JP4359519B2 - 1,1-bis (trifluoromethyl) -1,3-diols acrylic ester and method for producing the same - Google Patents

Description

  The present invention is a 1,1-bis (trifluoromethyl) -1,3-diol acrylic acid ester represented by the general formula [1], which is a novel acrylic acid ester containing a hexafluorocarbinol group. And a manufacturing method thereof.

(In the formula [1], R ¹ is a hydrogen atom, a methyl group, an ethyl group, a lower alkyl group, a trifluoromethyl group, a trifluoroethyl group, or a lower perfluoroalkyl group.)

 Fluorine-based compounds are in the field of advanced materials due to the characteristics of fluorine such as water repellency, oil repellency, low water absorption, heat resistance, weather resistance, corrosion resistance, transparency, photosensitivity, low refractive index, and low dielectric properties. It is used or developed in a wide range of application fields. Especially when taking advantage of the characteristics of transparency behavior at each wavelength, it is applied in the coating field. It is an anti-reflective film that applies low refractive index and transparency of visible light, in the high wavelength band (optical communication wavelength band). Active research and development is being conducted in the fields of optical devices applying transparency, resist materials applying transparency in the ultraviolet region (particularly in the vacuum ultraviolet wavelength region), and the like.

  As a common polymer design in these application fields, by introducing as much fluorine as possible to achieve transparency at each wavelength used, adhesion to the substrate, high glass transition point (Tg), that is, high It is intended to achieve hardness. However, various proposals have been made to improve the transparency at each wavelength by improving the fluorine content as a material design, but at the same time, the fluorine-containing monomer itself is improved in hydrophilicity and adhesion and has a high Tg. There are few examples that are devised.

Recently, particularly in the field of next-generation F ₂ resist in the vacuum ultraviolet region, hydroxyl group-containing fluorine-based styrene (see, for example, Non-Patent Document 1) and hydroxyl group-containing fluorine-based norbornene compounds (for example, Non-Patent Document 2). As a result, the idea of containing fluorine and allowing the polarity of the hydroxyl group to coexist has come to be seen.

Further, the present applicant has found a fluorine-containing polymerizable monomer in which fluorine and a hydroxyl group coexist in the molecule as a hexafluoroisopropanol group, and a resist containing the polymerizable monomer as a constituent element transmits light. Patent Document 1 discloses that the surface property and surface adsorbability are excellent.
T. H. Fedynhyyn, A. Cabral, et al, J. Photopolym. Sci. Technol., 15, 655-666 (2002) (Japan) Ralph R. Dammel, Raj Sakamura, et al, J. Photopolym. Sci. Technol., 14, 603-612 (2001) (Japan) JP 2003-040840 A

  As described above, although a report on a resist material containing fluorine and a hydroxyl group in the molecule has recently been made, it cannot be said that the existing resist material has both sufficient transparency of ultraviolet rays and etching resistance, There are many factors that need to be improved. Therefore, the functions that these existing compounds can exhibit are not necessarily sufficient, and it has been desired to create a novel monomer that can efficiently provide a superior polymer compound or a raw material thereof.

  In addition, Patent Document 1 discloses a fluorine-containing polymerizable monomer in which fluorine and a hydroxyl group coexist in a molecule as a hexafluoroisopropanol group in a broad concept. There is no specific description of 1,1-bis (trifluoromethyl) -1,3-diols acrylic ester represented by the following formula.

  In view of such circumstances, the present invention provides a fluorine-containing acrylic ester which is a novel polymerizable monomer by having a high fluorine content and having a polar group in the same molecule. This is the issue. Another object of the present invention is to find an industrially advantageous production method for this novel compound.

  In view of the problems of the prior art, the present inventors have conducted extensive studies to establish 1,1-bis (trifluoromethyl) -1,3-diols acrylic acid ester and an industrial production method thereof. It was. As a result, the novel fluorine-containing polymerizable monomer 1,1-bis (trifluoromethyl) -1, represented by the formula [1], having a high fluorine content and having a polar group in the same molecule, 3-diols were found.

