocarbon groups" include alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups, cycloalkadienyl groups, aryl groups, aralkyl groups, and groups that are combinations of these.

[0092] In this specification, unless otherwise limited, examples of the "alkyl group" include straight-chain or branched-chain alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, and docosyl.

[0093] In this specification, the "alkyl group" may be, for example, an alkyl group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, 1 to 3 carbon atoms, 6 carbon atoms, 5 carbon atoms, 4 carbon atoms, 3 carbon atoms, 2 carbon atoms, or 1 carbon atom.

[0094] Unless otherwise specified, examples of the "alkenyl group" used herein include straight-chain or branched-chain C2-10 alkenyl groups such as vinyl, 1-propen-1-yl, 2-propen-1-yl, isopropenyl, 2-buten-1-yl, 4-penten-1-yl, and 5-hexen-1-yl.

[0095] Unless otherwise specified, examples of the "alkynyl group" used herein include straight-chain or branched-chain C2-C10 alkynyl groups such as ethynyl, 1-propyn-1-yl, 2-propyn-1-yl, 4-pentyn-1-yl, and 5-hexyn-1-yl.

[0096] In this specification, unless otherwise limited, examples of the "cycloalkyl group" include C3-C7 cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.

[0097] In this specification, unless otherwise limited, examples of the "cycloalkenyl group" include C3-C7 cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, etc.

[0098] In this specification, unless otherwise limited, examples of the "cycloalkadienyl group" include C4-C10 cycloalkadienyl groups such as cyclobutadienyl, cyclopentadienyl, cyclohexadienyl, cycloheptadienyl, cyclooctadienyl, cyclononadienyl, and cyclodecadienyl.

[0099] In this specification, unless otherwise specified, the "aryl group" may be monocyclic, bicyclic, tricyclic, or tetracyclic.

[0100] Unless otherwise specified, the "aryl group" used herein may be a C6-C18 aryl group. Unless otherwise specified, examples of the "aryl group" used herein include phenyl, 1-naphthyl, 2-naphthyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, and 2-anthryl.

[0101] As used herein, a "fluoroaryl group" is an aryl group in which at least one hydrogen atom is substituted with a fluorine atom.

[0102] In this specification, unless otherwise limited, examples of the "aralkyl group" include benzyl, phenethyl, diphenylmethyl, 1-naphthylmethyl, 2-naphthylmethyl, 2,2-diphenylethyl, 3-phenylpropyl, 4-phenylbutyl, 5-phenylpentyl, 2-biphenylylmethyl, 3-biphenylylmethyl, and 4-biphenylylmethyl.

[0103] R ｒ has the same meaning as the above-mentioned hydrocarbon group having 1 to 20 carbon atoms, for example.

[0104] R using KF ａ -SO ２ In the synthesis of F (sulfonyl fluoride), for example, R ａ -SO ２ X can be used as a reactant, where X is a halo group, for example, chlorine or bromine.

[0105] R using KF ａ -SO ２ The reaction conditions for synthesizing F (sulfonyl fluoride) are not particularly limited, and for example, known reaction conditions can be widely adopted.

[0106] R using KF ａ -SO ２ Examples of the synthesis product of F (sulfonyl fluoride) include compounds having the structural formulas shown in the following formulas (1a) to (10a).

[0107]

[0108] Next, R using KF ｂ In the synthesis of —COF (acyl fluoride), R ｂ is the aforementioned R ａ Also, R ｂ A —C═C— bond may be present between the aromatic ring and the COF.

[0109] R using KF ｂ In the synthesis of —COF (acyl fluoride), for example, R ｂ -COX can be used as a reactant, where X is a halo group, for example, chlorine or bromine.

[0110] R using KF ｂ The reaction conditions for synthesizing —COF (acyl fluoride) are not particularly limited, and for example, known reaction conditions can be widely adopted.

[0111] R using KF ｂ Examples of the synthesis product of —COF (acyl fluoride) include compounds having the structural formulas shown in the following formulas (1b) to (3b).

[0112]

[0113] Next, R using KF ｃ -CH ２ In the synthesis of F, R ｃ is the aforementioned R ａ In addition, R ｂ Examples of the heterocyclic group include a "non-aromatic heterocyclic group." The "non-aromatic heterocyclic group" can be saturated or unsaturated.

[0114] In the specification, unless otherwise limited, examples of the "non-aromatic heterocyclic group" include tetrahydrofuryl, oxazolidinyl, imidazolinyl (e.g., 1-imidazolinyl, 2-imidazolinyl, 4-imidazolinyl), aziridinyl (e.g., 1-aziridinyl, 2-aziridinyl), azetidinyl (e.g., 1-azetidinyl, 2-azetidinyl), pyrrolidinyl (e.g., 1-pyrrolidinyl), and the like. nyl, 2-pyrrolidinyl, 3-pyrrolidinyl), piperidinyl (e.g., 1-piperidinyl, 2-piperidinyl, 3-piperidinyl), azepanyl (e.g., 1-azepanyl, 2-azepanyl, 3-azepanyl, 4-azepanyl), azocanyl (e.g., 1-azocanyl, 2-azocanyl, 3-azocanyl, 4-azocanyl), piperazinyl (e.g., 1,4-piperazine-1 -yl, 1,4-piperazin-2-yl), diazepinyl (e.g., 1,4-diazepin-1-yl, 1,4-diazepin-2-yl, 1,4-diazepin-5-yl, 1,4-diazepin-6-yl), diazocanyl (e.g., 1,4-diazocan-1-yl, 1,4-diazocan-2-yl, 1,4-diazocan-5-yl, 1,4-diazocan-6-yl, 1,5-diazocan-1-yl, 1,5-diazocan-2-yl, 1,5-diazocan-3-yl), tetrahydropyranyl (e.g., tetrahydropyran-4-yl), morpholinyl (e.g., 4-morpholinyl), thiomorpholinyl (e.g., 4-thiomorpholinyl), 2-oxazolidinyl, dihydrofuryl, dihydropyranyl, and dihydroquinolyl.

[0115] R ｃ and an aromatic or non-aromatic heterocyclic ring in ２ There may be a —C(═O)— bond between F and the ring.

[0116] R using KF ｃ -CH ２ In the synthesis of F, for example, R ｃ -CH ２ X can be used as a reactant, where X is a halo group, for example, chlorine or bromine.

