WO2024111485A1

WO2024111485A1 - Method for producing fluoroester compound

Info

Publication number: WO2024111485A1
Application number: PCT/JP2023/041150
Authority: WO
Inventors: 弘毅渡邉; 元志青山; 英介室谷
Original assignee: Ａｇｃ株式会社
Priority date: 2022-11-21
Filing date: 2023-11-15
Publication date: 2024-05-30

Abstract

A method for producing a fluoroester compound, which includes fluorinating an ester compound having at least one atom or bond capable of being fluorinated, in an organic solvent having fluorine gas introduced thereinto, wherein the organic solvent contains a compound having a C-H bond, the amount of the compound having a C-H bond being at least 0.1 time by mass the amount of the ester compound having at least one atom or bond capable of being fluorinated.

Description

Method for producing fluorine-containing ester compound

This disclosure relates to a method for producing a fluorine-containing ester compound.

There are many industrially useful fluorine-containing ester compounds, and various production methods have been developed. For example, Patent Document 1 describes a method for producing fluorine-containing compounds such as fluorine-containing ester compounds by fluorinating ester compounds in a liquid phase.

International Publication No. 2000/056694

In the synthesis of fluorine-containing ester compounds involving fluorination in a liquid phase, a high fluorination conversion rate is desirable in order to fully express the properties of the compound. However, in conventional techniques, there is room for improvement in the conversion rate. In view of this situation, the present disclosure relates to a method for producing fluorine-containing ester compounds with a high fluorination conversion rate.

The present disclosure includes the following aspects.
<1> A method for producing a fluorinated product comprising: fluorinating an ester compound having at least one fluorinatable atom or bond in an organic solvent into which fluorine gas has been introduced;
The organic solvent contains a compound having a C—H bond,
the amount of the compound having a C—H bond is 0.1 times or more by mass of the ester compound having at least one fluorinable atom or bond;
A method for producing a fluorine-containing ester compound.
<2> The method for producing a fluorine-containing ester compound according to <1>, wherein the compound having a C—H bond contains 1 to 10 hydrogen atoms.
<3> The method for producing a fluorine-containing ester compound according to <1> or <2>, wherein the organic solvent contains a compound having the C-H bond and a fluorine-containing compound not having a C-H bond. <4> The method for producing a fluorine-containing ester compound according to any one of <1> to <3>, wherein a content of the compound having the C-H bond in the organic solvent is 0.01 mass% or more.
<5> The method for producing a fluorine-containing ester compound according to <3>, wherein the compound having a C—H bond is a compound that can be fluorinated to convert it into a fluorine-containing compound not having the C—H bond.
<6> The method for producing a fluorine-containing ester compound according to any one of <1> to <5>, wherein the compound having a C—H bond has a fluorine content of 5 to 99 mass %.
<7> The method for producing a fluorine-containing ester compound according to any one of <1> to <6>, wherein the compound having a C—H bond is an alkane, an ether compound, an ester compound, a ketone compound, or a compound in which at least one hydrogen atom of these compounds has been substituted with a halogen atom.
<8> The method for producing a fluorine-containing ester compound according to any one of <1> to <7>, wherein the ester compound having at least one fluorinatable atom or bond is a compound represented by the following formula (1) or (2):
R ^A1 -O-(C=O)-R ^B1 ... (1)
R ^B2 -(C=O)-O-R ^A2 -O-(C=O)-R ^B3 ... (2)
In formulas (1) and (2),
R ^A1 , R ^B1 , R ^B2 , and R ^B3 each independently represent a monovalent saturated hydrocarbon group, a halogeno monovalent saturated hydrocarbon group, a heteroatom-containing monovalent saturated hydrocarbon group, or a halogeno (heteroatom-containing monovalent saturated hydrocarbon) group;
R ^A2 is a divalent saturated hydrocarbon group, a halogeno divalent saturated hydrocarbon group, a heteroatom-containing divalent saturated hydrocarbon group, or a halogeno (heteroatom-containing divalent saturated hydrocarbon) group.
<9> The method for producing a fluorine-containing ester compound according to any one of <1> to <8>, wherein the ester compound having at least one fluorinatable atom or bond contains a fluorine atom.

The present disclosure provides a method for producing a fluorine-containing ester compound with a high fluorination conversion rate.

Below, the form for carrying out the embodiment of the present disclosure will be described in detail. However, the embodiment of the present disclosure is not limited to the following embodiment. In the following embodiment, the components (including element steps, etc.) are not essential unless specifically stated. The same applies to the numerical values and their ranges, and they do not limit the embodiment of the present disclosure.

In the present disclosure, the term "step" includes not only a step that is independent of other steps, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.
In the present disclosure, the numerical range indicated using "to" includes the numerical values before and after "to" as the minimum and maximum values, respectively.
In the present disclosure, each component may contain multiple types of the corresponding substance. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified.
In this disclosure, "organic group" refers to a group that contains essentially a carbon atom.
In the present disclosure, the "hydrocarbon group" may be any of linear, branched, and cyclic, and may be any of saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, and aromatic hydrocarbon groups.
In this disclosure, "partially halogenated" means that only some of the halogenatable sites of a compound are halogenated. "Partially fluoro" means that only some of the fluorinatable sites of a compound are fluorinated.
In the present disclosure, when a compound is represented by a specific formula (X), the compound represented by the formula (X) may be referred to as compound (X).

[Method of producing fluorine-containing ester compound]
The method for producing a fluorinated ester compound according to the present disclosure (hereinafter also referred to as "the production method") comprises fluorinating an ester compound having at least one fluorinatable atom or bond (hereinafter also referred to as "raw material ester compound") in an organic solvent into which fluorine gas has been introduced, the organic solvent containing a compound having a C-H bond, and the amount of the compound having the C-H bond is 0.1 times or more by mass of the ester compound having at least one fluorinatable atom or bond.

This manufacturing method includes a fluorination step in the liquid phase (hereinafter, also referred to as "liquid-phase fluorination"). Generally, in liquid-phase fluorination, a fully fluorinated compound that does not have a C-H bond in the molecule is used as a solvent. This is to prevent side reactions and a decrease in the efficiency of fluorination due to the fluorination of the solvent. On the other hand, the present inventors have found that when liquid-phase fluorination is performed in an organic solvent that is a compound having a C-H bond, the fluorination conversion rate is improved. The reason for this is not entirely clear, but is presumed to be as follows. First, when a compound having a C-H bond in the molecule is used as a solvent, the solubility of the raw material ester compound in the solvent increases, promoting gas-liquid mixing in liquid-phase fluorination and increasing the fluorination conversion rate. Second, the compound having a C-H bond used as a solvent in liquid-phase fluorination is fluorinated, generating fluorine radicals. It is believed that these fluorine radicals promote the fluorination of the raw material ester compound and improve the conversion rate.

(Raw material ester compound)
The raw material ester compound is not particularly limited as long as it is a compound having at least one fluorinatable atom or bond and at least one ester bond.
Atoms that can be fluorinated include hydrogen atoms bonded to carbon atoms, chlorine atoms bonded to carbon atoms, bromine atoms bonded to carbon atoms, and iodine atoms bonded to carbon atoms.
Fluorinizable bonds include carbon-carbon unsaturated double bonds and carbon-carbon unsaturated triple bonds.
The number of fluorinable atoms or bonds in the raw material ester compound may be at least 1. From the viewpoint of excellent solubility, the number of fluorinable atoms is preferably 1 to 1,000, and more preferably 1 to 500. From the viewpoint of increasing the purity of the fluorinated product, the number of fluorinable bonds is preferably 1 to 30, and more preferably 1 to 10.
The raw material ester compound may have only one ester bond or may have two or more ester bonds. From the viewpoint of availability, the number of ester bonds contained in the raw material ester compound is preferably one or two, and more preferably one. That is, the raw material ester compound is preferably a monoester compound or a diester compound, and more preferably a monoester.

Examples of the raw material ester compound include a compound represented by the following formula (1) and a compound represented by the following formula (2).
R ^A1 -O-(C=O)-R ^B1 ... (1)
R ^B2 -(C=O)-O-R ^A2 -O-(C=O)-R ^B3 ... (2)

In formulas (1) and (2),
R ^A1 , R ^B1 , R ^B2 , and R ^B3 each independently represent a monovalent saturated hydrocarbon group, a halogeno monovalent saturated hydrocarbon group, a heteroatom-containing monovalent saturated hydrocarbon group, or a halogeno (heteroatom-containing monovalent saturated hydrocarbon) group;
R ^A2 is a divalent saturated hydrocarbon group, a halogeno divalent saturated hydrocarbon group, a heteroatom-containing divalent saturated hydrocarbon group, or a halogeno (heteroatom-containing divalent saturated hydrocarbon) group.

