JP2020023450A - Method for producing 2-chloro-3,3-difluoropropene, method for producing 2-chloro-1,1,2-trifluoropropane, method for producing 2,3,3-trifluoropropene, method for producing 1,2-dichloro-2,3,3-trifluoropropane, and method for producing 1-chloro-2,3,3-trifluoropropene - Google Patents

Abstract

To provide a method for producing 1242xf that makes it possible to produce 1242xf efficiently.SOLUTION: A method for producing 2-chloro-3,3-difluoropropene includes subjecting a compound represented by formula (1) to hydrogen reduction to produce 2-chloro-3,3-difluoropropene. In the formula (1): CHF-CCl=CClX, X is a hydrogen atom or a chlorine atom.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing 2-chloro-3,3-difluoropropene, a method for producing 2-chloro-1,1,2-trifluoropropane, a method for producing 2,3,3-trifluoropropene, The present invention relates to a method for producing 2-dichloro-2,3,3-trifluoropropane and a method for producing 1-chloro-2,3,3-trifluoropropene.

1-chloro-2,3,3-trifluoropropene (CHCl = CF-CHF _2; HCFO-1233yd; hereinafter also referred to as 1233yd) is 3,3-dichloro-1,1,1,2,2- It is a compound that has a low global warming potential (GWP) in place of pentafluoropropane and 1,3-dichloro-1,1,2,2,3-pentafluoropropane and has various uses (for example, detergents, refrigerants, heat Medium, foaming agent, solvent).
In the present specification, a halogenated hydrocarbon has an abbreviation of the compound in parentheses after the compound name, but in the present specification, the abbreviation is used instead of the compound name as necessary. In some cases, as abbreviations, only the numbers after the hyphen (-) and the lowercase letters of the alphabet (for example, "1233yd" in "HCFO-1233yd") may be used.

  As a production example of 1233yd, Patent Document 1 discloses a method in which 3-chloro-1,1,2,2-tetrafluoropropane is subjected to a dehydrofluorination reaction.

International Publication No. WO 2016/136744

On the other hand, in the method described in Patent Document 1, although 1233yd is obtained, there is a problem that a large amount of impurities such as 1-chloro-3,3-difluoropropyne are generated, and therefore, development of a new manufacturing method is required. is optionally the present inventors have studied a method of synthesizing 1233Yd, as a synthetic intermediate, the 2-chloro-3,3-difluoro-propene _{(CHF 2 -CCl = CH 2 .1242xf} ) are useful I learned.
An object of the present invention is to provide a method for manufacturing 1242xf, which can efficiently manufacture 1242xf.

  The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the following structure can solve the above-mentioned problems.

(1) A method for producing 2-chloro-3,3-difluoropropene, wherein a compound represented by formula (1) described below is subjected to a hydrogen reduction reaction to produce 2-chloro-3,3-difluoropropene.
(2) The production method according to (1), wherein the reaction is performed in the presence of a catalyst.
(3) The method according to (1) or (2), wherein the reaction is performed under a condition of 50 ° C. or higher.
(4) 2-chloro-1,1 by reacting 2-chloro-3,3-difluoropropene produced by the production method according to any one of (1) to (3) with hydrogen fluoride. A process for producing 2-chloro-1,1,2-trifluoropropane, characterized by obtaining 2,2-trifluoropropane.
(5) The 2-chloro-1,1,2-trifluoropropane produced by the production method described in (4) is subjected to a dehydrochlorination reaction to obtain 2,3,3-trifluoropropene. A method for producing 2,3,3-trifluoropropene.
(6) The 2,3,3-trifluoropropene produced by the production method described in (5) is reacted with chlorine to obtain 1,2-dichloro-2,3,3-trifluoropropane. A method for producing 1,2-dichloro-2,3,3-trifluoropropane, comprising:
(7) 1,2-Dichloro-2,3,3-trifluoropropane produced by the production method described in (6) is subjected to a dehydrochlorination reaction to give 1-chloro-2,3,3-trifluoro. A method for producing 1-chloro-2,3,3-trifluoropropene, which comprises obtaining propene.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of 1242xf which can manufacture 1242xf efficiently can be provided.

The meanings of the terms in the present invention are as follows.
The numerical range represented by using “to” means a range including the numerical values described before and after “to” as the lower limit and the upper limit.
1233yd has a geometric isomer, Z-form and E-form, depending on the position of the substituent on the double bond. In the present specification, when a compound name or an abbreviation of a compound is used unless otherwise specified, it indicates at least one selected from a Z-form and an E-form, and more specifically, a Z-form or an E-form, or It shows a mixture of Z-form and E-form at an arbitrary ratio. When (E) or (Z) is added after the compound name or the abbreviation of the compound, the (E) or (Z) form of each compound is shown. For example, 1233yd (Z) indicates a Z-form and 1233yd (E) indicates an E-form.

The method for producing 1242xf of the present invention is a method for producing 1242xf by hydrogen reducing a compound represented by the formula (1) (hereinafter, also referred to as “compound 1”). That is, this is a method of reacting compound 1 with hydrogen.
Formula (1) CHF ₂ -CCl = CClX
X represents a hydrogen atom or a chlorine atom.

In the production method of the present invention, the compound 1 is used as a raw material. Compound 1 can be synthesized by a known method. As a specific example of a method for producing CF ₂ CCl = CHCl, a method in which 1,1-dichloro-2,3-difluorocyclopropane is thermally decomposed to be obtained as a by-product (Journal of Fluorine Chemistry, Volume 15, Issue 6) , Pages 497-509, Journal, 1980).

  The hydrogen reduction reaction of compound 1 in the production method of the present invention may be either a liquid phase reaction or a gas phase reaction. The liquid-phase reaction refers to causing a hydrogen reduction reaction of compound 1 in a liquid state. In addition, the gas phase reaction refers to causing a gaseous compound 1 to undergo a hydrogen reduction reaction.

  In the above reaction (liquid phase reaction, gas phase reaction), the molar ratio of hydrogen to compound 1 to be used (the molar amount of hydrogen / the molar amount of compound 1) is determined from the viewpoint of the yield and selectivity of 1242 × f. , 0.1 to 10, and more preferably 0.5 to 2.0.

The above reaction may be performed in a batch system, a semi-continuous system, or a continuous flow system.
Specific examples of the material of the reactor include glass, iron, nickel, and stainless steel.