[0117] R using KF ｃ -CH ２The reaction conditions for the synthesis of F are not particularly limited, and for example, known reaction conditions can be widely adopted.

[0118] R using KF ｃ -CH ２ Examples of the product of the synthesis of F include compounds having the structural formulae shown in the following formulae (1c) to (4c).

[0119]

[0120] Next, in the Halex reaction using KF, the product is R ｄ -F. R ｄ represents a heteroaryl group which may have a substituent.

[0121] Unless otherwise specified, examples of the "heteroaryl group" used herein include monocyclic aromatic heterocyclic groups (e.g., 5- or 6-membered monocyclic aromatic heterocyclic groups) and aromatic fused heterocyclic groups (e.g., 5- to 18-membered aromatic fused heterocyclic groups).

[0122] In this specification, unless otherwise limited, examples of the "5- or 6-membered monocyclic aromatic heterocyclic group" include pyrrolyl (e.g., 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl), furyl (e.g., 2-furyl, 3-furyl), thienyl (e.g., 2-thienyl, 3-thienyl), pyrazolyl (e.g., 1-pyrazolyl, 3-pyrazolyl, 4-pyrazolyl), imidazolyl (e.g., 1-imidazolyl, 2-imidazolyl, 4-imidazolyl), isoxazolyl (e.g., 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl), oxazolyl (e.g., 2-oxazolyl, 4-oxazolyl, 5-oxazolyl), isothiazolyl (e.g., 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl), aryl), thiazolyl (e.g., 2-thiazolyl, 4-thiazolyl, 5-thiazolyl), triazolyl (e.g., 1,2,3-triazol-4-yl, 1,2,4-triazol-3-yl), oxadiazolyl (e.g., 1,2,4-oxadiazol-3-yl, 1,2,4-oxadiazol-5-yl), thiadiazolyl (e.g., 1,2,4-thiadiazol-3-yl, 1,2,4-thiadiazol-5-yl), tetrazolyl, pyridyl (e.g., 2-pyridyl, 3-pyridyl, 4-pyridyl), pyridazinyl (e.g., 3-pyridazinyl, 4-pyridazinyl), pyrimidinyl (e.g., 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl), pyrazinyl, and the like.

[0123] In this specification, unless otherwise limited, examples of the "5- to 18-membered aromatic fused heterocyclic group" include isoindolyl (e.g., 1-isoindolyl, 2-isoindolyl, 3-isoindolyl, 4-isoindolyl, 5-isoindolyl, 6-isoindolyl, 7-isoindolyl), indolyl (e.g., 1-indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl), benzo[b]furanyl (e.g., 2-benzo[b]furanyl, 3-benzo[b]furanyl, 4-benzo[b]furanyl, benzo[b]furanyl, 5-benzo[b]furanyl, 6-benzo[b]furanyl, 7-benzo[b]furanyl), benzo[c]furanyl (e.g., 1-benzo[c]furanyl, 4-benzo[c]furanyl, 5-benzo[c]furanyl), benzo[b]thienyl, (e.g., 2-benzo[b]thienyl, 3-benzo[b]thienyl, 4-benzo[b]thienyl, 5-benzo[b]thienyl, 6-benzo[b]thienyl, 7-benzo[b]thienyl), benzo[c]thienyl (e.g., 1-benzo[c]thienyl, 4-benzo [c]thienyl, 5-benzo[c]thienyl), indazolyl (e.g., 1-indazolyl, 2-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl), benzimidazolyl (e.g., 1-benzimidazolyl, 2-benzimidazolyl, 4-benzimidazolyl, 5-benzimidazolyl), 1,2-benzisoxazolyl (e.g., 1,2-benzisoxazol-3-yl, 1,2-benzisoxazol-4-yl, 1,2-benzisooxazol-5-yl, 1,2-benzisooxazol-6-yl, 1,2-benzisooxazol-7-yl, 1,2-benzisooxazol-8-yl, 1,2-benzisooxazol-9-yl, 1,2-benzisooxazol-10-yl, 1,2-benzisooxazol-11-yl, 1,2-benzisooxazol-12-yl, 1,2-benzisooxazol-13-yl, 1,2-benzisooxazol-14-yl, 1,2-benzisooxazol-15-yl, 1,2-benzisooxazol-16-yl, 1,2-benzisooxazol-17-yl, 1,2-benzisooxazol-18-yl, 1,2-benzisooxazol-19-yl, 1,2-benzisooxazol-20-yl, 1,2-benzisooxazol-21-yl, 1,2-benzisooxazol-22-yl, 1,2-benzisooxazol benzoxazolyl (e.g., 2-benzoxazolyl, 4-benzoxazolyl, 5-benzoxazolyl, 6-benzoxazolyl, 7-benzoxazolyl), 1,2-benzisothiazolyl (e.g., 1,2-benzisothiazol-3-yl, 1,2-benzisothiazol-4-yl, 1,2-benzisothiazol-5-yl, 1,2-benzisothiazol-6-yl, 1,2-benzisoxazol-7-yl), benzoxazolyl (e.g., 2-benzoxazolyl, 4-benzoxazolyl, 5-benzoxazolyl, 6-benzoxazolyl, 7-benzoxazolyl), 1,2-benzisothiazolyl (e.g., 1,2-benzisothiazol-3-yl, 1,2-benzisothiazol-4-yl, 1,2-benzisothiazol-5-yl, 1,2-benzisothiazol-6-yl, 1,2-benzisothiazol-7-yl), benzothiazolyl (e.g., 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl), isoquinolyl (e.g., 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl), quinolyl (e.g., 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 8-quinolyl), cinnolinyl (e.g., : 3-cinnolinyl, 4-cinnolinyl, 5-cinnolinyl, 6-cinnolinyl, 7-cinnolinyl, 8-cinnolinyl), phthalazinyl (e.g., 1-phthalazinyl, 4-phthalazinyl, 5-phthalazinyl, 6-phthalazinyl, 7-phthalazinyl, 8-phthalazinyl), quinazolinyl (e.g., 2-quinazolinyl, 4-quinazolinyl, 5-quinazolinyl, 6-quinazolinyl, 7-quinazolinyl, 8-quinazolinyl), quinoxalinyl (e.g., 2-quinoxalinyl, 3-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 7-quinoxalinyl, 8-quinoxalinyl), pyrazolo[1,5-a]pyridyl (e.g., pyrazolo[1,5-a]pyridin-2-yl, pyrazolo[1,5-a]pyridin-3-yl, pyrazolo[1,5-a]pyridin-4-yl, pyrazolo[1,5-a]pyridin-5-yl, pyrazolo[1,5-a] pyridin-6-yl, pyrazolo[1,5-a]pyridin-7-yl), imidazo[1,2-a]pyridyl (e.g., imidazo[1,2-a]pyridin-2-yl, imidazo[1,2-a]pyridin-3-yl, imidazo[1,2-a]pyridin-5-yl, imidazo[1,2-a]pyridin-6-yl, imidazo[1,2-a]pyridin-7-yl, imidazo[1,2-a]pyridin-8-yl), and the like.