In the present disclosure, a "monovalent saturated hydrocarbon group" may be any of a linear alkyl group, a branched alkyl group, and a cycloalkyl group. A "divalent saturated hydrocarbon group" may be any of a linear alkylene group, a branched alkylene group, and a cycloalkylene group. The linear alkyl group, the branched alkyl group, the linear alkylene group, and the branched alkylene group may contain an alicyclic structure.

In this disclosure, "halogeno" means that one or more hydrogen atoms present in the group are replaced with at least one halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Hydrogen atoms may or may not be present in the group.

In this disclosure, a "halogeno monovalent saturated hydrocarbon group" refers to a group in which one or more hydrogen atoms present in a monovalent saturated hydrocarbon group have been replaced by a halogen atom. A "halogeno divalent saturated hydrocarbon group" refers to a group in which one or more hydrogen atoms present in a divalent saturated hydrocarbon group have been replaced by a halogen atom.

In this disclosure, "heteroatom" means an atom other than a carbon atom or a hydrogen atom, and examples include a nitrogen atom, an oxygen atom, and a sulfur atom.

In the present disclosure, a "heteroatom-containing monovalent saturated hydrocarbon group" refers to a group in which a divalent heteroatom or a divalent group containing a heteroatom is contained in a monovalent saturated hydrocarbon group. A "heteroatom-containing divalent saturated hydrocarbon group" refers to a group in which a divalent heteroatom or a divalent group containing a heteroatom is contained in a divalent saturated hydrocarbon group. Examples of divalent heteroatoms include -O- and -S-. Examples of divalent groups containing a heteroatom include -NH-, -C(=O)-, and _-SO2- .

In this disclosure, the term "halogeno (heteroatom-containing monovalent saturated hydrocarbon) group" refers to a group in which one or more hydrogen atoms in the heteroatom-containing monovalent saturated hydrocarbon group have been replaced with a halogen atom. The term "halogeno (heteroatom-containing divalent saturated hydrocarbon) group" refers to a group in which one or more hydrogen atoms in the heteroatom-containing divalent saturated hydrocarbon group have been replaced with a halogen atom.

In formula (1), it is preferable that at least one of R ^A1 and R ^B1 contains a hydrogen atom. Also, in formula (2), it is preferable that at least one selected from the group consisting of R ^A2 , R ^B2 , and R ^B3 contains a hydrogen atom.

[R ^A1 ]
In formula (1), R ^A1 represents a monovalent saturated hydrocarbon group, a halogeno monovalent saturated hydrocarbon group, a heteroatom-containing monovalent saturated hydrocarbon group, or a halogeno (heteroatom-containing monovalent saturated hydrocarbon) group.

Examples of the monovalent saturated hydrocarbon group represented by R ^A1 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, and a cyclohexyl group.

The halogeno monovalent saturated hydrocarbon group represented by R ^A1 is preferably a halogenoalkyl group. The halogen atom contained in the halogeno monovalent saturated hydrocarbon group is preferably a fluorine atom, a chlorine atom or a bromine atom, and more preferably a fluorine atom.

The heteroatom-containing monovalent saturated hydrocarbon group represented by R ^A1 is preferably a monovalent saturated hydrocarbon group containing an ethereal oxygen atom (that is, --O--), and more preferably an alkyl group containing an ethereal oxygen atom.

The halogeno (heteroatom-containing monovalent saturated hydrocarbon) group represented by R ^A1 is preferably a halogeno (heteroatom-containing alkyl group). The halogen atom contained in the halogeno (heteroatom-containing monovalent saturated hydrocarbon) group is preferably a fluorine atom, a chlorine atom, or a bromine atom. The halogeno (heteroatom-containing monovalent saturated hydrocarbon) group is preferably a halogeno monovalent saturated hydrocarbon group containing an ethereal oxygen atom, and more preferably a halogenoalkyl group containing an ethereal oxygen atom.

The carbon number of R ^A1 is preferably 1 to 500, more preferably 1 to 200, and even more preferably 3 to 100, from the viewpoint of excellent solubility in a solvent.

In particular, from the viewpoint of excellent solubility in a solvent, R ^is preferably represented by the following formula ( ^A1 ): In other words, R preferably further has an ether bond, and more preferably includes at least one selected from the group consisting of a polyether chain and a fluoropolyether chain.
R ¹¹ O-(R ¹² O) _m1 -R ¹³ - ... (A1)

In formula (A1), R ¹¹ is an alkyl group which may have a fluorine atom, R ¹² is each independently an alkylene group having 1 to 6 carbon atoms which may have a fluorine atom, R ¹³ is an alkylene group having 1 to 6 carbon atoms which may have a fluorine atom, and m1 is an integer from 0 to 500.

In formula (A1), examples of R ¹¹ include an alkyl group and a fluoroalkyl group.

The number of carbon atoms in R ¹¹ is preferably 1 to 100, more preferably 1 to 50, even more preferably 1 to 10, and particularly preferably 1 to 6, from the viewpoint of excellent solubility in a solvent.

The alkyl group represented by R ¹¹ may be a linear alkyl group, a branched alkyl group, or an alkyl group having a ring structure.

The fluoroalkyl group represented by R ¹¹ may be a straight-chain fluoroalkyl group, a branched-chain fluoroalkyl group, or a fluoroalkyl group having a ring structure.

Among these, R ¹¹ is preferably an alkyl group, more preferably a linear alkyl group, and even more preferably a linear alkyl group having 1 to 6 carbon atoms.

In formula (A1), -(R ¹² O) _m1 - is preferably represented by the following formula (A2).
-[(R ^f1 O) _k1 (R ^f2 O) _k2 (R ^f3 O) _k3 (R ^f4 O) _k4 (R ^f5 O) _k5 (R ^f6 O) _k6 ]- ... (A2)
however,
R ^f1 is a fluoroalkylene group having 1 carbon atom;
R ^f2 is a fluoroalkylene group having 2 carbon atoms,
R ^f3 is a fluoroalkylene group having 3 carbon atoms,
R ^f4 is a fluoroalkylene group having 4 carbon atoms,
R ^f5 is a fluoroalkylene group having 5 carbon atoms;
R ^f6 is a fluoroalkylene group having 6 carbon atoms.
k1, k2, k3, k4, k5, and k6 each independently represent an integer of 0 or 1 or more, and k1+k2+k3+k4+k5+k6 is an integer of 0 to 500.

From the viewpoint of excellent solubility in a solvent, k1+k2+k3+k4+k5+k6 is preferably an integer from 1 to 500, more preferably an integer from 1 to 300, even more preferably an integer from 5 to 200, and particularly preferably an integer from 10 to 150.

In addition, the bonding order of (R ^f1 O) to (R ^f6 O) in formula (A2) is arbitrary. k1 to k6 in formula (A2) respectively represent the number of (R ^f1 O) to (R ^f6 O), and do not represent the arrangement. For example, (R ^f5 O) _k5 represents that the number of (R ^f5 O) is k5, and does not represent a block arrangement structure of (R ^f5 O) _k5 . Similarly, the order of (R ^f1 O) to (R ^f6 O) does not represent the bonding order of each unit.

In R ^f3 to R ^f6 , the fluoroalkylene group may be a linear fluoroalkylene group, a branched fluoroalkylene group, or a fluoroalkylene group having a ring structure.

Specific examples of R ^f1 include --CF ₂ -- and --CHF--.

Specific examples of R ^f2 include -CF ₂ CF ₂ -, -CF ₂ CHF-, -CHFCF ₂ -, -CHFCHF-, -CH ₂ CF ₂ -, and -CH ₂ CHF-.

Specific examples of R ^f3 include -CF ₂ CF ₂ CF ₂ -, -CF ₂ CHFCF ₂ -, -CF ₂ CH ₂ CF ₂ -, -CHFCF ₂ CF ₂ -, -CHFCHFCF ₂ -, -CHFCHFCHF-, -CHFCH ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ -, -CH ₂ CHFCF ₂ -, -CH ₂ CH 2 CF ₂ -, -CH ₂ CF ₂ CHF-, _{-CH 2 CHFCHF-, -CH 2 CH 2} _CHF- _, _-CF (CF ₃ )-CF ₂ -, -CF(CHF ₂ )-CF ₂ -, -CF(CH ₂ F)-CF ₂ -, -CF( _CH3 ) _-CF2- , -CF(CF3)-CHF-, -CF( _CHF2 )-CHF-, -CF( _CH2F )-CHF- _, -CF( _CH3 )-CHF-, -CF( _CF3 ) _-CH2- , -CF(CHF2) _-CH2- , -CF( _CH2F ) _-CH2- , -CF( _CH3 ₎ _-CH2- , -CH ₍ _CF3 )-CF2-, -CH( _CHF2 )-CF2-, -CH(CH2F) _-CF2- _, -CH( _CH3 ) _-CF2- , -CH( _CF3 )-CHF-, -CH( _CHF2 ₎ -CHF-, -CH( _CH2 Examples of such groups include -CH(CH ₃ )-CHF-, -CH(CH 3 )-CHF-, -CH(CF ₃ )-CH ₂ -, -CH(CHF ₂ )-CH ₂ -, and -CH(CH ₂ F)-CH ₂ -.