(R ¹ in the general formula [1] is a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trifluoroethyl group.)

  The polymer compound comprising 1,1-bis (trifluoromethyl) -1,3-diol acrylic acid ester as a constituent element of the present invention has water repellency, oil repellency, low water absorption, heat resistance and weather resistance. It is expected to be used or developed in a wide range of application fields, particularly in the field of advanced materials, due to its characteristics such as corrosion resistance, corrosion resistance, transparency, photosensitivity, low refractive index, and low dielectric properties. In particular, the coating field that makes use of the characteristics of transparency behavior at each wavelength, antireflective film that applies low refractive index and transparency of visible light, and optical devices that apply transparency in the high wavelength band (optical communication wavelength band) It is expected to be used in the field of interlayer insulation films that take advantage of features such as low water absorption and low dielectric properties.

Further, a fluorine-containing 2,4-diol represented by the formula [2], in the general formula is reacted with an acrylic acid derivative represented by [3], represented by general formula [1] 1,1-bis a process for the preparation of (trifluoromethyl) -1,3-diols acrylic acid ester, a reaction by the performed coexistence of a base and an alkene, found that the ester industrially advantageously produced, the present invention Was completed.

(The meaning of R ¹ in general formula [3] is the same as in general formula [1]. X represents either F or Cl.)

Represents one of the following. In addition, the meaning of R ¹ in formula [3a] is the same as in formula [3]. )

  The polymer compound comprising 1,1-bis (trifluoromethyl) -1,3-diol acrylic acid ester as a constituent element of the present invention has water repellency, oil repellency, low water absorption, heat resistance and weather resistance. It is expected to be used or developed in a wide range of application fields, particularly in the field of advanced materials, due to its characteristics such as corrosion resistance, corrosion resistance, transparency, photosensitivity, low refractive index, and low dielectric properties. In particular, the coating field that makes use of the characteristics of transparency behavior at each wavelength, antireflective film that applies low refractive index and transparency of visible light, and optical devices that apply transparency in the high wavelength band (optical communication wavelength band) It is expected to be used in the field of interlayer insulation films that take advantage of features such as low water absorption and low dielectric properties.

  The 1,1-bis (trifluoromethyl) -1,3-diol acrylic acid ester represented by the general formula [1], which is an object of the present invention, is a fluorine-containing compound represented by the general formula [2]. It can be synthesized by reacting 2,4-diol with an acrylic acid derivative represented by the general formula [3].

  First, the fluorine-containing 2,4-diol represented by the formula [2] as a starting material

Is, for example, hexafluoroacetone represented by the formula [4]

And methyl ethyl ketone using concentrated sulfuric acid as a catalyst, for example, by heating to 50 ° C. to 60 ° C., to obtain a fluorine-containing hydroxy ketone represented by the formula [5]

This can then be obtained by reduction with hydrogen gas using Ru / C (ruthenium-activated carbon supported catalyst) as a catalyst. Manufacturing by this method is particularly preferable because it is simple in operation and economically advantageous.

  In addition, the fluorine-containing 2,4-diol represented by the formula [2], which is a starting material, is heated to 160 ° C. without any catalyst from the hexafluoroacetone represented by the formula [4] and methyl ethyl ketone. It is also known that a fluorine-containing hydroxyketone represented by the formula [5] can be obtained by reduction with aluminum isopropoxide using isopropanol as a solvent (US Pat. No. 3,660,711). .

  Next, preferred methods and conditions for the esterification reaction of the present invention will be described. First, the case where the acrylic acid derivative represented by the general formula [3] is an α-substituted acrylic acid halide will be described.

  When the acrylic acid derivative is an α-substituted acrylic acid halide, the reaction is preferably performed in the presence of a base and an alkene. In addition, by making alkene coexist, hydrogen chloride addition to the unsaturated bond of α-substituted acrylic acid can be competitively reduced.