[0124] In the Halex reaction using KF, for example, R ｄ -X can be used as a reactant, where X is a halo group, for example, chlorine or bromine.

[0125] The reaction conditions for the Halex reaction using KF are not particularly limited, and for example, reaction conditions for known Halex reactions can be widely adopted.

[0126] Examples of products of the Halex reaction using KF include compounds having the structural formulae shown in the following formulae (1d) to (4d).

[0127]

[0128] In the deoxyfluorination reaction using KF, for example, a wide variety of raw materials that can be used in known deoxyfluorination reactions can be used, including a wide variety of alcohol compounds. For example, in the deoxyfluorination reaction using KF, hydrocarbon compounds having a hydroxyl group can be used. Such hydrocarbon groups are the same as those described above, and therefore include hydrocarbon groups having 1 to 20 carbon atoms. The hydrocarbon group can have a chain structure (acyclic structure), a cyclic structure, or a structure that is a combination of one or more of these. Examples of such "hydrocarbon groups" include alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups, cycloalkadienyl groups, aryl groups, aralkyl groups, and groups that are combinations of these.

[0129] The reaction conditions for the deoxyfluorination reaction using KF are not particularly limited, and for example, known reaction conditions for the deoxyfluorination reaction using KF can be widely adopted.

[0130] In specifying the inventions included in the present disclosure, the components (properties, structures, functions, etc.) described in each embodiment of the present disclosure may be combined in any manner. In other words, the present disclosure includes all subject matter consisting of all combinations of the components that can be combined as described in this specification.

[0131] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0132] (Example 1A) In an NMR tube, potassium hexamethyldisilazide (KHMDS, solid at room temperature) as a basic compound, 0.7 mL of toluene-d8 as a solvent, and 0.01 mmol of C as an internal standard substance were added. ６ F ６The NMR tube was frozen under a nitrogen atmosphere, then depressurized, and 0.025 mol of the raw material pentafluoroethane was introduced into the NMR tube. Subsequently, the NMR tube was kept at -50°C, and this temperature was used as the reaction temperature (temperature of base treatment), and the mixture was vibrated for 3 hours to produce tetrafluoroethylene (TFE) (Step 1). In Step 1, the amount of KHMDS used was 2 equivalents relative to pentafluoroethane. Thereafter, the contents of the NMR tube were heated at -94°C. １９ F-NMR was measured. Based on the obtained NMR spectrum, the internal standard C ６ F ６ The yield was calculated from the signal, and it was confirmed that TFE was produced in a yield of 79%.

[0133] (Example 2A) TFE was produced in the same manner as in Example 1A, except that the amount of KHMDS used was changed to 1.5 equivalents relative to pentafluoroethane, and it was confirmed that TFE was produced in a yield of 75%.

[0134] (Example 3A) TFE was produced in the same manner as in Example 1A, except that the amount of KHMDS used was changed to 3 equivalents relative to pentafluoroethane, and it was confirmed that TFE was produced in a yield of 52%.

[0135] (Example 4A) TFE was produced in the same manner as in Example 1A, except that the amount of KHMDS used was changed to 1 equivalent relative to pentafluoroethane, and it was confirmed that TFE was produced in a yield of 27%.

[0136] (Example 5A) The same procedure as in Example 4A was carried out except that the reaction temperature was changed to 25°C. １９ The production of TFE was confirmed by F-NMR.

[0137] (Example 6A) The same method as in Example 4A was carried out except that the basic compound was changed from KHMDS to sodium hexamethyldisilazide (NaHMDS, solid at room temperature) and the reaction temperature was changed to 25°C. １９ The production of TFE was confirmed by F-NMR.

[0138] (Example 7A) The same procedure as in Example 4A was carried out except that the basic compound was changed from KHMDS to lithium hexamethyldisilazide (LHMDS, solid at room temperature) and the reaction temperature was changed to 25°C. １９ The production of TFE was confirmed by F-NMR.

[0139] (Example 8A) The same procedure as in Example 4A was carried out except that the solvent was changed to n-hexane instead of toluene and the reaction temperature was changed to 25°C. １９ The production of TFE was confirmed by F-NMR.

[0140] Example 9A The same procedure as in Example 4A was carried out except that the solvent was changed to tetrahydrofuran instead of toluene and the reaction temperature was changed to 25°C. １９ The production of TFE was confirmed by F-NMR.

[0141] Example 10A The same procedure as in Example 4A was carried out except that potassium tert-butoxide (tBuOK) was used instead of KHMDS as the basic compound, the reaction temperature was changed to 25°C, and 1 equivalent of tetrabutylammonium iodide (TBAI) was added as a phase transfer catalyst relative to pentafluoroethane. １９ The production of TFE was confirmed by F-NMR.

[0142] (Example 11A) The same procedure as in Example 4A was carried out except that the basic compound was changed to lithium diisopropylamide (LDA) instead of KHMDS. １９ The production of TFE was confirmed by F-NMR.

