Method for producing tetrafluoroethylene and TFE composition

Abstract

This invention provides a method for producing tetrafluoroethylene using fluorocarbons as a raw material, and a composition containing tetrafluoroethylene. [Solution] The manufacturing method of the present disclosure includes the step of obtaining tetrafluoroethylene by performing a basic treatment on pentafluoroethane with a basic compound. The composition of the present disclosure comprises tetrafluoroethylene and pentafluoroethane. According to the manufacturing method of tetrafluoroethylene of the present disclosure, tetrafluoroethylene can be obtained at a mild temperature by a simple process.

Description

[Technical Field]

[0001] This invention relates to a method for producing tetrafluoroethylene and a TFE composition. [Background technology]

[0002] Developing methods to reuse fluorocarbons (CFCs) used in refrigerants and other applications as resin raw material monomers is important from the perspective of efficient utilization of CFCs. Among the monomers that can be used as resin raw materials, tetrafluoroethylene (TFE) is a highly important fluorine compound, serving as a raw material for producing fluororesins such as PTFE, FEP, PFA, and ETFE, and as an effective intermediate in the synthesis of organofluorine compounds.

[0003] As a method for producing the above-mentioned TFE, for example, Patent Document 1 discloses that an intermediate is obtained by treating pentafluoroethane (CF3CF2H) in the presence of chlorine gas, and then the intermediate is treated with hydrogen in the presence of a catalyst to produce TFE. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] U.S. Patent Publication No. 2004 / 0127757 [Overview of the project] [Problems that the invention aims to solve]

[0005] This disclosure aims to provide a method for producing tetrafluoroethylene using fluorocarbons as a raw material in a single step, and also aims to provide a composition containing tetrafluoroethylene that places less burden on the purification process. [Means for solving the problem]

[0006] This disclosure includes the configurations described in the following sections. Item 1 A method for producing tetrafluoroethylene, comprising the step of obtaining tetrafluoroethylene by treating pentafluoroethane with a basic compound. Section 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 of 25°C. Section 3 The method for producing tetrafluoroethylene according to claim 1 or 2, wherein the basic compound has a pKa value of its conjugate acid of 13 or more. Section 4 The method for producing tetrafluoroethylene according to any one of claims 1 to 3, wherein the basic compound is a metal-containing compound. Section 5 The method for producing tetrafluoroethylene according to any one of claims 1 to 4, wherein the process is carried out in the presence or absence of a phase transfer catalyst. Section 6 The method for producing tetrafluoroethylene according to any one of claims 1 to 5, wherein the process is carried out in the presence or absence of a solvent. Section 7 A composition comprising tetrafluoroethylene and pentafluoroethane. Section 8 The composition according to item 7, wherein pentafluoroethane is contained in an amount of 52 mol% or less relative to the total amount of tetrafluoroethylene and pentafluoroethane. Section 9 The composition according to item 7, wherein pentafluoroethane is contained in an amount of 30 mol% or less relative to the total amount of tetrafluoroethylene and pentafluoroethane. Section 10 The composition according to item 7, wherein pentafluoroethane is contained in an amount of 10 mol% or less relative to the total amount of tetrafluoroethylene and pentafluoroethane. Section 11 A composition according to any one of claims 7 to 10, wherein pentafluoroethane is contained in an amount of 0.1 mol% or more relative to the total amount of tetrafluoroethylene and pentafluoroethane. [Effects of the Invention]

[0007] According to the method for producing tetrafluoroethylene described herein, tetrafluoroethylene can be easily obtained in a single step even under mild conditions. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram illustrating the synthesis apparatus used in Example 1B, etc. [Figure 2] (a) is the reaction scheme used in Examples 16A to 16D, (b) is the reaction scheme used in Examples 17A to 17C, (c) is the reaction scheme used in Examples 18A to 18C, (d) is the reaction scheme used in Examples 19A to 19D, and (e) is the reaction scheme used in Example 20. [Figure 3] This is a schematic diagram of the reaction apparatus used in the reaction carried out in Example 21A. [Figure 4] This is a schematic diagram of the reaction apparatus used in the reaction carried out in Example 22A. [Modes for carrying out the invention]

[0009] The inventors have diligently conducted research to obtain tetrafluoroethylene in a simple manner. First, the method disclosed in the aforementioned Patent Document 1 requires a step of chlorination to obtain an intermediate, thus requiring at least two steps to obtain tetrafluoroethylene. Furthermore, it is a process that requires high-temperature heating of 300°C or higher and consumes a lot of energy, and although the yield is not clear, a high yield cannot be expected considering the complexity of the process.

[0010] This disclosure has been made in view of the above, and aims to provide a manufacturing method that can produce tetrafluoroethylene at a mild temperature and in a single step. Specifically, the above objective is achieved by a reaction using a basic compound.

[0011] Embodiments of the present invention will be described in detail below. In this specification, the expressions "containing" and "including" include the concepts of "containing," "including," "substantially consisting of," and "consisting only of."

[0012] In the numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. In the numerical ranges described in this specification, the upper or lower limit of a numerical range may be replaced with values ​​shown in the examples or values ​​that can be uniquely derived from the examples. Furthermore, in this specification, numbers connected by "~" mean a numerical range that includes the numbers before and after "~" as the lower and upper limits.

[0013] 1. Method for producing tetrafluoroethylene The present disclosure provides a method for producing tetrafluoroethylene using pentafluoroethane as a basic compound The method includes a step of obtaining tetrafluoroethylene by processing with a basic compound. In other words, the manufacturing method of the present disclosure is a method for producing tetrafluoroethylene by carrying out the reaction of pentafluoroethane in the presence of a basic compound.

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

[0015] The pentafluoroethane (HFC-125) used in step 1 is used as a raw material to obtain tetrafluoroethylene (TFE). Pentafluoroethane can be obtained, for example, by known methods, or it can be obtained from commercially available products. Alternatively, the pentafluoroethane used in step 1 can be recovered 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 at atmospheric pressure and 25°C can be used. That is, it is preferable that the basic compound used in step 1 is solid at room temperature. In this case, the base treatment can be carried out simply, and it also becomes easier to carry out the treatment in the gas phase of step 1, as will be described later.

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

[0018] The basic compound used in step 1 preferably has a conjugate acid with a pKa value of 13 or higher. In this case, the conversion rate from pentafluoroethane to tetrafluoroethylene tends to increase, the yield of tetrafluoroethylene tends to increase, and the reaction tends to proceed more rapidly.

[0019] In order to facilitate the reaction in step 1 at a milder temperature, the basic compound used in step 1 is more preferably of which the pKa value of its conjugate acid is 15 or higher, even more preferably 16 or higher, even more preferably 17 or higher, particularly preferably 18 or higher, and also preferably 40 or lower, more preferably 38 or lower, even more preferably 35 or lower, and particularly preferably 32 or lower.

[0020] The pKa of this disclosure refers to the acid dissociation constant in water or DMSO at 25°C. The pKa values ​​are those listed in publicly available information such as literature (e.g., Basic Chemical Handbook (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 G You can refer to reen 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, the basic compound is preferably in a solid state, and its conjugate acid is preferably within the range described above.

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

[0023] On the other hand, if the basic compound is a compound containing ammonium, the ammonium contained in such a compound is called "ammonium R4N + It is written as "Ammonium R4N". + Examples include ammonium, quaternary alkylammonium, ammonium formed from all or part of the amine moiety of polyethyleneimine, and ammonium formed from all or part of the amine moiety of aminoethylated acrylic polymers. Ammonium R4N + In this configuration, it is preferable that at least some or all of the four R atoms are selected from the group consisting of hydrogen and alkyl groups. The four R atoms may all be the same, or some may be different. Also, two R atoms may bond together to form a cyclic structure. More preferably, the R atoms 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 specifically, it is preferably an amide anion having the aforementioned metal or the aforementioned ammonium as a countercation. An amide anion refers to an anion formed by removing a proton from an amine skeleton.

