JP7722382B2 - Hydrochlorofluorocarbon manufacturing method - Google Patents

Description

The present invention relates to a method for producing hydrochlorofluorocarbons.

Hydrochlorofluorocarbons (hereinafter referred to as HCFCs) are used as new cleaning agents, refrigerants, blowing agents, and aerosols, or as raw materials for their synthesis. For example, HCFCs are sometimes used as raw materials for the synthesis of hydrochlorofluoroolefins (hereinafter referred to as HCFOs). Specifically, Patent Document 1 describes that 3-chloro-1,1,2,2-tetrafluoropropane (HCFC-244ca, hereinafter referred to as 244ca) is used as a raw material for the synthesis of 1-chloro-2,3,3-trifluoropropene (HCFO-1233yd, hereinafter referred to as 1233yd). Furthermore, Patent Document 2 describes that 5-chloro-1,1,2,2,3,3,4,4-octafluoropentane (HCFC-448occc, hereinafter also referred to as 448occc) is used as a synthetic raw material for producing 1-chloro-2,3,3,4,4,5,5-heptafluoropentene (HCFO-1437dycc, hereinafter also referred to as 1437dycc).

International Publication No. 2018/131394 International Publication No. 2019/124220

HCFCs can be obtained by reacting a fluorine-containing alcohol with a chlorinating agent. However, in the HCFC production methods described in the prior art documents, a by-product is produced in addition to the target HCFC, such as a compound in which two molecules of a fluorine-containing alcohol are added to the chlorinating agent (hereinafter also referred to as a fluorine-containing alcohol diadduct). Therefore, a process for converting such by-products into HCFCs after chlorination is required.
The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for producing HCFCs in high yield and high purity while producing a small amount of by-products.

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.
(1) A method for producing a hydrochlorofluorocarbon, comprising reacting a fluorine-containing alcohol with a chlorinating agent in the presence of a catalyst to substitute a hydroxyl group of the fluorine-containing alcohol with a chlorine atom,
the catalyst is a phosphine oxide;
A method for producing a hydrochlorofluorocarbon, characterized in that the chlorinating agent used is at least one chlorinating agent selected from the group consisting of thionyl chloride, oxalyl chloride and phosgene.
(2) The method according to (1), wherein the fluorine-containing alcohol is a compound represented by the following formula (1):
X-R ^f -CH ₂ OH (1)
(In the formula, X represents a hydrogen atom or a fluorine atom, and ^Rf represents a fluoroalkylene group having one or more carbon atoms.)
(3) The method according to (1) or (2), wherein the fluorine-containing alcohol is 2,2,3,3-tetrafluoropropanol or 2,2,3,3,4,4,5,5-octafluoropentanol.
(4) The method according to any one of (1) to (3), wherein the phosphine oxide is a compound represented by the following formula (2):
(In the formula, R ¹ , R ² , and R ³ each independently represent a monovalent hydrocarbon group which may have a substituent, or a monovalent nitrogen-containing heterocyclic group which may have a substituent (provided that a carbon atom constituting the ring is bonded to the phosphorus atom).)
(5) The production method according to (4), wherein R ¹ to R ³ are all phenyl groups, R ¹ and R ² are phenyl groups and R ³ is a pyridyl group, R ¹ to R ³ are all 4-fluorophenyl groups, or R ¹ to R ³ are all 2-tolyl groups.
(6) The production method according to any one of (1) to (5), wherein the chlorinating agent is thionyl chloride or oxalyl chloride.
(7) The method according to any one of (1) to (6), wherein the reaction does not involve any alcohol other than the fluorine-containing alcohol.
(8) The production method according to any one of (1) to (7), wherein the content of the fluorine-containing alcohol diadduct contained in the reaction solution obtained by the reaction is 10 mass% or less based on the total amount of the reaction solution.
(9) The method according to any one of (1) to (8), wherein the reaction temperature is 0 to 150°C.
(10) The method according to any one of (1) to (9), wherein the reaction time is 2 to 8 hours.
(11) The method according to any one of (1) to (10), wherein the fluorine-containing alcohol is reacted at a molar ratio of the chlorinating agent to the fluorine-containing alcohol (chlorinating agent/fluorine-containing alcohol) of 0.01 to 100.
(12) The method according to any one of (1) to (11), wherein the phosphine oxide is reacted with the fluorine-containing alcohol at a molar ratio of 0.0001 to 10 (phosphine oxide/fluorine-containing alcohol).
(13) A method for producing a hydrochlorofluoroolefin, which comprises subjecting a hydrochlorofluorocarbon obtained by the production method according to any one of (1) to (12) above to a dehydrofluorination reaction in the presence of a base and/or a catalyst.
(14) The production method according to (13), wherein the hydrochlorofluorocarbon is 3-chloro-1,1,2,2-tetrafluoropropane or 5-chloro-1,1,2,2,3,3,4,4-octafluoropentane.
(15) The production method according to (13) or (14), wherein the hydrochlorofluoroolefin is 1-chloro-2,3,3-trifluoropropene or 1-chloro-2,3,3,4,4,5,5-heptafluoropentene.

