Method for producing 1-chloro-2,3,3-trifluoropropene

Abstract

The present invention addresses the problem of providing a novel method for producing 1233yd.　Provided is a method for producing 1-chloro-2,3,3-trifluoropropene by causing contact between 1,3-dichloro-2,3,3-trifluoropropene, a metal salt, and a zerovalent metal, and subsequently causing contact with an acid.

Description

[Technical Field]

[0001] The present invention relates to a method for producing 1-chloro-2,3,3-trifluoropropene. [Background technology]

[0002] 1-Chloro-2,3,3-trifluoropropene (CHCl=CF-CHF2, HCFO-1233yd, hereafter also referred to as 1233yd) is a compound with a low global warming potential (GWP) that is used in cleaning agents, refrigerants, blowing agents, solvents, and aerosols. As an example of the production of 1233yd, Patent Document 1 describes in its working examples that when 3-chloro-1,1,2,2-tetrafluoropropane and hydrogen fluoride are introduced in a gaseous state into a Hastelloy C reaction tube filled with a chromium hydroxide catalyst under a nitrogen stream, a trace amount of 1233yd is by-produced together with 1,1,2,2,3-pentafluoropropane. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 1994 / 014737 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the reaction described in Patent Document 1 is not suitable for industrial-scale mass production because the amount of 1233yd produced is a by-product and is extremely small. An object of the present invention is to provide a novel method for producing 1233yd. [Means for solving the problem]

[0005] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration.

[0006] (1) A method for producing 1-chloro-2,3,3-trifluoropropene, comprising contacting 1,3-dichloro-2,3,3-trifluoropropene with a metal salt and a zero-valent metal, and then contacting the resulting mixture with an acid to produce 1-chloro-2,3,3-trifluoropropene. (2) The method according to (1), wherein the metal atom contained in the metal salt is a copper atom, an iron atom, a cobalt atom, or a nickel atom. (3) The method according to (1) or (2), wherein the metal salt is copper chloride. (4) The method according to any one of (1) to (3), wherein the zero-valent metal is zinc, magnesium, iron, cobalt, or nickel. (5) The method according to (4), wherein the zero-valent metal is zinc. (6) The method according to any one of (1) to (5), wherein the acid is hydrogen chloride, sulfuric acid, nitric acid, acetic acid, or phosphoric acid.

[0007] (7) The method according to any one of (1) to (6), wherein the temperature when the 1,3-dichloro-2,3,3-trifluoropropene, the metal salt, and the zero-valent metal are brought into contact with each other is 0 to 200°C. (8) The method according to any one of (1) to (7), wherein the production of 1-chloro-2,3,3-trifluoropropene is carried out in a liquid phase. (9) The method according to (8), wherein the production of 1-chloro-2,3,3-trifluoropropene is carried out in the presence of a solvent. (10) The production method according to any one of (1) to (9), wherein the 1,3-dichloro-2,3,3-trifluoropropene is obtained by defluorinating and dechlorinating 1,3,3-trichloro-1,1,2,2-tetrafluoropropane in an aprotic solvent. [Effects of the Invention]

[0008] According to the present invention, a novel method for producing 1233yd can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0009] The terms used in this specification have the following meanings. 1233yd exists as geometric isomers, Z and E isomers, depending on the position of the substituent on the double bond. Unless otherwise specified, when a compound name or abbreviation is used in this specification, it refers to at least one selected from the Z and E isomers, and when a compound name or abbreviation is followed by (E) or (Z), it indicates the (E) or (Z) isomer of the respective compound. For example, HCFO-1233yd(Z) indicates the Z isomer, and HCFO-1233yd(E) indicates the E isomer.

[0010] The method for producing 1233yd of the present invention (hereinafter also referred to simply as "the method for producing 1233yd of the present invention") is a method for producing 1233yd by contacting 1,3-dichloro-2,3,3-trifluoropropene (CF2Cl-CF=CHCl. ​​HCFO-1223yd. hereinafter also referred to as 1223yd), a metal salt, and a zero-valent metal, and then contacting the mixture with an acid. Although the details of why 1233yd is obtained by the above manufacturing method are unknown, it is speculated that by contacting 1223yd with a metal salt and a zero-valent metal, an intermediate for obtaining 1233yd is formed, and that an acid acts on this intermediate to obtain 1233yd. The materials and procedures used are described below.