[0025] In other words, it is preferable that the basic compound used in step 1 has at least one countercation and amide anion in one molecule. In this case, the number of countercations and amide anions contained in one molecule is not particularly limited.

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

[0027] Specific examples of basic compounds used in step 1 include silazides, amides, salts containing countercations in which all or part of the amine moiety of polyethyleneimine is an amide anion, salts containing countercations in which all or part of the amine moiety of aminoethylated acrylic polymer is an amide anion, salts containing countercations in which all or part of the amine moiety of polysilazane is an amide anion, alkyl metal compounds, metal salts of tetramethylpiperidide, metal alkoxides, metal hydrides, metal or ammonium hydroxides, ammonium fluorides, and the like.

[0028] The type of metal or ammonium contained in each basic compound can be the same metal as metal M mentioned above, or it can be in the form of ammonium. The pKas of the conjugate acids of these basic compounds are 29.5 for hexamethyldisilazide salts, 35.7 for diisopropylamide salts, 40-53 for alkyl metal compounds, 37.3 for tetramethylpiperidide salts, 15.9-19.2 for metal alkoxides, 35.0 for metal hydrides, 14.0 for metal or ammonium hydroxides, and 15.0 for ammonium fluorides (see Green Chem., 2015, 17, 945-949).

[0029] In particular, the reaction in step 1 (base treatment) can be carried out at a milder temperature, and tetrafluoroethylene can be obtained in a higher yield. Therefore, it is preferable that the basic compound contains one or more selected from the group consisting of metal salts of disilazide, metal alkoxides, and salts containing a countercation in which all or part of the amine moiety of polysilazane is an amide anion, and it is more preferable that it contains a metal salt of silazide. In particular, when the basic compound contains a metal salt of silazide, the reaction can be carried out at an even milder temperature without using the phase transfer catalyst described later, and the yield of tetrafluoroethylene can be particularly increased. Yes, it is possible. Moreover, if the basic compound contains a metal salt of silazide, it is highly soluble in the starting material, pentafluoroethane, so even if the reaction in step 1 is carried out in the absence of a solvent, tetrafluoroethylene can be efficiently obtained.

[0030] Examples of metal salts of the above-mentioned silazides include lithium hexamethyldisilazide, sodium hexamethyldisilazide, and potassium hexamethyldisilazide. Among these, potassium hexamethyldisilazide is preferred. The pKa of the conjugate acid of these metal salts of hexamethyldisilazides is 29.5.

[0031] Examples of metal alkoxides include metal salts of methoxides, ethoxides, and tert-butoxides. Among these, metal salts of tert-butoxides are preferred, with specific examples including lithium tert-butoxide, sodium tert-butoxide, and potassium tert-butoxide. The pKa of the conjugate acids of these metal alkoxides is 19.2 (Graduate Lecture Organic Chemistry (Tokyo Kagaku Dojin)).

[0032] Examples of metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. The pKa of the conjugate acids of these metal hydroxides is 15.7 (Graduate Lecture Organic Chemistry (Tokyo Kagaku Dojin)).

[0033] When the basic compound is a polymer, examples of the basic compound include polyethyleneimine; an aminoethylated acrylic polymer obtained by aminoethylating the carboxylic acid portion of an acrylic acid polymer; and a compound obtained by amid anionizing all or part of the amine moiety generated by treating polysilazane with a metal or ammonium-containing basic compound.

[0034] A preferred form of the metal salt containing a counter cation in which all or part of the amine site of polysilazane has become an amide anion 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 CH3, and R 2 is the same or different and is H, CH3, or -CH=CH2. M 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 thus is preferably lithium, sodium, potassium, or the like. In formula (l), m and n are each independently 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, more preferably 10 to 490. Also, in formula (1), -r- means that the repeating units of (SiR 1 R 2 2-NH-) and (SiR 1 R 2 2-NM-) are bonded in an arbitrary order (that is, randomly).

[0036] A preferred form of the ammonium containing a counter cation in which all or part of the amine site of polysilazane has become an amide anion is represented by the following formula (2) -(SiR 3 R 4 2-NH-) m -r-(SiR3 R 4 2-N - (R4N + )-) n - (2) (In formula (2), R 3 is H or CH3, R 4 The four R atoms are identical or different from H, -CH3, and -CH=CH2, and the four R atoms are one or more selected from the group consisting of H and alkyl groups. The four R atoms may be the same or different from each other, and two or more R atoms may be bonded together to form a cyclic structure. In formula (2), m and n are each independent integers of 0 or more, and the sum of m and n is not particularly limited, for example, 2 to 3200, preferably 5 to 1600, and more preferably 10 to 320. In formula (2), -r- is (SiR 3 R 4 2-NH-) and (SiR 3 R 4 2-N - (R4N + The repeating units of )-) are in any order (i.e., randomly) ) This means they are joined together.

[0037] A preferred form of the metal salt containing a countercation in which all or part of the amine moiety of polyethyleneimine is an amide anion is given by the following formula (3): -(CH2CH2-NH-) m -r-(CH2CH2-NM-) n - (3) It can be expressed as follows: In equation (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, etc. In formula (3), m and n are each independent integers of 0 or more, and the sum of m and n is not particularly limited, for example, 2 to 5600, preferably 5 to 2800, and more preferably 10 to 560. Also, in formula (3), -r- means that the repeating units of (CH2CH2-NH-) and (CH2CH2-NM-) are combined in any order (i.e., randomly).

[0039] A preferred form of ammonium containing a countercation in which all or part of the amine moiety of polyethyleneimine is an amide anion is given by the following formula (4): -(CH2CH2-NH-) m -r-(CH2CH2-N - (R4N + )-) n - (4) (In formula (4), the four Rs are one or more selected from the group consisting of H and alkyl groups.) The four Rs may be the same or different from each other, and two or more Rs may be bonded together to form a cyclic structure. In formula (4), m and n are each independent integers of 0 or more, and the sum of m and n is not particularly limited, for example, 2 to 3500, preferably 5 to 1800, and more preferably 10 to 350. Also, in formula (4), -r- refers to (CH2CH2-NH-) and (CH2CH2-N - (R4N + This means that the repeating units of )-) are joined in any order (i.e., randomly).

[0040] A preferred form of the metal salt containing a countercation in which all or part of the amine moiety of the aminoethylated acrylic polymer is an amide anion is the following formula (5) -(CH2CR(COOR)) m -r1-(CH2CR(COO-(CH2CH2-NH) n -r2-(CH2CH2-NM) p -H))k - (5) (In formula (5), R is one or more selected from the group consisting of H and alkyl groups.) It can be expressed as follows: In equation (5), M is an alkali metal, an alkaline earth metal, or a transition metal.

[0041] In formula (5), metal M is preferably an alkali metal, and therefore preferably lithium, sodium, potassium, etc. In formula (5), m, n, p, and k are each independent integers of 0 or more, and the sum of m, n, p, and k is not particularly limited. For example, it 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). Also, in formula (5), -r1- refers to (CH2CR(COOR)) and (CH2CR(COO-(CH2CH2-NH) n ―(CH2CH2-NM) p -H)) means that the repeating units are joined in any order (i.e., randomly). Also, in equation (5), -r2- means that the repeating units of (CH2CH2-NH) and (CH2CH2-NM) are joined in any order (i.e., randomly).