  As the base, at least one selected from the group consisting of trimethylamine, triethylamine, pyridine, 2,6-dimethylpyridine, dimethylaminopyridine, sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide is preferably used. . Of these, pyridine and 2,6-dimethylpyridine are particularly preferred. Alkenes include ethylene, propylene, 1-butene, 2-butene, 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, At least one selected from the group of 2-methyl-2-pentene, hexene, cyclohexene and norbornylene is preferably used.

  The amount of the base used in the present invention is 0.2 to 2.0 mol, preferably 0.5 to 1.5, more preferably 0.9 to 1.2 mol based on 1 mol of the fluorine-containing 2,4-diol represented by the general formula [2] of the substrate. preferable. If the amount of the base is less than 0.2 mol per mol of the fluorine-containing 2,4-diol of the substrate, both the selectivity of the reaction and the yield of the target product decrease, and if it exceeds 2.0 mol, the amount of the base not involved in the reaction increases. This is economically undesirable.

  The amount of alkene used in the present invention is 0.2 to 4.0 moles, preferably 1.0 to 3.0, more preferably 1.5 to 2.5 moles per mole of fluorine-containing 2,4-diol represented by the general formula [2] of the substrate. preferable. If the amount of the base is less than 0.2 mol per mol of the fluorine-containing 2,4-diol of the substrate, both the selectivity of the reaction and the yield of the target product decrease, and if it exceeds 4.0 mol, the amount of the base not involved in the reaction increases. This is economically undesirable.

  The amount of the α-substituted acrylic acid halide used in the present invention is 0.2 to 2.5 mol, preferably 0.5 to 2.0 mol, relative to 1 mol of the fluorine-containing 2,4-diol represented by the general formula [2]. 0.9-1.8 mol is more preferable. If the amount of the α-substituted acrylate halide is less than 0.2 mol per mol of the fluorine-containing 2,4-diol, both the selectivity of the reaction and the yield of the target product are reduced. If the amount exceeds 2.5 mol, α is not involved in the reaction. -Substituted acrylic acid halide increases, and it is economically unpreferable from the effort of disposal.

  In this reaction, a basic hydrochloride is precipitated as a by-product. It is necessary to use a solvent to improve operability. There are no particular restrictions on the type of solvent that can be used, but aromatic compounds such as benzene, toluene, xylene, and mesitylene, ether solvents such as diethyl ether, methyl-t-butyl ether, diisopropyl ether, and tetrahydrofuran, methylene chloride, and chloroform And halogen-based solvents such as carbon tetrachloride are preferable, and these may be used alone or in combination with a plurality of solvents.

  The amount of the solvent used in this reaction is 0.5 to 100 g, preferably 1.0 to 20 g, more preferably 2.0 to 10 g, based on 1 g of fluorine-containing 2,4-diol. When the amount of the solvent is less than 0.5 g with respect to 1 g of the substituted norbornanyl alcohol, the slurry concentration of the basic hydrochloride precipitated during the reaction is too high, so that the operability is lowered. If it exceeds 100 g, it is not economically preferable from the viewpoint of productivity.

  The reaction temperature for carrying out the present invention is −20 to 200 ° C., preferably 0 to 150 ° C., and more preferably 20 ° C. to 120 ° C. If it is less than -20 ° C, the reaction rate is very slow and it is not a practical production method. Further, when the temperature exceeds 200 ° C., 1,1-bis (trifluoromethyl) -1,3-diols acrylic ester represented by the general formula [1] of the raw material α-substituted acrylate halide or product Is not preferable because of polymerization.

  The reaction of the present invention may be carried out in the presence of a polymerization inhibitor for the purpose of preventing polymerization of the raw material α-substituted acrylate halide or the product fluorine-containing ester compound. The polymerization inhibitors used are 2,5-di-t-butylhydroquinone, 1,2,4-trihydroxybenzene, 2,5-bistetramethylbutylhydroquinone, leucoquinizarin, nonflex F, nonflex H, nonflex DCD. , Nonflex MBP, ozonone 35, phenothiazine, tetraethylthiuram disulfide, 1,1-diphenyl-2-picrylhydrazyl, 1,1-diphenyl-2-picrylhydrazine, Q-1300, Q-1301 It is a kind of compound. These polymerization inhibitors are commercially available products and can be easily obtained.