[0143] Example 12A 5 mmol of potassium hexamethyldisilazide (KHMDS) as a basic compound was placed in vessel 1, which was then sealed. Vessel 1 was removed from the glove box, cooled with liquid nitrogen, and then depressurized. Pentafluoroethane was then introduced into vessel 1, and vessel 1 was then maintained at −50°C. This temperature was used as the reaction temperature (temperature for base treatment), and the vessel was vibrated for 3 hours (reaction time) to produce tetrafluoroethylene (TFE) (Step 1). In Step 1, the amount of pentafluoroethane used was 2.88 equivalents relative to KHMDS. The yield of TFE was calculated by reacting the produced TFE with dimethylamine to obtain the amino compound, and this was used as the TFE yield in Step 1. Specifically, the TFE yield was calculated using the following procedure. First, a new autoclave containing dimethylamine (20 mmol) and tetrahydrofuran was prepared as vessel 2, and vessel 2 was sealed, cooled to −85°C, and depressurized. On the other hand, TFE produced while gradually increasing the temperature of the vessel 1 was transferred to the vessel 2 via a PFA tube, and the vessel 2 was stirred at 0° C. for 12 hours. The yield of the amino compound thus obtained was calculated to be 55%, and therefore the yield of TFE in step 1 was estimated to be 55%.

[0144] (Example 13A) TFE was produced in the same manner as in Example 12A, except that the amount of pentafluoroethane used was changed to 2.79 equivalents relative to KHMDS and the reaction time was changed to 6 hours. It was confirmed that TFE was produced in a yield of 55%.

[0145] (Example 14A) TFE was produced in the same manner as in Example 12A, except that the amount of pentafluoroethane used was changed to 2.23 equivalents relative to KHMDS, and it was confirmed that TFE was produced in a yield of 57%.

[0146] (Example 15A) TFE was produced in the same manner as in Example 12A, except that the amount of pentafluoroethane used was changed to 0.5 equivalents relative to KHMDS, and it was confirmed that TFE was produced in a yield of 44%.

[0147] (Example 1B) Using the reaction apparatus shown in Figure 1, tetrafluoroethylene (TFE) was synthesized according to the following procedures 1) to 7). 1) In a glove box, 4 equivalents of KHMDS and a stir bar were placed in an oven-dried 10 mL vial relative to 0.75 mmol of pentafluoroethane to be introduced into the vial, and the solution was dissolved in anhydrous toluene to prepare a 1.0 M KHMDS-toluene solution as a "reaction vessel." 2) Meanwhile, 20 mL of toluene and 0.1 mmol of hexafluorobenzene as an internal standard were placed in a 25 mL screw vial, which was then capped and cooled to -85°C to prepare a "recovery vessel." 3) The flow line shown in Figure 1 was assembled under a nitrogen atmosphere. As shown in Figure 1, pentafluoroethane cylinder 1, reaction tank 2, and recovery tank 3 were each connected to one another by pipe 4, with the inlet and outlet of the pipes of each tank positioned above the liquid surface (however, the outlet side of pipe 4 connecting cylinder 1 and reaction tank 2 was immersed in the reaction liquid in the reaction tank. A needle was inserted into the septum of the recovery tank to create an open system. 4) Pentafluoroethane was flowed from cylinder 1 at a pressure of 0.1 MPa, while controlling the flow rate to 3.35 mL / min using a mass flow controller. By flowing pentafluoroethane in this way, bubbling of pentafluoroethane into the solution in the reaction tank began. The solution in the reaction tank into which pentafluoroethane had been introduced was vigorously stirred at room temperature (25°C). 5) Meanwhile, gas was evacuated from the recovery tank side for 1 minute, and then the needle inserted into the recovery tank was removed to create a closed system. Immediately thereafter, the gas outlet on the recovery tank side was immersed in toluene cooled to -85°C, and recovery of the product (tetrafluoroethylene) began. 6) Five minutes after the start of the pentafluoroethane flow, the flow of pentafluoroethane was stopped by removing the tube 4 connecting the cylinder 1 and the reaction tank 2 from the reaction tank (the amount of pentafluoroethane introduced was 0.75 mmol, and the pentafluoroethane flow time was 5 minutes), after which stirring was continued for another five minutes. 7) After confirming that no more gas was being generated in the solution in the reaction tank 2, the outlet of the tube 4 on the recovery tank side 3 was removed from the toluene solution, and the recovery tank 3 was immersed in liquid nitrogen to transfer the gas from the reaction tank to the recovery tank side.The septum of the recovery tank was quickly replaced with a screw cap to seal it, and the tank was immersed in a methanol bath at -85°C for 1 hour. The solution in the recovery tank was then quickly collected and placed in an NMR tube that had been pre-cooled to -85°C. This was used as a sample. １９ The yield of the product was estimated by measuring F-NMR.

[0148] (Example 2B) The same procedure as in Example 1B was carried out, except that the flow time of pentafluoroethane was changed to 10 minutes, the amount of KHMDS used was changed to 2 equivalents relative to pentafluoroethane, and the amount of toluene used in the recovery tank was changed to 23 mL, and the yield of the obtained product was estimated.

[0149] Example 3B The same procedure as in Example 2B was carried out except that the amount of KHMDS used was changed to 3 equivalents relative to pentafluoroethane, and the yield of the obtained product was estimated.

[0150] Example 4B The same procedure as in Example 1B was carried out, except that the flow time of pentafluoroethane was changed to 30 minutes, the amount of KHMDS used was changed to 3 equivalents relative to pentafluoroethane, the vial for forming the reaction vessel was changed to a volume of 25 mL, the vial for forming the recovery vessel was changed to a volume of 50 mL, and the amount of toluene used in the recovery vessel was changed to 45 mL, and the yield of the obtained product was estimated.

[0151] Example 5B The same procedure as in Example 1B was carried out except that the amount of KHMDS used was changed to 3 equivalents relative to pentafluoroethane, and the yield of the obtained product was estimated.

[0152] Table 1 shows the synthesis conditions for Examples 1B to 5B and the estimated yields of the resulting product (tetrafluoroethylene). These results show that the target product, tetrafluoroethylene (TFE), was obtained in high yield in all cases. In particular, the longer the pentafluoroethane flow time (i.e., the greater the amount of pentafluoroethane introduced), the higher the yield, and there was a tendency for the greater the number of equivalents of the basic compound to be.

[0153]

[0154] Fluorination reaction using KF by-produced in step 1 (Production Example 1: Production of KF under conditions of excessive HFC-125) A solution was prepared by dissolving 120 mg (0.6 mmol) of KHMDS in 1.2 mL of anhydrous toluene in a vacuum sample tube. Oxygen was removed by freeze-degassing, and the inside of the tube was decompressed. 18 mL (0.8 mmol) was taken from the balloon filled with HFC-125 using a gas-tight syringe and charged into the tube under liquid nitrogen. Thereafter, the inside of the tube was stirred at -50°C for 3 hours, thereby obtaining a KF / toluene suspension.