[0011] In the production method of the present invention, the materials and procedures used when contacting 1223yd, a metal salt, and a zero-valent metal are described in detail below.

[0012] In the production method of the present invention, 1223 yd is used as the raw material. 1223yd can be produced by known methods. When 1223yd is used, it may contain impurities. In other words, the raw material for the production method of the present invention may contain 1223yd, and for example, a composition containing 1223yd and impurities may be used as the raw material. Impurities include raw materials for producing 1223yd, by-products other than 1223yd that are produced during the production of 1223yd, and the like. For example, when 1223yd is produced using 1,3,3-trichloro-1,1,2,2-tetrafluoropropane (hereinafter also referred to as 224ca) described later, the resulting product may contain 1223yd, unreacted 224ca, and the by-product 1,3-dichloro-1,1,2,2-tetrafluoropropane (234cc). This product may be used as a raw material in the production method of the present invention.

[0013] When the raw material contains the above-mentioned impurities, the impurities may be removed by known means such as distillation, extractive distillation, azeotropic distillation, membrane separation, two-phase separation, or adsorption.

[0014] In terms of efficiently producing 1233yd, it is preferable that 1223yd is contained as the main component in the raw material. The main component means that the content of 1223yd is 50% by mass or more, preferably 75% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, relative to the total mass of the raw material. The upper limit can be 100% by mass. Furthermore, when using 1223yd produced by the above-mentioned production method, the content of 224ca in the raw material is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, based on the total mass of the raw material. By keeping it below the upper limit, 1233yd can be produced efficiently without inhibiting the reaction from 1223yd to 1233yd.

[0015] Specific examples of metal salts include halides, carbonates, hydroxides, and alkoxides. Among these, halides are preferred, and metal chlorides are more preferred, in that they provide a better yield of 1233yd. Specific examples of metal atoms contained in the metal salt include transition metals, and more specifically, copper atoms, iron atoms, cobalt atoms, and nickel atoms are preferred. Among these, nickel atoms and copper atoms are preferred, and copper atoms are more preferred, in terms of a better yield of 1233yd. Specific examples of metal salts include copper(I) chloride, copper(II) chloride, nickel(I) chloride, and nickel(II) chloride. Two or more kinds of metal salts may be used in combination.

[0016] In order to improve reactivity, the metal salt may be used in a powder form, formed into pellets, or supported on a carrier to be used as a metal salt-supported carrier. Examples of the carrier include carbon materials such as activated carbon, carbon black, and carbon fiber, and oxide materials such as alumina, silica, titania, zirconia, alkali metal oxides, and alkaline earth metal oxides, with activated carbon, alumina, silica, zirconia, alkali metal oxides, and alkaline earth metal oxides being preferred. Among these, activated carbon, alumina, and zirconia are more preferred because they have a large specific surface area and are easy to support metal salts.

[0017] The average particle size (D50) of the powdered metal salt is preferably from 0.05 to 1000 μm, more preferably from 0.1 to 500 μm, and even more preferably from 0.5 to 200 μm.

[0018] As a method for forming the metal salt into pellets, for example, the metal salt is crushed into powder and then formed into pellets using a tablet press or the like. As the pellet-shaped metal salt, for example, a cylindrical shape having a diameter of about 3.0 mm and a height of about 4.0 mm can be used. If necessary, a binder may be mixed with the metal salt to use as a metal salt composition containing the metal salt and the binder. The amount of binder used is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the metal salt. In this case, the mixture of the metal salt and the binder can be formed into pellets using a tablet press or the like. Specific examples of the binder include graphite, carbon, cellulose, alumina, and silica.

[0019] In order to improve the reactivity, the metal salt is preferably dried in advance in an inert atmosphere (e.g., in a nitrogen stream.) From the viewpoint of simplifying the operation and improving the working efficiency, the metal salt may be dried in the same manner as above while it is contained in the reactor.