  The amount of the polymerization inhibitor used in the present invention is 0 to 0.1 mol, preferably 0.00001 to 0.05 mol, more preferably 0.0001 to 0.01 mol, per 1 mol of the fluorine-containing 2,4-diol as a raw material. Even if the amount of the polymerization inhibitor exceeds 0.1 mol relative to 1 mol of the fluorine-containing 2,4-diol as a raw material, there is no significant difference in the ability to prevent polymerization, which is economically undesirable.

  The reactor for carrying out the reaction of the present invention is preferably a tetrafluoroethylene resin, chlorotrifluoroethylene resin, vinylidene fluoride resin, PFA resin, glass lined inside, glass container, or stainless steel. .

  Next, the case where the acrylic acid derivative represented by the general formula [3] is an α-substituted acrylic acid anhydride will be described.

  The amount of the α-substituted acrylic anhydride to be used is usually 0.5 to 5.0 mol, preferably 0.7 to 3.0 mol based on 1.0 mol of the fluorinated 2,4-diol represented by the general formula [2], and 1.0 -2.0 mol is more preferable. If the amount of α-substituted acrylic anhydride is less than 0.5 moles relative to 1.0 mole of fluorine-containing 2,4-diol, both the conversion rate of the reaction and the yield of the target product are not sufficient. The α-substituted acrylic anhydride does not increase, which is economically undesirable from the time of disposal.

  Additives can be added to promote the reaction. As the additive used, at least one acid selected from the group of organic sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, trifluoromethanesulfonic acid and Lewis acids is preferably used. It is done. The amount of the additive used in this reaction is 0.01 to 2.0 mol, preferably 0.02 to 1.8, more preferably 0.05 to 1.5 mol, relative to 1.0 mol of fluorine-containing 2,4-diol as a substrate. If the amount of the additive is less than 0.01 mol with respect to 1.0 mol of the fluorine-containing 2,4-diol of the substrate, both the conversion rate of the reaction and the yield of the target product decrease, and if it exceeds 2.0 mol, the amount of the additive not involved in the reaction Is not economically preferable.

  When this reaction is carried out, the reaction temperature is usually 80 to 200 ° C., preferably 100 to 180 ° C., more preferably 120 to 160 ° C. when no additive is added. In this case, the reaction rate is extremely low at less than 80 ° C., and when it exceeds 200 ° C., 1,1-bis (trifluoromethyl)-represented by the general formula [1] of the raw material α-substituted acrylic anhydride or product Since 1,3-diol acrylic acid ester may polymerize, it is not preferable. When an additive is added, it is carried out at 0 to 80 ° C, preferably 10 to 70 ° C, more preferably 20 to 60 ° C. In this case, if it is less than 0 ° C., the reaction rate is slow and the production method is not practical. Moreover, when it exceeds 80 degreeC, a side reaction will advance easily and it is unpreferable since the selectivity of the target fluorine-containing ester compound may fall. In the present invention, it is preferable to add an additive because sufficient reactivity is obtained at a low temperature and the selectivity is improved. That is, it is possible to carry out the reaction in the temperature range of 20 to 60 ° C. by coexisting additives such as methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, and trifluoromethanesulfonic acid in the system. This is a particularly preferred embodiment of this step.

  This reaction proceeds even without solvent, but it is desirable to use a solvent in consideration of the uniformity of the reaction and the operability after the reaction. There are no particular restrictions on the type of solvent that can be used, but aromatic compounds such as benzene, toluene, xylene, and mesitylene, ether solvents such as diethyl ether, methyl-t-butyl ether, diisopropyl ether, and tetrahydrofuran, methylene chloride, and chloroform And halogen-based solvents such as carbon tetrachloride are preferable, and these may be used alone or in combination with a plurality of solvents.