The present invention provides a method for producing HCFCs with high yield and purity, while producing little by-products.

The method for producing an HCFC of the present invention (hereinafter also referred to simply as "the production method of the present invention") is characterized by using a phosphine oxide as a catalyst and reacting a fluorine-containing alcohol with a specific chlorinating agent in the presence of the phosphine oxide. The reaction between the fluorine-containing alcohol and the specific chlorinating agent substitutes hydroxyl groups of the fluorine-containing alcohol with chlorine atoms to produce an HCFC.
In the production method of the present invention, the amount of by-products produced is small, and HCFCs can be produced in high yield and with high purity.
In the following, first, the components used in the production method of the present invention will be described in detail, and then the procedure of the production method will be described in detail.

(Fluorine-containing alcohol)
In the production method of the present invention, a fluorine-containing alcohol is used as a raw material. The fluorine-containing alcohol raw material may be a mixture of two or more kinds of fluorine-containing alcohols. In other words, the production method of the present invention is industrially advantageous because it allows simultaneous production of two or more kinds of HCFCs.

The fluorine-containing alcohol used in the production method of the present invention is not particularly limited, but from the viewpoint of reactivity, it is preferably a primary alcohol, that is, a compound represented by the following formula (1).
X-R ^f -CH ₂ OH (1)
(In the formula, X represents a hydrogen atom or a fluorine atom, and ^Rf represents a fluoroalkylene group having one or more carbon atoms.)
The number of carbon atoms in ^Rf is preferably 1 to 7, more preferably 1 to 5, still more preferably 1 to 4, and particularly preferably 2 to 4. ^Rf may contain a hydrogen atom, but is preferably a perfluoroalkylene group, and particularly preferably a linear perfluoroalkylene group.

Examples of the fluorine-containing alcohol include 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoropropanol (hereinafter also referred to as TFPO), 2,2,3,3,3-pentafluoropropanol, 2,2,3,3,4,4,4-heptafluorobutanol, 2,2,3,4,4,4-hexafluorobutanol, 2,2,3,3,4,4,5,5-octafluoropentanol (hereinafter also referred to as OFPO), 3,3,4,4,5,5,6,6,6-nonafluorohexanol, and 4,4,5,5,6,6,7,7,7-nonafluoroheptanol.
The fluorine-containing alcohol is preferably 2,2,2-trifluoroethanol, TFPO, 2,2,3,3,3-pentafluoropropanol, 2,2,3,3,4,4,4-heptafluorobutanol, 2,2,3,4,4,4-hexafluorobutanol, OFPO, or 3,3,4,4,5,5,6,6,6-nonafluorohexanol, more preferably TFPO, 2,2,3,3,3-pentafluoropropanol, 2,2,3,3,4,4,4-heptafluorobutanol, 2,2,3,4,4,4-hexafluorobutanol, or OFPO, and particularly preferably TFPO or OFPO.

When a fluorine-containing alcohol is used, it may be a mixture with other compounds. In other words, the raw materials for the manufacturing method of the present invention need only contain a fluorine-containing alcohol. For example, a mixture of a fluorine-containing alcohol and other compounds may be used as the raw material.

Other compounds contained in the raw materials used in the production method of the present invention include impurities such as raw materials for producing fluorinated alcohols and by-products other than fluorinated alcohols produced during the production of fluorinated alcohols. If the raw materials contain such impurities, the by-products produced from the impurities may be removed by known means such as distillation, extractive distillation, azeotropic distillation, membrane separation, two-phase separation, or adsorption. It is preferable that the impurities are compounds that are inactive in the production method of the present invention.

The raw material preferably contains a fluorinated alcohol as the main component. Based on the total mass of the raw material, the content of the fluorinated alcohol is preferably 50% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The upper limit can be 100% by mass.