[0020] The specific surface area of ​​the metal salt depends on the type of metal salt, and generally, the smaller the specific surface area, the lower the conversion rate, and the larger the specific surface area, the lower the selectivity and the faster the degradation tends to occur. For example, when a metal salt is used without using the binder, the specific surface area of ​​the metal salt is 0.1 to 300 m 2 / g is preferred. In this specification, the specific surface area is a value measured by the BET method.

[0021] Specific examples of zero-valent metals include transition metals and alkaline earth metals, and more specifically, zinc, magnesium, iron, cobalt, and nickel are preferred. Among these, zinc is preferred because it provides a better yield of 1233 yd. Two or more kinds of zero-valent metals may be used in combination.

[0022] In order to improve reactivity, the zero-valent metal may be used in the form of a powder, metal flakes, or pellets.

[0023] The average particle size (D50) of the powdered zero-valent metal is preferably from 0.05 to 1000 μm, more preferably from 0.1 to 500 μm, and even more preferably from 0.5 to 200 μm.

[0024] An example of a method for forming a zero-valent metal into pellets is to crush the zero-valent metal into powder and form it into pellets using a tablet press or the like. The zero-valent metal pellets can be, for example, cylindrically shaped with a diameter of about 3.0 mm and a height of about 4.0 mm. If necessary, the zero-valent metal may be mixed with a binder to form a composition containing the zero-valent metal and the binder. The amount of binder used is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the zero-valent metal. In this case, the mixture of the zero-valent metal and the binder can be formed into pellets using a tablet press or the like. Specific examples of the binder include graphite, carbon, cellulose, alumina, and silica.

[0025] In addition to the above-mentioned 1223yd, metal salt, and zero-valent metal, a solvent may be present in the reaction system. Specific examples of preferred solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and benzene; aliphatic hydrocarbons such as pentane, hexane, cyclohexane, heptane, and cyclopentane; halogenated hydrocarbons such as chloroform, dichloromethane, and carbon tetrachloride; amides such as N,N-dimethylformamide (DMF), dimethylacetamide, and N-methylpyrrolidone; sulfoxides such as dimethyl sulfoxide (DMSO); sulfones such as sulfolane; ethers such as dimethyl ether (DME), diethyl ether, diisopropyl ether, diglyme, tetrahydrofuran (THF), 1,4-dioxane, and t-butyl methyl ether; nitriles such as acetonitrile; esters such as methyl acetate, ethyl acetate, and propionocarbonate; ketones such as acetone and methyl ethyl ketone; and alcohols such as methanol, ethanol, and 2-propanol. Among these, DMF, acetonitrile and DMSO are preferred because they provide a better yield of 1233yd. Two or more solvents may be used in combination.

[0026] The method of contacting 1223yd with a metal salt and a zero-valent metal is not particularly limited, and examples thereof include a method of adding a metal salt and a zero-valent metal to liquid 1223yd and contacting them, a method of contacting liquid 1223yd with a metal salt and a zero-valent metal in the presence of a solvent, and a method of contacting gaseous 1223yd by supplying it into a reactor filled with a metal salt and a zero-valent metal. From the viewpoint of reactivity, a method of contacting liquid 1223yd with a metal salt and a zero-valent metal in the presence of a solvent is preferred. When contacting 1223yd with a metal salt and a zero-valent metal, these components may be contacted all at once, or 1223yd may be added in small amounts to a mixed system containing the metal salt and the zero-valent metal. When 1223yd, the metal salt, and the zero-valent metal are brought into contact with each other, it is preferable to carry out the contacting with stirring.

[0027] The amount of metal salt used is preferably 0.001 to 1.0 equivalent, more preferably 0.01 to 0.3 equivalent, per equivalent of 1223yd, in that the yield of 1233yd is better. The amount of the zero-valent metal used is preferably 0.01 to 10 equivalents, more preferably 0.1 to 5 equivalents, and even more preferably 0.3 to 3 equivalents per equivalent of 1223yd, in that the yield of 1233yd is better. When a solvent is used, the amount of the solvent used is preferably 1 to 1000 mass %, more preferably 10 to 750 mass %, relative to the amount of 1223 yd used, in terms of a better yield of 1233 yd and productivity.