  One of the preferable embodiments in the above reaction is an embodiment in which the above reaction is performed in the presence of a catalyst. The reaction in the presence of a catalyst can be performed in any of a gas phase reaction and a liquid phase reaction.

The catalyst may be any catalyst that can efficiently promote the hydrogen reduction reaction of compound 1, and examples thereof include a metal catalyst.
Examples of the metal catalyst include a catalyst containing a Group 8 element such as iron, ruthenium and osmium; a Group 9 element such as cobalt, rhodium and iridium; and at least one element selected from Group 10 elements such as nickel, palladium and platinum. Is preferred. These elements may be used alone or in combination of two or more.
Among the Group 8 to 10 elements, a catalyst containing a platinum group element such as palladium, platinum, ruthenium, and rhodium is preferable, and a catalyst containing palladium (hereinafter, also simply referred to as “palladium catalyst”) is more preferable.

  The palladium catalyst is preferably used by being supported on a carrier. The palladium catalyst may be not only palladium alone but also a palladium alloy. Further, a catalyst in which a mixture of palladium and another metal is supported, or a composite catalyst in which palladium and another metal are separately supported on a carrier may be used. Examples of the palladium alloy include a palladium / platinum alloy and a palladium / rhodium alloy.

As the catalyst, a catalyst in which only palladium or a palladium alloy is supported on a carrier, or a catalyst in which palladium and another metal other than palladium are supported on a carrier is preferable.
Specific examples of metals other than palladium include Group 8 elements (iron, ruthenium, osmium, etc.), Group 9 elements (cobalt, rhodium, iridium, etc.), and Group 10 elements (nickel, platinum, etc.). Can be
Other metals may be used alone or in combination of two or more.
The ratio of the other metal is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of palladium.

Specific examples of the carrier include activated carbon and metal oxides (alumina, zirconia, silica, etc.), and activated carbon is preferred from the viewpoint of activity, durability, and reaction selectivity.
Specific examples of the activated carbon include activated carbon obtained from plant raw materials (wood, charcoal, fruit shell, coconut shell, etc.) and activated carbon obtained from mineral raw materials (peat, lignite, coal, etc.). In view of this, activated carbon obtained from plant raw materials is preferred, and coconut shell activated carbon is more preferred.
Specific examples of the shape of the activated carbon include shaped coal having a length of about 2 to 10 m, crushed coal having a size of about 4 to 50 mesh, and granular coal. From the viewpoint of activity, crushed charcoal having a length of 4 to 20 mesh and a length of 2 ~ 5 mm of shaped coal is preferred.

  The supported amount of palladium is preferably from 0.1 to 10 parts by mass, more preferably from 0.5 to 1 part by mass, per 100 parts by mass of activated carbon.

As a specific procedure of the gas phase reaction using a catalyst, compound 1 which is a raw material heated to a gaseous state and hydrogen are continuously supplied into a reactor, and the catalyst filled in the reactor is , Gaseous compound 1 and hydrogen are brought into contact to obtain 1242xf.
Note that an inert gas such as N ₂ may be used in the reaction because it is effective in suppressing by-products and catalyst deactivation.
The reaction temperature in the gas phase reaction is preferably 50 ° C. or higher, more preferably 100 ° C. or higher, still more preferably 150 ° C. or higher, more preferably 400 ° C. or lower, and more preferably 300 ° C. or lower, from the viewpoint of the reaction activity and the selectivity of 1242 × f. Preferably, the temperature is 250 ° C. or lower.
The pressure of the reaction system in the gas phase reaction is preferably 0 to 0.2 MPa.
The reaction time in the gas phase reaction is preferably from 1 to 6000 seconds, more preferably from 10 to 1500 seconds, from the viewpoint of the reaction yield and the production efficiency. The reaction time means the residence time of the raw materials in the reactor.

As a specific procedure of the liquid phase reaction using a metal catalyst, compound 1 and compound 1 and hydrogen are continuously or discontinuously placed in a reactor in which a mixture of one of the catalyst and hydrogen exists in a liquid state. There is a procedure in which the other of hydrogen is supplied and 1242xf generated by the reaction is continuously or discontinuously extracted from the reactor.
The reaction temperature in the liquid phase reaction is preferably 20 ° C. or higher, more preferably 50 ° C. or higher, preferably 200 ° C. or lower, more preferably 150 ° C. or lower, from the viewpoint of the reaction yield and the selectivity of 1242 × f.
The reaction time in the liquid phase reaction is preferably 0.5 to 50 hours, more preferably 1 to 10 hours, from the viewpoint of the reaction yield and the production efficiency. The reaction time means the residence time of the raw materials in the reactor.
The liquid phase reaction may be performed in the presence of a solvent, if necessary. The solvent may be any compound that is inert to hydrogen, such as water.
By the reaction of compound 1 with hydrogen, 3,3-difluoropropene (HFO-1252zf), 2-chloro-1,1-difluoropropane (HCFC-262db), 1,1-difluoro Propane (HFC-272fb) and the like are obtained as by-products. The product obtained by the above reaction may be used as it is as a raw material for producing 253bb described below, or 1242xf purified by a known method such as distillation may be used as a raw material for producing 253bb described below. Since the residual liquid after purification of 1242xf usually contains unreacted compound 1, it is preferable to reuse it as a raw material for producing 1242xf. In that case, the residual liquid after 1242xf purification may be used as it is. The residual liquid after 1242xf purification contains 1252zf, 262db, 272fb, 1242xf, and the like.

  The produced 1242xf is useful as a synthetic intermediate of 1233yd. Hereinafter, a method for synthesizing 1233yd using 1242xf will be described in detail.

First, by reacting hydrogen fluoride with 1242Xf, 2-chloro-1,1,2-trifluoro-propane _{(CHF 2} CClFCH 3 _.253bb) is obtained (see scheme below).

  The reaction between 1242xf and hydrogen fluoride may be either a liquid phase reaction or a gas phase reaction. Note that the liquid phase reaction refers to reacting 1242xf in a liquid state with hydrogen fluoride. The gas phase reaction refers to reacting 1242xf in a gaseous state with hydrogen fluoride.