Furthermore, in order to increase the selectivity of HCFCs in the reaction between a fluorinated alcohol and a specific chlorinating agent, it is preferable that no alcohol other than the fluorinated alcohol is contained. The amount of alcohol other than the fluorinated alcohol is preferably 1,000 ppm by mass or less, more preferably 500 ppm by mass or less, and even more preferably 100 ppm by mass or less, based on the total amount of the fluorinated alcohol.

(Chlorinating agent)
The chlorinating agent used in the production method of the present invention is at least one chlorinating agent selected from the group consisting of thionyl chloride, oxalyl chloride and phosgene, in view of reactivity with the catalyst described below.
As these chlorinating agents, a mixture of two or more thereof may be used.
As the chlorinating agent, thionyl chloride and oxalyl chloride are preferred because they allow for more efficient production of HCFCs.

In the production method of the present invention, the molar ratio of the chlorinating agent used to the fluorinated alcohol used (molar amount of chlorinating agent/molar amount of fluorinated alcohol) is preferably 0.01 to 100, more preferably 0.05 to 50, even more preferably 0.1 to 10, and particularly preferably 0.5 to 5, in order to produce HCFCs more efficiently. Within the above ranges, the production of by-products is suppressed and the volumetric efficiency of the reactor is improved.

(catalyst)
The phosphine oxide used as the catalyst in the production method of the present invention is preferably a phosphine oxide compound represented by the following formula (2):

In formula (2), R ¹ , R ² , and R ³ each independently represent a monovalent hydrocarbon group which may have a substituent, or a monovalent nitrogen-containing heterocyclic group which may have a substituent (provided that a carbon atom constituting the ring is bonded to a phosphorus atom).

Examples of the monovalent hydrocarbon group include monovalent aliphatic hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, monovalent alicyclic hydrocarbon groups such as cycloalkyl groups and cycloalkenyl groups, and aryl groups such as phenyl groups. The number of carbon atoms in the monovalent hydrocarbon group, excluding substituents, is preferably 8 or less, and more preferably 6 or less.
Examples of the substituent that the monovalent aliphatic hydrocarbon group may have include a monovalent alicyclic hydrocarbon group, an aryl group, a monovalent heterocyclic group, a halogen atom such as a fluorine atom, an alkoxy group, etc. Examples of the substituent that the monovalent alicyclic hydrocarbon group may have include a monovalent alicyclic hydrocarbon group, an aryl group, a monovalent heterocyclic group, a halogen atom such as a fluorine atom, an alkoxy group, etc. Examples of the substituent that the aryl group may have include a monovalent alicyclic hydrocarbon group, a monovalent heterocyclic group, a halogen atom such as a fluorine atom, an alkoxy group, etc.
Examples of the monovalent nitrogen-containing heterocyclic group include heterocyclic groups having 1 or 2 nitrogen atoms, such as a pyridyl group and an imidazolyl group. Examples of the substituent that the monovalent nitrogen-containing heterocyclic group may have include a monovalent alicyclic hydrocarbon group, an aryl group, and a halogen atom such as a fluorine atom.

In the production method of the present invention, from the viewpoint of more efficient production of HCFCs, R ¹ , R ² , and R ³ are each preferably independently a phenyl group, a pyridyl group, a 4-fluorophenyl group, a 2-tolyl group, a methyl group, a butyl group, or a 3-methylcyclopentenyl group, more preferably a phenyl group, a pyridyl group, a 4-fluorophenyl group, or a 2-tolyl group, even more preferably a phenyl group, a pyridyl group, or a 4-fluorophenyl group, and particularly preferably a phenyl group.

Specifically, it is preferred that R ¹ to R ³ are all phenyl groups, that R ¹ and R ² are phenyl groups and R ³ is a pyridyl group, that R ¹ to R ³ are all 4-fluorophenyl groups, or that R ¹ to R ³ are all 2-tolyl groups; it is more preferred that R ¹ to R ³ are all phenyl groups, that R ¹ and R ² are phenyl groups and R ³ is a pyridyl group, or that R ¹ to R ³ are all 4-fluorophenyl groups, and it is particularly preferred that R ¹ to R ³ are all phenyl groups.

In the production method of the present invention, the molar ratio of the phosphine oxide used to the fluorinated alcohol used (molar amount of phosphine oxide/molar amount of fluorinated alcohol) is preferably 0.0001 to 10, more preferably 0.001 to 5, even more preferably 0.01 to 1, and particularly preferably 0.1 to 0.5, in order to obtain a sufficient reaction rate.