  The amount of the solvent used in this reaction is usually from 0.1 to 100 g, preferably from 0.5 to 50 g, more preferably from 1.0 to 20 g, based on 1 g of fluorine-containing 2,4-diol. If the amount of the solvent is less than 0.1 g with respect to 1 g of the fluorine-containing 2,4-diol, the merit of using the solvent cannot be sufficiently extracted. If it exceeds 100 g, it is not economically preferable from the viewpoint of productivity.

  A polymerization inhibitor for the purpose of preventing polymerization of α-substituted acrylic anhydride or product (1,1-bis (trifluoromethyl) -1,3-diols acrylic ester) in this reaction. In general, it is desirable to use a polymerization inhibitor. Polymerization inhibitors used are hydroquinone, methoquinone, 2,5-di-t-butylhydroquinone, 1,2,4-trihydroxybenzene, 2,5-bistetramethylbutylhydroquinone, leucoquinizarin, nonflex F, nonflex H Nonflex DCD, Nonflex MBP, Ozonon 35, Phenothiazine, Tetraethylthiuram disulfide, 1,1-diphenyl-2-picrylhydrazyl, 1,1-diphenyl-2-picrylhydrazine, Q-1300, Q-1301 Is at least one compound selected from the group consisting of The above polymerization inhibitors are commercially available products and can be easily obtained.

  The amount of the polymerization inhibitor used in the present invention is usually from 0.00001 to 0.1 mol, preferably from 0.0001 to 0.05 mol, more preferably from 0.001 to 0.01 mol, per 1.0 mol of the fluorine-containing 2,4-diol as a raw material. Even if the amount of the polymerization inhibitor exceeds 0.1 mol with respect to 1.0 mol of the fluorine-containing 2,4-diol as a raw material, there is no great difference in the ability to prevent polymerization, which is economically undesirable.

  The reactor used in this reaction is made of tetrafluoroethylene resin, chloro-trifluoroethylene resin, vinylidene fluoride resin, PFA resin, glass lined inside, glass container, or stainless steel. preferable.

  Although the method for carrying out the present invention is not limited, details will be described with respect to an example of a desirable embodiment.

(1) When the acrylic acid derivative represented by the general formula [3] is an α-substituted acrylic halide)
To a reactor that can withstand the reaction conditions, a base, an alkene, a solvent, a fluorine-containing 2,4-diol represented by the general formula [2], an α-substituted acrylic acid halide, and a polymerization inhibitor are added and stirred. The reaction proceeds by heating from the outside. It is preferable to monitor the consumption of the raw material by sampling or the like, confirm that the reaction is completed, and cool the reaction solution.

  The 1,1-bis (trifluoromethyl) -1,3-diols acrylic ester represented by the general formula [1] produced by the method of the present invention is purified by applying a known method. However, for example, after removing the hydrochloride of the base contained in the reaction solution by filtration, the filtrate is treated with an aqueous hydrochloric acid solution, an aqueous sodium carbonate solution and an aqueous sodium chloride solution in this order, and the solvent is distilled off to obtain a crude organic material. It is done. High purity 1,1-bis (trifluoromethyl) -1,3-diols acrylic ester can be obtained by performing purification such as column chromatography or distillation on the obtained crude organic matter.

(2) When the acrylic acid derivative represented by the general formula [3] is an α-substituted acrylic anhydride)
Add a solvent, a fluorine-containing 2,4-diol represented by the general formula [2] of the raw material, an α-substituted acrylic anhydride, a polymerization inhibitor and an additive to a reactor that can withstand the reaction conditions, and stir externally. The reaction is allowed to proceed with further heating. It is preferable to monitor the consumption of the raw material by sampling or the like, confirm that the reaction is completed, and cool the reaction solution. The 1,1-bis (trifluoromethyl) -1,3-diol acrylic acid ester represented by the general formula [1] produced by the method of the present invention is purified by applying a known method. For example, the reaction solution is treated in the order of water, aqueous sodium hydrogen carbonate solution and brine, and the solvent is distilled off to obtain a crude organic material. High purity 1,1-bis (trifluoromethyl) -1,3-diols acrylic ester can be obtained by performing purification such as column chromatography or distillation on the obtained crude organic matter. .