  In the above reaction (liquid phase reaction, gas phase reaction), the molar ratio of the used hydrogen fluoride to the used 1242xf (the molar amount of hydrogen fluoride / the molar amount of 1242xf) depends on the reaction yield and the production efficiency. Therefore, 0.5 to 100 is preferable, and 1 to 50 is more preferable.

In the case of a liquid phase reaction, the above reaction may be carried out in the presence of a catalyst, if necessary.
Specific examples of the catalyst include metal halides such as antimony, tin, thallium, iron, titanium, and tantalum. More specifically _{include SbCl 5, SbCl 3, SbF 5} , SnCl 4, TiCl 4, FeCl 3.
In the liquid phase reaction procedure, the other of hydrogen fluoride and 1242xf is continuously or discontinuously supplied into a reactor in which a mixture of one of hydrogen fluoride and 1242xf and a catalyst exists in a liquid state, 253bb produced by the above method is continuously or discontinuously withdrawn from the reactor.
The reaction temperature in the liquid phase reaction is preferably from 20 to 200 ° C, more preferably from 30 to 150 ° C, from the viewpoint of the reaction yield and the selectivity of 253bb.
The reaction time in the liquid phase reaction is preferably 0.5 to 50 hours, more preferably 1 to 10 hours, from the viewpoint of the reaction yield and the production efficiency.
The pressure of the reaction system in the liquid phase reaction is preferably from 0.1 to 3.0 MPa, more preferably from 0.2 to 2.0 MPa, from the viewpoint of reaction yield and apparatus cost.
The liquid phase reaction may be performed in the presence of a solvent, if necessary.

In the case of a gas phase reaction, the above reaction may be carried out in the presence of a catalyst, if necessary.
Specific examples of the catalyst include metal oxide catalysts such as alumina, zirconia, titania, and chromia; metal halides such as antimony, tin, thallium, iron, titanium, and tantalum; and antimony as a simple substance such as activated carbon and metal oxides. , Tin, thallium, iron, titanium, tantalum, and other metal halides.
As a procedure of the gas phase reaction, 1242xf, which is a raw material heated to a gas state, and hydrogen fluoride are continuously supplied into the reactor, and the catalyst filled in the reactor, 1242xf and There is a procedure for obtaining 253bb by contacting with hydrogen fluoride.
Note that an inert gas such as N ₂ may be used in the reaction because it is effective in suppressing by-products and catalyst deactivation.
The reaction temperature in the gas phase reaction is preferably from 50 to 700 ° C, more preferably from 50 to 600 ° C, further preferably from 50 to 400 ° C, and particularly preferably from 100 to 300 ° C, in view of the reaction activity and the selectivity of 253bb.
In the case of a gas phase reaction, the raw material 1242xf may be preheated and then supplied to the reaction. The preheating temperature is preferably from 80 to 400 ° C, more preferably from 150 to 400 ° C, from the viewpoint of efficiently vaporizing the raw material.
The reaction time in the gas phase reaction is preferably from 1 to 6000 seconds, more preferably from 60 to 1500 seconds, from the viewpoint of the reaction yield and the production efficiency. The reaction time of the gas phase reaction means the residence time of the raw material in the reactor.

  In the above reaction (liquid-phase reaction, gas-phase reaction), the molar ratio of the used catalyst to the used 1242xf (the molar amount of the catalyst / the molar amount of 1242xf) is determined from the viewpoint of the reaction yield and the selectivity of 253bb. 0.0001-1.0 is preferable, and 0.001-0.1 is more preferable.

Next, a 253bb by dehydrochlorination, 2,3,3-trifluoro-propene _{(CHF 2 CF = CH 2 .1243yf} ) is obtained (see scheme below).

  The 253bb dehydrochlorination reaction may be either a liquid phase reaction or a gas phase reaction. Note that the liquid phase reaction means that 253bb in a liquid state is subjected to a dehydrochlorination reaction. Further, the gas phase reaction means that a gaseous state of 253bb is subjected to a dehydrochlorination reaction.

As a preferred embodiment of the dehydrochlorination reaction, there is an embodiment in which 253bb is subjected to a dehydrochlorination reaction in the presence of a base. The dehydrochlorination reaction in the presence of a base can be performed by any of a gas phase reaction and a liquid phase reaction.
The base may be any base capable of performing a dehydrochlorination reaction, and examples thereof include metal hydroxides, metal oxides, and metal carbonates.
In addition, a base may be used individually by 1 type, and may use 2 or more types together.

  Specific examples of the metal hydroxide include an alkali metal hydroxide and an alkaline earth metal hydroxide. Specific examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Specific examples of the alkaline earth metal hydroxide include magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide.

  Specific examples of the metal oxide include an alkali metal oxide and an alkaline earth metal oxide. Specific examples of the alkali metal oxide include sodium oxide. Specific examples of the alkaline earth metal oxide include calcium oxide.

  Specific examples of the metal carbide include an alkali metal carbonate and an alkaline earth metal carbonate. Specific examples of the alkali metal carbonate include lithium, sodium, potassium, rubidium, cesium and francium carbonates. Specific examples of the alkaline earth metal carbonate include beryllium, magnesium, calcium, strontium, barium, and radium carbonate.

  As the base, a metal hydroxide is preferred, and potassium hydroxide and sodium hydroxide are more preferred, from the viewpoints of high solubility in water, easy handling, and high reactivity.

The amount of the base to be used is preferably 0.5 to 10 mol, more preferably 0.5 to 5.0 mol, and preferably 0.8 to 5.0 mol, per 1 mol of 253bb, from the viewpoint of the reaction yield and the selectivity of 1243yf. ~ 3.0 mol is more preferred.
The reaction temperature of 253bb and the base is preferably from 0 to 100 ° C, more preferably from 10 to 80 ° C, still more preferably from 15 to 70 ° C, from the viewpoint of the reaction activity and the selectivity of 1243yf.
The reaction time of 253bb and a base is preferably 0.5 to 50 hours, more preferably 1 to 20 hours in the case of a batch system. In the case of a continuous system, it is preferably from 0.5 to 6000 seconds, more preferably from 1 to 1500 seconds. In addition, the reaction time in the case of a continuous type means the residence time of the raw material in a reactor.