[0155] (Production Example 2: Production of 1.2 mmol of KF under conditions of excessive HFC-125) A solution was prepared by dissolving 240 mg (1.2 mmol) of KHMDS in 4.0 mL of anhydrous toluene in a vacuum sample tube. Oxygen was removed by freeze-degassing, and the inside of the tube was decompressed. 35 mL (1.56 mmol) was taken from a balloon filled with HFC-125 using a gas-tight syringe and charged into the tube under liquid nitrogen. Thereafter, the contents of the tube were stirred at −50° C. for 3 hours, thereby obtaining a KF / toluene suspension.

[0156] Example 16A: Synthesis of sulfonyl fluoride Sulfonyl fluoride was synthesized using sulfonyl chloride (0.4 mmol) according to the reaction scheme shown in FIG. 2(a). 76.3 mg (0.4 mmol) of 4-methylbenzenesulfonyl chloride was used as sulfonyl chloride (0.4 mmol). First, the KF / toluene suspension obtained in Production Example 1 was concentrated under vacuum, and the toluene and HMDS were removed to obtain solid crude KF. Next, sulfonyl chloride (0.4 mmol) was dissolved in 2.0 mL of acetone, and 12.3 μL (0.1 mmol) of trifluorotoluene was added thereto as an internal standard to obtain a solution. This solution was added to a tube containing the crude KF (0.6 mmol, 1.5 equivalents). 14.5 μL (0.8 mmol, 2.0 equivalents) of pure water was added to the tube, and the mixture was stirred at room temperature (25° C.) for 1 hour. １９F NMR was measured. Finally, the precipitate was removed by suction filtration and washed with ethyl acetate. The obtained filtrate was concentrated using an evaporator, and the obtained concentrate was purified by silica gel chromatography to obtain sulfonyl fluoride. The obtained sulfonyl fluoride was １９ The F-NMR yield was 88%, and the isolated yield was 77% (53.9 mg, 0.309 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / ethyl acetate = 95:5 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (500 MHz, chloroform-d) δ: 7.90 (d, J = 8.2 Hz, 2H), 7.42 (d, J = 8.2 Hz, 2H), 2.50 (s, 3H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: 65.8 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (11).

[0157]

[0158] (Example 16B; Synthesis of sulfonyl fluoride) Sulfonyl fluoride was obtained in the same manner as in Example 16A, except that sulfonyl chloride (0.4 mmol) was changed to 84.4 mg (0.4 mmol) of 4-chlorobenzenesulfonyl chloride. The obtained sulfonyl fluoride was １９ The F-NMR yield was 79%, and the isolated yield was 72% (56.2 mg, 0.289 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / ethyl acetate = 95:5 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (500 MHz, chloroform-d) δ: 8.00-7.95 (m, 2H), 7.64-7.60 (m, 2H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: 66.0 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (12).

[0159]

[0160] (Example 16C; Synthesis of sulfonyl fluoride) Sulfonyl fluoride was obtained in the same manner as in Example 16A, except that sulfonyl chloride (0.4 mmol) was changed to 80.6 mg (0.4 mmol) of 4-cyanobenzenesulfonyl chloride. The obtained sulfonyl fluoride was １９ The F-NMR yield was 90%, and the isolated yield was 77% (56.9 mg, 0.307 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / ethyl acetate = 9:1 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (500 MHz, chloroform-d) δ: 8.17 (dt, J １ = 8.4 Hz, J ２ =1.8Hz, 2H), 7.97-7.95(m, 2H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: 65.5 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (13).

[0161]

[0162] (Example 16D; Synthesis of sulfonyl fluoride) Sulfonyl fluoride was obtained in the same manner as in Example 16A, except that sulfonyl chloride (0.4 mmol) was changed to 88.6 mg (0.4 mmol) of 4-nitrobenzenesulfonyl chloride. The obtained sulfonyl fluoride was １９ The F-NMR yield was 98%, and the isolated yield was 77% (62.9 mg, 0.307 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / ethyl acetate = 9:1 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (500 MHz, chloroform-d) δ: 8.50 (d, J = 8.2 Hz, 2H), 8.25 (dt, J １ = 9.2 Hz, J ２=2.2Hz, 2H)ppm. １９ F NMR (282 MHz, chloroform-d) δ: 65.7 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (14).

[0163]

[0164] (Example 17A: Synthesis of Acyl Fluoride) Acyl fluoride was synthesized using acyl chloride (0.4 mmol) according to the reaction scheme shown in Figure 2(b). 86.7 mg (0.4 mmol) of [1,1'-biphenyl]-4-carbonyl chloride was used as acyl chloride (0.4 mmol). First, the KF / toluene suspension obtained in Production Example 1 was concentrated under vacuum, and the toluene and HMDS were removed to obtain solid crude KF. Next, acyl chloride (0.4 mmol) and 9.3 µL (0.1 mmol) of fluorobenzene as an internal standard were dissolved in 2.0 mL of acetone, and this acetone solution was added to a tube containing the crude KF (0.6 mmol, 1.5 equivalents). The mixture was heated and stirred at room temperature (25°C) for 12 hours, and the resulting reaction mixture was then eluted. １９ F NMR was measured. Finally, the precipitate was removed by suction filtration and washed with ethyl acetate. The filtrate was concentrated using an evaporator, and the obtained concentrate was purified by silica gel chromatography to obtain acyl fluoride. The obtained acyl fluoride was １９ The F-NMR yield was 60%, and the isolated yield was 48% (38.4 mg, 0.192 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / dichloromethane = 9:1 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (500MHz, chloroform-d) δ: 8.13-8.11 (m, 2H), 7.74 (d, J = 7.6Hz, 2H), 7.65-7.62 (m, 2H), 7.51-7.48 (m, 2H), 7.45-7.43 (m, 1H) ppm. １９F NMR (282 MHz, chloroform-d) δ: 17.6 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (15).