Specific examples of R ^f4 include -CF ₂ CF ₂ CF ₂ _- , -CF ₂ CF 2 CF _{2 CHF-, -CF 2 CF 2 CF 2} _CH ₂ _- _, -CF ₂ CHFCF ₂ CF ₂ -, -CHFCHFCF ₂ CF ₂ -, -CH 2 CHFCF ₂ CF ₂ -, -CF ₂ CH ₂ CF ₂ CF ₂ -, -CHFCH 2 CF ₂ CF ₂ -, -CH ₂ CH ₂ CF ₂ CF ₂ _{-, -CHFCF 2 CHFCF 2 -, -CH 2 CF 2 CHFCF 2 -, -CF 2} _CHFCFCF ₂ _- _, _and _-CF ₂ _CHFCFCF ₂ -, -CHFCHFCHFCF ₂ -, -CH ₂ CHFCHFCF ₂ -, -CF ₂ CH ₂ CHFCF ₂ -, -CHFCH ₂ CHFCF ₂ -, -CH ₂ CH ₂ CHFCF ₂ -, -CF ₂ CH 2 CH ₂ CF ₂ -, -CHFCH ₂ CH ₂ CF ₂ -, -CH ₂ CH ₂ CH ₂ CF ₂ -, -CHFCH ₂ CH ₂ CHF-, -CH ₂ CH ₂ _{CH 2} _CHF- , and -cycloC ₄ F ₆ -.

Specific examples of R ^f5 include -CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -, -CHFCF ₂ CF _{2 CF 2} _CF ₂ -, -CH ₂ CHFCF ₂ CF ₂ CF ₂ -, -CF ₂ CHFCF ₂ CF ₂ CF ₂ -, -CHFCHFCF ₂ CF ₂ CF ₂ -, -CF ₂ CH ₂ CF ₂ CF ₂ CF ₂ -, -CHFCH ₂ CF ₂ CF ₂ CF ₂ -, -CH ₂ CH ₂ CF ₂ CF ₂ CF ₂ -, -CF ₂ CF ₂ CHFCF ₂ CF ₂ -, -CHFCF ₂ CHFCF ₂ Examples include -CF ₂ -, -CH ₂ CF ₂ CHFCF ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ CF ₂ CH ₂ -, and -cycloC ₅ F ₈ -.

Specific examples of R ^f6 include -CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -, -CF ₂ CF ₂ CHFCHFCF ₂ CF ₂ -, -CHFCF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -, -CHFCHFCHFCHFCHFCHF-, -CHFCF ₂ CF ₂ CF ₂ CF ₂ _{CH 2} _- , -CH ₂ CF ₂ CF ₂ CF ₂ _{CH 2} _- , and -cycloC ₆ F ₁₀ -.
Here, -cycloC ₄ F ₆ - means a perfluorocyclobutanediyl group, a specific example of which is a perfluorocyclobutane-1,2-diyl group, -cycloC ₅ F ₈ - means a perfluorocyclopentanediyl group, a specific example of which is a perfluorocyclopentane-1,3-diyl group, -cycloC ₆ F ₁₀ - means a perfluorocyclohexanediyl group, a specific example of which is a perfluorocyclohexane-1,4-diyl group.

Among these, —(R ¹² O) _m1 — preferably contains at least one selected from the group consisting of structures represented by the following formulas (F1) to (F3), and more preferably contains a structure represented by formula (F2).
-(R ^f1 O) _k1 -(R ^f2 O) _k2 - ... (F1)
-(R ^f2 O) _k2 -(R ^f4 O) _k4 - ... (F2)
-(R ^f3 O) _k3 - ... (F3)
However, the symbols in formulas (F1) to (F3) are the same as those in formula (A2) above.

In formula (F1) and formula (F2), the bonding order of (R ^f1 O) and (R ^f2 O), and (R ^f2 O) and (R ^f4 O) are each arbitrary. For example, (R ^f1 O) and (R ^f2 O) may be arranged alternately, (R ^f1 O) and (R ^f2 O) may be arranged in blocks, or may be arranged randomly. The same applies to formula (F2).
In formula (F1), k1 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20. Also, k2 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20.
In formula (F2), k2 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20. Also, k4 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20.
In formula (F3), k3 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20.

In formula (A1), examples of R ¹³ include the same as R ^f1 to R ^f6 above.

Of these, R ¹³ is preferably a fluoroalkylene group having 1 to 4 carbon atoms.

Specific examples of R ^A1 include the following structures. * represents a bonding site with --O--, n1 represents an integer of 0 to 60, and n2 represents an integer of 0 to 500. n1 is, for example, 13, and n2 is, for example, 7.

[R ^B1 ]
In formula (1), R ^B1 is a monovalent saturated hydrocarbon group, a halogeno monovalent saturated hydrocarbon group, a heteroatom-containing monovalent saturated hydrocarbon group, or a halogeno (heteroatom-containing monovalent saturated hydrocarbon) group.

Examples of the monovalent saturated hydrocarbon group represented by R ^B1 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, and a cyclohexyl group.

The halogeno monovalent saturated hydrocarbon group represented by R ^B1 is preferably a halogenoalkyl group. The halogen atom contained in the halogeno monovalent saturated hydrocarbon group is preferably a fluorine atom, a chlorine atom, or a bromine atom.

The heteroatom-containing monovalent saturated hydrocarbon group represented by ^R is preferably a monovalent saturated hydrocarbon group containing an ethereal oxygen atom (i.e., -O-), and more preferably an alkyl group containing an ethereal oxygen atom. In other words, R ^preferably further has an ether bond.

The halogeno (heteroatom-containing monovalent saturated hydrocarbon) group represented by R ^B1 is preferably a halogeno (heteroatom-containing alkyl group). The halogen atom contained in the halogeno (heteroatom-containing monovalent saturated hydrocarbon) group is preferably a fluorine atom, a chlorine atom, or a bromine atom. The halogeno (heteroatom-containing monovalent saturated hydrocarbon) group is preferably a halogeno monovalent saturated hydrocarbon group containing an ethereal oxygen atom, and more preferably a halogenoalkyl group containing an ethereal oxygen atom.

The number of carbon atoms in R ^B1 is preferably 1 to 100, more preferably 2 to 50, and even more preferably 3 to 20, from the viewpoint of excellent solubility in a solvent.

From the viewpoint of excellent solubility in a solvent, R ^B1 preferably contains at least one fluorine atom and preferably does not contain a hydrogen atom.

Among these, from the viewpoint of excellent solubility in a solvent, R ^B1 is preferably represented by the following formula (B1).
^R21O- ( ^R22O ) _m2 - ^R23 -... (B1)

In formula (B1), R ²¹ is an alkyl group which may have a fluorine atom, R ²² is each independently an alkylene group having 1 to 6 carbon atoms which may have a fluorine atom, R ²³ is an alkylene group having 1 to 6 carbon atoms which may have a fluorine atom, and m2 is an integer of 0 to 20.

In formula (B1), examples of R ²¹ include an alkyl group and a fluoroalkyl group.

The carbon number of R ²¹ is preferably 1 to 50, more preferably 1 to 10, and even more preferably 1 to 6, from the viewpoint of excellent solubility in a solvent.

The alkyl group represented by ^R21 may be a linear alkyl group, a branched alkyl group, or an alkyl group having a ring structure.
The fluoroalkyl group represented by R ²¹ may be a straight-chain fluoroalkyl group, a branched-chain fluoroalkyl group, or a fluoroalkyl group having a ring structure.

Among these, R ²¹ is preferably a fluoroalkyl group, more preferably a linear fluoroalkyl group, still more preferably a linear fluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a linear perfluoroalkyl group having 1 to 6 carbon atoms.

In formula (B1), —(R ²² O) _m2 — is preferably represented by the above formula (A2).

In formula (B1), m2 is preferably 0 to 15, more preferably 0 to 10, even more preferably 0 to 4, and particularly preferably 0 to 2.