When the above base is used, a dehydrochlorination reaction of 253 bb occurs. In order for the base to participate in the reaction, it is necessary to physically contact 253bb with the base.
As a method of bringing 253bb into contact with a base, a method of bringing a base dissolved in a solvent (that is, a base solution) into contact with 253bb (preferably, 253bb in a liquid state) and a method of bringing into a solid state (preferably, a powder state) And 253bb (preferably, 253bb in a gaseous state). The former method is preferable in terms of reaction time, reaction yield, and selectivity of 1243yf.

The solvent used for preparing the base solution may be any solvent that can dissolve a predetermined amount of the base and does not contribute to the dechlorination hydrogen reaction, and is preferably water. That is, the base solution is preferably an aqueous base solution.
The concentration of the base in the base solution is preferably from 10 to 50% by mass based on the total mass of the base solution. When the concentration of the base is 10% by mass or more, a sufficient reaction rate is easily obtained, and the target substance is easily separated by two-layer separation. When the concentration of the base is 50% by mass or less, the base is easily dissolved sufficiently, and the metal salt is hardly precipitated, which is advantageous in an industrial process. The concentration of the base in the base solution is more preferably 20 to 40% by mass based on the total mass of the base solution.

The dehydrochlorination reaction is preferably performed in the presence of a phase transfer catalyst to increase the reaction rate.
Specific examples of the phase transfer catalyst include quaternary ammonium salts, quaternary phosphonium salts, quaternary arsonium salts, sulfonium salts, and crown ethers. Quaternary ammonium salts, quaternary phosphonium salts, Quaternary arsonium salts and sulfonium salts are preferred, and quaternary ammonium salts are more preferred.
Examples of the quaternary ammonium salt include a compound represented by the following formula (i).

In Formula (i), R ^{11 to} R ¹⁴ each independently represent a monovalent hydrocarbon group or a monovalent hydrocarbon group to which a functional group inert to a reaction is bonded, and Y ₁ ^— Represents an anion.
R ^{11 to} R ¹⁴ may be the same group or different groups.

  Specific examples of the monovalent hydrocarbon group include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group, and an alkyl group and an aryl group are preferable. The monovalent hydrocarbon group preferably has 4 to 100 carbon atoms, more preferably 6 to 30 carbon atoms.

  Specific examples of the functional group inert to the reaction in the monovalent hydrocarbon group to which the functional group inert to the reaction is bonded include a halogen atom, an alkoxycarbonyl group, an acyloxy group, a nitrile group, an acyl group, and a carboxyl group. And alkoxyl groups.

Specific examples of formula (i) quaternary ammonium in ^{(R 11 R 12 R 13 R} 14 N +), tetramethylammonium, tetraethylammonium, tetra -n- propyl ammonium, tetra -n- butylammonium, methyl tri - n-octyl ammonium, cetyl trimethyl ammonium, benzyl trimethyl ammonium, benzyl triethyl ammonium, cetyl benzyl dimethyl ammonium, cetyl pyridinium, n-dodecyl pyridinium, phenyl trimethyl ammonium, phenyl triethyl ammonium, N-benzyl picolinium, pentamethonium, hexamethoate For example.

Y ₁ ^- Examples of the fluorine ion, a chlorine ion, a bromine ion, an iodine ion, sulfate ion, nitrate ion, phosphate ion, perchlorate ion, hydrogen sulfate ion, hydroxide ion, acetate ion, benzoate Ions, benzenesulfonate, and p-toluenesulfonate; fluorine, chlorine, bromine, iodine, hydrogensulfate, and hydroxide are preferred; fluorine, chlorine, bromine, and iodine Ions and hydroxide ions are more preferred, and chlorine ions and bromide ions are even more preferred.

As the compound represented by the formula (i), a combination of the following quaternary ammonium (R ¹¹ R ¹² R ¹³ R ¹⁴ N ⁺ ) and the following Y ₁ ⁻ is preferable from the viewpoint of versatility and reactivity.
Quaternary ammonium ^{(R 11 R 12 R 13 R} 14 N +): tetramethylammonium, tetraethylammonium, tetra -n- propyl ammonium, tetra -n- butylammonium methyltri -n- octyl ammonium.
Y ₁ ⁻ : a fluorine ion, a chlorine ion, a bromine ion, an iodine ion, and a hydroxide ion.

  Specific examples of the quaternary ammonium salt include tetra-n-butylammonium chloride (TBAC), tetra-n-butylammonium bromide (TBAB), and methyltri-n-octylammonium chloride (TOMAC).

  Examples of the quaternary phosphonium salt include compounds represented by the following formula (ii).

In the formula (ii), R ^{21 to} R ²⁴ each independently represent a monovalent hydrocarbon group, and Y ₂ ⁻ represents an anion.
R ^{21 to} R ²⁴ may be the same group or different groups.

  Specific examples of the monovalent hydrocarbon group include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group, and an alkyl group and an aryl group are preferable.

Specific examples of the quaternary phosphonium (R ²¹ R ²² R ²³ R ²⁴ P ⁺ ) in the above formula (ii) include tetraethylphosphonium, tetra-n-butylphosphonium, ethyltri-n-octylphosphonium, cetyltriethylphosphonium, and cetyltrinium. -N-butylphosphonium, n-butyltriphenylphosphonium, n-amyltriphenylphosphonium, methyltriphenylphosphonium, benzyltriphenylphosphonium, tetraphenylphosphonium.

Y ₂ ^- Specific examples of chlorine ion, fluorine ion, bromine ion, iodine ion, sulfate ion, nitrate ion, phosphate ion, perchlorate ion, hydrogen sulfate ion, hydroxide ion, acetate ion, benzoate Ions, benzenesulfonate, and p-toluenesulfonate; and fluorine, chlorine, and bromine are preferred.

  Examples of the quaternary arsonium salt include compounds represented by the following formula (iii).

In the formula (iii), R ^{31 to} R ³⁴ each independently represent a monovalent hydrocarbon group, and Y ₃ ^— represents an anion.
Specific examples of the monovalent hydrocarbon group represented by R ^{31 to} R ³⁴ in the formula (iii) are specific examples of the monovalent hydrocarbon group represented by R ^{21 to} R ²⁴ in the formula (ii). Is the same as
Specific examples of the anion represented by Y ₃ ^— in the formula (iii) are the same as the specific examples of the anion represented by Y ₂ ^— in the formula (ii).