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, it is not restricted to these embodiments. Here, “%” of the composition analysis value represents “area%” obtained by collecting a part of the reaction mixture and measuring it by gas chromatography.

[Example 1]
Production of 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl acrylate A 1000 mL three-neck flask equipped with a thermometer and reflux condenser was coated with tetrafluoroethylene resin. And 1,1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol 140.0 g (0.58 mol), 2,6-lutidine 75 g (0.699 mol), 2-methyl-2 -Butene 81.8g (1.2 mol), toluene 700mL, and nonflex MBP 0.7g (0.5 wt%) were put as a polymerization inhibitor, and acryloyl chloride 78.7g (0.87 mol) was added, stirring with a stirrer. After stirring for 9 hours in the range of 80 to 81 ° C., the reaction solution was measured by gas chromatography. The target 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) was measured. ) Butyl acrylate was 78.2%, raw material 1,1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol was 2.5%, and others were 19.3%. After removing the lutidine salt in the reaction solution by suction filtration, the filtrate was subjected to solvent distillation, followed by distillation under reduced pressure (0.6 to 0.8 kPa), and a fraction at 66 to 75 ° C. was collected. -Ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl acrylate was obtained. When the composition was examined by gas chromatography, 94.6% of the target product, 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl acrylate, 1,1, 1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol was 1.6%, and the others were 3.8%. The yield was 28.8%.

1H NMR (solvent: CDCl ₃ , reference material: TMS); δ6.50 (d, J = 17.3 Hz, 1H), 6.20 (bs, 1H), 6.14 (dd, J = 10.5 Hz, J = 17.3 Hz, 1H ), 5.96 (d, J = 10.5 Hz), 4.95−4.96 (m, 1H), 2.33 (dd, J = 16.5 Hz, J = 3.54 Hz, 1H), 2.23 (dd, J = 16.5 Hz, J = 2.6 Hz, 1H), 1.73-1.84 (m, 2H), 0.99 (t, J = 7.20 Hz, 3H).
19F NMR (solvent: CDCl ₃ , reference material: CCl ₃ F); δ−77.10 (q, J = 10.5 Hz, 3F), −79.47 (q, J = 10.5 Hz, 3F).

[Example 2]
Production of 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl 2-methyl acrylate Tetrafluoroethylene resin in a 100 mL three-necked flask equipped with a thermometer and reflux condenser 20.0 g (83.3 mmol) of 1,1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol, 0.80 g (8.3 mmol) of methanesulfonic acid, 40 mL of toluene, In addition, 0.06 g (0.3 wt%) of non-flex MBP was added as a polymerization inhibitor, and 15.4 g (99.9 mol) of methacrylic anhydride was added while stirring with a stirrer. After stirring for 5 hours in the range of 71-73 ° C., the reaction solution was measured by gas chromatography, and the target 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) was measured. ) 89.13% butyl 2-methyl acrylate, 1.3% raw material 1,1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol, 5.6% methacrylic anhydride, 3.97 others %Met. The reaction solution was washed twice with 30 ml of saturated aqueous NaHCO ₃ solution, and the organic layer was separated into two layers. After the toluene in the organic layer was distilled off, the residue was distilled under reduced pressure (1.8 to 2.4 kPa), and the fraction at 94 to 102 ° C. was collected to obtain 12.31 g of 1-ethyl-4,4,4-trifluoro. -3-Hydroxy-3- (trifluoromethyl) butyl 2-methyl acrylate was obtained. The composition was examined by gas chromatography. As a result, 97.5% of 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl 2-methylacrylate, which was the target product, was 1 1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol was 0.9%, and the others were 1.6%. The yield was 46.7%.