[0042] All or part of the amine moiety of the aminoethylated acrylic polymer is an amide anion. A preferred form of ammonium containing a countercation is given by the following formula (6): -(CH2CR(COOR)) m -r1-(CH2CR(COO-((CH2CH2-NH) n -r2-(CH2CH2-N - (R4N + )) p -H) k - (6) (In formula (6), R is one or more selected from the group consisting of H and alkyl groups.) It can be represented as follows. Two Rs or two or more Rs may bond together to form a cyclic structure. In formula (6), m, n, p, and k are each independent integers of 0 or more, and the sum of m, n, p, and k is not particularly limited and can be appropriately set, for example, 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). Also, in formula (6), -r1- refers to (CH2CR(COOR)) and (CH2CR(COO-((CH2CH2-NH) n -r2-(CH2CH2-N - (R4N + )) p This means that the repeating units of -H) are joined in any order (i.e., randomly). Also, in equation (6), -r2- refers to (CH2CH2-NH) and (CH2CH2-N - (R4N + This means that the repeating units of )) are joined in any order (i.e., randomly).

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

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

[0045] In step 1, the pentafluoroethane treatment can be carried out in a solvent if necessary. That is, in step 1, the base treatment can be carried out in or without a solvent.

[0046] When the above treatment is carried out in the presence of a solvent, the type of solvent that can be used is not particularly limited, and various organic solvents can be widely used, for example. 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 as a mixture of two or more solvents.

[0047] When the above process 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 tends to increase. Suitable solvents with low polarity include aromatic hydrocarbon solvents and aliphatic hydrocarbons. Examples of solvents include alicyclic hydrocarbons and ether-based solvents, among which aromatic hydrocarbon solvents and aliphatic hydrocarbons are more preferred, and aromatic hydrocarbon solvents are even more preferred. From the above viewpoint, preferred examples of solvents 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, the ratio of solvent to pentafluoroethane used is not particularly limited. For example, the molar concentration of pentafluoroethane relative to the solvent can be in the range of 0.01 to 3 M.

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

[0050] Step 1 can be carried out in the presence of a phase transfer catalyst, if necessary. That is, Step 1 can be carried out with or without a phase transfer catalyst. For example, when a solvent is used in Step 1, if the basic compound is poorly soluble in the solvent, it is preferable to perform 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, if the basic compound is a metal alkoxide, using a phase transfer catalyst facilitates the reaction in Step 1. If the basic compound is a metal salt of hexamethyldisilazide, the reaction proceeds easily even without using 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 range of known phase transfer catalysts can be used. Specific examples of phase transfer catalysts include quaternary ammonium salts, phosphonium salts, amines, crown ethers, etc., with quaternary ammonium salts being preferred among them.

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

[0053] In step 1, if a phase transfer catalyst is used, one type of phase transfer catalyst may be used alone or in combination of two or more types.

[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 the same as that used in known reactions using phase transfer catalysts. For example, 0.05 to 2.0 moles of phase transfer catalyst can be used per mole of pentafluoroethane.

[0055] The process in step 1, namely the reaction to obtain tetrafluoroethylene from pentafluoroethane, can be carried out in either the gas phase or the liquid phase.

[0056] If the reaction in step 1 is a gas-phase reaction, for example, if gaseous pentafluoroethane is used as a basic solution... The above treatment can be performed by contacting the compound. In this case, the basic compound is preferably in a solid state. That is, in the gas-phase reaction, gaseous pentafluoroethane is brought into contact with the solid basic compound. The basic compound may be supported on a carrier.

[0057] If the base treatment in step 1 is a gas-phase reaction, the reaction can be carried out by, for example, placing the basic compound in a reactor and introducing pentafluoroethane into the reactor to bring it into contact with the basic compound. In this case, one reactor containing the basic compound may be used, or two or more may be used. If two or more reactors containing basic compounds are used, each reactor can be connected in series, for example. The reactors can be connected to each other by connecting tubes, for example. The product containing tetrafluoroethylene after the reaction can be collected, for example, from the outlet of the reactor. If the base treatment in step 1 is a gas-phase reaction, for example, the flow rate (also called flow rate) of pentafluoroethane introduced into the reactor is not particularly limited.

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

[0059] In the gas-phase reaction, the ratio of pentafluoroethane to the basic compound used is not particularly limited; 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 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 also preferably 4.50 moles or less, more preferably 4.00 moles or less, even more preferably 3.50 moles or less, even 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; the reaction can be carried out under reduced pressure, under increased pressure, or at atmospheric pressure. The gas-phase reaction can be carried out using either a continuous or batch method.

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

[0062] One example of a liquid-phase reaction is a method in which gaseous pentafluoroethane is introduced into a solution of a basic compound by a method such as bubbling, and the pentafluoroethane comes into contact with the basic compound (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 is better, 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, it 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 used is not particularly limited; for example, 0.70 to 4.00 of the basic compound can be used per mole of pentafluoroethane. It can be used in moles. In the liquid-phase reaction, the amount of 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 also preferably 20 moles or less, more preferably 10 moles or less, even more preferably 8 moles or less, even more preferably 6 moles or less, 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; the reaction can be carried out under reduced pressure, increased pressure, or atmospheric pressure. The liquid-phase reaction can be carried out in either a continuous or batch manner.

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

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

[0067] For example, if the process 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 to an appropriate range depending on the temperature, for example, in the range of 0.5 hours or more and 48 hours or less, preferably 1 hour or more and 10 hours or less.

[0068] On the other hand, if the process in step 1 is the liquid-phase reaction described above, 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 also 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. The reaction time can be set to an appropriate range depending on the temperature, for example, in the range of 0.5 hours or more and 48 hours or less, preferably 1 hour or more and 10 hours or less.

[0069] Within the temperature range of the liquid-phase reaction described above, a reaction temperature lower than room temperature is preferable because it makes it easier to selectively obtain tetrafluoroethylene.

[0070] Furthermore, when the aforementioned liquid-phase reaction is carried out in the absence of a solvent, the reaction temperature is preferably below the boiling point of pentafluoroethane, and more preferably below -50°C. A reaction temperature within this range allows the pentafluoroethane to liquefy and efficiently come into contact with the basic compound.

[0071] If liquefaction can be achieved by adjusting the pressure, the preferred range of the reaction temperature is the same as in the case of the liquid phase reaction, even if the aforementioned liquid phase reaction is carried out in the absence of a solvent. Therefore, the reaction temperature when liquefaction can be achieved by adjusting the pressure 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 also 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 processing of step 1. For example, a tubular flow-through reactor. Vessels, pressure-resistant autoclaves, etc., can be used as reactors for the hydrogen chloride dechlorination reaction. As flow-through reactors, for example, adiabatic reactors and multi-tube reactors cooled slowly 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, etc.

[0073] The reactor may also be equipped with a jacket for regulating the temperature inside the vessel, through which a heat transfer medium, for example, can be circulated. This allows for adjustment of the ambient 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 may also contain by-products such as products obtained from the reaction of carbene intermediates, products derived from CF3 anions, and unreacted pentafluoroethane.

[0075] In the product obtained by the processing in step 1, the content of pentafluoroethane relative to the total amount of tetrafluoroethylene and pentafluoroethane is 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 disclosed herein may include other steps besides step 1, or it may consist only of step 1.

[0078] Other steps, such as those mentioned above, include recovering and regenerating the basic compound used in step 1. The method for regenerating the basic compound is not particularly limited, and for example, known regeneration methods can be widely adopted.