In the production method of the present invention, it is preferable to use phosphine oxide dissolved in a reaction component or an inert solvent. To reduce waste liquid, it is preferable to use phosphine oxide dissolved in a fluorinated alcohol or a chlorinating agent.

(Manufacturing method)
In the production method of the present invention, a fluorine-containing alcohol is contacted with a chlorinating agent in the presence of phosphine oxide using a reactor.

The reactor is not particularly limited in shape or structure, as long as it can be used to introduce and react the fluorine-containing alcohol and chlorinating agent. Examples of such a reactor include glass reactors, SUS reactors, glass-lined reactors, and resin-lined reactors. The temperature adjustment unit can be used to adjust the reaction temperature between the fluorine-containing alcohol and chlorinating agent. Examples of such a unit include an oil bath. The temperature adjustment unit may be integrally provided in the reactor.

The production method of the present invention can be carried out as either a gas phase reaction or a liquid phase reaction, but is preferably carried out as a liquid phase reaction because it is more advantageous for industrial implementation. Carrying out a liquid phase reaction means reacting a fluorine-containing alcohol and a chlorinating agent in the presence of phosphine oxide, each in a liquid state.

A specific procedure for the gas phase reaction is to supply a fluorine-containing alcohol and a chlorinating agent, which are raw materials heated to a gaseous state, into a reactor, and bring the phosphine oxide filled in the reactor into contact with the gaseous fluorine-containing alcohol and chlorinating agent to obtain an HCFC.
A gas inert to the reaction (dilution gas) may be supplied to the reactor because it is effective in adjusting the flow rate, suppressing by-products, suppressing catalyst deactivation, etc. Specific examples of the dilution gas include nitrogen, carbon dioxide, helium, and argon.

Specific procedures for the liquid-phase reaction include dissolving phosphine oxide in a fluorine-containing alcohol or a chlorinating agent in advance, and then contacting the liquid fluorine-containing alcohol with the liquid chlorinating agent using means such as stirring to obtain an HCFC. It is preferable to dissolve phosphine oxide in a chlorinating agent, and then contacting the liquid fluorine-containing alcohol with the liquid chlorinating agent using means such as stirring.

The liquid fluorine-containing alcohol, the catalyst, and the chlorinating agent may be added to the reactor simultaneously, and the reactor may be heated after the addition, or the reactor containing the catalyst and the chlorinating agent may be heated and then the fluorine-containing alcohol may be added. In order to control the sulfur dioxide gas and hydrogen chloride gas generated at the start of the reaction, it is preferable to control the addition rate.
Of these, the latter liquid phase reaction is preferred from the viewpoints of reaction temperature, reaction time, reaction yield, and HCFC selectivity. Furthermore, when the production method of the present invention is carried out by a liquid phase reaction, it is preferred from the viewpoint that a reactor of a smaller size can be used compared to a gas phase reaction.

The reaction temperature (temperature inside the reactor) in the production method of the present invention is preferably 0 to 150°C, more preferably 10 to 125°C, and even more preferably 20 to 100°C, from the viewpoint of more efficient production of HCFC. If the reaction temperature does not reach the above range, the reaction rate and reaction yield may decrease, and an excessive amount of unreacted fluorine-containing alcohol may remain, which tends to reduce the conversion rate of the fluorine-containing alcohol. On the other hand, if the reaction temperature exceeds the above range, an excessive amount of fluorine-containing alcohol diadduct is produced, which tends to reduce the selectivity to HCFC.
The temperature inside the reactor can be controlled by adjusting the temperature and pressure of the raw materials supplied to the reactor. If necessary, the inside of the reactor can be supplementarily heated by an electric heater, a microwave generator, or the like.

The production method of the present invention may be carried out batchwise or continuously. When carried out batchwise, a predetermined amount of either the fluorine-containing alcohol or the chlorinating agent is placed in a reactor as a feed material, and the other is gradually added to the feed material in the reactor. For example, a predetermined amount of the chlorinating agent is placed in a reactor as a feed material, and the fluorine-containing alcohol is gradually added to the chlorinating agent. Alternatively, a predetermined amount of the fluorine-containing alcohol is placed in a reactor as a feed material, and the chlorinating agent is gradually added to the fluorine-containing alcohol. In this case, it is preferable to premix the phosphine oxide with the fluorine-containing alcohol or the chlorinating agent. The entire predetermined amount of phosphine oxide may be mixed with either the fluorine-containing alcohol or the chlorinating agent. Alternatively, a predetermined amount of phosphine oxide may be divided and mixed with the fluorine-containing alcohol and the chlorinating agent.