In formula (B1), examples of R ²³ include the same as R ^f1 to R ^f6 above.

Among these, R ²³ is preferably a fluoroalkylene group having 1 to 3 carbon atoms, and more preferably a perfluoroalkylene group having 1 to 3 carbon atoms.

Specific examples of R ^B1 include the following structures: * represents the bonding site with -O-(C=O)-.

[R ^A2 ]
In formula (2), R ^A2 is a divalent saturated hydrocarbon group, a halogeno divalent saturated hydrocarbon group, a heteroatom-containing divalent saturated hydrocarbon group, or a halogeno (heteroatom-containing divalent saturated hydrocarbon) group.

Examples of the divalent saturated hydrocarbon group, halogeno divalent saturated hydrocarbon group, heteroatom-containing divalent saturated hydrocarbon group, or halogeno (heteroatom-containing divalent saturated hydrocarbon) group represented by ^R include groups in which one hydrogen atom or one halogen atom has been removed from the monovalent saturated hydrocarbon group, halogeno monovalent saturated hydrocarbon group, heteroatom-containing monovalent saturated hydrocarbon group, or halogeno (heteroatom-containing monovalent saturated hydrocarbon) group represented by R in ^{formula (} 1).

The carbon number of R ^A2 is preferably 1 to 200, and more preferably 3 to 100, in terms of excellent solubility in a solvent.

Among these, from the viewpoint of excellent solubility in a solvent, R ^A2 is preferably represented by the following formula (A5): In other words, R ^A2 preferably further has an ether bond, and more preferably includes at least one selected from the group consisting of a polyether chain and a fluoropolyether chain.
-R ³¹ O-(R ³² O) _m5 -R ³³ - ... (A5)

In formula (A5), R ³¹ and R ³³ each independently represent an alkylene group having 1 to 6 carbon atoms which may have a fluorine atom, R ³² each independently represent an alkylene group having 1 to 6 carbon atoms which may have a fluorine atom, and m5 is an integer of 0 to 500.

In formula (A5), R ³¹ and R ³³ each independently have the same meaning as R ¹³ in formula (A1).
In formula (A5), examples of -(R ³² O) _m5 - include the same as -(R ¹² O) _m1 - in formula (A1).

Specific examples of R ^A2 include the following structures: * represents a bonding site with —O—, and n2 represents an integer of 0 to 500.

[R ^B2 and R ^B3 ]
In formula (2), R ^B2 and R ^B3 each independently represent a monovalent saturated hydrocarbon group, a halogeno monovalent saturated hydrocarbon group, a heteroatom-containing monovalent saturated hydrocarbon group, or a halogeno (heteroatom-containing monovalent saturated hydrocarbon) group.

Examples of the monovalent saturated hydrocarbon group, halogeno monovalent saturated hydrocarbon group, heteroatom-containing monovalent saturated hydrocarbon group, or halogeno (heteroatom-containing monovalent saturated hydrocarbon) group represented by R ^or ^R include groups similar to the monovalent saturated hydrocarbon group, halogeno monovalent saturated hydrocarbon group, heteroatom-containing monovalent saturated hydrocarbon group, or halogeno (heteroatom-containing monovalent saturated hydrocarbon) group represented by R in ^formula (1).

Examples of the raw material ester compound include the following compound ( T1 ) .

Further examples of the raw material ester compound include CH ₃ —O(CF ₂ CFHO-CF ₂ CF ₂ CF ₂ CH ₂ O) _n1 -C(═O)-CF(CF ₃ )OCF ₂ CF ₂ CF _3. Here, n1 represents a number of 1 or more, preferably 1 to 50, more preferably 1 to 40, and even more preferably 1 to 30.

From the viewpoint of improving the yield of the fluorine-containing compound, the boiling point of the raw material ester compound is preferably 30°C or higher, more preferably 50°C or higher, and more preferably 100°C or higher. From the same viewpoint, the boiling point of the raw material ester compound is preferably 500°C or lower, more preferably 400°C or lower, and even more preferably 300°C or lower. From the above viewpoint, the boiling point of the raw material ester compound is preferably 30 to 500°C, more preferably 50 to 400°C, and even more preferably 100 to 300°C. In this disclosure, "boiling point" refers to the boiling point at normal pressure (760 mmHg).

The number average molecular weight (Mn) of the raw material ester compound is preferably 100 to 100,000, more preferably 100 to 20,000, further preferably 300 to 10,000, and particularly preferably 400 to 6,000. When Mn is equal to or greater than the lower limit, the decomposition reaction in the gas phase during liquid phase fluorination is easily suppressed. When Mn is equal to or less than the upper limit, the purification of the fluorine-containing compound is easily performed. Mn is the number average value of the molecular weight of each molecule calculated from the molecular structure identified by ¹ H-NMR and ¹⁹ F-NMR.

In one embodiment, the raw material ester compound preferably contains fluorine atoms. From the viewpoint of excellent solubility in the reaction solvent, the fluorine content in the raw material ester compound (i.e., the proportion of fluorine atoms in the molecule) is preferably 10 to 86 mass%, more preferably 10 to 76 mass%, and even more preferably 30 to 76 mass%.

The raw material ester compound may be a commercially available product or a synthesized compound.
In one embodiment, the raw material ester compound may be an ester of a compound having a hydroxyl group and a compound having an acyl fluoride group (FC(O)-). The method of obtaining the ester is not particularly limited as long as the ester has a structure of a compound produced when a compound having a hydroxyl group and a compound having an acyl fluoride group are subjected to an esterification reaction. For example, the raw material ester compound may be a compound obtained by esterifying a compound having a hydroxyl group and a compound having one or more groups selected from the group consisting of a ClC(O)- group, a BrC(O)- group, and a carboxy group. The raw material ester compound may also be a compound obtained by subjecting a portion other than the ester bond to another chemical conversion after the esterification reaction. The chemical conversion may include a reaction in which chlorine is added to a carbon-carbon double bond (C=C) to give a Vic-dichloro structure (CCl-CCl).
In one embodiment, the raw material ester compound is preferably a compound produced by esterification reaction between a compound having a hydroxyl group and a compound having an acyl fluoride group. The compound having a hydroxyl group may be a compound having one or more hydroxyl groups. The compound having an acyl fluoride group may be a compound having one or more acyl fluoride groups. The raw material ester compound is preferably an ester of a compound having one hydroxyl group and a compound having one acyl fluoride group.

(Organic solvent)
In the liquid phase fluorination, an organic solvent is used as a solvent in the liquid phase. The organic solvent includes a compound having a C-H bond. The organic solvent may include a compound not having a C-H bond in addition to the compound having a C-H bond, or may not include a compound not having a C-H bond. From the viewpoint of improving the conversion rate in the liquid phase fluorination, the content of the compound having a C-H bond relative to the total amount of the organic solvent is preferably 0.01% by mass or more, more preferably 30% by mass or more, may be 50% by mass or more, or may be 70% by mass or more. When it is desirable to suppress the amount of the compound having a C-H bond used from the viewpoint of cost, ease of availability, etc., the content of the compound having a C-H bond relative to the total amount of the organic solvent may be 90% by mass or less, or may be 80% by mass or less. From the above viewpoint, the content of the compound having a C-H bond relative to the total amount of the organic solvent may be 0.01 to 90% by mass, may be 30 to 80% by mass, may be 50 to 80% by mass, or may be 70 to 80% by mass.

The organic solvent is preferably a compound that has high solubility for the raw material ester compound, and is preferably a compound that can dissolve 1% or more by mass of the raw material ester compound at 25°C, and more preferably a compound that can dissolve 5% or more by mass.

The amount of the organic solvent is preferably 1 time by mass or more, more preferably 2 times by mass or more, relative to the raw ester compound. The amount of the organic solvent may be 100 times by mass or less, 50 times by mass or less, or 10 times by mass or less, relative to the raw ester compound. The amount of the organic solvent may be 1 to 100 times by mass, 2 to 50 times by mass, or 2 to 10 times by mass, relative to the raw ester compound.

From the viewpoint of improving the yield of the fluorine-containing ester compound, the boiling point of the organic solvent is preferably 10 to 500°C, more preferably 30 to 250°C, and even more preferably 50 to 150°C. When the organic solvent contains multiple types of compounds, the boiling point is the boiling point of each compound.

From the viewpoint of improving the yield of the fluorine-containing ester compound, the molecular weight of the organic solvent is preferably 200 or more, more preferably 200 to 50,000, even more preferably 200 to 25,000, particularly preferably 200 to 10,000, and most preferably 200 to 1,000.
When the molecular weight is distributed, the molecular weight is expressed as a weight average molecular weight (Mw). Mw is measured in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as an eluent. When the organic solvent contains multiple types of compounds, the molecular weight is the molecular weight of each compound.