  Specific examples of the quaternary arsonium salts include triphenylmethylarsonium fluoride, tetraphenylarsonium fluoride, triphenylmethylarsonium chloride, tetraphenylarsonium chloride, and tetraphenylarsonium bromide.

  Examples of the sulfonium salt include a compound represented by the following formula (iv).

Wherein ^{(iv), R} 41 ~R ⁴³ independently represent a monovalent hydrocarbon group, _{Y 4} ^- represents an anion.
Specific examples of the monovalent hydrocarbon group represented by R ^{41 to} R ⁴³ in the formula (iv) include specific examples of the monovalent hydrocarbon group represented by R ^{21 to} R ²⁴ in the formula (ii). Is the same as
Y ₄ in the formula (iv) ^- Examples of represented by anions, Y ₂ in the formula (ii) ^- is the same as the specific examples of the represented by anions.

  Specific examples of the sulfonium salt include di-n-butylmethylsulfonium iodide, tri-n-butylsulfonium tetrafluoroborate, dihexylmethylsulfonium iodide, dicyclohexylmethylsulfonium iodide, dodecylmethylethylsulfonium chloride, and tris (diethylamino) Sulfonium difluorotrimethyl silicate.

Specific examples of the crown ether include 18-crown-6, dibenzo-18-crown-6, and dicyclohexyl-18-crown-6.
Among the above phase transfer catalysts, TBAC, TBAB, and TOMAC are preferable from the viewpoint of industrial availability, price, ease of handling, and reactivity.

  The amount of the phase transfer catalyst to be used is preferably 0.001 to 10 parts by mass, more preferably 0.05 to 5.0 parts by mass, per 100 parts by mass of 253bb.

When the reaction system separates into an aqueous phase and an organic phase, a water-soluble organic solvent is present in the reaction system in place of the phase transfer catalyst, and the organic phase and the aqueous phase containing a base are separated. The phase transfer catalyst and the water-soluble organic solvent may be used in combination.
Specific examples of the water-soluble organic solvent include tetraethylene glycol dimethyl ether, sulfolane, and t-butanol.

The above reaction may be performed in a batch system, a semi-continuous system, or a continuous flow system.
Specific examples of the material of the reactor include glass, iron, nickel, and stainless steel.

  When a mode in which 253 bb is subjected to a dehydrochlorination reaction in the presence of a base is carried out by a liquid phase reaction, the reaction solution may be allowed to stand after the reaction is completed and separated into an organic phase and an aqueous phase. Usually, the organic phase contains 1243yf, and the product containing 1243yf can be easily recovered by recovering the organic phase.

  Another preferred embodiment of the dehydrochlorination reaction is an embodiment in which 253bb is subjected to a dehydrochlorination reaction in the presence of activated carbon or a metal catalyst. The dehydrochlorination reaction in the presence of activated carbon or a metal catalyst can be performed by a gas phase reaction.

The specific surface area of the activated carbon, from the viewpoint of improving the reaction conversion rate and the by-product suppression, preferably 10~3000m ² / g, more preferably 20~2500m ² / g, more preferably 50~2000m ² / g. The specific surface area of the activated carbon is measured by a method based on the BET method.

  Specific examples of activated carbon include activated carbon prepared from charcoal, coal, coconut shell, and the like. More specifically, there are formed coal having a length of about 2 to 5 mm, crushed coal having a length of about 4 to 50 mesh, granular coal, and powdered coal.

  The activated carbon is preferably sufficiently dried before use in the reaction. The amount of water in the activated carbon is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, when the total amount of activated carbon and water is 100% by mass.

  Specific examples of the metal catalyst include zero-valent iron, zero-valent cobalt, zero-valent nickel, zero-valent palladium, chromium oxide, aluminum oxide, zinc oxide, tin oxide, magnesium oxide, lanthanum oxide, nickel oxide, and nickel oxide. Examples include aluminum fluoride oxide, chromium fluoride oxide, magnesium fluoride oxide, lanthanum fluoride oxide, alkali metal halides, and alkaline earth metal halides.

In the present embodiment, activated carbon or alkaline earth metal fluoride is preferably used, and activated carbon, BaF ₂ , SrF ₂ , and CaF ₂ are more preferably used.

When activated carbon or a metal catalyst is used, a 253 bb dehydrochlorination reaction occurs. In order for the activated carbon or the metal catalyst to participate in the reaction, it is necessary to physically contact 253bb with the activated carbon or the metal catalyst.
As a method of contacting 253bb with an activated carbon or a metal catalyst, a method of contacting activated carbon or a metal catalyst with 253bb in a gaseous state is exemplified.
As a specific procedure, there is a procedure in which 253bb in a gaseous state is continuously supplied into a reactor, and activated carbon or a metal catalyst filled in the reactor is brought into contact with 253bb in a gaseous state to obtain 1243yf. Can be When recovering the product from the gas phase in the reactor, the product is cooled by cooling. If necessary, the product is passed through a deacidification tower to remove hydrogen chloride.

Note that an inert gas such as N ₂ may be used in the reaction because it is effective in suppressing by-products and catalyst deactivation.
The contact temperature (reaction temperature) is preferably from 200 to 700 ° C, more preferably from 350 to 450 ° C, in view of the reaction activity and the selectivity of 1243yf.
In addition, after preheating 253bb which is a raw material, you may provide for reaction. The preheating temperature is preferably 80 to 400 ° C. from the viewpoint of efficiently vaporizing the raw material.
The contact time (reaction time) is preferably from 0.5 to 1000 seconds, more preferably from 1 to 100 seconds, from the viewpoint of the reaction rate and the conversion.

Next, 1243yf is reacted with chlorine to obtain 1,2-dichloro-2,3,3-trifluoropropane (CHF ₂ -CCIF-CH ₂ Cl. 243ba) (see scheme below).

  The reaction between 1243yf and chlorine may be either a liquid phase reaction or a gas phase reaction. Note that the liquid phase reaction refers to reacting 1243yf in a liquid state with chlorine. In addition, the gas phase reaction refers to a reaction between 1243yf in a gaseous state and chlorine.

  In the above reaction (liquid phase reaction, gas phase reaction), the molar ratio of chlorine used to 1243yf used (molar amount of chlorine / molar amount of 1243yf) depends on the reaction yield and the selectivity of 243ba. 0.1-10 are preferable, and 0.5-5 are more preferable.