When carried out continuously, the fluorine-containing alcohol, chlorinating agent, and phosphine oxide are continuously fed into a reactor at a predetermined molar ratio and at a predetermined feed rate, and are allowed to contact each other in the reactor for a predetermined period of time. In this case, it is preferable from the standpoint of operational efficiency to premix the phosphine oxide with the fluorine-containing alcohol or chlorinating agent before feeding it into the reactor. When the production method of the present invention is carried out continuously, the feed rates of the fluorine-containing alcohol, chlorinating agent, and phosphine oxide to the reactor are adjusted based on the feed flow rates of each compound and the sulfur dioxide gas or hydrogen chloride gas generated during the reaction.

The reaction time in the production method of the present invention varies depending on the amounts of phosphine oxide, fluorine-containing alcohol, and chlorinating agent, but is, for example, 2 to 8 hours. The reaction time in the production method of the present invention is expressed as the contact time between the fluorine-containing alcohol and the chlorinating agent. For example, as described above, when the reaction is carried out in a batchwise manner by placing a predetermined amount of either the fluorine-containing alcohol or the chlorinating agent in a reactor as a feed material and gradually adding the other to the feed material in the reactor, the reaction time is the time from the start of feeding either the fluorine-containing alcohol or the chlorinating agent as a feed material to the end of the reaction when the generation of hydrogen chloride gas subsides. When the production method of the present invention is carried out in a continuous manner, the reaction time is the residence time of the fluorine-containing alcohol and the chlorinating agent in the reactor.

When the production method of the present invention is carried out using a liquid-phase reaction, it is preferable to contact the reaction mixture containing HCFC with an aqueous alkaline solution in order to neutralize the hydrogen chloride and sulfur dioxide in the reaction mixture containing HCFC. Examples of aqueous alkaline solutions that can be used in this case include aqueous sodium hydroxide and aqueous potassium hydroxide. After contact with the aqueous alkaline solution, the reaction mixture containing HCFC is allowed to stand and separated into an organic phase and an aqueous phase. Since the HCFC is contained in the organic phase, the HCFC can be obtained by separating and recovering the organic phase.

The obtained liquid of the organic layer may contain, in addition to HCFC, for example, phosphine oxide, the unreacted raw material fluorine-containing alcohol, and a chlorinating agent, and may also contain, as by-products, fluorine-containing alcohol diadducts and by-products derived from fluorine-containing alcohols other than fluorine-containing alcohol diadducts. However, in the production method of the present invention, fluorine-containing alcohol diadducts are usually not contained.
The liquid of the organic layer containing the unreacted raw materials and by-products is preferably separated and purified by ordinary distillation or the like, if necessary, to obtain HCFCs containing less of the unreacted raw materials and by-products.

The reaction liquid obtained after purification, if necessary, preferably contains HCFC as the main component. The HCFC content, based on the total mass of the reaction liquid, is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass. The upper limit can be 100% by mass.

The HCFC obtained by the production method of the present invention may be subjected to a dehydrofluorination reaction to produce an HCFO. Specifically, the HCFC obtained by the production method of the present invention is subjected to a dehydrofluorination reaction in the presence of a base and/or a catalyst to produce an HCFO.
When a fluorine-containing alcohol diadduct is contained in the raw material for producing an HCFO, the fluorine-containing alcohol diadduct may decompose into a fluorine-containing alcohol in the reactor and react with the HCFO product, which may reduce the selectivity for the HCFO.
The content of fluorine-containing alcohol diadducts contained in the reaction liquid containing HCFC obtained by the reaction of a fluorine-containing alcohol with a chlorinating agent is preferably 10 mass % or less, more preferably 5 mass % or less, and particularly preferably 1 mass % or less, based on the total amount of the reaction liquid containing HCFC. Most preferably, the reaction liquid does not contain fluorine-containing alcohol diadducts. The production method of the present invention is preferably applied to the production of HCFO, since it can suppress the production of by-products.

Unless otherwise specified, compound names or abbreviations used throughout this specification refer to at least one selected from the Z and E isomers, and more specifically, refer to the Z or E isomer, or a mixture of the Z and E isomers in any proportion. When (E) or (Z) is added after a compound name or abbreviation, it refers to the (E) or (Z) isomer of the respective compound. For example, 1233yd(Z) refers to the Z isomer, and 1233yd(E) refers to the E isomer.

In the production method of the present invention, when the fluorine-containing alcohol is TFPO, 244ca is obtained.
The reaction liquid contains 244ca as a main component. Components other than 244ca can be removed to the desired extent by known means such as distillation, extractive distillation, azeotropic distillation, membrane separation, two-phase separation, and adsorption.