[0028] The temperature when 1223yd, the metal salt, and the zero-valent metal are brought into contact with each other is not particularly limited, but is preferably 0 to 200°C, more preferably 10 to 160°C, in that the production time can be shortened. The contact time between 1223yd, the metal salt, and the zero-valent metal is not particularly limited, but when reacting with liquid 1223yd, in terms of a better yield of 1233yd and productivity, in the case of a batch system, 0.01 to 100 hours is preferred, and 0.1 to 50 hours is more preferred. In the case of a continuous system, 0.01 to 50 hours is preferred, and 0.1 to 20 hours is more preferred. In the case of a batch system, the contact time is the contact time between 1223yd, the metal salt, and the zero-valent metal in the reactor, and in the case of a continuous system, it is the residence time between 1223yd, the metal salt, and the zero-valent metal in the reactor. The reactor pressure is preferably 0 to 30 MPaG, more preferably 0 to 10 MPaG, from the viewpoints of reaction activity and availability of a pressure-resistant reactor.

[0029] Next, an acid is added to a system containing the reaction mixture obtained by contacting 1223yd with a metal salt and a zero-valent metal (hereinafter also referred to as the "first-stage reaction system"), and the product in the first-stage reaction system is brought into contact with the acid to produce 1233yd. The materials and procedures used in this second-stage reaction are described in detail below.

[0030] Before adding the acid to the primary reaction system, a weakly acidic pH buffer solution may be added to the primary reaction system to change the components in the system. The effect of this pH buffer solution may improve the yield of 1233 yd. The contact time and temperature of the components in the primary reaction system with the pH buffer solution are not particularly limited. A specific example of a pH buffer solution is an acetate buffer solution made of acetic acid, which is a weak acid, and its salt, sodium acetate.

[0031] Specific examples of the acid include organic acids and inorganic acids, and more specifically, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, and phosphoric acid are preferred. Among these, hydrochloric acid is preferred because it provides a better yield of 1233 yd.

[0032] In the production method of the present invention, the method of contacting with the acid is not particularly limited, and examples thereof include a method of contacting the primary reaction system with an acid dissolved in water, and a method of contacting the primary reaction system with an acid in a gaseous state. When the primary reaction system is contacted with the acid, these components may be mixed all at once, or the acid may be added in small portions to the primary reaction system for contact, or the primary reaction system may be added in small portions to the acid for contact. From the viewpoint of suppressing heat generation in the primary reaction system, it is preferable to add the acid in small portions to the primary reaction system.

[0033] The amount of acid used is preferably 0.01 to 10 equivalents, more preferably 0.1 to 5 equivalents, and even more preferably 0.3 to 3 equivalents relative to 1 equivalent of 1223 yd.

[0034] The temperature when the primary reaction system is brought into contact with the acid is not particularly limited, but is preferably from -40 to 100°C, more preferably from -20 to 60°C, in that a better yield of 1233yd is obtained. The reaction pressure is preferably 0 to 30 MPaG, more preferably 0 to 10 MPaG, from the viewpoints of reaction activity and availability of a pressure-resistant reactor. The contact time between the primary reaction system and the acid is not particularly limited, but in terms of a better 1233 yd yield and productivity, in the case of a batch system, it is preferably 0.001 to 100 hours, more preferably 0.002 to 50 hours. In the case of a continuous system, it is preferably 0.001 to 50 hours, more preferably 0.002 to 20 hours. In the case of a batch system, the contact time is the contact time between the primary reaction system and the acid in the reactor, and in the case of a continuous system, it is the residence time of the primary reaction system and the acid in the reactor.

[0035] The contact of the primary reaction system with the acid may be carried out in the presence of the above-mentioned solvent. For example, when the primary reaction system contains a solvent, the primary reaction system containing the solvent may be brought into contact with the acid.