The above reaction may be performed under light irradiation, if necessary.
A specific example of light at the time of light irradiation includes visible light. The visible light is light having a short wavelength limit of 360 to 400 nm and a long wavelength limit of 760 to 830 nm. The wavelength of light used for irradiation is preferably from 400 to 750 nm, more preferably from 420 to 730 nm.
Specific examples of the light source that emits the light include a fluorescent lamp, an incandescent lamp, and an LED light. Light having a wavelength of less than 400 nm included in light obtained from a fluorescent lamp or an incandescent lamp may be removed using a filter.
The above reaction may be carried out in the presence of a solvent, if necessary. Examples of the solvent include carbon tetrachloride, 1,1,2-trichloro-1,2,2-trifluoroethane (R113), CF ₃ (CF ₂ ) _n CF ₃ (where n is 3 to 6) A perhalo compound such as a linear perfluoroalkyl compound having 5 to 8 carbon atoms and hexachloroacetone represented by the following formula:

As a method for irradiating light, any method can be used as long as the reaction system can be irradiated with light.
The reaction temperature is preferably −20 to 50 ° C., and more preferably −10 to 30 ° C., in view of the reaction yield and the selectivity of 243 ba.
The reaction time is preferably 0.5 to 50 hours, more preferably 1 to 10 hours, from the viewpoint of the reaction yield and the production efficiency.

Then, 243ba is subjected to a dehydrochlorination reaction to obtain 1-chloro-2,3,3-trifluoropropene (CHF ₂ -CF = CHCl.1233yd) (see the scheme below).

  The 243ba dehydrochlorination reaction may be either a liquid phase reaction or a gas phase reaction. Note that the liquid phase reaction means that 243ba in a liquid state is subjected to a dehydrochlorination reaction. In addition, the gas phase reaction means that a gaseous 243ba is subjected to a dehydrochlorination reaction.

  As the procedure of the dehydrochlorination reaction of 243ba, the procedure of the dehydrochlorination reaction of 253bb described above can be mentioned. Specifically, as the procedure of the 243 ba dehydrochlorination reaction, a procedure in which 253 ba is replaced by 243 ba in the description of the 253 bb dehydrochlorination reaction described above may be used.

The above procedure gives 1233yd as a product. As described above, the obtained 1233yd may be 1233yd (Z) alone, may be 1233yd (E) alone, or may be a mixture of 1233yd (Z) and 1233yd (E).
When the obtained 1233yd is a mixture of 1233yd (Z) and 1233yd (E), the ratio of the mass of 1233yd (Z) to the mass of 1233yd (E) (1233yd (Z) / 1233yd (E)) is 2 The above is preferable, 5 or more is more preferable, 10 or more is more preferable, and 15 or more is particularly preferable. The upper limit of the above ratio is usually 100.
Since 1233yd (Z) has higher chemical stability than 1233yd (E), if the mass ratio of 1233yd (Z) (1233yd (Z) / 1233yd (E)) is equal to or more than the above lower limit, various applications ( For example, it is easy to use in a cleaning agent, a refrigerant, a heat medium, a foaming agent, and a solvent.

The obtained product may contain impurities in addition to the target product of 1233yd.
Specific examples of impurities include 1-chloro-3,3-difluoropropyne generated by further dehydrofluorination of unreacted 243ba and 1233yd, and 1,2-dichloroproduced by dehydrofluorination of 243ba. -3,3-difluoropropene.
From the viewpoint of purification efficiency, the content of 1,2-dichloro-3,3-difluoropropene in the product is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the product. The lower limit of the content is usually 0.

When impurities are included in the product, a process of separating 1233yd from the obtained product may be performed. More specifically, a process of distilling the obtained product to obtain a fraction containing 1233yd as a main component may be performed. Here, “mainly containing 1233yd” means that the mass of 1233yd is the largest in the fraction, and the content of 1233yd is preferably 90% by mass or more based on the total mass of the fraction, and 95% by mass or more. % Is more preferred.
Since the difference in boiling point between 1233yd and 243ba as a raw material is as large as 40 to 50 ° C, 1233yd and 243ba can be easily separated by distillation. On the other hand, in the method of obtaining 1233yd 3-chloro-1,1,2,2-tetrafluoro-propane according _{(CHF 2 CF 2 CH 2 Cl.HCFC} -244ca) as a raw material in Patent Document 1, 244Ca and 1233yd Is very small, and when unreacted 244ca remains in the product, it is difficult to separate them.
The unreacted 243ba can be reused as a raw material again. At that time, the crude liquid after separating 1233yd from the product may be used as it is, or unreacted 243ba may be purified from the crude liquid and used.

In the distillation operation, a distillation apparatus such as a packed column or a tray column can be used. In order to efficiently purify and recover the target compound 1233yd from a plurality of impurities, for example, multi-stage distillation is preferable. When using multi-stage distillation, the number of theoretical stages is preferably 30 or more.
The temperature at the time of the distillation operation (for example, the temperature of the distillation still) is preferably 80 ° C or less, more preferably 70 ° C or less, from the viewpoint of energy cost. The temperature during the distillation operation is preferably 48 ° C. or higher, which is the boiling point of 1233 yd (E).

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

(Conditions for gas chromatography)
In the production of the following various compounds, the composition of the obtained product was analyzed using a gas chromatograph (GC). The column used was DB-1301 (length 60 m × inner diameter 250 μm × thickness 1 μm, manufactured by Agilent Technologies).

(Example 1: Method for synthesizing 1242xf from 1,2-dichloro-3,3-difluoropropene)
A U-shaped reaction tube made of Inconel 600 having an inner diameter of 1/2 inch and a length of 100 cm was filled with a catalyst (50 mL) in which 0.5% by mass of palladium was supported on coconut shell activated carbon as a catalyst, and nitrogen gas was used. (150 NmL / min), and the temperature was raised to 200 ° C. While maintaining the inside of the reaction tube at atmospheric pressure, the catalyst was dried until the moisture in the crude gas after passing through the reaction tube became 20 ppm or less. After completion drying of the catalyst, the reaction tube was heated to 200 ° C., and 1,2-dichloro-3,3-difluoro-propene obtained by gasification _{(CHF 2 -CCl = CHCl.1232xd) (} 62.0NmL / min), Hydrogen (62.0 NmL / min) and nitrogen (124.0 NmL / min) were supplied and reacted under atmospheric pressure. The reaction crude gas was passed through a 10% by mass aqueous sodium hydroxide solution. After a lapse of 3 hours, the organic layer separated in a 10% by mass aqueous solution of potassium hydroxide was recovered, and the result of analyzing the recovered organic layer using gas chromatography is shown in Table 1.