[0079] Furthermore, the manufacturing method of this disclosure allows the regenerated basic compound to be reused in the processing of step 1. In addition, since the manufacturing method of this disclosure may produce by-products due to the basic compound used in step 1, these by-products can be reused as raw materials for other reactions. Such by-products are fluoride salts; for example, if the basic compound used in step 1 is a metal salt, the by-product is a metal fluoride, and if the basic compound used in step 1 is an ammonium salt, the by-product is an ammonium fluoride salt. More specifically, when a compound containing potassium (for example, potassium hexamethyldisilazide) is used as the basic compound, KF (potassium fluoride) may be produced as a by-product in step 1, and such KF can be used in other reactions. Specific reactions utilizing fluoride salts will be described in detail in section 3, "Fluorination Reactions Using By-product Fluoride Salts," below. The fluoride salt is preferably a metal fluoride, and in this case, lithium, sodium, and potassium are preferred as the metal, with potassium being more preferred.

[0080] The manufacturing method disclosed herein involves obtaining tetrafluoroethylene by base treatment of pentafluoroethane (HFC-125) in step 1, and is readily available in large quantities. Tetrafluoroethylene can be obtained from a certain pentafluoroethane. Conventionally, tetrafluoroethylene was produced through two or more reaction or processes from the raw materials, but in process 1, tetrafluoroethylene can be obtained in one step, making it a simpler method of obtaining tetrafluoroethylene.

[0081] Moreover, the manufacturing method disclosed herein uses pentafluoroethane, which has a high GWP, as a raw material and converts it to obtain tetrafluoroethylene, which has high utility value, making it an extremely useful manufacturing method from an environmental perspective. In other words, the manufacturing method disclosed herein is expected to develop into a technology that reuses fluorocarbon substances used as refrigerants and converts them into TFE, a resin raw material, and can contribute to the development of technologies for the effective utilization of fluorocarbon substances.

[0082] Furthermore, the manufacturing method disclosed herein allows for the production of tetrafluoroethylene even under mild temperature conditions for both the gas-phase and liquid-phase reactions. The method disclosed in Patent Document 1 requires a step of chlorination to obtain an intermediate, thus requiring high-temperature heating of 300°C or higher to obtain tetrafluoroethylene, resulting in a process with high energy consumption. In contrast, the manufacturing method disclosed herein allows for the production of tetrafluoroethylene under mild temperature conditions and can be produced in a single step, which is advantageous from the standpoint of reducing energy consumption. Moreover, the method disclosed in Patent Document 1 generates hydrochloric acid, which poses a problem for post-treatment of chlorine compounds, whereas the manufacturing method disclosed herein is less prone to such problems.

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

[0084] 2. Composition This disclosure encompasses compositions comprising tetrafluoroethylene and pentafluoroethane (hereinafter referred to as "the compositions of this disclosure"). The compositions of this disclosure can be obtained, for example, by the manufacturing method of this disclosure described above; that is, the product obtained in step 1 can be the composition of this disclosure. Therefore, even when the compositions of this disclosure are purified by a purification step, the burden on the purification step is low. Furthermore, since the compositions of this disclosure are manufactured without chlorination, the chlorine content is low. From the viewpoint of stable storage of tetrafluoroethylene and reduction of the separation and purification steps from chlorine and by-products derived from reactions with chlorine, a low chlorine content is desirable. The lower limit of the 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 compositions of this disclosure, pentafluoroethane is preferably present in an amount of 52 mol% or less, more preferably 30 mol% or less, and even more preferably 10 mol% or less, relative to the total amount of tetrafluoroethylene and pentafluoroethane. Furthermore, in the compositions of this disclosure, the lower limit of the pentafluoroethane content is not particularly limited, and is, for example, 0.1 mol% or more relative to the total amount of tetrafluoroethylene and pentafluoroethane. In these compositions, a lower pentafluoroethane content is preferable, and even more preferably 5 mol% or less, because it is easy to purify tetrafluoroethylene and the compositions can be used in the production of fluororesins and fluorine-containing intermediates that can be derived from tetrafluoroethylene without purification.

[0086] 3. Fluorination reaction using by-product fluoride salts As described above, the manufacturing method of this disclosure may generate by-products due to the basic compound used in step 1. Such by-products can be reused as raw materials for other reactions. In other words, this disclosure can encompass a method for reusing the fluoride salt (by-product fluoride salt) produced as a by-product in step 1. For example, if a compound containing potassium is used as the basic compound, KF (potassium fluoride) may be produced as a by-product in step 1, and such KF can be used in other reactions. That is, this disclosure can encompass a method for reusing the KF produced as a by-product in step 1. A specific embodiment of a method for reusing KF will be described below as an example.

[0087] The types of reactions that use recycled KF are not particularly limited; for example, any known reactions using KF can be broadly cited. Examples of such reactions include: R using KF a - Synthesis of SO2F (sulfonyl fluoride) R using KF b - Synthesis of COF (Acyl Fluoride) R using KF c - CH2F synthesis Halex reaction using KF Deoxygenation and fluorination reaction using KF Examples include:

[0088] R using KF a -In the synthesis of SO2F (sulfonyl fluoride), for example, R a This is an aromatic ring that may have substituents. Examples of aromatic rings that may have substituents include monocyclic aromatic rings such as benzene rings, and polycyclic aromatic rings (e.g., bicyclic or tricyclic) such as naphthalene rings and anthracene rings.

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

[0090] In an aromatic ring which may have substituents, the type of substituent is not particularly limited, for example, a hydrocarbon group having 1 to 20 carbon atoms which may have an oxygen atom, R r O-, R r CO-, R r SO2-, R r Examples include OCO-, halo groups, nitro groups, cyano groups, oxo groups, thioxo groups, sulfo groups, sulfamoyl groups, sulfinamoyl groups, and sulfenamoyl groups. The substituent is preferably bonded to the ortho position relative to SO2F.

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

[0092] Unless otherwise specified, examples of "alkyl group" can include linear or branched 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, "alkyl group" can 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] In this specification, unless otherwise specified, examples of "alkenyl group" include vinyl, 1-propen-1-yl, 2-propen-1-yl, isopropenyl, 2-buten-1-yl, and 4-pentene. It can include linear or branched C2-10 alkenyl groups such as ten-1-yl and 5-hexen-1-yl.

[0095] In this specification, unless otherwise specified, examples of "alkynyl group" may include linear or branched C2-C10 alkynyl groups such as ethynyl, 1-propyne-1-yl, 2-propyne-1-yl, 4-pentin-1-yl, and 5-hexyne-1-yl.

[0096] Unless otherwise specified, examples of "cycloalkyl groups" may include C3-C7 cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

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

[0098] In this specification, unless otherwise specified, examples of "cycloalkadienyl group" can 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, dicyclic, tricyclic, or tetracyclic.

[0100] In this specification, unless otherwise specified, "aryl group" may be a C6-C18 aryl group. In this specification, unless otherwise specified, examples of "aryl group" may include phenyl, 1-naphthyl, 2-naphthyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, and 2-anthuryl.

[0101] In this specification, "fluoroaryl group" refers to an aryl group in which at least one hydrogen atom is substituted with a fluorine atom.

[0102] Unless otherwise specified herein, examples of "aralkyl group" may 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 This is synonymous with, for example, the hydrocarbon group having 1 to 20 carbon atoms mentioned above.

[0104] R using KF a -In the synthesis of SO2F (sulfonyl fluoride), for example, R a -SO2X can be used as a reaction raw material, where X is a halo group, such as chlorine or bromine.

[0105] R using KF aThe reaction conditions for the synthesis of -SO2F (sulfonyl fluoride) are not particularly limited, and for example, a wide range of known reaction conditions can be employed.