From the viewpoint of improving the yield of the fluorine-containing ester compound, the viscosity of the organic solvent at 25°C is preferably 2,000 mPa·s or less overall, more preferably 1,000 mPa·s or less, and even more preferably 500 mPa·s or less. The lower the viscosity, the better, but the lower limit of the viscosity may be 0.5 mPa·s or 1 mPa·s. The viscosity of the organic solvent can be measured according to JIS Z8803:2011 using a rheometer (for example, device name RE-215L, Toki Sangyo Co., Ltd.).

From the viewpoint of improving the yield of the fluorine-containing ester compound, the vapor pressure of the organic solvent in the container is preferably 0.009 MPa or less, more preferably 0.007 MPa or less, even more preferably 0.006 MPa or less (49 mmHg), particularly preferably 0.005 MPa or less (38 mmHg), and extremely preferably 0.003 MPa or less (23 mmHg).

Compound having a C—H bond
A compound having a C-H bond is a compound in which hydrogen atoms are bonded to the carbon atoms of an organic compound. The number of hydrogen atoms in a compound having a C-H bond may be equal to or less than the maximum number of atoms that can theoretically be bonded to a carbon atom, and is preferably 1 to 10, more preferably 1 to 8, and even more preferably 1 to 6. When the number of hydrogen atoms is equal to or more than the lower limit, the effect of improving the conversion rate can be exhibited well, and when the number is equal to or less than the upper limit, the reaction heat can be reduced and the decomposition reaction can be suppressed.

The compound having a C-H bond is preferably a compound that, as a single compound, has high solubility in the raw material ester compound, and is preferably a compound that can dissolve 1% by mass or more of the raw material ester compound at 25°C, and more preferably a compound that can dissolve 5% by mass or more.

From the viewpoint of improving the conversion rate, the carbon number of the compound having a C-H bond is preferably 4 or more, more preferably 4 to 100, even more preferably 4 to 50, particularly preferably 4 to 20, and extremely preferably 4 to 10.

From the viewpoint of improving the solubility and conversion rate of the raw material ester compound, it is preferable that the compound having a C-H bond has a halogen atom, and more preferably a fluorine atom. The fluorine content of the compound having a C-H bond is preferably 5 to 99% by mass, more preferably 5% to less than 86% by mass, even more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass.

Examples of compounds having a C--H bond include alkanes, ether compounds, ester compounds, ketone compounds, and compounds in which at least one hydrogen atom of these compounds has been substituted with a halogen atom.
The alkane may be one having 4 to 100 carbon atoms, preferably 4 to 50 carbon atoms, more preferably 4 to 20 carbon atoms, and even more preferably 4 to 10 carbon atoms.
The ether compound may be an ether compound having a carbon number of 4 to 100, preferably 4 to 50, more preferably 4 to 20, and even more preferably 4 to 10. The number of ether bonds in the ether compound may be one or more.
The ester compound may be an ester compound having a carbon number of 4 to 100, preferably 4 to 50, more preferably 4 to 20, and even more preferably 4 to 10. The number of ester bonds in the ester compound may be one or more.
The ketone compound may have a carbon number of 4 to 100, preferably 4 to 50, more preferably 4 to 20, and even more preferably 4 to 10. The number of carbonyl groups in the ketone compound may be one or more.
Examples of the above-mentioned compounds in which at least one hydrogen atom has been substituted with a halogen atom include fluoroalkanes, fluoroether compounds, chlorofluorocarbons, and chlorofluoroether compounds.
The compound having a C--H bond may be used alone or in combination of two or more kinds.

Specific examples of compounds with C-H bonds are shown in the table below along with their abbreviations.

In liquid phase fluorination, the amount of the compound having a C-H bond is 0.1 times by mass or more of the raw ester compound, preferably 0.5 times by mass or more, and more preferably 1 times by mass or more. The amount of the compound having a C-H bond is preferably 100 times by mass or less of the raw ester compound, more preferably 50 times by mass or less, and even more preferably 10 times by mass or less. When the amount of the compound having a C-H bond is equal to or more than the lower limit, the solubility of the raw ester compound becomes sufficient and the fluorination reaction proceeds smoothly. When the amount of the compound having a C-H bond is equal to or less than the upper limit, the amount of solvent is not excessive, and raw material costs can be reduced. From the above viewpoint, the amount of the compound having a C-H bond is preferably 0.1 to 100 times by mass of the raw ester compound, more preferably 0.5 to 50 times by mass, and even more preferably 1 to 10 times by mass.

In one embodiment, the compound having a C-H bond is preferably a compound that can be fluorinated and converted into the fluorine-containing compound having no C-H bond. In one embodiment, it is preferable to use a compound having a C-H bond and its fluoride, a fluorine-containing compound having no C-H bond, as a mixed solvent, from the viewpoint of effectively utilizing the fluoride by recycling. The content of the compound having a C-H bond relative to the total amount of the compound having a C-H bond and its fluoride, a fluorine-containing compound having no C-H bond, is preferably 0.01% by mass, more preferably 10% by mass or more, even more preferably 30% by mass or more, and particularly preferably 50% by mass or more. When it is desirable to reduce the amount of the compound containing a C-H bond from the viewpoint of cost, availability, etc., the content of the compound having a C-H bond relative to the total amount may be 90% by mass or less, 80% by mass or less, or 70% by mass or less. From this viewpoint, the content of the compound having a C-H bond relative to the total amount may be 0.01 to 90% by mass, 10 to 80% by mass, 30 to 70% by mass, or 50 to 70% by mass.

Compounds not having a C—H bond
The compound having no C-H bond is preferably a fluorine-containing compound having no C-H bond, for example, a perfluoroalkane or an organic solvent obtained by perfluorinating an organic solvent having at least one atom selected from the group consisting of a chlorine atom, a nitrogen atom, and an oxygen atom.

The fluorine-containing compound that does not have a C-H bond is preferably a compound that, as a single compound, has high solubility for the raw material ester compound, and is preferably a compound that can dissolve 1% by mass or more of the raw material ester compound at 25°C, and more preferably a compound that can dissolve 5% by mass or more.

The fluorine-containing compound having no C—H bond may be at least one selected from the group consisting of chlorine-containing solvents and fluorine-containing solvents other than chlorine-containing solvents.
Examples of chlorine-containing solvents include CClF ₂ CClFCF ₂ OCF ₂ CClF ₂ (CFE-419), 1,2,3,4-tetrachloroperfluorobutane (R-113), CF ₂ ClCFClCFClOCF ₂ CF ₂ Cl (CFE-418), and the like.
Examples of fluorine-containing solvents other than chlorine-containing solvents include perfluoroalkanes (FC-72, etc.), perfluoroethers (FC-75, FC-77, etc.), perfluoropolyethers (trade names: Krytox, Fomblin, Galden, Demnum, etc.), inert fluids (trade name: Fluorinert), and perfluorocarboxylic acid fluorides.
Further, examples of the fluorine-containing compound having no C—H bond include the following acid fluorides.
_CF3CF2CF2OCF ( _CF3 ₎ _COF
_CF3CF2CF2OCF ₍ _CF3 ₎ _CF2OCF ( _CF3 )COF
_CF3CF2CF2OCF ₍ _CF3 ₎ CF2OCF( _CF3 ₎ _CF2OCF ( _CF3 )COF
The compound having no C--H bond may be used alone or in combination of two or more kinds.

In one embodiment, the organic solvent preferably contains a compound having a C-H bond and a fluorine-containing compound not having a C-H bond. When the organic solvent contains a compound having a C-H bond and a fluorine-containing compound not having a C-H bond, the content of the compound having a C-H bond relative to the total amount of the compound having a C-H bond and the fluorine-containing compound not having a C-H bond is preferably 0.01% by mass, more preferably 10% by mass or more, even more preferably 30% by mass or more, and particularly preferably 50% by mass or more. When it is desirable to reduce the amount of the compound having a C-H bond used from the viewpoint of cost, availability, etc., the content of the compound having a C-H bond relative to the total amount may be 90% by mass or less, 80% by mass or less, or 70% by mass or less. From the above viewpoint, the content of the compound having a C-H bond relative to the total amount may be 0.01 to 90% by mass, 10 to 80% by mass, 30 to 70% by mass, or 50 to 70% by mass.