[0036] By carrying out the above procedure, 1233 yd is obtained. The product obtained by mixing the primary reaction system with the acid may contain impurities. Impurities include raw materials for producing 1223yd, raw materials for producing 1233yd (specifically, 1223yd), by-products other than 1233yd produced during the production of 1233yd, metal salts, zero-valent metals, solvents, acids, etc. For example, when 1223yd is produced via 224ca (described later), the raw materials for producing 1223yd may include unreacted 224ca and the by-products 1,3-dichloro-1,1,2,2-tetrafluoropropane (234cc) and 3-chloro-1,1,2,2-tetrafluoropropane (244ca).

[0037] When the product contains the above-mentioned impurities, the impurities may be removed by known means such as distillation, extractive distillation, azeotropic distillation, membrane separation, two-phase separation, or adsorption.

[0038] The 1233yd obtained by the above-mentioned purification method may contain impurities. Impurities may include 1223yd, 234cc, 244ca, etc. The content of the above impurities is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0.1% by mass or less, based on the total amount of the purified product.

[0039] As the starting material 1223yd in the present invention, it is preferable to use 1223yd obtained by subjecting 224ca to a defluorination reaction and a dechlorination reaction in an aprotic solvent. Defluorination and dechlorination of 224ca in aprotic solvents such as DMF and diglyme suppresses the formation of the by-product 234cc and improves the selectivity for 1223yd. Although the details of the above reason are unclear, in aprotic solvents, there is no proton source, so when 224ca is defluorinated and dechlorinated, the chlorine atom attached to the carbon atom at the 3rd position of 224ca is abstracted, and then the side reaction of a hydrogen atom attaching to the carbon atom at the 3rd position is less likely to occur, which is thought to improve the selectivity of 1223yd.

[0040] The defluorination and dechlorination of 224ca are carried out in a liquid phase, which means that 224ca is reacted in a liquid state.

[0041] An example of a method for producing 224ca is the method described in Japanese Patent No. 5413451.

[0042] Preferred aprotic solvents for use in the defluorination and dechlorination of 224ca include aromatic hydrocarbons such as benzene, toluene, xylene, and benzene; aliphatic hydrocarbons such as pentane, hexane, cyclohexane, heptane, and cyclopentane; halogenated hydrocarbons such as chloroform, dichloromethane, and carbon tetrachloride; amides such as N,N-dimethylformamide (DMF), dimethylacetamide, and N-methylpyrrolidone; sulfoxides such as dimethyl sulfoxide (DMSO); sulfones such as sulfolane; ethers such as dimethyl ether (DME), diethyl ether, diisopropyl ether, diglyme, tetrahydrofuran (THF), 1,4-dioxane, and t-butyl methyl ether; nitriles such as acetonitrile; esters such as methyl acetate, ethyl acetate, and propionocarbonate; and ketones such as acetone and methyl ethyl ketone. Among these, DMF, acetonitrile, and DMSO are preferred because they provide a superior yield of 1233yd.

[0043] The content of the aprotic solvent is preferably 1 to 500 mass %, more preferably 10 to 250 mass %, relative to the content of 224ca.

[0044] One preferred embodiment of the defluorination and dechlorination reactions is to defluorinate and dechlorinate 224ca in the presence of at least one metal selected from the group consisting of alkaline earth metals and transition metals (hereinafter, these are collectively referred to as "specific metals").

[0045] Specific examples of alkaline earth metals include magnesium, calcium, and strontium. Specific examples of transition metals include zinc, copper, and nickel. Among these, magnesium, zinc, copper, and nickel are preferred from the viewpoint of reactivity, with magnesium and zinc being more preferred. Two or more of the above specific metals may be used in combination. In order to improve reactivity, the specific metal may be used in the form of a powder, metal flakes, or pellets.

[0046] The amount of the specific metal used is preferably 0.01 to 10 equivalents, more preferably 0.1 to 5 equivalents, and even more preferably 0.3 to 3 equivalents per equivalent of 224ca, from the viewpoint of reaction yield and selectivity for 1223yd.

[0047] The reaction temperature in the defluorination and dechlorination of 224ca (particularly the reaction temperature in the presence of a specific metal) is preferably 0 to 250°C, more preferably 30 to 200°C, and even more preferably 50 to 170°C, from the viewpoints of reaction activity and selectivity to 1223yd.