In Table _1, H 2 / _1232xd [molar ratio] is for the amount of 1232Xd, represents the molar ratio of the amount of hydrogen.
The 1232xd conversion represents the ratio (unit:%) of the molar amount of the raw material consumed in the reaction to the molar amount of the raw material (1232xd) used in the reaction.
The 1242xf selectivity indicates the ratio (unit:%) of the amount (molar amount) of 1242xf in the product to the molar amount of the raw materials consumed in the reaction.
The 1252xf selectivity represents the ratio (unit:%) of the amount (molar amount) of 1252xf (CHF ₂ CH = CH ₂ ) in the product to the molar amount of the raw materials consumed in the reaction.
The 262db selectivity represents a ratio (unit:%) of a production amount (molar amount) of 262db (CHF ₂ CHClCH ₃ ) in a product to a molar amount of a raw material consumed in the reaction.
The 272fb selectivity represents the ratio (unit:%) of the amount (molar amount) of 272fb (CHF ₂ CH ₂ CH ₃ ) in the product to the molar amount of the raw materials consumed in the reaction.
The other selectivity is a ratio (unit:%) of a production amount (molar amount) of components other than the above-mentioned components (1242xf, 1252zf, 262db, 272fb) in the product with respect to a molar amount of the raw material consumed in the reaction. Represents

(Example 2: Method of synthesizing 253bb from 1242xf)
A Hastelloy-made autoclave having an internal volume of 200 mL equipped with a stirrer was charged with 1242xf (30.1 g) obtained in Example 1 and antimony pentachloride (5.53 g), and cooled in a liquid nitrogen bath. Next, after introducing 67.9 g of hydrogen fluoride into the autoclave under reduced pressure, the internal temperature was kept at 50 to 60 ° C., and the mixture was stirred at an internal pressure of 0.5 MPa for 5 hours. After the completion of the reaction, the internal temperature of the autoclave was returned to room temperature, and then the valve at the gas phase outlet was opened to take out the crude gas produced by the reaction, and this was flowed through a 10% by mass aqueous solution of potassium hydroxide. Thereafter, the organic layer separated in a 10% by mass aqueous solution of potassium hydroxide was collected, and the result of analyzing the collected organic layer using a gas chromatograph is shown in Table 2.

In Table 2, HF / 1240xf [molar ratio] represents the molar ratio of the amount of hydrogen fluoride used to the amount of 1242xf used.
SbCl ₅ / 1242xf [molar ratio] is for the amount of 1242Xf, represents the molar ratio of the amount of SbCl _5.
The conversion rate of 1242xf indicates the ratio (unit:%) of the molar amount of the raw material consumed in the reaction to the molar amount of the raw material (1242xf) used in the reaction.
The 253bb selectivity indicates the ratio (unit:%) of the amount (molar amount) of 253bb in the product to the molar amount of the raw materials consumed in the reaction.
The 254cb selectivity indicates the ratio (unit:%) of the amount (molar amount) of 254cb (CHF ₂ CF ₂ CH ₃ ) in the product to the molar amount of the raw materials consumed in the reaction.
The 252ab selectivity represents the ratio (unit:%) of the amount (molar amount) of 252ab (CHF ₂ CCl ₂ CH ₃ ) in the product to the molar amount of the raw materials consumed in the reaction.
251Ab selectivity, the ratio of the amount of relative molar amounts of raw materials consumed in the reaction, 251Ab in the product (CHClFCCl ₂ CH ₃₎ (molar amount) (Unit:%) represents the.
The 250ab selectivity indicates the ratio (unit:%) of the amount (molar amount) of 250ab (CHCl ₂ CCl ₂ CH ₃ ) in the product to the molar amount of the raw materials consumed in the reaction.
The other selectivity is a ratio (unit: unit) of the amount of production (molar amount) of other components other than the above-mentioned components (253b, 254cb, 252ab, 251ab, 250ab) to the molar amount of the raw material consumed in the reaction. %).

(Example 3: Method of synthesizing 1243yf from 253bb)
A gas phase reaction vessel made of Inconel 600 having an inner diameter of 1/4 inch and a length of 60 cm was charged with a crushed activated carbon catalyst (16 mL) as a catalyst, and the temperature was raised to 400 ° C. while flowing a nitrogen gas (40 NmL / min). While maintaining the inside of the gas phase reactor at atmospheric pressure, the catalyst was dried until the moisture in the crude gas after passing through the gas phase reactor became 20 ppm or less. After drying of the catalyst was completed, the reactor was heated to 400 ° C., and 253 bb (45.1 mg / min) obtained in Example 2 was supplied through a preheater maintained at 80 ° C.
253bb supplied to the gas phase reactor is dehydrochlorinated by contacting with an activated carbon catalyst under the condition of a reaction temperature of 400 ° C. while passing through the gas phase reactor (passing time: 1 second) to become 1243yf, The reaction product crude gas containing this 1243yf was recovered from the outlet of the gas phase reactor. Table 3 shows the results of analyzing the collected reaction product crude gas using a gas chromatograph.

In Table 3, the conversion rate of 253bb indicates the ratio (unit:%) of the molar amount of the raw material consumed in the reaction to the molar amount of the raw material (253bb) used in the reaction.
The 1243yf selectivity indicates the ratio (unit:%) of the amount (molar amount) of 1243yf produced in the product to the molar amount of the raw materials consumed in the reaction.
The other selectivity indicates the ratio (unit:%) of the amount (molar amount) of other components other than the above-mentioned component (1243yf) in the product to the molar amount of the raw materials consumed in the reaction.