(Fluorine-containing ester compound)
The fluorine-containing ester compound produced by the present production method is a compound having fluorine atoms and ester bonds, which is obtained by liquid-phase fluorination of a raw material ester compound. In the liquid-phase fluorination, a fluorine-containing ester compound having a structure corresponding to the carbon skeleton of the raw material ester compound is produced. However, when the raw material ester compound has carbon-carbon unsaturated bonds, a fluorine atom may be added to one or more of the unsaturated bonds to change the bonding state.
The fluorine-containing ester compound is a compound having a higher fluorine content than the raw material ester compound, and the raw material ester compound is preferably a perfluorinated compound.

When the raw material ester compound is a compound represented by the formula (1), the fluorine-containing ester compound is preferably a compound represented by the following formula (6): When the raw material ester compound is a compound represented by the formula (2), the fluorine-containing ester compound is preferably a compound represented by the following formula (7):
R ^AF1 -O-(C=O)-R ^BF1 ... (6)
R ^BF2 -(C=O)-OR ^AF2 -O-(C=O)-R ^BF3 ... (7)
In formulas (6) and (7),
R ^AF1 , R ^BF1 , R ^AF2 , R ^BF2 , and R ^BF3 are groups corresponding to R ^A1 , R ^B1 , R ^A2 , R ^B2 , and R ^B3 , respectively;
when R ^A1 , R ^B1 , R ^A2 , R ^B2 and R ^B3 are each independently a group not containing a hydrogen atom, R ^AF1 , R ^BF1 , R ^AF2 , R ^BF2 and R ^BF3 are the same group as R ^A1 , R ^B1 , R ^A2 , R ^B2 and R ^B3 ;
When R ^A1 , R ^B1 , R ^A2 , R ^B2 , and R ^B3 are each independently a group containing a hydrogen atom, R ^AF1 , R ^BF1 , R ^AF2 , R ^BF2 , and R ^BF3 are groups in which all hydrogen atoms present in R ^A1 , R ^B1 , R ^A2 , R ^B2 , and R ^B3 have been replaced with fluorine atoms.

[R ^AF1 ]
In formula (6), R ^AF1 is a group corresponding to R ^A1 .
When R ^A1 contains a hydrogen atom, R ^AF1 is a group in which all hydrogen atoms present in R ^A1 are substituted with fluorine atoms. When R ^A1 does not contain a hydrogen atom, R ^AF1 is the same group as R ^A1 .
From the viewpoint of excellent solubility in a solvent, R ^AF1 is preferably represented by the following formula (A3).
^R14O- ( ^R15O ) _m3 - ^R16- ... (A3)

In formula (A3), R ¹⁴ is a perfluoroalkyl group, R ¹⁵ is each independently a perfluoroalkylene group having 1 to 6 carbon atoms, R ¹⁶ is a perfluoroalkylene group having 1 to 6 carbon atoms, and m3 is an integer of 0 to 500.

In formula (A3), R ¹⁴ corresponds to R ¹¹ in formula (A1). When R ¹¹ contains a hydrogen atom, R ¹⁴ is a group in which all hydrogen atoms contained in R ¹¹ are substituted with fluorine atoms. When R ¹¹ does not contain a hydrogen atom, R ¹⁴ is the same as R ¹¹ .

In formula (A3), -(R ¹⁵ O) _m3 - corresponds to -(R ¹² O) _m1 - in formula (A1). When R ¹² contains a hydrogen atom, R ¹⁵ is a group in which all hydrogen atoms contained in R ¹² are substituted with fluorine atoms. When R ¹² does not contain a hydrogen atom, R ¹⁵ is the same as R ¹² .

In formula (A3), —(R ¹⁵ O) _m3 — is preferably represented by the following formula (A4).
-[(R ^ff1 O) _k7 (R ^ff2 O) _k8 (R ^ff3 O) _k9 (R ^ff4 O) _k10 (R ^ff5 O) _k11 (R ^ff6 O) _k12 ]- ... (A4)
however,
R ^ff1 is a perfluoroalkylene group having 1 carbon atom;
R ^ff2 is a perfluoroalkylene group having 2 carbon atoms,
R ^ff3 is a perfluoroalkylene group having 3 carbon atoms,
R ^ff4 is a perfluoroalkylene group having 4 carbon atoms,
R ^ff5 is a perfluoroalkylene group having 5 carbon atoms,
R ^ff6 is a perfluoroalkylene group having 6 carbon atoms.
k7, k8, k9, k10, k11, and k12 each independently represent an integer of 0 or 1 or more, and k7+k8+k9+k10+k11+k12 is an integer of 0 to 500.

In formula (A4), R ^ff1 to R ^ff6 correspond to R ^f1 to R ^f6 in formula (A2). For example, when R ^f1 contains a hydrogen atom, R ^ff1 is a group in which all hydrogen atoms contained in R ^f1 are substituted with fluorine atoms. When R ^f1 does not contain a hydrogen atom, R ^ff1 is the same as R ^f1 . ^The same applies to R ^ff2 to R ^ff6 .

From the viewpoint of excellent solubility in a solvent, k7+k8+k9+k10+k11+k12 is preferably an integer from 1 to 500, more preferably an integer from 1 to 300, even more preferably an integer from 5 to 200, and particularly preferably an integer from 10 to 150.

Among these, —(R ¹⁵ O) _m3 — preferably contains at least one selected from the group consisting of structures represented by the following formulae (G1) to (G3), and more preferably contains a structure represented by formula (G2).
-(R ^ff1 O) _k7 -(R ^ff2 O) _k8 - ... (G1)
-(R ^ff2 O) _k8 -(R ^ff4 O) _k10 - ... (G2)
-(R ^ff3 O) _k9 - ... (G3)
However, the symbols in formulas (G1) to (G3) are the same as those in formula (A4) above.

In formula (G1) and formula (G2), the bonding order of ( ^Rff1O ) and ( ^Rff2O ), and ( ^Rff2O ) and ( ^Rff4O ) are each arbitrary. For example, ( ^Rff1O ) and ( ^Rff2O ) may be arranged alternately, ( ^Rff1O ) and ( ^Rff2O ) may be arranged in blocks, or may be arranged randomly. The same applies to formula (G2).
In formula (G1), k7 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20. Furthermore, k8 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20.
In formula (G2), k8 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20. Also, k10 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20.
In formula (G3), k9 is preferably an integer of 1 to 30, and more preferably an integer of 1 to 20.

In formula (A3), R ¹⁶ corresponds to R ¹³ in formula (A1). When R ¹³ contains a hydrogen atom, R ¹⁶ is a group in which all hydrogen atoms contained in R ¹³ are substituted with fluorine atoms. When R ¹³ does not contain a hydrogen atom, R ¹⁶ is the same as R ¹³ .

Examples of R ¹⁶ include the same as R ^ff1 to R ^ff6 above.

Of these, R ¹⁶ is preferably a perfluoroalkylene group having 1 to 3 carbon atoms.

In formula (A3), m3 corresponds to m1 in formula (A1). m3 is the same as m1.

Specific examples of R ^AF1 include the following structures, in which * represents a bonding site with --O--, n1 represents an integer of 0 to 60, and n2 represents an integer of 0 to 500. n1 is, for example, 13, and n2 is, for example, 7.

[R ^BF1 ]
In formula (6), R ^BF1 is a group corresponding to R ^B1 .
When R ^B1 contains a hydrogen atom, R ^BF1 is a group in which all hydrogen atoms present in R ^B1 are substituted with fluorine atoms. When R ^B1 does not contain a hydrogen atom, R ^BF1 is the same group as R ^B1 .
From the viewpoint of excellent solubility in a solvent, R ^BF1 is preferably represented by the following formula (B2).
R ²⁴ O-(R ²⁵ O) _m4 -R ²⁶ - ... (B2)

In formula (B2), R ²⁴ is a perfluoroalkyl group, R ²⁵ is each independently a perfluoroalkylene group having 1 to 6 carbon atoms, R ²⁶ is a perfluoroalkylene group having 1 to 6 carbon atoms, and m4 is an integer of 0 to 20.

In formula (B2), R ²⁴ corresponds to R ²¹ in formula (B1). When R ²¹ contains a hydrogen atom, R ²⁴ is a group in which all hydrogen atoms contained in R ²¹ are substituted with fluorine atoms. When R ²¹ does not contain a hydrogen atom, R ²⁴ is the same as R ²¹ .

In formula (B2), -(R ²⁵ O) _m4 - corresponds to -(R ²² O) _m2 - in formula (B1). When R ²² contains a hydrogen atom, R ²⁵ is a group in which all of the hydrogen atoms contained in R ²² are substituted with fluorine atoms. When R ²² does not contain a hydrogen atom, R ²⁵ is the same as R ²² .

In formula (B2), —(R ²⁵ O) _m4 — is preferably represented by the above formula (A4).