[0048] The reaction pressure in step 3 is preferably 0 to 30 MPaG, more preferably 0 to 10 MPaG, from the viewpoints of reaction activity and availability of a pressure-resistant reactor.

[0049] The reaction time in step 3 (particularly the reaction time in the presence of the specific metal) is preferably 0.1 to 100 hours, more preferably 1 to 30 hours, in the case of a batch system. In the case of a continuous system, it is preferably 0.01 to 50 hours, more preferably 0.1 to 20 hours. In the case of a continuous system, the reaction time means the residence time of the raw materials in the reactor.

[0050] As a method for carrying out the defluorination and dechlorination of 224ca in the presence of the specific metal, for example, a method in which the specific metal in powder form is dispersed in an aprotic solvent can be mentioned.

[0051] A further preferred embodiment of the defluorination and dechlorination reactions in the above-mentioned 1223yd production method is to defluorinate and dechlorinate 224ca in the presence of an activator. In this embodiment, it is preferable to use the above-mentioned specific metal in combination with the activator. That is, it is preferable to defluorinate and dechlorinate 224ca in the presence of the above-mentioned specific metal and activator. Furthermore, activated metals can be obtained by premixing the above-mentioned specific metals with an activator. Using activated metals can achieve the same effects as when using the above-mentioned specific metals and activators in combination.

[0052] The activator may be any agent that activates the defluorination and dechlorination reactions of 224ca, and examples thereof include chlorides of the metals used in the defluorination and dechlorination reactions (e.g., zinc chloride when zinc is used, or magnesium chloride when magnesium is used), 1,2-dibromoethane, and hydrogen chloride. Of these, zinc chloride is preferred. Two or more of the above activators may be used in combination. The amount of the activator used is preferably 0.001 to 10 equivalents, more preferably 0.01 to 2 equivalents, and even more preferably 0.01 to 1.5 equivalents per equivalent of 224ca, from the standpoints of reaction yield, selectivity to 1223yd, and economy.

[0053] The products obtained by the defluorination and dechlorination of 224ca may contain impurities in addition to the target product, 1223yd. Specific examples of impurities include unreacted 224ca and 234cc. When the product contains impurities, it is preferable to carry out a process to separate 1223 yd from the obtained product. More specifically, this process includes filtering the obtained product, distilling the obtained product to obtain a fraction containing 1223 yd as the main component, and the like. Here, "1223 yd as the main component" means that 1223 yd is the most abundant component by mass in the fraction, and the content of 1223 yd relative to the total mass of the fraction is preferably 90 mass% or more, more preferably 95 mass%. As described above, the difference in boiling point between the target product 1223yd and the raw material 224ca is large, at 40 to 50°C, so 1223yd and 224ca can be easily separated by distillation.

[0054] The distillation operation can be carried out using a distillation apparatus such as a packed column or a plate column. For example, multi-stage distillation is preferred to efficiently purify and recover the target compound 1223yd from multiple impurities. When multi-stage distillation is used, the number of theoretical plates is preferably 20 or more. The temperature during the distillation operation (for example, the temperature of the still) is preferably 80° C. or lower, more preferably 70° C. or lower, from the viewpoint of energy costs. The temperature during the distillation operation is preferably 58° C. or higher, which is the boiling point of 1223 yd(Z). [Example]

[0055] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. Examples 1 and 2 described below are examples.

[0056] (Gas chromatograph conditions) In the production of the following compounds, the composition of the obtained products was analyzed using a gas chromatograph (GC). The column used was a DB-1301 (length 60 m × inner diameter 250 μm × thickness 1 μm, manufactured by Agilent Technologies).

[0057] <1223yd manufacturing example> (224ca production) 224ca was produced in accordance with the following reaction scheme: CHCl3 + trifluoroethylene (TFE) → 224ca

[0058] First, anhydrous aluminum chloride (25 g, 0.19 mol), CHCl3 (500 g, 4.19 mol), and 224 Ca (100 g, 0.45 mol) were placed in a 500 mL stainless steel autoclave. The reaction mixture was degassed under reduced pressure while stirring. TFE was then added to the autoclave until the pressure inside the autoclave reached 0.05 MPa, and the temperature inside the autoclave was raised to 80°C. Subsequently, TFE was further added while maintaining the pressure inside the autoclave at 0.8 MPa. A total of 0.17 kg (1.65 mol) of TFE was added to the autoclave.