1H NMR (solvent: CDCl ₃ , reference material: TMS); δ 6.38 (bs, 1H), 6.19 (d, J = 1.34 Hz, 1H), 5.67 (d, J = 1.34 Hz, 1H), 4.90-4.94 (m, 1H), 2.33 (dd, J = 16.5, 4.14Hz, 1H), 2.24 (dd, J = 16.5 Hz, 2.93 Hz, 1H), 1.95 (s, 3H), 1.70−1.84 (m, 2H) , 1.00 (t, J = 7.20 Hz, 3H).
19F NMR (solvent: CDCl ₃ , reference material: CCl ₃ F); δ−77.07 (q, J = 10.5 Hz, 3F), −79.43 (q, J = 10.5 Hz, 3F).

[Example 3]
Preparation of 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl 2- (trifluoromethyl) acrylate A 100 mL three-necked flask equipped with a thermometer was equipped with tetrafluoroethylene resin. Coated stir bar and 1,1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol 20.0 g (83.3 mmol), 2,6-lutidine 9.82 g (91.6 mmol), 2- Methyl-2-butene 8.76 g (125 mmol), toluene 40 mL, and non-flexible MBP 0.1 g (0.5 wt%) as a polymerization inhibitor were added and stirred with a stirrer, 2- (trifluoromethyl) acryloyl chloride 15.9 g (100 mmol) was added at room temperature (around 20 ° C.). After stirring for 4 hours in the range of 45 to 55 ° C., the reaction solution was measured by gas chromatography. The target 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) was measured. ) Butyl 2- (trifluoromethyl) acrylate was 71.3%, raw material 1,1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol was 6.9%, others were 21.8% . After removing the lutidine salt precipitated in the reaction solution by suction filtration, the solvent of the filtrate was distilled off, followed by distillation under reduced pressure (17 Torr = 2.27 kPa), and a fraction at 115 to 120 ° C. was collected. As a result, 18.0 g of 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl 2- (trifluoromethyl) acrylate was obtained. When the composition was examined by gas chromatography, it was found that the target 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl 2- (trifluoromethyl) acrylate was 97.5% The raw material 1,1,1-trifluoro-2- (trifluoromethyl) hexane-2,4-diol was 1.0%, and the others were 1.5%. The yield was 58.2%.

1H NMR (solvent: CDCl ₃ , reference material: TMS); δ 6.80 (q, J = 1.71 Hz, 1H), 6.51 (q, J = 1.22 Hz, 1H), 5.15-5.21 (m, 1H), 5.15 (bs, 1H), 2.32 (d, J = 4.88 Hz, 2H), 1.81 (dq, J = 7.44, 2.26 Hz, 2H), 0.99 (t, J = 7.44 Hz, 3H).
19F NMR (solvent: CDCl ₃ , reference material: CCl ₃ F); δ−65.93 (s, 3F), −77.31 (q, J = 9.92 Hz, 3F), −79.05 (q, J = 9.92 Hz, 3F)

Claims (5)

1,1-bis (trifluoromethyl) -1,3-diols acrylic ester represented by the general formula [1].
(However, R ¹ in the general formula [1] is a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trifluoroethyl group.) 1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl acrylate represented by the formula [1a].
1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl 2-methyl acrylate represented by the formula [1b].
1-ethyl-4,4,4-trifluoro-3-hydroxy-3- (trifluoromethyl) butyl 2- (trifluoromethyl) acrylate represented by the formula [1c].
The fluorine-containing 2,4-diol represented by the formula [2], in the general formula is reacted with an acrylic acid derivative represented by [3], represented by 1,1-bis general formula [1] (tri A process for producing a fluoromethyl) -1,3-diol acrylic ester, wherein the reaction is carried out in the presence of a base and an alkene.

(In the general formula [3] and the general formula [1], R ¹ is a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trifluoroethyl group. In the general formula [3], X is F , Or Cl.)