[0106] R using KF a Products of the synthesis of -SO2F (sulfonyl fluoride) include, for example, compounds having structural formulas shown in the following formulas (1a) to (10a).

[0107] [ka]

[0108] Next, R using KF b - In the synthesis of COF (acyl fluoride), R b This is the aforementioned R a It is synonymous with R. b A -C=C- bond may be interposed between the aromatic ring and the COF in the compound.

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

[0110] R using KF b The reaction conditions for the synthesis of -COF (acyl fluoride) are not particularly limited; for example, a wide range of known reaction conditions can be employed.

[0111] R using KF b Products of the synthesis of -COF (acyl fluoride) include, for example, compounds having structural formulas shown in the following formulas (1b) to (3b).

[0112] [ka]

[0113] Next, R using KF c-In the synthesis of CH2F, R c This is the aforementioned R a This is synonymous with R b One example is a "non-aromatic heterocyclic group." A "non-aromatic heterocyclic group" can be saturated or unsaturated.

[0114] Unless otherwise specified in the specification, examples of "non-aromatic heterocyclic groups" include tetrahydrofuryl, oxazolidinyl, imidazolinyl (e.g., 1-imidazolinyl, 2-imidazolinyl, 4-imidazolinyl), azilidinyl (e.g., 1-azilidinyl, 2-azilidinyl), azetidinyl (e.g., 1-azetidinyl, 2-azetidinyl), pyrrolidinyl (e.g., 1-pyrrolidinyl, 2-pyrrolidinyl, 3-pyrrolidinyl), piperidinyl (e.g., 1-piperidinyl, 2-piperidinyl, 3-piperidinyl), and azepanyl (e.g., 1-azepanyl, 2-azepanyl). Panyl (3-azepanyl, 4-azepanyl), azocanyl (e.g., 1-azocanyl, 2-azocanyl, 3-azocanyl, 4-azocanyl), piperazinyl (e.g., 1,4-piperazin-1-yl, 1,4-piperazin-2-yl), diazepinyl (e.g., 1,4-diazepine-1-yl, 1,4-diazepine-2-yl, 1,4-diazepine-5-yl, 1,4-diazepine-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) This can include 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, etc.

[0115] R c A -C(=O)- bond may be interposed between the aromatic ring or non-aromatic heterocycle and CH2F in the compound.

[0116] R using KF cIn the synthesis of -CH2F, for example, R c -CH2X can be used as a reaction raw material. Here, X is a halo group, for example, chlorine or bromine.

[0117] For the synthesis of R c -CH2F using KF, the reaction conditions are not particularly limited. For example, well-known reaction conditions can be widely adopted.

[0118] For the synthesis of R c -CH2F using KF, the products include, for example, compounds having structural formulas represented by the following formulas (1c) to (4c).

[0119]

Chemical formula

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

[0121] In this specification, unless otherwise particularly limited, examples of the "heteroaryl group" can include monocyclic aromatic heterocyclic groups (e.g., 5- or 6-membered monocyclic aromatic heterocyclic groups), and aromatic condensed heterocyclic groups (e.g., 5- to 18-membered aromatic condensed heterocyclic groups).

[0122] Unless otherwise specified herein, examples of "5 or 6-membered monocyclic aromatic heterocyclic groups" 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-pyrrolyl, 3-pyrrolyl, 4-pyrrolyl), 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) This can include thiazolyl (e.g., 2-thiazolyl, 4-thiazolyl, 5-thiazolyl), triazolyl (e.g., 1,2,3-triazole-4-yl, 1,2,4-triazole-3-yl), oxadiazolyl (e.g., 1,2,4-oxadiazole-3-yl, 1,2,4-oxadiazole-5-yl), thiadiazolyl (e.g., 1,2,4-thiadiazole-3-yl, 1,2,4-thiadiazole-5-yl), tetrazolyl, pyridyl (e.g., 2-pyridyl, 3-pyridyl, 4-pyridyl), pyridazinil (e.g., 3-pyridazinil, 4-pyridazinil), pyrimidinil (e.g., 2-pyridazinil, 4-pyridazinil, 5-pyridazinil), pyrazinil, etc.

[0123] Unless otherwise specified herein, examples of “5- to 18-membered aromatic condensed heterocyclic groups” 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-ben Zo[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[b]thienyl) [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-benzoisoxazolyl (e.g., 1,2-benzoisoxazole-3-yl, 1,2-benzoisoxazole-4-yl, 1,2-benzoiso Xazol-5-yl, 1,2-benzoisoxazole-6-yl, 1,2-benzoisoxazole-7-yl), benzoxazol (e.g., 2-benzoxazol, 4-benzoxazol, 5-benzoxazol, 6-benzoxazol, 7-benzoxazol), 1,2-benzoisothiazolyl (e.g., 1,2-benzoisothiazol-3-yl, 1,2-benzoisothiazol-4-yl, 1,2-benzoisothiazol-5-yl, 1,2-benzoisothiazol-6-yl, 1,2-Benzisothiazole-7-yl), benzothiazolyl (e.g., 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl), isoquinolil (e.g., 1-isoquinolil, 3-isoquinolil, 4-isoquinolil, 5-isoquinolil), quinolil (e.g., 2-quinolil, 3-quinolil, 4-quinolil, 5-quinolil, 8-quinolil), cinnorinyl (e.g., :3-Synnorinyl, 4-Synnorinyl, 5-Synnorinyl, 6-Synnorinyl, 7-Synnorinyl, 8-Synnorinyl), 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] This can include pyridine-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), etc.

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

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

[0126] Products of the Halex reaction using KF include, for example, compounds having structural formulas represented by the following formulas (1d) to (4d).

[0127] [ka]

[0128] In a deoxygenation and fluorination reaction using KF, a wide range of raw materials that can be used in known deoxygenation and fluorination reactions can be used, for example, a wide range of alcohol compounds can be cited. For example, in a deoxygenation and fluorination reaction using KF, hydrocarbon compounds having a hydroxyl group can be cited. Such hydrocarbon groups are the same as described above, and therefore, hydrocarbon groups having 1 to 20 carbon atoms can be cited. The hydrocarbon group 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" can include alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups, cycloalkadienyl groups, aryl groups, aralkyl groups, and groups that are combinations thereof.

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

[0130] In specifying the inventions contained herein, the components (properties, structures, functions, etc.) described in each embodiment of this disclosure may be combined in any way. That is, this disclosure encompasses all subject matter consisting of any combination of the combinatable components described herein. [Examples]

[0131] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to the embodiments of these examples.

[0132] (Example 1A) Potassium hexamethyldisilazide (KHMDS, solid at room temperature) was placed in an NMR tube as a basic compound, 0.7 mL of toluene-d8 as a solvent, and 0.01 mmol of C6F6 as an internal standard. The contents of the NMR tube were frozen under a nitrogen atmosphere, then the pressure was reduced, and 0.025 mol of pentafluoroethane, the starting material, was introduced into the NMR tube. Subsequently, the contents of the NMR tube were maintained at -50°C, and this temperature was used as the reaction temperature (base treatment temperature), and the tube was oscillated for 3 hours to produce tetrafluoroethylene (TFE) (Step 1). In Step 1, the amount of KHMDS used was 2 equivalents relative to pentafluoroethane. After that, the contents of the NMR tube were cooled to -94°C. 19 F-NMR was measured. Based on the obtained NMR spectrum, the yield was calculated from the internal standard C6F6 signal, confirming 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. It was confirmed that TFE was produced in a yield of 75%.

[0134] (Example 3A) Aside from changing the amount of KHMDS used to 3 equivalents relative to pentafluoroethane, the actual changes were the same. When TFE was produced using the same method as in Example 1A, it was confirmed that TFE was produced with 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. It was confirmed that TFE was produced in a yield of 27%.