[0059] The reaction mixture was stirred for another hour, cooled to room temperature, and analyzed by gas chromatography. The conversion of CHCl3 was 33% and the selectivity for 224ca was 84%. The reaction mixture was filtered, and 102 g of molecular sieves 4A was added to the resulting crude liquid, which was then stirred overnight for dehydration. The crude liquid was filtered, and the resulting crude product was purified by distillation to produce 224ca (230 g, 1.05 mol).

[0060] (1223yd production) A 30 cc glass flask cooled to 10°C and equipped with a reflux condenser was charged with 9.44 g of DMF (Kanto Chemical), 1.57 g of zinc powder (D50; 6-9 μm, for organic synthesis: Fujifilm Wako Pure Chemical Industries, Ltd.), 1.36 g of zinc chloride (Junsei Chemical), 4.39 g of 224ca, and a magnetic rotor. The flask was then placed in an oil bath and heated to the reaction temperature of 130°C. The temperature was raised over approximately 30 minutes, and during the temperature increase and reaction, the magnetic rotor was rotated at 300 rpm using a magnetic stirrer. After maintaining the temperature at 130°C for 5.5 hours, the temperature of the oil bath was lowered and the mixture was cooled to room temperature. After cooling to room temperature, the reaction mixture was analyzed by GC. The composition of the reaction mixture was analyzed by GC, and the conversion rate and selectivity were calculated. The reaction mixture contained 1223 yd. The conversion of 224ca was 65.4%, and the selectivity to 1223yd was 94.4% (the selectivity to 1223yd(Z) was 83.5%, and the selectivity to 1223yd(E) was 10.9%). The selectivity to 234cc was 1.5%. The above reaction was repeated until the total amount of the product reached about 150 g, and then the product was purified by distillation, and a distillate containing 93.2 mass% of 1223 yd(Z), 6.0 mass% of 1223 yd(E), and 0.2 mass% of 234 cc was obtained from the top of the distillation column. Using the above distillate, the following 1233 yd was produced.

[0061] <Example 1> To a 10 ml glass container were added 0.165 g of zinc powder (D50; 6 to 9 μm, for organic synthesis: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.021 g of CuCl (manufactured by Kanto Chemical Co., Inc.), 1.9 g of DMF (manufactured by Kanto Chemical Co., Inc.), and 0.349 g of the above distillate, and the resulting mixture was stirred at room temperature. After 4.5 hours of mixing, 0.05 g of ion-exchanged water and 0.03 g of pH 4 buffer solution (acetic acid / sodium acetate) were added to the mixture. Stirring was continued, and 28 hours later, 1 ml of 1 M HCl aqueous solution was added to the mixture to stop the reaction. The supernatant of the resulting mixture was collected and analyzed by GC. The resulting mixture contained 1233 yd. The conversion rate of 1223yd was 82.2%, and the selectivity to 1233yd was 78.0% (selectivity to 1233yd(Z) was 76.2%, and selectivity to 1233yd(E) was 1.8%).

[0062] <Example 2> To a 10 ml glass container were added 0.161 g of zinc powder (D50; 6 to 9 μm, for organic synthesis: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.024 g of CuCl (manufactured by Kanto Chemical Co., Inc.), 1.89 g of DMF (manufactured by Kanto Chemical Co., Inc.), and 0.361 g of the above distillate, and the mixture was stirred while being heated (temperature: 60°C). After 2 hours of mixing, 0.05 g of pH 4 buffer solution (acetic acid / sodium acetate) was added to the mixture. Stirring was continued, and after 4 hours, heating was stopped and the mixture was cooled to room temperature. 1 ml of 1 M HCl aqueous solution was added to the mixture to stop the reaction. The supernatant of the resulting mixture was collected and analyzed by GC. The resulting mixture contained 1233 yd. The conversion rate of 1223yd was 62.8%, and the selectivity to 1233yd was 76.8% (selectivity to 1233yd(Z) was 75.4%, and selectivity to 1233yd(E) was 1.4%).