[0165]

[0166] (Example 17B; Synthesis of acyl fluoride) Acyl fluoride was obtained in the same manner as in Example 17A, except that acyl chloride (0.4 mmol) was changed to 66.2 mg (0.4 mmol) of 4-cyanobenzoyl chloride. The obtained sulfonyl fluoride was １９ The F-NMR yield was 68%, and the isolated yield was 33% (19.7 mg, 0.132 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / ethyl acetate = 9:1 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (500 MHz, chloroform-d) δ: 8.18-8.17 (m, 2H), 7.86-7.84 (m, 2H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: 19.7 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (16).

[0167]

[0168] Example 17C: Synthesis of acyl fluoride Acyl fluoride was obtained in the same manner as in Example 17A, except that acyl chloride (0.4 mmol) was replaced with 66.4 mg (0.4 mmol) of cinnamoyl chloride. The obtained sulfonyl fluoride was １９ The F-NMR yield was 61%, and the isolated yield was 48% (29.1 mg, 0.194 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / ethyl acetate = 9:1 to obtain a pale yellow liquid. The NMR measurement results are shown below. １H NMR (500 MHz, chloroform-d) δ: 7.85 (d, J = 15.9 Hz, 1H), 7.59-7.56 (m, 2H), 7.50-7.43 (m, 3H), 6.38 (dd, J １ = 16.2 Hz, J ２ =7.3Hz, 1H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: 25.1 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (17).

[0169]

[0170] (Example 18A;R ｃ -CH ２ Synthesis of F) According to the reaction scheme shown in FIG. ｃ -CH ２ F was synthesized. First, the KF / toluene suspension obtained in Production Example 1 was concentrated under vacuum, and the toluene and HMDS were removed to obtain solid crude KF. Next, 1-(bromomethyl)-4-nitrobenzene (43.2 mg, 0.2 mmol) and 12.3 μL (0.1 mmol) of trifluorotoluene as an internal standard were dissolved in 2.0 mL of tert-butanol, and this tert-butanol solution was added to a tube containing the crude KF (0.6 mmol, 3 equivalents). Next, 52.9 mg (0.2 mmol, 1.0 equivalents) of 18-crown-6 and 18 μL (5.0 equivalents) of pure water were added at room temperature, and the mixture was heated and stirred at 100°C for 12 hours. The resulting reaction mixture was then eluted with 100°C for 12 hours. １９ F NMR was measured. Finally, the precipitate was removed by suction filtration and washed with ethyl acetate. The filtrate was concentrated using an evaporator, and the resulting concentrate was purified by silica gel chromatography to obtain R ｃ -CH ２ F was obtained. ｃ -CH ２ F is, １９The F-NMR yield was 73%, and the isolated yield was 67% (20.9 mg, 0.135 mmol). Purification was performed by silica gel column chromatography, and the target product was eluted with a mixed solvent of n-hexane / ethyl acetate = 9:1 to obtain a pale yellow liquid. The NMR measurement results are shown below. １ HNMR (500MHz, chloroform-d) δ: 8.28-8.25 (m, 2H), 7.55-7.53 (m, 2H), 5.51 (d, J = 46.7Hz, 2H) ppm. １９ FNMR (282 MHz, chloroform-d) δ: −216.2 (t, J=46.6 Hz, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (18).

[0171]

[0172] (Example 18B; R ｃ -CH ２ Reaction of F) R was prepared in the same manner as in Example 18A, except that 1-(bromomethyl)-4-nitrobenzene (0.2 mmol) was replaced with 44.2 mg (0.2 mmol) of 2-(bromomethyl)naphthalene. ｃ -CH ２ F was obtained. ｃ -CH ２ The isolated yield of F was 60% (19.1 mg, 0.119 mmol). The purified product was eluted with n-hexane and obtained as a white solid. The NMR measurement results are shown below. １ H NMR (500 MHz, chloroform-d) δ: 8.07 (dd, J １ = 8.4 Hz, J ２ =0.8Hz, 1H), 7.90-7.88 (m, 1H), 7.60-7.52 (m, 3H) 7.48-7.45 (m, 1H), 5.85 (d, J = 48.2Hz, 2H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: −207.3 (t, J = 47.6 Hz, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (19).

[0173]

[0174] (Example 18C; R ｃ -CH ２ Reaction of F) R was prepared in the same manner as in Example 18A, except that 1-(bromomethyl)-4-nitrobenzene (0.2 mmol) was replaced with 38.4 mg (0.2 mmol) of 2-bromo-1-(pyrrolidine-1-yl)ethanol-1-one. ｃ -CH ２ F was obtained. ｃ -CH ２ The isolated yield of F was 40% (10.4 mg, 0.08 mmol). The purified product was eluted with ethyl acetate and obtained as a yellow liquid. The NMR measurement results are shown below. １ H NMR (500 MHz, chloroform-d) δ: 4.91 (d, J = 47.3 Hz, 2H), 3.54 (t, J = 7.0 Hz, 2H), 3.43 (td, J １ = 6.8 Hz, J ２ = 1.3Hz, 2H) 2.01-1.96 (m, 2H), 1.90-1.84 (m, 2H) ppm. １９ F NMR (658 MHz, chloroform-d) δ: −227.1 (t, J = 47.4 Hz, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (20).

[0175]

[0176] Example 19A: Halex Reaction According to the reaction scheme shown in FIG. d-F was synthesized. First, the KF / toluene suspension obtained in Production Example 1 was concentrated under vacuum, and the toluene and HMDS were removed to obtain a solid crudely purified KF. Next, 3-chloro-6-phenylpyridazine (0.4 mmol, 76.3 mg) and 12.3 μL (0.1 mmol) of trifluorotoluene as an internal standard were dissolved in 1.6 mL of DMSO, and this DMSO solution was added to a tube containing the crudely purified KF (0.6 mmol, 5 equivalents). 21.9 mg (0.2 mmol, 0.5 equivalents) of tetramethylammonium chloride was added to the tube at room temperature, and the mixture was heated and stirred at 140°C for 12 hours. The resulting reaction product was １９ F NMR was measured. Finally, the precipitate was removed by suction filtration and washed with ethyl acetate. The filtrate was concentrated using an evaporator, and the resulting concentrate was purified by silica gel chromatography to obtain R d -F was obtained. d -F is １９ The F-NMR yield was 65%, and the isolated yield was 64% (44.3 mg, 0.254 mmol). The product was purified by elution with a mixed solvent of n-hexane / ethyl acetate = 9:1 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (700MHz, chloroform-d) δ: 8.03-7.99 (m, 3H), 7.55-7.50 (m, 3H), 7.29 (dd, J １ = 9.2 Hz, J ２ =2.0Hz, 1H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: −82.6 (d, J=7.1 Hz, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (21).