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

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

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

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

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

[0141] (Example 10A) The procedure was the same as in Example 4A, 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 to pentafluoroethane. 19 It was confirmed by 19F-NMR that TFE was produced.

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

[0143] (Example 12A) Container 1 was filled with 5 mmol of potassium hexamethyldisilazide (KHMDS) as a basic compound and sealed. Container 1 was removed from the glove box, cooled with liquid nitrogen, and then depressurized. Pentafluoroethane was then introduced into container 1, and container 1 was maintained at -50°C. This temperature was used as the reaction temperature (base treatment temperature), and the container was oscillated for 3 hours (reaction time) to produce tetrafluoroethylene (TFE) (Step 1). Note that in Step 1, The amount of pentafluoroethane used was 2.88 equivalents relative to KHMDS. The yield of TFE was calculated by determining the yield of the amino compound obtained by reacting the generated TFE with dimethylamine, and this was taken as the yield of TFE in step 1. Specifically, the yield of TFE was calculated using the following procedure. First, a new autoclave containing dimethylamine (20 mmol) and tetrahydrofuran was prepared as container 2, and this container 2 was sealed, cooled to -85°C, and reduced in pressure. Meanwhile, the TFE generated in container 1 was gradually heated and transferred to container 2 via a PFA tube, and then container 2 was stirred at 0°C for 12 hours. The yield of the resulting amino compound was calculated to be 55%, so 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. 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. It was confirmed that TFE was produced in a yield of 44%.

[0147] (Example 1B) Tetrafluoroethylene (TFE) was synthesized using the reaction apparatus shown in Figure 1, following the steps 1) to 7) below. 1) Inside a glove box, a 10 mL oven-dried vial was prepared as a "reaction vessel" by adding 4 equivalents of KHMDS and a stirring bar to 0.75 mmol of pentafluoroethane intended to be introduced into the vial, and dissolving it in anhydrous toluene to create a 1.0 M KHMDS-toluene solution. 2) On the other hand, a 25 mL screw vial was filled with 20 mL of toluene and 0.1 mmol of hexafluorobenzene as an internal standard, then sealed and cooled to -85°C to prepare it as a "recovery tank". 3) The flowline shown in Figure 1 was assembled under a nitrogen atmosphere. As shown in Figure 1, the pentafluoroethane cylinder 1, the reaction vessel 2, and the recovery vessel 3 were each connected to each other by pipes 4, with the inlets and outlets of the pipes in each vessel above the liquid level (however, the outlet end of the pipe 4 connecting cylinder 1 and reaction vessel 2 was immersed in the reaction liquid in the reaction vessel). The septum of the recovery vessel was made open by inserting a needle. 4) Pentafluoroethane was flowed from cylinder 1 at a pressure of 0.1 MPa, with a flow rate controlled to 3.35 mL / min using a mass flow controller. By flowing the pentafluoroethane in this way, bubbling of the solution in the reaction vessel with pentafluoroethane was initiated. The solution in the reaction vessel into which the pentafluoroethane had been introduced was vigorously stirred at room temperature (25°C). 5) On the other hand, after exhausting the gas from the recovery tank for 1 minute, the needle that had been inserted into the recovery tank was removed to create a sealed system. Immediately thereafter, the gas outlet on the recovery tank side was immersed in toluene cooled to -85°C, and the recovery of the product (tetrafluoroethylene) was started. 6) Five minutes after the start of the pentafluoroethane flow, the flow of pentafluoroethane was stopped by removing the tube 4 connecting cylinder 1 and reaction vessel 2 from the reaction vessel (Pentaful The amount of oloethane introduced was 0.75 mmol, the flow time of pentafluoroethane was 5 minutes, and stirring was continued for another 5 minutes. 7) After confirming that gas generation in the solution in reaction vessel 2 had ceased, the outlet of tube 4 on the recovery vessel side 3 was removed from the toluene solution, and recovery vessel 3 was immersed in liquid nitrogen to move the gas from the reaction vessel to the recovery vessel side. The septum of the recovery vessel was quickly replaced with a screw cap and sealed, and after being immersed in a methanol bath at -85°C for 1 hour, the solution in the recovery vessel was quickly collected into an NMR tube that had been pre-cooled to -85°C and used as a sample. 19 The yield of the product was estimated by measuring F-NMR.

[0148] (Example 2B) The procedure was carried out in the same manner as in Example 1B, 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. The yield of the obtained product was then estimated.

[0149] (Example 3B) The procedure was carried out in the same manner as in Example 2B, 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 procedure was carried out in the same manner as in Example 1B, 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 25 mL capacity, the vial for forming the recovery vessel was changed to a 50 mL capacity, and the amount of toluene used in the recovery vessel was changed to 45 mL. The yield of the obtained product was then estimated.

[0151] (Example 5B) The procedure was carried out in the same manner as in Example 1B, 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 yield of the resulting product (tetrafluoroethylene). From these results, it can be seen that in all cases, the target product, tetrafluoroethylene (TFE), was obtained in high yield. In particular, the longer the flow time of pentafluoroethane (i.e., the larger the amount of pentafluoroethane introduced), the higher the yield tended to be, as did the higher the equivalent number of basic compounds.

[0153] [Table 1]

[0154] Fluorination reaction using KF produced as a by-product in step 1 (Manufacturing Example 1: Production of KF under HFC-125 excess conditions) A solution of 120 mg (0.6 mmol) of KHMDS dissolved in 1.2 mL of anhydrous toluene was prepared in a vacuum sample tube. Oxygen was removed by freeze-degassing, and the inside of the tube was reduced in pressure. 18 mL (0.8 mmol) of HFC-125 was taken from a balloon filled with HFC-125 using a gas-tight syringe and charged into the tube under liquid nitrogen. The contents of the tube were then stirred at -50°C for 3 hours to obtain a KF / toluene suspension.

[0155] (Manufacturing Example 2: Production of 1.2 mmol of KF under HFC-125 excess conditions) A solution of 240 mg (1.2 mmol) of KHMDS dissolved in 4.0 mL of anhydrous toluene was prepared in a vacuum sample tube. Oxygen was removed by freeze-degassing, and the inside of the tube was reduced in pressure. 35 mL (1.56 mmol) of HFC-125 was taken from a balloon filled with HFC-125 using a gas-tight syringe and charged into the tube under liquid nitrogen. The contents of the tube were then stirred at -50°C for 3 hours to obtain 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 Figure 2(a). 76.3 mg (0.4 mmol) of 4-methylbenzenesulfonyl chloride was used as the sulfonyl chloride (0.4 mmol). First, the KF / toluene suspension obtained in Preparation Example 1 was concentrated under vacuum, and toluene and HMDS were removed to obtain solid crude purified 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 as an internal standard to obtain a solution. This solution was added to a tube containing the crude purified 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. The resulting reaction product was then... 19 The 1F NMR spectrum was measured. Finally, the precipitate was removed by suction filtration, washed with ethyl acetate, and the resulting filtrate was concentrated using an evaporator. The resulting 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 isolation 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(500MHz,chloroform-d)δ:7.90(d,J=8. 2Hz,2H),7.42(d,J=8.2Hz,2H),2.50(s,3H)ppm. 19 F NMR(282MHz,chloroform-d)δ:65.8(s,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (11) below.

[0157] [ka]

[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 replaced with 84.4 mg (0.4 mmol) of 4-chlorobenzenesulfonyl chloride. The obtained sulfonyl fluoride was 19 The F-NMR yield was 79%, and the isolation 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(500MHz,chloroform-d)δ:8.00-7.95(m,2H),7.64-7.60(m,2H)ppm. 19 F NMR(282MHz,chloroform-d)δ:66.0(s,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (12) below.