[0063] <Example 3> To a 10 ml glass container were added 0.060 g of magnesium (turnings, for Grignard reaction: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.022 g of CuCl (manufactured by Kanto Chemical Co., Ltd.), 1.90 g of DMF (manufactured by Kanto Chemical Co., Ltd.), and 0.360 g of the above distillate, and the mixture was stirred while heating (temperature: 60°C). After 2 hours of mixing, 0.05 g of pH 4 buffer solution (acetic acid / sodium acetate) was added to the mixture. Stirring was continued, and after 4 hours, heating was stopped and the mixture was cooled to room temperature. 1 ml of 1 M HCl aqueous solution was added to the mixture to stop the reaction. The supernatant of the resulting mixture was collected and analyzed by GC. The resulting mixture contained 1233 yd. The conversion rate of 1223yd was 45.6%, and the selectivity to 1233yd was 73.1% (selectivity to 1233yd(Z) was 71.9%, and selectivity to 1233yd(E) was 1.2%).

[0064] <Example 4> To a 10 ml glass container were added 0.160 g of zinc powder (D50; 6-9 μm, for organic synthesis: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.034 g of NiCl2 (anhydrous, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 1.89 g of DMF (manufactured by Kanto Chemical Co., Inc.), and 0.355 g of the above distillate, and the mixture was stirred while being heated (temperature: 60°C). After 2 hours of mixing, 0.05 g of pH 4 buffer solution (acetic acid / sodium acetate) was added to the mixture. Stirring was continued, and after 4 hours, heating was stopped and the mixture was cooled to room temperature. 1 ml of 1 M HCl aqueous solution was added to the mixture to stop the reaction. The supernatant of the resulting mixture was collected and analyzed by GC. The resulting mixture contained 1233 yd. The conversion rate of 1223yd was 29.8%, and the selectivity to 1233yd was 65.0% (the selectivity to 1233yd(Z) was 63.4%, and the selectivity to 1233yd(E) was 1.6%).

[0065] The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2021-094497, filed on June 4, 2021, are hereby incorporated by reference as part of the disclosure of the specification of the present invention.

Claims

1. A method for producing 1-chloro-2,3,3-trifluoropropene, comprising contacting 1,3-dichloro-2,3,3-trifluoropropene with a metal salt and a zero-valent metal, and then contacting the resulting mixture with an acid to produce 1-chloro-2,3,3-trifluoropropene, the metal salt is a halide, and the metal atom contained in the metal salt is a transition metal; The method for producing the metal having a valence of zero is a transition metal or an alkaline earth metal.

2. The method according to claim 1 , wherein the metal atom contained in the metal salt is a copper atom, an iron atom, a cobalt atom, or a nickel atom.

3. 3. The method according to claim 1, wherein the metal salt is copper chloride.

4. 3. The method according to claim 1, wherein the zero-valent metal is zinc, magnesium, iron, cobalt, or nickel.

5. The method according to claim 4, wherein the zero-valent metal is zinc.

6. 3. The method according to claim 1, wherein the acid is hydrogen chloride, sulfuric acid, nitric acid, acetic acid, or phosphoric acid.

7. 3. The method according to claim 1, wherein the temperature when the 1,3-dichloro-2,3,3-trifluoropropene, the metal salt, and the zero-valent metal are contacted is 0 to 200°C.

8. The method according to claim 1 or 2, wherein the production of 1-chloro-2,3,3-trifluoropropene is carried out in a liquid phase.

9. The method according to claim 8, wherein the production of 1-chloro-2,3,3-trifluoropropene is carried out in the presence of a solvent.

10. The method according to claim 1 or 2, wherein the 1,3-dichloro-2,3,3-trifluoropropene used is 1,3-dichloro-2,3,3-trifluoropropene obtained by subjecting 1,3,3-trichloro-1,1,2,2-tetrafluoropropane to a defluorination reaction and a dechlorination reaction in an aprotic solvent.