In formula (B2), R ²⁶ corresponds to R ²³ in formula (B1). When R ²³ contains a hydrogen atom, R ²⁶ is a group in which all hydrogen atoms contained in R ²³ are substituted with fluorine atoms. When R ²³ does not contain a hydrogen atom, R ²⁶ is the same as R ²³ .

In formula (B2), m4 corresponds to m2 in formula (B1). m4 is the same as m2.

Specific examples of R ^BF1 include the following structures, in which * represents the bonding site with -O-(C=O)-.

[R ^AF2 ]
In formula (7), R ^AF2 is a group corresponding to R ^A2 .
When R ^A2 contains a hydrogen atom, R ^AF2 is a group in which all hydrogen atoms present in R ^A2 are substituted with fluorine atoms. When R ^A2 does not contain a hydrogen atom, R ^AF2 is the same group as R ^A2 .

From the viewpoint of excellent solubility in a solvent, R ^AF2 is preferably represented by the following formula (A6): That is, R ^AF2 preferably further has an ether bond.
^-R34O- ( ^R35O ) _m6 - ^R36- ... (A6)

In formula (A6), R ³⁴ and R ³⁶ are each independently a perfluoroalkylene group having 1 to 6 carbon atoms; R ³⁵ are each independently a perfluoroalkylene group having 1 to 6 carbon atoms; and m6 is an integer of 0 to 500.

In formula (A6), R ³⁴ and R ³⁶ correspond to R ³¹ and R ³³ in formula (A5), respectively. When R ³¹ contains a hydrogen atom, R ³⁴ is a group in which all hydrogen atoms contained in R ³¹ are substituted with fluorine atoms. When R ³¹ does not contain a hydrogen atom, R ³⁴ is the same as R ^31. When R ³³ contains a hydrogen atom, R ³⁶ is a group in which all hydrogen atoms contained in R ³³ are substituted with fluorine atoms. When R ³³ does not contain a hydrogen atom, R ³⁶ is the same as R ³³ .

In formula (A6), -(R ³⁵ O) _m6 - corresponds to -(R ³² O) _m5 - in formula (A5). When R ³² contains a hydrogen atom, R ³⁵ is a group in which all hydrogen atoms contained in R ³² are substituted with fluorine atoms. When R ³² does not contain a hydrogen atom, R ³⁵ is the same as R ³² .

In formula (A6), R ³⁴ and R ³⁶ each independently have the same meaning as R ³¹ and R ³³ in formula (A5).
In formula (A6), examples of -(R ³⁵ O) _m6 - include the same as -(R ³² O) _m5 - in formula (A5).

Specific examples of R ^AF2 include the following structures: * represents a bonding site with --O--, and n2 represents an integer of 0 to 500.

[ ^RBF2 and ^RBF3 ]
In formula (7), R ^{3 BF2} and R ^{3 BF3} are groups corresponding to R ^{3 B2} and R ^{3 B3} , respectively.
When R ^B2 contains a hydrogen atom, R ^BF2 is a group in which all hydrogen atoms present in R ^B2 are substituted with fluorine atoms. When R ^B2 does not contain a hydrogen atom, R ^BF2 is the same group as R ^B2 .
When R ^B3 contains a hydrogen atom, R ^BF3 is a group in which all hydrogen atoms present in R ^B3 are substituted with fluorine atoms. When R ^B3 does not contain a hydrogen atom, R ^BF3 is the same group as R ^B3 .

Examples of the group represented by R ^{3 BF2} or R ^{3 BF3} include the same groups as the group represented by R ^{3 BF1} in formula (6).

The number average molecular weight of the fluorine-containing ester compound is not particularly limited, but is preferably 100 to 100,000, more preferably 100 to 20,000, even more preferably 300 to 10,000, and particularly preferably 400 to 6,000.

The fluorine-containing ester compound, which is the reaction product of the liquid-phase fluorination, can be useful as it is or after being chemically converted into another compound. When the fluorine-containing ester compound is a compound having an ester bond that can be decomposed, particularly when it is compound (6) or (7), it may be converted into another compound by carrying out a decomposition reaction of the ester bond.

[Liquid Phase Fluorination Process]
The reaction type of the fluorination reaction may be a batch system or a continuous system, and the continuous system is preferred. The fluorination method may be the fluorination methods 1 and 2 described below. From the viewpoint of excellent conversion, the fluorination method 2 described below is preferably carried out in a continuous system.

Fluorination method 1: A reactor is charged with a raw material ester compound and a solvent, and stirring is started. The mixture is reacted at a given reaction temperature and pressure while continuously supplying fluorine gas.
Fluorination method 2: A solvent is charged into a reactor and stirring is started. A raw material ester compound and fluorine gas are continuously and simultaneously fed at a predetermined molar ratio under a predetermined reaction temperature and reaction pressure.

When supplying the raw ester compound in fluorination method 2, the raw ester compound may be supplied as is without diluting it with a solvent. When diluting the raw ester compound with a solvent, the amount of the solvent is preferably at least 1-fold by mass, and more preferably at least 2-fold by mass, relative to the raw ester compound.

In liquid-phase fluorination, fluorine gas may be used as is, or a mixed gas in which fluorine gas is diluted with an inert gas may be used. Examples of inert gases include nitrogen gas, helium gas, neon gas, and argon gas. Nitrogen gas or helium gas is preferred, and nitrogen gas is more preferred. From the viewpoint of excellent conversion, the concentration of fluorine gas in the mixed gas is preferably 10% by volume or more, more preferably 15% by volume or more, and even more preferably 20% by volume or more. From the viewpoint of suppressing excessive reactivity, it is preferably 60% by volume or less, more preferably 50% by volume or less, and even more preferably 40% by volume or less. From the above viewpoints, the concentration of fluorine gas in the mixed gas is preferably 10 to 60% by volume, more preferably 15 to 50% by volume, and even more preferably 20 to 40% by volume.

From the viewpoint of achieving a good conversion rate, the amount of fluorine used in the liquid-phase fluorination is preferably an amount that results in an excess equivalent of fluorine relative to the hydrogen atoms in the raw material ester compound, and more preferably an amount that results in 1.5 equivalents (i.e., 1.5 moles) or more. It is preferable that the amount of fluorine is such that an excess equivalent is maintained from the beginning to the end of the liquid-phase fluorination.

The reaction temperature for the liquid phase fluorination is preferably −60° C. or higher and not higher than the boiling point of the raw material ester compound, and from the viewpoints of reaction yield, selectivity, and ease of industrial implementation, it is more preferably −50° C. to 100° C., and even more preferably −20° C. to 50° C.
The reaction pressure for the liquid phase fluorination is not particularly limited, but from the viewpoints of excellent conversion rate and ease of industrial implementation, it is preferably 0 to 2 MPa.

The reaction time in liquid phase fluorination (i.e., the time it takes for the raw material ester compound to pass through the reaction field) is preferably 200 hours or less, more preferably 190 hours or less, even more preferably 170 hours or less, particularly preferably 150 hours or less, and extremely preferably 100 hours or less. The reaction time is preferably 0.3 hours or more, more preferably 0.6 hours or more, and even more preferably 1 hour or more. If the reaction time is equal to or greater than the lower limit, the reaction is likely to be sufficient, and if it is equal to or less than the upper limit, the production time and cost are likely to be reduced. From the above viewpoint, the reaction time is preferably 0.3 to 200 hours, more preferably 0.6 to 190 hours, even more preferably 1 to 170 hours, particularly preferably 1 to 150 hours, and most preferably 1 to 100 hours.

In the fluorination process, the content of the raw material ester compound in the liquid phase is preferably 10 to 70% by mass, and more preferably 20 to 50% by mass.

In order to efficiently proceed with the liquid phase fluorination and improve the yield, it is preferable to irradiate the reaction system with ultraviolet light. In a batch reaction, it is preferable to irradiate the reaction system with ultraviolet light in the later stages of the liquid phase fluorination. The ultraviolet light irradiation time is preferably 0.1 to 3 hours.

In order to efficiently proceed with the liquid phase fluorination, a compound having a C-H bond or a compound having a carbon-carbon double bond may be added as an auxiliary. When a compound having one specific type of C-H bond or a compound having a carbon-carbon double bond is used in an amount less than 0.1 times by mass relative to the raw material ester compound, the compound is classified as an auxiliary.
The auxiliary compound having a C-H bond is preferably an aromatic hydrocarbon, more preferably benzene, toluene, etc. The amount of the compound having a C-H bond added is preferably 0.1 to 10 mol %, more preferably 0.1 to 5 mol %, based on the hydrogen atoms of the raw material ester compound.
Examples of the auxiliary compound having a carbon-carbon double bond include CF ₃ CF═CF ₂ and CF ₂ ═CF-CF═CF ₂ .
The amount of the compound having a carbon-carbon double bond added is preferably 0.1 to 10 mol %, more preferably 0.1 to 5 mol %, based on the hydrogen atoms in the raw material ester compound.

For example, in a batch reaction, an auxiliary may be added to the reaction system in the later stages of liquid phase fluorination. The auxiliary is preferably added in a state where fluorine is present in the reaction system. When the auxiliary is added, it is preferable to pressurize the reaction system. The pressure during pressurization is preferably 0.01 to 5 MPa.

In one embodiment, it is preferable that the present manufacturing method does not use an auxiliary compound having a C-H bond or a compound having a carbon-carbon double bond. According to the present manufacturing method, even without using an auxiliary, the compound having a C-H bond used as a solvent becomes a radical generating source, and the conversion rate can be improved. By not using an auxiliary, it is expected that the process of adding and removing the auxiliary can be simplified.

If a reaction occurs in which hydrogen atoms are replaced by fluorine atoms during liquid-phase fluorination of raw material esterification, HF is produced as a by-product. To capture HF, it is preferable to either have an HF scavenger present in the reaction system or to bring the HF scavenger into contact with the outlet gas at the reactor gas outlet. For example, NaF is a preferred HF scavenger.

The crude product containing the fluorinated ester compound obtained by liquid phase fluorination may be used as is in the next step, or may be purified to a high purity. Examples of purification methods include distilling the crude product directly under normal or reduced pressure.

Next, the embodiments of the present disclosure will be described in detail using examples, but the embodiments of the present disclosure are not limited to these examples. Example 1 is a comparative example, and Examples 2 to 5 are working examples.

The structures of the compounds used in the examples are shown below.
_CFE _- ₄₁₉ : _{CF2ClCFClCF2OCF2CF2Cl}
HCFE _- 428a,b _: _{CF2ClCFClCHFOCF2CF2Cl}
HCFE _- 473 _: _{CH2ClCHClCH2OCF2CHFCl}

[Synthesis Example 1: Synthesis of compound (A)]
The following compound (A) was obtained by the method described in WO 2013/121984.

[Example 1]
A fluorination reaction was carried out to replace most of the hydrogen atoms of compound (A) with fluorine atoms by the following method.
An autoclave (made of nickel, internal volume 500 mL) was prepared, and a cooler maintained at 0° C., a NaF pellet packed layer, and a cooler maintained at −10° C. were installed in series at the gas outlet of the autoclave. In addition, a liquid return line was installed to return the coagulated liquid from the cooler maintained at −10° C. to the autoclave.
100 g of CFE-419 was charged into the autoclave and stirred while maintaining the temperature at 20° C. Nitrogen gas was blown into the autoclave at 25° C. for 1 hour, and then a raw material solution in which 100 g of the compound (A) obtained in Synthesis Example 1 was dissolved in 200 g of CFE-419 was injected into the autoclave over 24 hours while blowing in 30% by volume fluorine gas at the same flow rate.
After the injection was completed, stirring was continued for 1 hour. Then, the pressure inside the autoclave was adjusted to atmospheric pressure, and nitrogen gas was blown in for 1 hour. The contents of the autoclave were concentrated with an evaporator, and the fluorinated sample was analyzed by ^19F -NMR to calculate the hydrogen remaining ratio (hereinafter referred to as "H remaining ratio") defined below.

H remaining ratio = average number of hydrogen atoms remaining in one molecule / average number of fluorine atoms in one molecule

^19F -NMR (282.7MHz, solvent: deuterated chloroform, standard: 1,4-bistrifluoromethylbenzene)
σ (ppm): -55 to -56, -75 to -95, -115 to -135, -144 to -145, -129 to -130.

The H remaining ratio was calculated as follows.
(integral value from -144 to -145)/(integral value from -55 to -145) in ^19F -NMR

[Example 2]
A fluorination reaction was carried out in the same manner as in Example 1, except that the raw material solution was changed to a solution in which 100 g of compound (A) was dissolved in 200 g of HCFE-428a,b, and the residual H ratio was calculated.

[Example 3]
A fluorination reaction was carried out in the same manner as in Example 1, except that the raw material solution was changed to a solution in which 100 g of compound (A) was dissolved in 200 g of HCFE-473, and the H remaining ratio was calculated.

[Example 4]
A fluorination reaction was carried out in the same manner as in Example 1 except that the raw material solution was changed to a solution in which 100 g of compound (A) was dissolved in 200 g of a mixed solution of HCFE-473 and CFE-419 in a mass ratio of 1:1, and the H remaining ratio was calculated.

[Example 5]
A fluorination reaction was carried out in the same manner as in Example 1 except that the raw material solution was changed to a solution in which 100 g of compound (A) was dissolved in 200 g of a mixed solution of HCFE-473 and CFE-419 in a mass ratio of 1:10, and the H remaining ratio was calculated.

The analytical values of the residual hydrogen ratio of the fluorinated products obtained in Examples 1 to 5 are shown in Table 2. The number of hydrogen atoms in CFE-419 is 0, the number of hydrogen atoms in HCFE-428 is 1, and the number of hydrogen atoms in HCFE-473 is 6. In the table, the reaction solvent is the combined solvent initially charged in the autoclave and the solvent in the raw material solution, and the ratio of the solvent amounts is expressed by mass ratio.

As shown in Table 2, liquid-phase fluorination using a compound having a C-H bond as a solvent improves the fluorination conversion rate.

The method for producing a fluorine-containing ester compound disclosed herein can produce a fluorine-containing ester compound with a high fluorination conversion rate. The obtained fluorine-containing ester compound can be derived into a fluorine-containing compound having various functional groups (e.g., a hydroxyl group, an ethylenically unsaturated group, an epoxy group, a carboxy group, etc.). In addition, the obtained fluorine-containing ester compound and fluorine-containing compound can be used as a surface treatment agent, an emulsifier, rubber, a surfactant, a solvent, a heat transfer medium, a pharmaceutical, an agricultural chemical, a lubricant, an intermediate thereof, etc.

The disclosure of Japanese Patent Application No. 2022-185986, filed on November 21, 2022, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

The method includes fluorinating an ester compound having at least one fluorinatable atom or bond in an organic solvent into which fluorine gas has been introduced,
The organic solvent contains a compound having a C—H bond,
the amount of the compound having a C—H bond is 0.1 times or more by mass of the ester compound having at least one fluorinatable atom or bond;
A method for producing a fluorine-containing ester compound.
The method for producing a fluorine-containing ester compound according to claim 1, wherein the compound having a C-H bond contains 1 to 10 hydrogen atoms.
The method for producing a fluorine-containing ester compound according to claim 1 or 2, wherein the organic solvent contains a compound having the C-H bond and a fluorine-containing compound not having a C-H bond.
The method for producing a fluorine-containing ester compound according to claim 1 or 2, wherein the content of the compound having a C-H bond in the organic solvent is 0.01% by mass or more.
The method for producing a fluorine-containing ester compound according to claim 3, wherein the compound having a C-H bond is a compound that can be fluorinated to convert it into a fluorine-containing compound that does not have the C-H bond.
The method for producing a fluorine-containing ester compound according to claim 1 or 2, wherein the fluorine content of the compound having a C-H bond is 5 to 99 mass %.
The method for producing a fluorine-containing ester compound according to claim 1 or 2, wherein the compound having a C-H bond is an alkane, an ether compound, an ester compound, a ketone compound, or a compound in which at least one hydrogen atom of these compounds has been substituted with a halogen atom.
The method for producing a fluorine-containing ester compound according to claim 1 or 2, wherein the ester compound having at least one fluorinatable atom or bond is a compound represented by the following formula (1) or (2):
R A1 -O-(C=O)-R B1 ... (1)
R B2 -(C=O)-O-R A2 -O-(C=O)-R B3 ... (2)
In formulas (1) and (2),
R A1 , R B1 , R B2 , and R B3 each independently represent a monovalent saturated hydrocarbon group, a halogeno monovalent saturated hydrocarbon group, a heteroatom-containing monovalent saturated hydrocarbon group, or a halogeno (heteroatom-containing monovalent saturated hydrocarbon) group;
R A2 is a divalent saturated hydrocarbon group, a halogeno divalent saturated hydrocarbon group, a heteroatom-containing divalent saturated hydrocarbon group, or a halogeno (heteroatom-containing divalent saturated hydrocarbon) group.
The method for producing a fluorine-containing ester compound according to claim 1 or 2, wherein the ester compound having at least one fluorinatable atom or bond contains a fluorine atom.