[0177]

[0178] Example 19B: Halex reaction R was carried out in the same manner as in Example 19A, except that 3-chloro-6-phenylpyridazine (0.4 mmol) was replaced with 55.4 mg (0.4 mmol) of 6-chloronicotinnitrile and the heating and stirring time was changed to 1 hour. d-F was obtained. d The isolated yield of -F was 70% (34.3 mg, 0.281 mmol). The product was purified by elution with a mixed solvent of n-hexane / ethyl acetate / triethylamine = 80:15:5, and obtained as a white solid. The NMR measurement results are shown below. １ H NMR (700 MHz, chloroform-d) δ: 8.59 (d, J = 2.4 Hz, 1H), 8.09 (ddd, J １ = 9.0 Hz, J ２ = 6.6 Hz, J ３ =1.8Hz, 1H), 7.12-7.10(m, 1H) ppm. １９ F NMR (658 MHz, chloroform-d) δ: −57.8 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (22).

[0179]

[0180] Example 19C: Halex reaction R was carried out in the same manner as in Example 19A, except that 3-chloro-6-phenylpyridazine (0.4 mmol) was changed to 65.4 mg (0.4 mmol) of 1-chloroisoquinoline and the heating and stirring time was changed to 22 hours. d -F was obtained. d The isolated yield of -F was 44% (26.1 mg, 0.177 mmol). The purified product was eluted with a mixed solvent of n-hexane / diethyl ether = 95:5, and obtained as a colorless, transparent liquid. The NMR measurement results are shown below. １ H NMR (700 MHz, chloroform-d) δ: 8.17 (d, J = 8.4 Hz, 1H), 8.05 (d, J = 6.0 Hz, 1H), 7.86 (d, J = 8.4 Hz, 1H), 7.77 (dd, J １ = 8.2 Hz, J ２ =7.0Hz, 1H), 7.66 (t, J=7.6Hz, 1H), 7.53 (d, J=6.0Hz, 1H) ppm. １９ F NMR (658 MHz, chloroform-d) δ: −71.7 (s, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (23).

[0181]

[0182] Example 19D: Halex Reaction R was carried out in the same manner as in Example 19A, except that 3-chloro-6-phenylpyridazine (0.4 mmol) was replaced with 79.3 mg (0.4 mmol) of 4,7-dichloroquinoline, and the heating and stirring time was changed to 13 hours. d -F was obtained. d The isolated yield of -F was 61% (44.5 mg, 0.245 mmol). The purified product was eluted with a mixed solvent of n-hexane / ethyl acetate = 95:5 to obtain a white solid. The NMR measurement results are shown below. １ H NMR (700 MHz, chloroform-d) δ: 8.87 (dd, J １ = 8.4 Hz, J ２ = 4.8Hz, 1H), 8.14 (t, J = 1.8Hz, 1H), 8.05 (d, J = 8.8Hz, 1H), 7.57 (dd, J １ = 8.8 Hz, J ２ =2.0Hz, 1H), 7.11(dd, J １ = 9.4 Hz, J ２ = 5.0Hz, 1H), 7.53 (d, J = 6.0Hz, 1H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: −112.2 (t, J = 10.0 Hz, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (24).

[0183]

[0184] (Example 20; Deoxyfluorination Reaction) A deoxyfluorination reaction was carried out according to the reaction scheme shown in Figure 2(e). First, the KF / toluene suspension obtained in Production Example 2 was concentrated under vacuum, and the toluene and HMDS were removed to obtain solid crude KF. Next, adamantan-1-ol (0.2 mmol, 30.5 mg) was dissolved in 2.0 mL of dichloromethane, and this solution was added to a tube containing the crude KF (1.2 mmol, 6 equivalents). 64.3 µL (1.2 mmol, 6.0 equivalents) of concentrated sulfuric acid was added to the tube at 0°C, and the mixture was stirred at 0°C for 1 hour. The resulting reaction product was １９ F NMR was measured. Finally, the reaction solution was dissolved in saturated NaHCO ３ The mixture was quenched with aqueous solution of 1,000 mg of HCl and extracted with dichloromethane. ２ SO ４ The mixture was dried at 77°C and filtered to remove the solids. The filtrate was concentrated using a rotary evaporator. The concentrate was purified by silica gel chromatography to give the product R ｅ -F was obtained. ｅ The isolated yield of -F was 25% (7.7 mg, 0.050 mmol). Purification was carried out by elution with n-hexane to obtain a white solid. The NMR measurement results are shown below. １ H NMR (500MHz, chloroform-d) δ: 2.23 (s, 3H), 1.89 (q, J = 2.8Hz, 6H), 1.66-1.59 (m, 6H) ppm. １９ F NMR (282 MHz, chloroform-d) δ: −128.9 to −129.0 (m, 1F) ppm. From the above, the obtained product was determined to be a compound represented by the following formula (25).

[0185]

[0186] Example 21A The reaction apparatus shown in FIG. 3 was assembled by the following procedure. In a glove box with a nitrogen atmosphere, 400 mg (2.01 mmol) of potassium hexamethyldisilazide (KHMDS) was loaded into a cartridge. Next, the cartridge was removed from the glove box, and a gas cylinder containing pentafluoroethane (HFC-125), a mass flow controller, and the cartridge were connected in series, in this order, via fluororesin tubing. A fluororesin tube was also connected to the connection on the opposite side of the cartridge to the mass flow controller, and a septum was attached to the tip of the fluororesin tube, thereby assembling the reaction apparatus. In addition, a vial was used as a recovery tank for recovering the reaction product (tetrafluoroethylene). The vial was previously filled approximately 80% with toluene, and a certain amount of hexafluorobenzene was added as an internal standard for NMR. However, as described below, the recovery tank was not connected to the reaction apparatus until 1 minute had elapsed since the start of the flow of HFC-125.