(Example 4: Method of synthesizing 1243yf from 253bb)
A 253 bb (29.7 g) obtained in Example 3, TBAC (0.891 g), and a 25% aqueous solution of potassium hydroxide (KOH) (101.) were placed in a Hastelloy autoclave having an internal volume of 200 mL equipped with a stirrer and a condenser. 6g), the reaction temperature was maintained at 65 ° C. to 70 ° C., and the mixture was stirred for 14 hours, whereupon the internal pressure became 1.1 MPa. The product was extracted from the upper part of the condenser, dried by passing through a molecular sieve 3A, and the organic matter collected in a SUS304 cylinder cooled to -78 ° C was analyzed using a gas chromatograph. The results are shown in Table 4.

In Table 4, TBAC / 253bb [mass ratio] indicates the mass ratio of the used amount of TBAC to the used amount of 253bb.
KOH / 253bb [molar ratio] represents the molar ratio of the used amount of KOH to the used amount of 253bb.
The 253bb conversion represents the ratio (unit:%) of the molar amount of the raw material consumed in the reaction to the molar amount of the raw material (253bb) used in the reaction.
The 1243yf selectivity indicates the ratio (unit:%) of the amount (molar amount) of 1243yf produced in the product to the molar amount of the raw materials consumed in the reaction.
The 1242xf selectivity indicates the ratio (unit:%) of the amount (molar amount) of 1242xf in the product to the molar amount of the raw materials consumed in the reaction.
The other selectivity indicates the ratio (unit:%) of the amount (molar amount) of other components other than the above components (1243yf, 1242xf) in the product to the molar amount of the raw materials consumed in the reaction.

(Example 5: Method of synthesizing 243ba from 1243yf)
A 1-L glass flask was charged into a reactor with CCl ₄ (107 g) as a solvent, and cooled to 0 ° C. While irradiating visible light from an LED lamp (Mitsubishi Electric, bulb type: LHT15D-G-E39, output 15W), 1243yf (20.0 g / min) and chlorine gas (Cl ₂ ) (10.7 g / min) was fed into the reactor. The reaction was continued for 5 hours. After confirming that 100 g of 1243yf and 53.5 g of chlorine gas were supplied, the supply of 1243yf and chlorine gas was stopped.
After completion of the reaction, the obtained reaction solution was neutralized with a 20% by mass aqueous solution of sodium hydrogen carbonate, and then a liquid separation operation was performed. After standing, the organic matter containing 243ba recovered from the separated lower layer was analyzed using a gas chromatograph, and the results are shown in Table 5.

In Table 5, Cl ₂ / 1243yf [molar ratio] indicates the molar ratio of the amount of chlorine gas used to the amount of 1243yf used.
The 1243yf conversion rate represents the ratio (unit:%) of the molar amount of the raw material consumed in the reaction to the molar amount of the raw material (1243yf) used in the reaction.
The 243ba selectivity represents the ratio (unit:%) of the amount (molar amount) of 243ba in the product to the molar amount of the raw materials consumed in the reaction.
The other selectivity represents the ratio (unit:%) of the amount (molar amount) of other components other than the above-mentioned component (243ba) in the product to the molar amount of the raw materials consumed in the reaction.

(Example 6: Method of synthesizing 1233yd from 243ba)
In a 0.5-liter four-necked flask equipped with a stirrer and a Dimroth condenser, 243 ba (101.2 g) and TBAC (1.01 g) were added as raw materials, and the flask was heated to 50 ° C. The reaction temperature was maintained at 50 ° C., and a 40% by mass aqueous KOH solution (127.5 g) was added dropwise over 30 minutes. Thereafter, stirring was continued for 1 hour, and the organic layer was recovered. The reaction time is the total time of the time required for the dropping and the stirring time after the dropping, that is, 1.5 hours.
After the collected organic layer was washed with water, the result of analysis using a gas chromatograph is shown in Table 6.

In Table 6, TBAC / 243ba [mass ratio] indicates the mass ratio of the used amount of TBAC to the used amount of 243ba.
KOH / 243ba [molar ratio] represents the molar ratio of the used molar amount of KOH to the used molar amount of 243ba.
The 243ba conversion represents the ratio (unit:%) of the molar amount of the raw material consumed in the reaction to the molar amount of the raw material (243ba) used in the reaction.
The 1233yd (Z) selectivity represents the ratio (unit:%) of the amount (molar amount) of 1233yd (Z) in the product to the molar amount of the raw materials consumed in the reaction.
The 1233yd (E) selectivity represents the ratio (unit:%) of the amount (molar amount) of 1233yd (E) in the product to the molar amount of the raw materials consumed in the reaction.
The 1-chloro-3,3-difluoropropyne selectivity is the ratio of the amount (molar amount) of 1-chloro-3,3-difluoropropyne formed in the product to the molar amount of the raw materials consumed in the reaction. (Unit:%).
The other selectivity is based on the molar amount of the raw materials consumed in the reaction and other components other than the above components (1233yd (Z), 1233yd (E), 1-chloro-3,3-difluoropropyne) in the product. Represents the ratio (unit:%) of the generation amount (molar amount) of.

Claims (7)

A method for producing 2-chloro-3,3-difluoropropene, wherein a compound represented by formula (1) is subjected to a hydrogen reduction reaction to produce 2-chloro-3,3-difluoropropene.
Formula (1) CHF ₂ -CCl = CClX
X represents a hydrogen atom or a chlorine atom.   The production method according to claim 1, wherein the reaction is performed in the presence of a catalyst.   The method according to claim 1, wherein the reaction is performed under a condition of 50 ° C. or higher.   A reaction between 2-chloro-3,3-difluoropropene and hydrogen fluoride produced by the production method according to any one of claims 1 to 3, to give 2-chloro-1,1,2-. A method for producing 2-chloro-1,1,2-trifluoropropane, which comprises obtaining trifluoropropane.   The 2-chloro-1,1,2-trifluoropropane produced by the production method according to claim 4 is subjected to a dehydrochlorination reaction to obtain 2,3,3-trifluoropropene. A method for producing 2,3,3-trifluoropropene.   A reaction between 2,3,3-trifluoropropene produced by the production method according to claim 5 and chlorine to obtain 1,2-dichloro-2,3,3-trifluoropropane. A method for producing 1,2-dichloro-2,3,3-trifluoropropane.   The 1,2-dichloro-2,3,3-trifluoropropane produced by the production method according to claim 6 is subjected to a dehydrochlorination reaction to obtain 1-chloro-2,3,3-trifluoropropene. A method for producing 1-chloro-2,3,3-trifluoropropene, comprising: