Fluorine-containing acrylic acid ester and methods for producing the same

Abstract

To provide a method for producing α,β-halogenopropionic acid esters from fluorine-containing secondary benzyl alcohol simply, with high yield, and through a short process in an industrially advantageous manner.SOLUTION: A fluorine-containing secondary benzyl alcohol is contacted with an α,β-dihalogenopropionic acid under solvent-free conditions, in the presence of a specific acid catalyst, and within a specific temperature range. This process produces a fluorine-containing α,β-dihalogenopropionic acid ester.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to monomers (fluorine-containing α-halogenoacrylic acid esters), precursors thereof, and methods for producing them, which are used in producing polymers constituting resists.

Background Art

[0002] Conventionally, in the field of semiconductor manufacturing and the like, polymers whose main chains are cleaved by irradiation with ionizing radiation such as electron beams and short-wavelength light such as ultraviolet light (hereinafter, ionizing radiation and short-wavelength light may be collectively referred to as "ionizing radiation etc.") and whose solubility in a developer increases are used as main-chain cleavage type positive resists. In order to achieve higher performance, various monomers constituting the copolymer have been studied.

[0003] Against such a background, the present applicant has also developed a main-chain cleavage type resist that can cope with the most advanced lithography processing. In particular, it has been found that a copolymer composed of α-chloroacrylic acid ester has very excellent performance (Patent Documents 1 and 2).

[0004] Conventionally, several documents have disclosed methods for producing α-halogenoacrylic acid esters, particularly α-chloroacrylic acid esters. Usually, a method of inducing an α,β-dichloropropionic acid ester corresponding to an α-chloroacrylic acid ester into an α-chloroacrylic acid ester by causing a dehydrochlorination reaction by contacting it with an organic amine or an inorganic alkali is often used. For example, in Patent Document 3, pentafluoropropanol, which is a primary alcohol, and acrylic acid are esterified at room temperature in the presence of a sulfuric acid / sulfuric acid fuming mixture to synthesize a pentafluoroacrylic acid ester, and then chlorine addition is carried out to convert it into a pentafluoropropyl α,β-dichloropropionate (two-step synthesis). Further, a method of obtaining the target pentafluoropropyl α-chloroacrylate using quinoline as an organic amine is disclosed. In Patent Document 4, 1-phenyl-2,2,2-trifluoroethanol, which is a secondary benzyl alcohol, was esterified with acryloyl chloride under sodium hydroxide to obtain 1-phenyl-2,2,2-trifluoroethyl acrylate, and then an addition reaction with chlorine gas was carried out to obtain 1-phenyl-2,2,2-trifluoroethyl 2,3-dichloropropionate in two steps.

[0005] As methods for synthesizing α,β-dichloropropionic acid esters, as described in Patent Documents 3 and 4, in addition to the method of contacting the corresponding acrylic acid ester with chlorine gas for chlorine addition, as described in Patent Document 5, tetrafluoropropanol and α,β-dichloropropionic acid are contacted with concentrated sulfuric acid under a benzene solvent for azeotropic dehydration to synthesize α,β-dichloropropionic acid tetrafluoropropyl ester. In Patent Document 6, it is described that in converting a fluorine-containing alcohol to an unsaturated carboxylic acid ester (having no halogen at the α-position), esterification was carried out in a fluorine-containing solvent and in the presence of an acid catalyst. Also, in Patent Document 7, it is described that an α-halogenoacrylic acid fluoroalkyl ester was synthesized by carrying out a transesterification reaction between an α,β-dichloropropionic acid alkyl ester and a primary fluorine-containing alcohol in the presence of an acid catalyst.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Summary of the Invention

Problems to be Solved by the Invention

[0007] From the above prior art, it can be seen that α,β-dichloropropionate is an important precursor compound in the production of α-chloroacrylate. That is, α,β-dihalogenopropionate is a compound in an industrially important position, and it is desired that these can be easily obtained.

[0008] The present invention has been made under such circumstances, and an object thereof is to provide a method for industrially advantageously producing an α,β-halogenopropionate from a fluorine-containing secondary benzyl alcohol simply, in good yield, and in a short process.

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the present inventors have newly found that a fluorine-containing α,β-dihalogenopropionate represented by the following formula (3) can be produced by contacting a fluorine-containing secondary benzyl alcohol represented by the following formula (1) with an α,β-dihalogenopropionic acid represented by the following formula (2) in the absence of a solvent and in the presence of a specific acid catalyst at a temperature within a certain range, and thus the present invention has been completed.

[0010] That is, the object of the present invention is to advantageously solve the above problems. The present invention provides a method for producing a fluorine-containing α,β-dihalogenopropionic acid ester represented by the following formula (3), comprising contacting a fluorine-containing secondary benzyl alcohol represented by the following formula (1) with an α,β-dihalogenopropionic acid represented by the following formula (2) in the absence of a solvent and in the presence of at least one acid catalyst selected from sulfuric acid, phosphoric acid, alkylsulfonic acid, and fluoroalkylsulfonic acid in a temperature range of 50°C or higher and 120°C or lower.

Chemical formula

Chemical formula

Chemical formula

[0011] [2] Here, X and Y in formulas (2) and (3) in the above [1] are preferably chlorine atoms. If X and Y in formulas (2) and (3) are chlorine atoms, the yield of the α,β-halogenopropionic acid ester can be further increased.

[0012] [3] Here, the acid catalyst in the above [1] or [2] is preferably at least one selected from sulfuric acid, methanesulfonic acid, and trifluoromethanesulfonic acid. If the acid catalyst is at least one selected from the above, it is more suitable from the viewpoint of easy availability.

[0013] [4] Further, the present invention is a fluorine-containing α,β-dihalogenopropionic acid ester represented by the following structural formula (4). [Chemical formula] (In the formula, Rf 2 represents pentafluoroethyl or heptafluoroisopropyl.)

[0014] [5] Furthermore, the present invention is a method for producing a fluorine-containing α-halogenoacrylic acid ester represented by the following structural formula (5), characterized in that the fluorine-containing α,β-dihalogenopropionic acid ester represented by the above formula (3) produced by any of the methods [1] to [3] above is further contacted with a base. By using the above method, the fluorine-containing α,β-dihalogenopropionic acid ester represented by the above formula (3) can be easily converted into a fluorine-containing α-halogenoacrylic acid ester represented by the following structural formula (5). [Chemical formula] (In the formula, Rf and X have the same meanings as described above.)

[0015] [6] In the above [5], X in the formula (5) is preferably a chlorine atom.

[0016] [7] Furthermore, the present invention is a fluorine-containing α-chloroacrylic acid ester represented by the following structural formula (6). [Chemical formula] (In the formula, Rf 3 represents pentafluoroethyl or heptafluoroisopropyl.) [Advantages of the Invention]

[0017] According to the present invention, there are provided a method for industrially advantageously producing an α,β-halogenopropionic acid ester from a fluorine-containing secondary benzyl alcohol simply, in good yield, and in a short process, and further a method for producing an α-halogenoacrylic acid ester of a fluorine-containing secondary benzyl alcohol useful as a monomer by treating the α,β-halogenopropionic acid ester of the fluorine-containing secondary benzyl alcohol obtained by the above method with a base, a novel α,β-halogenopropionic acid ester of a fluorine-containing secondary benzyl alcohol, and an α-halogenoacrylic acid ester of a fluorine-containing secondary benzyl alcohol.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, the present invention will be described in detail. As shown in the following reaction formula, the present invention provides a method for producing a fluorine-containing α,β-dihalogenopropionic acid ester represented by formula (3) by contacting a fluorine-containing secondary benzyl alcohol represented by formula (1) with an α,β-dihalogenopropionic acid represented by formula (2) in the absence of a solvent and in the presence of at least one acid catalyst selected from sulfuric acid, phosphoric acid, alkylsulfonic acid, and fluoroalkylsulfonic acid in a temperature range of 50°C or higher and 120°C or lower.

Chemical formula

[0019] As described above, several methods for producing α,β-dihalogenopropionic acid esters have been conventionally known. However, in the method of chlorinating a fluoroalkyl acrylate using chlorine gas as disclosed in Patent Documents 3 and 4, due to the strong electron-withdrawing property of the fluoroalkyl group, the electron density of the double bond portion of the fluoroalkyl acrylate as a raw material has decreased, and an electrophilic chlorine addition reaction is less likely to proceed compared to a normal acrylic acid ester, and it takes a long time until the reaction is completed. Further, it is suggested that the addition reaction of chlorine gas to the double bond proceeds by a radical mechanism, and there are several problems such as the generation of various impurities due to undesirable side reactions by chlorine radicals in addition to the addition reaction to the target double bond, and the number of steps is also large. Furthermore, in Patent Document 4, although a strong catalyst such as a mixture of sulfuric acid and fuming sulfuric acid is used as an acid catalyst when producing an acrylic acid ester, the yield is only moderate even after a reaction time of about 70 hours, and it is difficult to say that it is an efficient production method. Patent Document 5 describes a method of esterifying α,β-dichloropropionic acid as a raw material and tetrafluoropropanol using benzene as a solvent and sulfuric acid as a catalyst. However, benzene is highly toxic and its use is avoided in modern times. Further, only tetrafluoropropanol, which is a primary alcohol, is exemplified, and its applicability to other fluorinated alcohols is unknown. In Patent Document 6, when converting a fluorinated alcohol to an unsaturated carboxylic acid ester, esterification is carried out in the presence of a fluorinated solvent and an acid catalyst. However, the fluorinated solvent is expensive and measures such as recovery and reuse are required. In addition, α,β-dichloropropionic acid ester has a problem that the halogen atom at the β-position is easily dehydrohalogenated, which complicates the composition of the product, and has problems on both sides of efficiently promoting esterification while suppressing the dehydrohalogenation reaction.

[0020] In contrast, the present invention aims to provide a method for industrially advantageously producing α,β-halogenopropionic acid ester from fluorine-containing secondary benzyl alcohol simply, with good yield, and in a short process by the above configuration.

[0021] (Method for producing fluorine-containing α,β-dihalogenopropionic acid ester) <Fluorine-containing secondary benzyl alcohol> In this reaction, fluorine-containing secondary benzyl alcohol represented by the formula (1) is used as a raw material. Several reports have been made on the production method of fluorine-containing secondary benzyl alcohol, and it can be synthesized according to these methods. For example, the one-step synthesis method described in Journal of American Chemical Society, Vol. 107, 5186 (1985) or Chemistry Letters, 1337 (1981) can be applied. The former describes that fluorine-containing secondary benzyl alcohol was synthesized by ultrasonic irradiation of aromatic aldehyde and the corresponding perfluoroalkyl iodide in the presence of zinc. The latter describes that fluorine-containing secondary benzyl alcohol was obtained by contacting aromatic aldehyde and perfluoroalkyl iodide in the presence of pyridine and tin(II) chloride. As another method, a method described in Chemistry Letters, 81 (1977) can be applied, in which benzoyl fluoride and heptafluoroisopropyl zinc iodide are reacted to synthesize the corresponding phenyl perfluoroalkyl ketone, and the obtained ketone is reduced to obtain fluorine-containing secondary benzyl alcohol. Alternatively, as described in Journal of Organic Chemistry, Vol. 24, 996 (1959), a phenyl Grignard reagent and pentafluoropropionic acid are reacted to obtain pentafluoropropiophenone, and then the ketone is reduced with lithium aluminum hydride to obtain 1-phenylpentafluoropropanol, and a two-step reaction synthesis method can be applied.

[0022] The fluorine-containing secondary benzyl alcohol represented by the formula (1) is not particularly limited, but preferably the number of carbon atoms of Rf in the above formula (1) is 1 or more and 4 or less, more preferably 1 or more and 3 or less. Further, preferably the number of fluorine substitution groups of Rf in the above formula (1) is 3 or more, more preferably 5 or more, preferably 11 or less, and more preferably 7 or less. Specifically, fluorine-containing secondary alcohols such as 1-phenyl-2,2,2-trifluoroethanol, 1-phenyl-2,2,3,3,3-pentafluoropropanol, 1-phenyl-2,2,3,3,4,4,4-heptafluorobutanol, 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropanol, 1-phenyl-2,2,3,3,4,4,5,5,5-nonafluoropentanol, 1-phenyl-2,2,3,3,4,4,5,5,6,6,6-undecafluorohexanol can be mentioned. Among these, 1-phenyl-2,2,2-trifluoroethanol, 1-phenyl-2,2,3,3,3-pentafluoropropanol, and 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropanol, which are relatively easy to synthesize, are preferred.

[0023] <α,β-dihalogenopropionic acid> The α,β-dihalogenopropionic acid used for esterification is not particularly limited, but specifically, α,β-dichloropropionic acid, α,β-dibromopropionic acid, α,β-difluoropropionic acid, α-fluoro-β-chloropropionic acid, α-bromo-β-chloropropionic acid and other α,β-dihalogenopropionic acids can be mentioned. Among these, α,β-dichloropropionic acid and α,β-dibromopropionic acid are preferred from the viewpoint of availability, and commercially available products can be used as they are.

[0024] The amount of α,β-dihalogenopropionic acid used is usually 1.0 to 5.0 equivalents, preferably 1.5 to 3.0 equivalents, relative to the fluorine-containing secondary benzyl alcohol. When the amount of α,β-dihalogenopropionic acid used is at least the above lower limit, the esterification proceeds easily and a decrease in the yield of the fluorine-containing α,β-dihalogenopropionic acid ester can be prevented. When the amount used is at most the above upper limit, it is economical and the purification operation after the reaction is easy.

[0025] <Solvent> In the present invention, the esterification reaction is carried out without using a solvent. By not using a solvent, the contact between the fluorine-containing secondary benzyl alcohol represented by the formula (1) and the α,β-dihalogenopropionic acid represented by the formula (2) under an acid catalyst is improved, and the esterification of the fluorine-containing secondary benzyl alcohol with low reactivity proceeds efficiently. Therefore, it has advantages such as being able to obtain the target fluorine-containing α,β-dihalogenopropionic acid ester represented by the formula (3) in good yield, and being able to carry out the esterification using a reactor with a small internal volume. In this esterification reaction, if an organic solvent is added for the purpose of separating (extracting) the target fluorine-containing α,β-dihalogenopropionic acid ester from the acid catalyst, the esterification reaction becomes very slow, and satisfactory results cannot be obtained even if the reaction is carried out for a long time.

[0026] In many prior arts, it is described regarding the (α-halogeno)acrylic acid ester of a primary fluorine-containing alcohol or the α,β-dihalogenopropionic acid ester, and the technique of converting the fluorine-containing secondary benzyl alcohol used in the present invention into an α,β-dihalogenopropionic acid ester is not touched upon. Since the esterification reaction of the fluorine-containing secondary benzyl alcohol has poor reactivity compared to the fluorine-containing primary alcohol, there has been a problem that satisfactory results are difficult to obtain with an esterification method using an acid catalyst under a solvent and a reaction temperature condition of about room temperature.

[0027] <Acid catalyst> As the acid catalyst used in the present invention, inorganic acids such as sulfuric acid and phosphoric acid, alkylsulfonic acids such as methanesulfonic acid and ethanesulfonic acid, and acids that are liquid at room temperature such as trifluoromethanesulfonic acid and pentafluoropropionic acid are used. Among these, sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, etc. can be preferably used from the viewpoint of easy availability.

[0028] This reaction is a dehydration esterification reaction under an acid catalyst, and water is generated as the reaction proceeds. By using an excessive amount of the acid catalyst with respect to the fluorine-containing secondary benzyl alcohol as the raw material, it is supplemented by the excess acid catalyst.

[0029] The amount of the acid catalyst used depends on the activity of the acid catalyst used, but is usually 1.0 mol or more and 5.0 mol or less, preferably 1.5 mol or more and 3.0 mol or less, in terms of equivalents to the fluorine-containing secondary benzyl alcohol used as the raw material. If the amount of the acid catalyst used is at least the above lower limit, the transesterification reaction can proceed smoothly and a decrease in the yield of the target fluorine-containing α,β-dihalogenopropionic acid ester can be prevented. On the other hand, if the amount of the acid catalyst used is at most the above upper limit, the separation operation during post-treatment becomes easy, or the amount of waste liquid can be suppressed.

[0030] <Reaction conditions of the esterification reaction> As the reaction form of the present invention, a reactor equipped with a cooling pipe is charged with a fluorine-containing secondary benzyl alcohol as the raw material, α,β-dihalogenopropionic acid, and a predetermined amount of an acid selected from sulfuric acid, phosphoric acid, alkylsulfonic acid, or fluoroalkylsulfonic acid, and the contents are heated to an arbitrary temperature while stirring. After heating is continued for a predetermined time, the reactor is cooled to room temperature. During heating, since the water generated as the esterification proceeds is supplemented by the excessive amount of the acid catalyst, the equilibrium of the dehydration esterification reaction can be shifted to the product side.

[0031] The reaction temperature for carrying out the esterification reaction is set according to the fluorine-containing secondary benzyl alcohol used, as well as the type and addition amount of α,β-dihalogenopropionic acid. Usually, it is 50°C or higher and 120°C or lower, preferably 80°C or higher and 110°C or lower. If the reaction temperature is at or above the lower limit value, the esterification reaction can proceed sufficiently. Further, if the reaction temperature is at or below the upper limit value, dehydrohalogenation of α,β-dihalogenopropionic acid and the resulting fluorine-containing α,β-dihalogenopropionic acid ester can be prevented, and the formation of α-halogenoacrylic acid and fluorine-containing α-halogenoacrylic acid ester in the system can be inhibited. If the reaction temperature is at or below the upper limit value, polymerization of these products due to the action of heat can be prevented, and the yield of the target product, fluorine-containing α,β-dihalogenopropionic acid ester, can be maintained.

[0032] The reaction time for carrying out the esterification reaction depends on the reaction temperature. Usually, it is 10 hours or longer and 5 days or shorter, preferably 20 hours or longer and 3 days or shorter. If the reaction time is at or above the lower limit value, the esterification reaction can be completed, and a large amount of the raw material, fluorine-containing secondary benzyl alcohol, remaining can be prevented. If the reaction time is at or below the upper limit value, dehydrohalogenation of α,β-dihalogenopropionic acid and the resulting fluorine-containing α,β-dihalogenopropionic acid ester can be caused, and problems such as the formation and polymerization of the corresponding α-halogenoacrylic acid and fluorine-containing α-halogenoacrylic acid ester can be prevented.

[0033] In order to prevent unexpected side reactions (polymerization) during the esterification reaction, a polymerization inhibitor may be added to the reaction system as necessary. The polymerization inhibitor is not particularly limited, but specifically, phenolic compounds such as hydroquinone, p-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, tert-butyl-catechol, 2,6-di-tert-butyl-4-methylphenol, pentaerythritol, tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), and 2-sec-butyl-4,6-dinitrophenol; amine compounds such as N,N'-diisopropyl paraphenylenediamine, N,N'-di-2-naphthyl paraphenylenediamine, N-phenylene-N'-(1,3-dimethylbutyl) paraphenylenediamine, N,N'-bis(1,4-dimethylphenyl)-paraphenylenediamine, and N-(1,4-dimethylphenyl)-N'-phenyl-paraphenylenediamine; and N-oxyl compounds such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, etc. can be mentioned.

[0034] As a post-treatment after the reaction is completed, the reaction solution is cooled, water is added, and then an organic solvent for extraction is added to extract the product. The extract is washed with weak alkaline water such as saturated sodium bicarbonate water to remove acid components, then washed with saturated brine, and dried with a desiccant. Thereafter, the solvent is distilled off from the post-treated extract, and the target fluorine-containing α,β-dihalogenopropionic acid ester can be obtained by means such as concentration, distillation purification, or column chromatography purification.

[0035] (Method for producing fluorine-containing α-halogenoacrylic acid ester) The fluorine-containing α,β-dihalogenopropionic acid ester obtained by the above method can be further converted into an industrially useful fluorine-containing α-halogenoacrylic acid ester by contacting it with a base.

[0036] <Base> The base to be used is not particularly limited. Specifically, as organic bases, tertiary amines such as triethylamine, tripropylamine, and tributylamine; pyridines such as pyridine, 2-methylpyridine, 2,6-dimethylpyridine, and 2,4,6-trimethylpyridine; dialkylanilines such as dimethylaniline and diethylaniline; and heterocyclic aromatic compounds such as quinoline and isoquinoline can be mentioned. As inorganic bases, carbonates such as sodium carbonate, potassium carbonate, and cesium carbonate, and phosphates such as sodium phosphate and potassium phosphate can be mentioned. Among these, organic bases such as triethylamine and pyridine are preferable from the viewpoint of ease of carrying out the reaction.

[0037] The amount of the base used is 1.0 mol or more and 3.0 mol or less equivalents, preferably 1.5 mol or more and 2.0 mol or less equivalents, relative to the fluorine-containing α,β-dihalogenopropionate ester as a raw material. If the amount of the base used is at least the above lower limit value, the dehydrohalogenation reaction can be completed, and the remaining unreacted fluorine-containing α,β-dihalogenopropionate ester can be prevented. On the other hand, if the amount of the base used is at most the above upper limit value, problems such as alteration of the fluorine-containing α-haloacrylate ester produced by the reaction can be prevented.

[0038] <Reaction conditions for the dehydrohalogenation reaction> When carrying out the dehydrohalogenation reaction by contacting with a base, usually, the fluorine-containing α,β-dihalogenopropionic acid ester as a raw material is diluted in an organic solvent. The organic solvent to be used is not particularly limited, but specifically, halogenated hydrocarbons such as methylene chloride, chloroform and 1,2-dichloroethane, ethers such as methyl t-butyl ether, tetrahydrofuran, diisopropyl ether and cyclopentyl methyl ether, and aromatic hydrocarbons such as toluene, xylene and chlorobenzene can be mentioned. Among these, halogenated hydrocarbons such as methylene chloride and chloroform, and ethers such as methyl t-butyl ether, tetrahydrofuran and diisopropyl ether are preferable in that the solvent can be easily distilled off from the reaction solution.

[0039] Since the dehydrohalogenation reaction of the fluorine-containing α,β-dihalogenopropionic acid ester by contact with a base may be accompanied by heat generation, the reaction is carried out under cooling, but usually, it is carried out in the range of -10°C or higher and 30°C or lower. If the reaction temperature is at or above the above lower limit value, the reaction can proceed at a sufficient rate. If the reaction temperature is at or below the above upper limit value, polymerization of the product, α-halogenoacrylic acid phenyl esters, can be prevented.

[0040] Also, the reaction time depends on the reaction conditions to be applied, but usually, it is 0.5 hours or more and 20 hours or less, preferably 1 hour or more and 10 hours or less. If the reaction time is at or above the above lower limit value, the reaction can be completed and a decrease in yield can be prevented. If the reaction time is at or below the above upper limit value, polymerization of the product, fluorine α-halogenoacrylic acid ester, can be prevented and the yield can be maintained.

[0041] In the dehydrohalogenation reaction of a fluorine-containing α,β-dihalogenopropionate ester by contact with a base, in order to prevent unexpected side reactions (polymerization) during the reaction, a polymerization inhibitor may be added to the reaction system as necessary. The polymerization inhibitor is not particularly limited, but specifically, phenolic compounds such as hydroquinone, p-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, tert-butylcatechol, 2,6-di-tert-butyl-4-methylphenol, pentaerythritol, tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), and 2-sec-butyl-4,6-dinitrophenol; amine compounds such as N,N'-diisopropyl paraphenylenediamine, N,N'-di-2-naphthyl paraphenylenediamine, N-phenylene-N'-(1,3-dimethylbutyl) paraphenylenediamine, N,N'-bis(1,4-dimethylphenyl)-paraphenylenediamine, and N-(1,4-dimethylphenyl)-N'-phenyl-paraphenylenediamine; and N-oxyl compounds such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, etc. can be mentioned.

[0042] As the form of the reaction, for example, the following form can be adopted. A solvent is added to the raw material fluorine-containing α,β-dihalogenopropionate ester and cooled to an arbitrary temperature. While stirring the content, an organic amine is added dropwise. After the addition dropwise is completed, it is stirred at that temperature for a while, then the temperature is raised to room temperature (about 15°C or more and 25°C or less), and stirring is continued. The content is analyzed by gas chromatography or the like, and when the raw material fluorine-containing α,β-dihalogenopropionate ester disappears, the stirring is stopped.

[0043] As a post-treatment method after the reaction, the organic amine-hydrogen halide salt generated by the reaction is removed by filtration, or the reaction solution is brought into contact with water to wash the organic amine-hydrogen halide salt with water and remove it into water, etc. In the former case, the filtrate after filtration, and in the latter case, the solution after washing with water, is brought into contact with a diluted acid (for example, dilute hydrochloric acid or dilute sulfuric acid, etc.) to remove the excess organic amine. Thereafter, the solution is washed with water, or an aqueous solution of a diluted alkali carbonate or alkali hydrogen carbonate (the concentration is an aqueous solution of 5% by weight or more and 20% by weight or less), and then washed with saturated brine. The solution obtained by such an operation is dried with a desiccant such as sodium sulfate or magnesium sulfate, and then the solvent is distilled off from the solution to obtain a fluorine-containing α-halogenoacrylate ester.

[0044] The thus-obtained crude α-halogenoacrylate ester is purified by a method such as distillation or column chromatography, or in the case of a solid, by a recrystallization method, etc., and can be made into a state of higher purity.

Examples

[0045] Hereinafter, the present invention will be described in more detail by way of examples, but the scope of the present invention is not limited by the following examples. Unless otherwise specified, “%” represents “% by weight”.

[0046] The analysis conditions adopted hereinafter are as follows. <NMR measurement> Nuclear magnetic resonance apparatus “Bruker Avance III 400 type” (manufactured by Bruker BioSpin Corporation) · Measurement solvent: deuterated chloroform (CDCl3) · Reference substance: tetramethylsilane (TMS) <IR measurement> “FTIR-8700” (manufactured by Shimadzu Corporation) · Window plate: NaCl (liquid film method)

[0047] (Synthesis of fluorine-containing secondary benzyl alcohol) <Synthesis Example 1> Synthesis of 1-Phenyl-2,2,3,3,3-pentafluoropropanol (1) Synthesis of Phenylheptafluoroisopropyl Ketone Into a 500 ml round-bottomed flask equipped with a Dimroth condenser, a dropping funnel with a side tube, and a stir bar, magnesium (2.43 g, 0.1 mol) and dry tetrahydrofuran (60 ml) were placed and immersed in a water bath. While stirring the contents, a small amount of iodine was added, and a solution prepared by dissolving bromobenzene (15.2 g, 0.10 mol) in dry tetrahydrofuran (20 ml) was added dropwise from the dropping funnel over about 25 minutes. After completion of the dropwise addition, the temperature of the water bath was raised, and the contents were stirred and heated at 60 °C for 3 hours. Then, the reactor was cooled with ice water, and a solution prepared by dissolving sodium pentafluoropropionate (22.3 g, 0.12 mol) in dry tetrahydrofuran (70 ml) was added dropwise from the dropping funnel over about 1 hour. After completion of the dropwise addition, stirring was continued for 3 hours while maintaining cooling with ice water. 10% ammonium chloride aqueous solution (100 ml) and water (100 ml) were sequentially added into the reactor, and the contents were transferred to a separatory funnel. Extraction was performed with methyl t-butyl ether, and the extract was washed with saturated sodium bicarbonate solution and saturated brine, and dried over magnesium sulfate. The obtained solution was concentrated using a rotary evaporator to obtain a brown oily substance (16.2 g). The crude product obtained by repeating this reaction several times was subjected to vacuum distillation, and when the fraction having a boiling point of 104 - 105 °C / 15 kPa was collected, 83 g of colorless phenylpentafluoroethyl ketone was obtained. (2) Synthesis of 1-Phenyl-2,2,3,3,3-pentafluoropropanol Into a Jim-Rhoades type condenser and a 500 ml round-bottomed flask equipped with a stir bar, phenylpentafluoroethyl ketone (22.4 g, 0.1 mol) synthesized in (1) and methanol (150 ml) were added and cooled with ice water. Sodium borohydride (2.84 g, 0.075 mol) was added in three portions thereto, and stirring was continued for about 10 hours. Stirring was stopped, and the contents were concentrated on a rotary evaporator to distill off most of the methanol. The resulting residue was cooled with ice water, and cold water (100 ml) was added. The contents were transferred to a separatory funnel, extracted with diethyl ether (80 ml × 1 time, 40 ml × 2 times), and the combined extracts were washed with saturated brine and dried over magnesium sulfate. The resulting solution was concentrated on a rotary evaporator to obtain a colorless oily substance (22.0 g). The crude product obtained by repeating this reaction several times was subjected to vacuum distillation, and when the fraction having a boiling point of 60 to 62 °C / 0.28 kPa was collected, 50.8 g of colorless 1-phenyl-2,2,3,3,3-pentafluoropropanol was obtained.

[0048] <Synthesis Example 2> Synthesis of 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropanol (1) Synthesis of phenylheptafluoroisopropyl ketone Into a 500 ml round-bottomed flask equipped with a Jim-Rhoades condenser, a dropping funnel with a side tube, and a stir bar, add benzoyl chloride (16.9 g, 0.1 mol), heptafluoroisopropyl iodide (41.5 g, 0.14 mol), and dry tetrahydrofuran (200 ml). Immerse the flask in a dry ice-ethanol bath and cool it to -40°C. While stirring the contents, add tris(dimethylamino)phosphine (25.8 g, 0.16 mol) dropwise from the dropping funnel over about 20 minutes. After the addition is complete, continue stirring for 2 hours while maintaining the contents at -40°C, and then gradually warm the temperature to 20°C over about 4 hours while stirring. Filter the contents through filter paper to remove solids, and then concentrate the filtrate using a rotary evaporator to distill off most of the tetrahydrofuran. Add n-hexane (150 ml) to the resulting residue and transfer the contents to a separatory funnel. Wash with water, saturated sodium bicarbonate solution, saturated sodium bicarbonate solution, and saturated brine, dry over magnesium sulfate, and then concentrate the resulting solution using a rotary evaporator to obtain a brown oil (19.6 g). The crude product obtained by repeating this reaction several times was distilled under reduced pressure, and when the fraction with a boiling point of 96-98°C / 10 kPa was collected, 78 g of colorless phenylheptafluoroisopropyl ketone was obtained. (2) Synthesis of 1-Phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropanol Into a Jimroth condenser and a 500 ml round-bottomed flask equipped with a stir bar, phenylheptafluoroisopropyl ketone (27.4 g, 0.1 mol) synthesized in (1) and methanol (150 ml) were added, and the mixture was cooled with ice water. Sodium borohydride (2.84 g, 0.075 mol) was added in three portions thereto, and stirring was continued for about 10 hours. Stirring was stopped, and the contents were concentrated on a rotary evaporator to distill off most of the methanol. The resulting residue was cooled with ice water, and cold water (100 ml) was added. The contents were transferred to a separatory funnel, extracted with diethyl ether (80 ml × 1 time, 40 ml × 2 times), and the combined extracts were washed with saturated brine and dried over magnesium sulfate. The resulting solution was concentrated on a rotary evaporator to obtain a colorless oily substance (24.7 g). The crude product obtained by repeating this reaction several times was distilled under reduced pressure, and when the fraction having a boiling point of 68 to 70 °C / 0.25 kPa was collected, 83.9 g of colorless 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropanol was obtained.

[0049] (Production of fluorine-containing α,β-dihalogenopropionic acid esters and fluorine-containing α-halogenoacrylic acid esters) [Example 1] Into a Jim-Rhoads type condenser and a 500 ml round-bottomed flask equipped with a stir bar, 1-phenyl-2,2,3,3,3-pentafluoropropanol (45.2 g, 0.2 mol) synthesized in Synthesis Example 1, α,β-dichloropropionic acid (manufactured by Tokyo Chemical Industry, 57.2 g, 0.4 mol), and 58.0 g (0.6 mol) of concentrated sulfuric acid as an acid catalyst were charged. A refrigerant at 0 °C was circulated through the condenser. The round-bottomed flask was immersed in an oil bath and heating was continued at 90 °C for 20 hours. After stopping the heating and cooling to room temperature, the reactor was cooled with ice water, and while stirring the contents, 150 ml of cold water was slowly added. The contents were transferred to a separatory funnel and extracted with methylene chloride (150 ml), and the extract was transferred to a 1 L beaker. The beaker was cooled with ice water, and while stirring the contents, saturated aqueous sodium bicarbonate (600 ml) was added little by little. After confirming that the aqueous layer was weakly alkaline, the liquid in the beaker was transferred to a separatory funnel again, washed with saturated brine, and dried over magnesium sulfate. When the solution was concentrated with an evaporator, a brown oily substance was obtained, and this oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)), and 66.2 g of α,β-dichloropropionic acid 1-phenyl-2,2,3,3,3-pentafluoropropyl was recovered as an oily substance (yield: 94%). 1 1H-NMR (CDCl3): δ 3.85 (d, 1H), 3.92 (m, 1H), 4.60 (t, 1H), 4.97 (m, 1H), 7.36 (m, 5H) FT-IR (neat): 1750 cm -1 (C=O)

[0050] [Example 2] In Example 1, the reaction was carried out in the same manner as in Example 1 except that the acid catalyst was changed from 58.0 g of concentrated sulfuric acid to 57.0 g (0.6 mol) of methanesulfonic acid. The solution after post-treatment was concentrated with an evaporator, and the obtained oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)), and 54.6 g of α,β-dichloropropionic acid 1-phenyl-2,2,3,3,3-pentafluoropropyl was recovered as an oily substance (yield: 77%).

[0051] [Example 3] In Example 1, the reaction was carried out in the same manner as in Example 1, except that the acid catalyst was changed from 58.0 g of concentrated sulfuric acid to 75.0 g (0.5 mol) of trifluoromethanesulfonic acid. The solution after post-treatment was concentrated with an evaporator, and the obtained oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)). As a result, 54.6 g of 1-phenyl-2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate was recovered as an oily substance (yield: 77%).

[0052] [Example 4] In Example 1, the reaction was carried out in the same manner as in Example 1, except that the raw material was changed from 1-phenyl-2,2,3,3,3-pentafluoropropanol (45.2 g, 0.2 mol) to 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropanol (55.2 g, 0.2 mol) synthesized in Synthesis Example 2. The solution after post-treatment was concentrated with an evaporator, and the obtained oily substance was purified by silica gel column chromatography (developing solvent n-hexane:ethyl acetate = 20:1 (volume ratio)). As a result, 69.7 g of 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropyl α,β-dichloropropionate was recovered as an oily substance (yield: 77%). 1 H-NMR (CDCl3): δ 3.85 (d, 1H), 3.92 (m, 1H), 4.61 (t, 1H), 4.99 (m, 1H), 7.36 (m, 5H) FT-IR (neat): 1751 cm -1 (C=O)

[0053] [Example 5] Into a Jim-Roth type condenser and a 500 ml round-bottomed flask equipped with a stir bar, 1-phenyl-2,2,3,3,3-pentafluoropropanol (11.3 g, 0.05 mol) synthesized in Synthesis Example 1, α,β-dibromopropionic acid (manufactured by Tokyo Chemical Industry, 46.7 g, 0.2 mol), and 15.0 g (0.15 mol) of concentrated sulfuric acid as an acid catalyst were charged. A refrigerant at 0 °C was circulated through the condenser. The round-bottomed flask was immersed in an oil bath and heating was continued at 90 °C for 30 hours. After stopping the heating and cooling to room temperature, the reactor was cooled with ice water, and while stirring the contents, 50 ml of cold water was slowly added. The contents were transferred to a separatory funnel and extracted with methylene chloride (100 ml), and the extract was transferred to a 1 L beaker. The beaker was cooled with ice water, and while stirring the contents, saturated aqueous sodium bicarbonate (300 ml) was added little by little. After confirming that the aqueous layer was weakly alkaline, the liquid in the beaker was transferred to a separatory funnel again, washed with saturated brine, and dried over magnesium sulfate. When the solution was concentrated with an evaporator, a brown oily substance was obtained, and this oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)), and 14.6 g of 1-phenyl-2,2,3,3,3-pentafluoropropyl α,β-dibromopropionate was recovered as an oily substance (yield: 61%). 1 1H-NMR (CDCl3): δ 3.88 (d, 1H), 3.95 (m, 1H), 4.65 (t, 1H), 4.99 (m, 1H), 7.36 (m, 5H) FT-IR (neat): 1750 cm -1 (C=O)

[0054] [Example 6] Into a 1 L round-bottomed flask equipped with a Jim-Rhoads condenser, a dropping funnel with a side tube, and a stir bar, add 1-phenyl-2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate (55.0 g, 0.156 mol) obtained in Example 1 and methyl t-butyl ether (300 ml), and cool the flask to 0 °C with ice water. After adding p-methoxyphenol (0.5 g), triethylamine (24.0 g, 0.235 mol) was added dropwise from the dropping funnel over about 20 minutes. After stirring the contents for 6 hours, the triethylamine hydrochloride produced by the reaction was removed by filtration, and the filtrate was transferred to a separatory funnel. The solution in the separatory funnel was washed with 5% hydrochloric acid, saturated sodium bicarbonate solution, and saturated brine, and dried over magnesium sulfate. When the solution was concentrated with an evaporator, a brownish oil was obtained, and this oil was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)) to recover 40.2 g of 1-phenyl-2,2,3,3,3-pentafluoropropyl α-chloropropionate as an oil (yield: 85%). 1 H-NMR(CDCl3):δ4.96(m,1H),6.28(s,1H),6.85(s,1H),7.36(m,5H)FT-IR(neat):1614cm -1 (C=C),1751cm -1 (C=O)

[0055] [Example 7] Into a Jim-Rhoads type condenser, a dropping funnel with a side tube, and a 1 L round-bottomed flask equipped with a stir bar, were placed 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropyl α,β-dichloropropionate (68.2 g, 0.17 mol), which was obtained in Example 4, and methyl t-butyl ether (400 ml), and the flask was cooled with ice water. After adding p-methoxyphenol (0.5 g), triethylamine (25.8 g, 0.255 mol) was added dropwise from the dropping funnel over about 20 minutes. After stirring the contents for 7 hours, the triethylamine hydrochloride produced by the reaction was removed by filtration, and the filtrate was transferred to a separatory funnel. The solution in the separatory funnel was washed with 5% hydrochloric acid, saturated aqueous sodium bicarbonate, and saturated brine, and dried over magnesium sulfate. When the solution was concentrated with an evaporator, a brown oily substance was obtained, and this oily substance was purified by silica gel column chromatography (developing solvent: n-hexane) to recover 58.0 g of 1-phenyl-2-trifluoromethyl-2,3,3,3-tetrafluoropropyl α-chloropropionate as an oily substance (yield: 93%). 1 H-NMR(CDCl3):δ4.99(m, 1H), 6.28(s,1H),6.85(s,1H),7.37(m, 5H)FT-IR(neat):1612cm -1 (C=C), 1755cm -1 (C=O)