The resulting 244ca may be subjected to a dehydrofluorination reaction to produce 1233yd.
The procedure for the dehydrofluorination reaction may include known methods such as those described in WO 2016/136744.

The dehydrofluorination reaction of the above-mentioned 244ca may be either a liquid phase reaction or a gas phase reaction. Note that a liquid phase reaction refers to the dehydrofluorination of 244ca in a liquid state or dissolved in a liquid. Furthermore, a gas phase reaction refers to the dehydrofluorination of 244ca in a gaseous state.

In the production method of the present invention, when the fluorine-containing alcohol is OFPO, 448 occc is obtained.
The reaction mixture contains 448occc as a major component. Components other than 448occc can be removed to a desired extent by known means such as distillation, extractive distillation, azeotropic distillation, membrane separation, two-phase separation, or adsorption.

The resulting 448occc may be subjected to a dehydrofluorination reaction to produce 1437dycc. It is particularly preferable to produce 1437dycc(Z).
The procedure for the dehydrofluorination reaction may be a known method such as that described in Zhurnal Organicheskoi Khimii (Russia), 1988, Vol. 24, No. 8, pp. 1626-1633.

The dehydrofluorination reaction of the above-mentioned 448occc may be either a liquid-phase reaction or a gas-phase reaction. A liquid-phase reaction refers to the dehydrofluorination of 448occc in a liquid state or dissolved in a liquid. A gas-phase reaction refers to the dehydrofluorination of 448occc in a gaseous state.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples. Examples 1 to 3, 6, 8, and 9 are examples of the present invention, and Examples 4, 5, and 7 are comparative examples.

(Example 1)
A four-neck flask (reactor) equipped with a stirrer, a glass distillation column (measured plate number: 5) packed with Raschig rings, and a Dimroth condenser was immersed in an oil bath to form a reaction apparatus. Triphenylphosphine oxide (in the above formula (2), R ¹ to R ³ are all phenyl groups) (hereinafter also referred to as Ph ₃ PO) (5.27 g), thionyl chloride (49.5 g), and TFPO (50.0 g) were added, and the temperature of the oil bath was adjusted so that the reaction temperature was 80°C. TFPO was converted to 244ca and simultaneously distilled, yielding a distillate containing 244ca. The reflux time/distillation time ratio (seconds/seconds) was set to 10/1 using a reflux timer.
The distillate was then brought into contact with a 10% by mass aqueous potassium hydroxide solution to neutralize sulfur dioxide gas and other substances in the distillate. The organic phase was recovered from the neutralized distillate and its composition was analyzed. The analysis was carried out using gas chromatography (GC). A DB-1301 column (length 60 m x inner diameter 250 μm x thickness 1 μm, manufactured by Agilent Technologies, Inc.) was used.
The reaction solution remaining in the reactor was analyzed by ¹ H-NMR and ¹⁹ C-NMR (JNM-EC P400, manufactured by JEOL Ltd.). The results are shown in Table 1.

(Example 2)
A four-neck flask (reactor) equipped with a stirrer, a glass distillation column (measured number of plates: 5) packed with Raschig rings, and a Dimroth condenser was immersed in an oil bath to form a reaction apparatus. The reaction was carried out in the same manner as in Example 1, except that OFPO was used as the raw material instead of TFPO. The results are shown in Table 1.

(Example 3)
A four-neck flask (reactor) equipped with a stirrer, a glass distillation column (measured number of plates: 5) packed with Raschig rings, and a Dimroth condenser was immersed in an oil bath to form a reaction apparatus. The reaction was carried out in the same manner as in Example 1, except that oxalyl chloride was used as the chlorinating agent instead of thionyl chloride. The results are shown in Table 1.

(Example 4)
(First step)
A four-neck flask (reactor) equipped with a stirrer, a glass distillation column (measured number of plates: 5) packed with Raschig rings, and a Dimroth condenser was immersed in an oil bath to form a reaction apparatus. Then, thionyl chloride was added to the four-neck flask, and a mixed solution consisting of TFPO and N,N-dimethylformamide (hereinafter also referred to as DMF) was added dropwise to the four-neck flask. During the dropwise addition of the mixed solution, the temperature of the oil bath and the dropwise addition rate of the mixed solution were adjusted so that the reaction temperature (temperature of the liquid phase in the four-neck flask) was 0°C. After the dropwise addition of the mixed solution was completed, stirring was continued until the generation of hydrogen chloride gas subsided, and the reaction product mixture containing 2,2,3,3-tetrafluoropropanesulfonic acid chloride was recovered.