[0159] [ka]

[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 replaced with 80.6 mg (0.4 mmol) of 4-cyanobenzenesulfonyl chloride. The obtained sulfonyl fluoride was, 19 The F-NMR yield was 90%, and the isolation 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(500MHz,chloroform-d)δ:8.17(dt,J1=8.4Hz,J2=1.8Hz,2H),7.97-7.95(m,2H)ppm. 19 F NMR(282MHz,chloroform-d)δ:65.5(s,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (13) below.

[0161] [ka]

[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 replaced with 88.6 mg (0.4 mmol) of 4-nitrobenzenesulfonyl chloride. The obtained sulfonyl fluoride was 19 The F-NMR yield was 98%, and the isolation 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. 1H NMR(500MHz,chloroform-d)δ:8.50(d,J=8.2Hz,2H),8.25(dt,J1=9.2Hz,J2=2.2Hz,2H)ppm. 19 F NMR(282MHz,chloroform-d)δ:65.7(s,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (14) below.

[0163] [ka]

[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-carbonylchloride was used as the acyl chloride (0.4 mmol). First, the KF / toluene suspension obtained in Preparation Example 1 was concentrated under vacuum, and toluene and HMDS were removed to obtain solid crude purified 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. This acetone solution was added to a tube containing the crude purified KF (0.6 mmol, 1.5 equivalents), and the mixture was heated and stirred at room temperature (25°C) for 12 hours. The resulting reaction product was then prepared. 19 The 1F NMR spectrum 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 acyl fluoride. The obtained acyl fluoride was, 19 The F-NMR yield was 60%, and the isolation 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. 1H 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. 19 F NMR(282MHz,chloroform-d)δ:17.6(s,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (15) below.

[0165] [ka]

[0166] (Example 17B; Synthesis of acyl fluoride) Acyl fluoride was obtained in the same manner as in Example 17A, except that 0.4 mmol of acyl chloride was replaced with 66.2 mg (0.4 mmol) of 4-cyanobenzoylchloride. The obtained sulfonyl fluoride was 19 The F-NMR yield was 68%, and the isolation 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(500MHz,chloroform-d)δ:8.18-8.17(m,2H),7.86-7.84(m,2H)ppm. 19 F NMR(282MHz,chloroform-d)δ:19.7(s,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (16) below.

[0167] [ka]

[0168] (Example 17C; Synthesis of acyl fluoride) Acyl fluoride was obtained in the same manner as in Example 17A, except that 0.4 mmol of acyl chloride was replaced with 66.4 mg (0.4 mmol) of cinnamoylchloride. The obtained sulfonyl fluoride was 19 The F-NMR yield was 61%, and the isolation 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. 1 H NMR(500MHz,chloroform-d)δ:7.85(d,J=15.9Hz,1H),7.59-7.56(m,2H),7.50-7.43(m,3H),6.38(dd,J1=16.2Hz,J2=7.3Hz,1H)ppm. 19 F NMR(282MHz,chloroform-d)δ:25.1(s,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (17) below.

[0169] [ka]

[0170] (Example 18A;R) c -CH2F synthesis) According to the reaction scheme shown in Figure 2(c), R c -CH2F was synthesized. First, the KF / toluene suspension obtained by Production Example 1 was concentrated under vacuum, and 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). Then, 52.9 mg (0.2 mmol, 1.0 equivalent) 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. After that, the resulting reaction product was 19 subjected to 19F NMR measurement. 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 -CH2F. The obtained R c -CH2F had a 19F-NMR yield of 73% and an isolated yield of 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 1H NMR (500 MHz, chloroform-d) δ: 8.28 - 8.25 (m, 2H), 7.55 - 7.53 (m, 2H), 5.51 (d, J = 46.7 Hz, 2H) ppm. 19 19F NMR (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]

Chemical formula

[0172] (Example 18B; Reaction of R c -CH2F) <00009​​R was obtained in the same manner as in Example 18A, except that 1-(bromomethyl)-4-nitrobenzene (0.2 mmol) was changed to 44.2 mg (0.2 mmol) of 2-(bromomethyl)naphthalene. c The resulting R c -CH2F had an isolated yield of 60% (19.1 mg, 0.119 mmol). Purification was carried out by eluting with n-hexane, and it was obtained as a white solid. The NMR measurement results are shown below. 1 1H NMR (500 MHz, chloroform-d) δ: 8.07 (dd, J1 = 8.4 Hz, J2 = 0.8 Hz, 1H), 7.90 - 7.88 (m, 1H), 7.60 - 7.52 (m, 3H), 7.48 - 7.45 (m, 1H), 5.85 (d, J = 48.2 Hz, 2H) ppm. 19 19F NMR (282 MHz, chloroform-d) δ: -207.3 (t, J = 47.6 Hz, 1F) ppm. The product obtained above was determined to be the compound represented by the following formula (19).

[0173]

Chemical formula

[0174] (Example 18C; Reaction of R c -CH2F) R-CH2F was obtained in the same manner as in Example 18A, except that 1-(bromomethyl)-4-nitrobenzene (0.2 mmol) was changed to 38.4 mg (0.2 mmol) of 2-bromo-1-(pyrrolidin-1-yl)ethan-1-one. c The resulting R c -CH2F had an isolated yield of 40% (10.4 mg, 0 .08 mmol). Purification was carried out by eluting with ethyl acetate, and it was obtained as a yellow liquid. The NMR measurement results are shown below. 1H NMR(500MHz,chloroform-d)δ:4.91(d,J=47.3Hz,2H),3.54(t,J=7.0Hz,2H),3.43(td,J1=6.8Hz,J2=1.3Hz,2H)2.01-1.96(m,2H),1.90-1.84(m,2H)ppm. 19 F NMR(658MHz,chloroform-d)δ:-227.1(t,J=47.4Hz,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (20) below.

[0175] [ka]

[0176] (Example 19A; Halex reaction) According to the reaction scheme shown in Figure 2(d), R d -F was synthesized. First, in manufacturing example 1... The resulting KF / toluene suspension was concentrated under vacuum, and toluene and HMDS were removed to obtain solid crude 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 crude purified KF (0.6 mmol, 5 equivalents). Tetramethylammonium chloride 21.9 mg (0.2 mmol, 0.5 equivalents) 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 19 The 1F NMR spectrum 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. d -F was obtained. The obtained R d -F is, 19The F-NMR yield was 65%, and the isolation yield was 64% (44.3 mg, 0.254 mmol). Purification was performed by elution with a mixed solvent of n-hexane / ethyl acetate = 9:1, and the result was obtained as 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,J1=9.2Hz,J2=2.0Hz,1H)ppm. 19 F NMR(282MHz,chloroform-d)δ:-82.6(d,J=7.1Hz,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (21) below.

[0177] [ka]

[0178] (Example 19B; Halex reaction) The same method as in Example 19A was used, except that 3-chloro-6-phenylpyridazine (0.4 mmol) was replaced with 55.4 mg (0.4 mmol) of 6-chloronicotinonitrile and the heating and stirring time was changed to 1 hour. d -F was obtained. The obtained R d -F had an isolation yield of 70% (34.3 mg, 0.281 mmol). It was found. Purification was performed by eluting with a mixed solvent of n-hexane / ethyl acetate / triethylamine = 80:15:5, and it was obtained as a white solid. The NMR measurement results are shown below. 1 H NMR(700MHz,chloroform-d)δ:8.59(d,J=2.4Hz,1H),8.09(ddd,J1=9.0Hz,J2=6.6Hz,J3=1.8Hz,1H),7.12-7.10(m,1H)ppm. 19 F NMR(658MHz,chloroform-d)δ:-57.8(s,1F)ppm. The product obtained as described above was determined to be a compound represented by the following formula (22).