[0056] [Comparative Example 1] Into a Jim-Rhoads type condenser and a 300 ml round-bottomed flask equipped with a stir bar were charged 1-phenyl-2,2,3,3,3-pentafluoropropanol (11.3 g, 0.05 mol) synthesized in Synthesis Example 1, α,β-dichloropropionic acid (manufactured by Tokyo Chemical Industry, 14.3 g, 0.1 mol), chloroform (100 ml) as a solvent, and 14.7 g (0.15 mol) of concentrated sulfuric acid as an acid catalyst. A refrigerant at 0 °C was circulated through the condenser. The round-bottomed flask was immersed in an oil bath and heating was continued at 90 °C for 20 hours. After stopping the heating and cooling to room temperature, the reactor was cooled with ice water, and while stirring the contents, 150 ml of cold water was slowly added. The contents were transferred to a separatory funnel, and the extract was transferred to a 1 L beaker. The beaker was cooled with ice water, and while stirring the contents, saturated aqueous sodium bicarbonate (300 ml) was added little by little. After confirming that the aqueous layer was weakly alkaline, the liquid in the beaker was transferred to a separatory funnel again, washed with saturated brine, and dried over magnesium sulfate. When the solution was concentrated with an evaporator, a brown oily substance was obtained, and this oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)), and 4.0 g of α,β-dichloropropionic acid 1-phenyl-2,2,3,3,3-pentafluoropropyl was recovered as an oily substance (yield: only 23%). From this, it can be seen that the reaction hardly proceeds when a solvent is added to this reaction.

[0057] [Comparative Example 2] In Comparative Example 1, the reaction was carried out in the same manner as in Comparative Example 1 except that the solvent was changed from chloroform to methyl nonafluorobutyl ether (100 ml), which is a fluorinated solvent. The solution after post-treatment was concentrated with an evaporator, and the obtained oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)), and 2.98 g of α,β-dichloropropionic acid 1-phenyl-2,2,3,3,3-pentafluoropropyl was recovered as an oily substance (yield: only 17%). Similar to Comparative Example 1, it can be seen that the reaction hardly proceeds even when a fluorinated solvent is used.

[0058] [Comparative Example 3] In Example 1, the reaction was carried out according to Example 1 except that the reaction temperature was changed to 25°C and the reaction time was changed to 50 hours. The solution after post-treatment was concentrated with an evaporator, and the obtained oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)). As a result, 15.3 g of 1-phenyl-2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate was recovered as an oily substance (yield: 22%). It can be seen that the esterification rate is slow at a reaction temperature near room temperature, and the reaction hardly proceeds even after a long reaction time.

[0059] [Comparative Example 4] In Example 1, the reaction was carried out according to Example 1 except that the reaction temperature was changed to 130°C. After stopping heating and cooling to room temperature, the reactor was cooled with ice water, and while stirring the contents, cold water (150 ml) was slowly added. When the contents were transferred to a separatory funnel and methylene chloride (150 ml) was added, precipitation of a polymer was observed. After removing the polymer by filtration through absorbent cotton, the filtrate was treated in the same manner as in Example 1. The solution after post-treatment was concentrated with an evaporator, and the obtained oily substance was purified by silica gel column chromatography (developing solvent, n-hexane:ethyl acetate = 20:1 (volume ratio)). As a result, 40.7 g of 1-phenyl-2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate was recovered as an oily substance (yield: 57.8%). It is presumed that part of 1-phenyl-2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate underwent dehydrochlorination by heat to form 1-phenyl-2,2,3,3,3-pentafluoropropyl α-chloropropionate, which polymerized. [Industrial Applicability]

[0060] According to the present invention, there are provided a method for industrially advantageously producing an α,β-halogenopropionic acid ester from a fluorine-containing secondary benzyl alcohol simply, in good yield, and in a short process, a method for producing an α-halogenoacrylic acid ester of a fluorine-containing secondary benzyl alcohol useful as a monomer by treating the α,β-halogenopropionic acid ester of the fluorine-containing secondary benzyl alcohol obtained by the method with a base, a novel α,β-halogenopropionic acid ester of a fluorine-containing secondary benzyl alcohol, and an α-halogenoacrylic acid ester of a fluorine-containing secondary benzyl alcohol.

Claims

1. A method for producing a fluorine-containing α,β-dihalogenopropionic acid ester represented by the following formula (3), characterized by contacting a fluorine-containing secondary benzyl alcohol represented by the following formula (1) and an α,β-dihalogenopropionic acid represented by the following formula (2) in the absence of a solvent and in the presence of at least one acid catalyst selected from sulfuric acid, phosphoric acid, alkylsulfonic acid, and fluoroalkylsulfonic acid in a temperature range of 50°C or higher and 120°C or lower. 【Chemical 1】 (In the formula, Rf represents a fluorine-containing alkyl group having 1 to 5 carbon atoms.) [Chemical Formula 2] (In the formula, X and Y independently represent a halogen atom selected from fluorine, chlorine, or bromine.) [Chemical Formula 3] (In the formula, Rf represents a fluorine-containing alkyl group having 1 to 5 carbon atoms, and X and Y independently represent a halogen atom selected from fluorine, chlorine, or bromine.)

2. The production method according to Claim 1, characterized in that X and Y in the formulas (2) and (3) are chlorine atoms.

3. The production method according to Claim 1, characterized in that the acid catalyst is at least one selected from sulfuric acid, methanesulfonic acid, and trifluoromethanesulfonic acid.

4. A fluorine-containing α,β-dihalogenopropionic acid ester represented by the following structural formula (4). 【Chemical 4】 (wherein, Rf ２ represents pentafluoroethyl or heptafluoroisopropyl.)

5. A method for producing a fluorine-containing α-halogenoacrylic acid ester represented by the following structural formula (5), characterized by further contacting the fluorine-containing α,β-dihalogenopropionic acid ester represented by the formula (3) produced by the method according to any one of Claims 1 to 3 with a base. 【Chemical Formula 5】 (In the formula, Rf and X have the same meanings as described above.)

6. The production method according to Claim 5, characterized in that X in the formula (5) is a chlorine atom.

7. A fluorine-containing α-chloroacrylic acid ester represented by the following structural formula (6). [Chemical Formula 6] (wherein, Rf ３ represents pentafluoroethyl or heptafluoroisopropyl.)

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