(Second step)
In the same reaction apparatus as in the first step, 40 g of DMF was placed in a four-necked flask, and the four-necked flask was heated to 120 ° C., while the Dimroth condenser was cooled to -20 ° C. The reaction product mixture containing 2,2,3,3-tetrafluoropropanesulfonic acid chloride obtained in the first step was fed thereto at 75 g / hr using a liquid feed pump, and then the reactor (four-necked flask) was cooled to room temperature, and the reaction was terminated. As a result, 2,2,3,3-tetrafluoropropanesulfonic acid chloride was pyrolyzed and distilled at the same time, and a distillate containing 244 ca was obtained. The reflux time / distillation time ratio (seconds / seconds) was set to 5 / 1 using a reflux timer.

The sulfur dioxide gas remaining in the distillate was then neutralized with a 20% by weight aqueous solution of potassium hydroxide. The organic phase was recovered from the neutralized distillate and its composition was analyzed. The results are shown in Table 1.

(Example 5)
(First step)
A four-neck flask (reactor) equipped with a stirrer, a glass distillation column (measured number of plates: 5) packed with Raschig rings, and a Dimroth condenser was immersed in an oil bath to form a reaction apparatus. Then, thionyl chloride was charged into the four-neck flask, and a mixed solution consisting of OFPO and DMF was added dropwise to the four-neck flask. During the dropwise addition of the mixed solution, the temperature of the oil bath and the dropwise addition rate of the mixed solution were adjusted so that the reaction temperature (temperature of the liquid phase in the four-neck flask) was 50°C. After the dropwise addition of the mixed solution was completed, stirring was continued until the generation of hydrogen chloride gas subsided, and the reaction product mixture containing 2,2,3,3,4,4,5,5-octafluoropentanesulfonic acid chloride was recovered.

(Second step)
In the same reaction apparatus as in the first step, 40 g of DMF was placed in a four-neck flask, and the four-neck flask was heated to 130 °C while the Dimroth condenser was cooled to -20 °C. The reaction product mixture containing 2,2,3,3,4,4,5,5-octafluoropentanesulfonic acid chloride obtained in the first step was fed to the flask at a rate of 75 g/hr using a liquid transfer pump. The reactor (four-neck flask) was then cooled to room temperature, and the reaction was terminated. This resulted in the pyrolysis of 2,2,3,3-tetrafluoropropanesulfonic acid chloride and simultaneous distillation, yielding a distillate containing 448 occc. The reflux time/distillation time ratio (seconds/seconds) was set to 5/1 using a reflux timer.

The sulfur dioxide gas remaining in the distillate was then neutralized with a 20% by weight aqueous solution of potassium hydroxide. The organic phase was recovered from the neutralized distillate and its composition was analyzed. The results are shown in Table 1.

In Tables 1 and 2, the conversion rate represents the ratio (%) of the molar amount consumed in the reaction to the amount (molar amount) charged, and the selectivity represents the molar amount consumed in producing each compound relative to the molar amount of raw material consumed. The amount of chlorinating agent (mol/mol) represents the molar ratio of chlorinating agent to fluorine-containing alcohol. The amount of catalyst (mol/mol) represents the molar ratio of catalyst to fluorine-containing alcohol.

(Example 6)
A four-neck flask (reactor) equipped with a stirrer, a glass distillation column (measured number of plates: 5) packed with Raschig rings, and a Dimroth condenser was immersed in an oil bath to form a reaction apparatus. The reaction was carried out in the same manner as in Example 1, except that a mixture of TFPO and OFPO was used as the raw material instead of TFPO. The results are shown in Table 2.

(Example 7)
A four-neck flask (reactor) equipped with a stirrer, a glass distillation column (measured plate number: 5) packed with Raschig rings, and a Dimroth condenser was immersed in an oil bath to form a reaction apparatus. The reaction was carried out in the same manner as in Example 4, except that a mixture of TFPO and OFPO was used as the raw material instead of TFPO. The results are shown in Table 2. The terms in Table 2 have the same meanings as in Table 1.

(Example 8)
The reaction was carried out in the same manner as in Example ₁ , except that 2-diphenylphosphorylpyridine (in the above (2), R ¹ and R ² are phenyl groups and R ³ is a pyridyl group) was used as the catalyst instead of Ph 3 PO. The results are shown in Table 3.