[0179] [Chemical formula]

[0180] (Example 19C; Halex reaction) 3-chloro-6-phenylpyridazine (0.4 mmol) was changed to 65.4 mg (0.4 mmol) of 1-chloroisoquinoline, and R was obtained in the same manner as in Example 19A except that the heating and stirring time was changed to 22 hours d -F was obtained. The obtained R d -F had an isolated yield of 44% (26.1 mg, 0.177 mmol) and was obtained as a colorless transparent liquid by eluting with a mixed solvent of n-hexane / diethyl ether = 95:5. The NMR measurement results are shown below. 1 1H 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, J1 = 8.2 Hz, J2 = 7.0 Hz, 1H), 7.66 (t, J = 7.6 Hz, 1H), 7.53 (d, J = 6.0 Hz, 1H) ppm. 19 19F NMR (658 MHz, chloroform-d) δ: -71.7 (s, 1F) ppm. The product obtained as described above was determined to be a compound represented by the following formula (23).

[0181] [Chemical formula]

[0182] (Example 19D; Halex reaction) Replace 3-chloro-6-phenylpyridazine (0.4 mmol) with 79.3 mg (0.4 mmol) of 4,7-dichloroquinoline. The method was the same as in Example 19A, except that the heating and stirring time was changed to 13 hours. d -F Obtained. Obtained R d -F had an isolation yield of 61% (44.5 mg, 0.245 mmol). It was found. Purification was performed by eluting with a mixed solvent of n-hexane / ethyl acetate = 95:5, and it was obtained as a white solid. The NMR measurement results are shown below. 1 H NMR(700MHz,chloroform-d)δ:8.87(dd,J1=8.4Hz,J2=4.8Hz,1H),8.14(t,J=1.8Hz,1H),8.05(d,J=8.8H) z,1H),7.57(dd,J1=8.8Hz,J2=2.0Hz,1H),7.11(dd,J1=9.4Hz,J2=5.0Hz,1H),7.53(d,J=6.0Hz,1H)ppm. 19 F NMR(282MHz,chloroform-d)δ:-112.2(t,J=10.0Hz,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (24) below.

[0183] [ka]

[0184] (Example 20; Deoxygenation and fluorination reaction) The deoxygenation and fluorination 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 toluene and HMDS were removed to obtain solid crude purified 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 purified KF (1.2 mmol, 6 equivalents). 64.3 μL of concentrated sulfuric acid (1.2 mmol, 6.0 equivalents) was added to the tube at 0°C, and the mixture was stirred at 0°C for 1 hour. The resulting reaction product was then prepared. 19 F NMR was measured. Finally, the reaction mixture was quenched with saturated NaHCO3 aqueous solution and extracted with dichloromethane. The resulting organic phase was dried over Na2SO4, and the solid was removed by filtration. The filtrate was concentrated using a rotary evaporator. The resulting concentrate was purified by silica gel chromatography and R e -F was obtained. The obtained R e -F was isolated in 25% yield (7.7 mg, 0.050 mmol). Purification was performed by elution with n-hexane, and it was obtained as 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(282MHz,chloroform-d)δ:-128.9--129.0(m,1F)ppm. Based on the above, the product obtained was determined to be the compound shown in formula (25) below.

[0185] [ka]

[0186] (Example 21A) The reaction apparatus shown in Figure 3 was assembled according to the following procedure. In a glove box under a nitrogen atmosphere, 400 mg (2.01 mmol) of potassium hexamethyldisilazide (KHMDS) was filled into a cartridge. Next, the cartridge was removed from the glove box, and the gas cylinder containing pentafluoroethane (HFC-125), the mass flow controller, and the cartridge were connected in series in this order via fluororesin tubing. Fluororesin tubing was also connected to the connection point on the opposite side of the cartridge from where the mass flow controller was connected, and a septum was attached to the end of the fluororesin tubing, thus assembling the reaction apparatus. A vial was used as a recovery tank for collecting the reaction product (tetrafluoroethylene). The vial was pre-filled to about 80% with toluene, and a certain amount of hexafluorobenzene was added as an internal standard for NMR. However, as described later, the recovery tank was not connected to the reaction apparatus until 1 minute had elapsed after the HFC-125 flow began.

[0187] The reaction using the aforementioned reactor was carried out in 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, the flow rate of HFC-125 was adjusted so that the flow rate of the mass flow controller was 1.15 mL / min, and HFC-125 was circulated through the cartridge. For the first minute after starting to circulate HFC-125, the mass flow controller... -In order to stabilize the controller and to fill the flow system with reaction gas, no gas recovery was performed. One minute after the HFC-125 flow began, the end of the tube to which the septum was attached was placed into the recovery tank. The time from placing the tube into the recovery tank until the flow of HFC-125 was stopped (hereinafter referred to as the flow time) was set to 10 minutes (see Table 2). After stopping the flow of HFC-125, the tube connected to the recovery tank was withdrawn from the septum, the recovery tank was cooled by immersing it in liquid nitrogen, the septum was replaced with a screw cap, and then it was cooled in a -85°C constant temperature bath for more than one hour. Next, a portion of the solution in the recovery tank was taken. 19 The yield of the generated tetrafluoroethylene (TFE) and the recovery rate of the raw material HFC-125 were calculated by measuring the 1F-NMR spectrum and comparing it with the peak area of ​​the internal standard hexafluorobenzene.

[0188] (Example 21B) As shown in Table 2 below, the yield of the generated tetrafluoroethylene and the recovery rate of the raw material HFC-125 were calculated using the same method 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 the generated tetrafluoroethylene and the recovery rate of the raw material HFC-125 were calculated using the same method 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] [Table 2]

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

[0193] The reaction using the aforementioned reactor 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 circulated 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 the first minute after starting to flow HFC-125, no gas recovery was performed in order to stabilize the mass flow controller and to fill the flow system with reaction gas. After one minute had elapsed since starting to flow HFC-125, 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 Figure 4). The flow time from the start of HFC-125 flow until the flow of HFC-125 was stopped was 10 minutes (see Table 3). After stopping the flow of HFC-125, the tube connected to the recovery tank was withdrawn from the septum, the recovery tank was cooled by immersing it in liquid nitrogen, the septum was replaced with a screw cap, and then it was cooled in a -85°C constant temperature bath for more than one hour. Next, a portion of the solution in the recovery tank was collected. 19 The yield of tetrafluoroethylene (TFE) produced was calculated by measuring the 1F-NMR spectrum and comparing it with the peak area of ​​the internal standard hexafluorobenzene.

[0194] (Example 22B) As shown in Table 3 below, the yield of the generated tetrafluoroethylene was calculated using the same method 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 Example 22A and Example 22B.

[0196] [Table 3]

Claims

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

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

3. The method for producing tetrafluoroethylene according to claim 1, wherein the basic compound has a pKa value of its conjugate acid 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. The method for producing tetrafluoroethylene according to any one of claims 1 to 3, wherein the above process is carried out in the presence or absence of a phase transfer catalyst.

6. The method for producing tetrafluoroethylene according to any one of claims 1 to 3, wherein the above 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 relative to 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 relative to the total amount of tetrafluoroethylene and pentafluoroethane.

10. The composition according to claim 7, wherein pentafluoroethane is contained in an amount of 10 mol% or less relative to 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 relative to the total amount of tetrafluoroethylene and pentafluoroethane.

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