[0187] The reaction using the reaction apparatus was carried out according to the following procedure. First, the valve of the gas cylinder was opened, and the secondary pressure value of the regulator attached to the gas cylinder was set to 0.1 MPa. As shown in Table 2 below, HFC-125 was passed through the cartridge while adjusting the flow rate of HFC-125 so that the flow rate of the mass flow controller was 1.15 mL / min. For one minute after the start of the flow of HFC-125, gas recovery was not performed in order to stabilize the mass flow controller and to fill the flow system with the reaction gas. One minute after the start of the flow of HFC-125, the end of the tube to which the septum was attached was placed in the recovery tank. The time from the placement of the tube in the recovery tank until the flow of HFC-125 was stopped (hereinafter referred to as flow time) was 10 minutes (see Table 2). After stopping the flow of HFC-125, the tube connected to the recovery tank was pulled out from the septum, and the recovery tank was immersed in liquid nitrogen to cool it. The septum was then replaced with a screw cap, and the tank was cooled in a constant temperature bath at −85° C. for at least one hour. Next, a portion of the solution in the recovery tank was sampled and １９ F-NMR was measured and compared with the peak area of ​​hexafluorobenzene as an internal standard to calculate the yield of tetrafluoroethylene (TFE) produced and the recovery rate of the raw material HFC-125.

[0188] Example 21B As shown in Table 2 below, the yield of produced tetrafluoroethylene and the recovery rate of the raw material HFC-125 were calculated in the same manner as in Example 21A, except that the flow time was changed to 15 minutes.

[0189] Example 21C As shown in Table 2 below, the yield of produced tetrafluoroethylene and the recovery rate of the raw material HFC-125 were calculated in the same manner as in Example 21A, except that the flow time was changed to 20 minutes.

[0190] Table 2 shows the results of the reactions carried out in Examples 21A, 21B, and 21C.

[0191]

[0192] Example 22A The reaction apparatus shown in FIG. 4 was assembled by the following procedure. Two cartridges (referred to as the first cartridge and the second cartridge, respectively) were prepared in a glove box under a nitrogen atmosphere, and each was filled with potassium hexamethyldisilazide (KHMDS). Specifically, 400 mg of potassium hexamethyldisilazide was filled into the first cartridge (labeled "1" in FIG. 4), and 150 mg of potassium hexamethyldisilazide was filled into the second cartridge (labeled "2" in FIG. 4). Next, the two cartridges were removed from the glove box, and a gas cylinder containing pentafluoroethane (HFC-125), a mass flow controller, the first cartridge, and the second cartridge were connected in series in this order via fluororesin tubing. A fluororesin tubing was also connected to the side of the second cartridge opposite to the side connected to the mass flow controller, and a septum was attached to the tip of the fluororesin tubing, thereby assembling the reaction apparatus. In addition, a vial was used as a recovery tank for recovering the reaction product (tetrafluoroethylene). The vial was filled with toluene to about 80% in advance, and a certain amount of hexafluorobenzene was added as an internal standard for NMR. However, as will be described later, the recovery tank was not connected to the reactor until 1 minute had elapsed since the start of the flow of HFC-125.

[0193] The reaction using the reaction apparatus was carried out according to the following procedure. First, the valve of the gas cylinder was opened, and the secondary pressure value of the regulator attached to the gas cylinder was set to 0.1 MPa. As shown in Table 3 below, HFC-125 was passed through each of the two cartridges while adjusting the flow rate of HFC-125 so that the flow rate of the mass flow controller was 4.99 mL / min. For one minute after the start of the HFC-125 flow, gas recovery was not performed in order to stabilize the mass flow controller and to fill the flow system with the reaction gas. One minute after the start of the HFC-125 flow, the end of the tube to which the septum was attached was placed into the recovery tank, and the recovery tank was sealed with the septum (see FIG. 4). The time from the start of flowing HFC-125 until the flow of HFC-125 was stopped (Flow time) was 10 minutes (see Table 3). After the flow of HFC-125 was stopped, the tube connected to the recovery tank was pulled out from the septum, the recovery tank was immersed in liquid nitrogen to cool, the septum was replaced with a screw cap, and the tank was cooled in a constant temperature bath at -85°C for 1 hour or more. Next, a portion of the solution in the recovery tank was sampled, and １９ F-NMR was measured and the yield of tetrafluoroethylene (TFE) produced was calculated by comparing the area of ​​the peak of hexafluorobenzene as an internal standard.

[0194] Example 22B As shown in Table 3 below, the yield of tetrafluoroethylene produced was calculated in the same manner as in Example 22A, except that the flow rate was changed to 2.31 mL / min.

[0195] Table 3 shows the results of the reactions carried out in Examples 22A and 22B.

[0196]

Claims

1. A method for producing tetrafluoroethylene, comprising the step of treating pentafluoroethane with a basic compound to obtain tetrafluoroethylene.

2. The method for producing tetrafluoroethylene according to claim 1, wherein the basic compound is in a solid state under atmospheric pressure and at 25°C.

3. The method for producing tetrafluoroethylene according to claim 1, wherein the basic compound has a conjugate acid with a pKa value of 13 or more.

4. The method for producing tetrafluoroethylene according to any one of claims 1 to 3, wherein the basic compound is a compound containing a metal.

5. A method for producing tetrafluoroethylene according to any one of claims 1 to 3, wherein the treatment is carried out in the presence or absence of a phase transfer catalyst.

6. A method for producing tetrafluoroethylene according to any one of claims 1 to 3, wherein the treatment is carried out in the presence or absence of a solvent.

7. A composition comprising tetrafluoroethylene and pentafluoroethane.

8. The composition according to claim 7, wherein pentafluoroethane is contained in an amount of 52 mol % or less based on the total amount of tetrafluoroethylene and pentafluoroethane.

9. The composition according to claim 7, wherein pentafluoroethane is contained in an amount of 30 mol % or less based on the total amount of tetrafluoroethylene and pentafluoroethane.

10. The composition according to claim 7, wherein pentafluoroethane is contained in an amount of 10 mole percent or less based on the total amount of tetrafluoroethylene and pentafluoroethane.

11. The composition according to any one of claims 7 to 10, wherein pentafluoroethane is contained in an amount of 0.1 mol % or more based on the total amount of tetrafluoroethylene and pentafluoroethane.

Images