(Example 9)
The reaction was carried out in the same manner as in Example 1, except that tris( ₄ -fluorophenyl)phosphine oxide (in the above (2), R ¹ to R ³ are all 4-fluorophenyl groups) was used as the catalyst instead of Ph 3 PO. The results are shown in Table 3. The terms in Table 3 have the same meanings as in Table 1.

According to the production method of the present invention, by carrying out the reaction of a fluorinated alcohol and a chlorinating agent in the presence of phosphine oxide without using any special operations or reaction equipment, HCFCs can be produced in high yield and with high purity, making it possible to apply this method to mass production on an industrial scale.

The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2020-150467, filed on September 8, 2020, are hereby incorporated by reference as part of the disclosure of the specification of the present invention.

Claims (15)

A method for producing a hydrochlorofluorocarbon, comprising reacting a fluorine-containing alcohol with a chlorinating agent in the presence of a catalyst to substitute a hydroxyl group of the fluorine-containing alcohol with a chlorine atom,
the catalyst is a phosphine oxide;
A method for producing a hydrochlorofluorocarbon, characterized in that the chlorinating agent used is at least one chlorinating agent selected from the group consisting of thionyl chloride, oxalyl chloride and phosgene. The method according to claim 1, wherein the fluorine-containing alcohol is a compound represented by the following formula (1):
X-R ^f -CH ₂ OH (1)
(In the formula, X represents a hydrogen atom or a fluorine atom, and ^Rf represents a fluoroalkylene group having one or more carbon atoms.) The manufacturing method described in claim 1 or 2, wherein the fluorine-containing alcohol is 2,2,3,3-tetrafluoropropanol or 2,2,3,3,4,4,5,5-octafluoropentanol. The method according to any one of claims 1 to 3, wherein the phosphine oxide is a compound represented by the following formula (2):

(In the formula, R ¹ , R ² , and R ³ each independently represent a monovalent hydrocarbon group which may have a substituent, or a monovalent nitrogen-containing heterocyclic group which may have a substituent (provided that a carbon atom constituting the ring is bonded to the phosphorus atom).) The method according to claim 4, wherein R ¹ to R ³ are all phenyl groups, R ¹ and R ² are phenyl groups and R ³ is a pyridyl group, R ¹ to R ³ are all 4-fluorophenyl groups, or R ¹ to R ³ are all 2-tolyl groups. The manufacturing method described in any one of claims 1 to 5, wherein the chlorinating agent is thionyl chloride or oxalyl chloride. The production method described in any one of claims 1 to 6, wherein the reaction does not involve any alcohol other than the fluorine-containing alcohol. The production method described in any one of claims 1 to 7, wherein the content of the fluorine-containing alcohol diadduct contained in the reaction liquid obtained by the reaction is 10 mass% or less based on the total amount of the reaction liquid. The manufacturing method described in any one of claims 1 to 8, wherein the reaction temperature in the reaction is 0 to 150°C. The manufacturing method described in any one of claims 1 to 9, wherein the reaction time for the reaction is 2 to 8 hours. The manufacturing method described in any one of claims 1 to 10, wherein the reaction is carried out at a molar ratio of the chlorinating agent to the fluorine-containing alcohol (chlorinating agent/fluorine-containing alcohol) of 0.01 to 100. The manufacturing method described in any one of claims 1 to 11, wherein the reaction is carried out at a molar ratio of the phosphine oxide to the fluorine-containing alcohol (phosphine oxide/fluorine-containing alcohol) of 0.0001 to 10. A method for producing a hydrochlorofluoroolefin, comprising reacting a fluorine-containing alcohol with a chlorinating agent in the presence of a catalyst to produce a hydrochlorofluorocarbon by substituting a hydroxyl group of the fluorine-containing alcohol with a chlorine atom, and then dehydrofluorinating the hydrochlorofluorocarbon in the presence of a base and/or a catalyst,
the catalyst is a phosphine oxide;
A method for producing a hydrochlorofluoroolefin, wherein the chlorinating agent used is at least one chlorinating agent selected from the group consisting of thionyl chloride, oxalyl chloride and phosgene. The manufacturing method described in claim 13, wherein the hydrochlorofluorocarbon is 3-chloro-1,1,2,2-tetrafluoropropane or 5-chloro-1,1,2,2,3,3,4,4-octafluoropentane. The production method described in claim 13 or 14, wherein the hydrochlorofluoroolefin is 1-chloro-2,3,3-trifluoropropene or 1-chloro-2,3,3,4,4,5,5-heptafluoropentene.