Process for producing fluoroalkyl esters of α,β-dihalogenopropionic acid

Abstract

To provide a method for producing an α,β-dihalogenopropionic acid alkyl ester by a simple operation in good yield and indusitrially favorably.SOLUTION: Provided is a method for producing an α,β-dihalogenopropionic acid alkyl ester represented by the following formula (1) (in the formula (1), X and Y each independently represent a halogen atom; and Rf represents a C3-6 fluoroalkyl group), comprising a step of reacting an ester represented by the following formula (2) and a fluoroalcohol represented by RfOH in the presence of an acid catalyst and a fluorine-containing solvent.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing α,β-dihalogenopropionic acid fluoroalkyl ester.

Background Art

[0002] α-Halogenoacrylic acid fluoroalkyl ester is a useful compound as a raw material monomer for polymers and the like. For example, α-chloroacrylic acid fluoroalkyl ester, which is one of α-halogenoacrylic acid fluoroalkyl esters, is used as a raw material monomer for a copolymer used as a main-chain cleavage type positive resist in the field of semiconductor manufacturing and the like (see, for example, Patent Document 1).

[0003] Such α-halogenoacrylic acid fluoroalkyl ester can be produced, for example, by subjecting α,β-dihalogenopropionic acid fluoroalkyl ester to dehalogenation by contacting it with an organic amine or an inorganic alkali (see, for example, Patent Documents 2 and 3). Therefore, α,β-dihalogenopropionic acid fluoroalkyl ester is an important precursor compound in the production of α-halogenoacrylic acid fluoroalkyl ester.

[0004] Here, Patent Document 2 discloses a method for synthesizing 2,2,2,3,3-pentafluoropropyl acrylate from 2,2,2,3,3-pentafluoropropanol and acrylic acid, and chlorinating this 2,2,2,3,3-pentafluoropropyl acrylate using chlorine gas to produce α,β-dichloropropionic acid-2,2,2,3,3-pentafluoropropyl. Further, Patent Document 3 discloses a method for chlorinating 2-(perfluorobutyl)ethyl acrylate using chlorine gas to produce α,β-dichloropropionic acid-(1H,1H,2H,2H-nonafluorohexyl). Furthermore, Patent Document 4 discloses a method for producing α,β-dichloropropionic acid-2,2,3,3-tetrafluoropropyl by dehydrative condensation of 2,2,3,3-tetrafluoropropanol and α,β-dichloropropionic acid in the presence of concentrated sulfuric acid.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the methods of Patent Documents 2 and 3, the electron density of the double bond portion of the fluoroalkyl acrylate, which is the raw material, is decreased by the fluoroalkyl group having strong electron-withdrawing properties. As a result, the electrophilic chlorination reaction proceeds with difficulty as compared with ordinary alkyl acrylates, and it takes a long time until the reaction is completed, which is industrially disadvantageous.

[0007] In addition, in the method of Patent Document 4, the raw material α,β-dichloropropionic acid has strong hygroscopicity and absorbs moisture, resulting in stickiness and other problems, so it is difficult to handle from the viewpoint of operation. In addition, due to this strong hygroscopicity, there is also a problem that the esterification reaction itself may not proceed.

[0008] The present invention has been made under such circumstances, and an object of the present invention is to provide a method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester with a simple operation, in good yield, and industrially advantageously.

Means for Solving the Problems

[0009] The present inventors have conducted intensive studies to achieve the above object. And the present inventors have found that an α,β-dihalogenopropionic acid fluoroalkyl ester can be produced with a simple operation, in good yield, and industrially advantageously by a method including a step of reacting a predetermined α,β-dihalogenopropionic acid alkyl ester with a predetermined fluoroalcohol in the presence of an acid catalyst and a fluorine-containing solvent, and thus the present invention has been completed.

[0010] That is, the present invention aims to advantageously solve the above problems, and the present invention provides a method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester represented by the following formula (1):

Chemical formula

Chemical formula

[0011] In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, it is preferable that the acid catalyst is at least one selected from the group consisting of sulfuric acid, trifluoromethanesulfonic acid, and rare earth metal triflates. If the acid catalyst is at least one selected from the group consisting of sulfuric acid, trifluoromethanesulfonic acid, and rare earth metal triflates, the fluoroalkyl α,β-dihalogenopropionate can be produced with a higher yield.

[0012] The method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention performs the reaction under reflux, and during the reflux, the reflux liquid is brought into contact with zeolite to remove the alkyl alcohol represented by the following formula (4): ROH (4) [In formula (4), R is the same as R in formula (2)]. By such a method for producing a fluoroalkyl α,β-dihalogenopropionate, the fluoroalkyl α,β-dihalogenopropionate can be produced with a higher yield and industrially more advantageously by a simpler operation.

[0013] In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, it is preferable that the zeolite is at least one selected from the group consisting of 4A synthetic zeolite and 5A synthetic zeolite. If the zeolite is at least one selected from the group consisting of 4A synthetic zeolite and 5A synthetic zeolite, since these compounds are easily available, α,β-dihalogenopropionic acid fluoroalkyl ester can be produced more industrially advantageously. Further, if the zeolite is at least one selected from the group consisting of 4A synthetic zeolite and 5A synthetic zeolite, the alkyl alcohol represented by the formula (4) can be effectively adsorbed, and α,β-dihalogenopropionic acid fluoroalkyl ester can be produced with a higher yield.

[0014] In the method for producing α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention, the α,β-dihalogenopropionic acid alkyl ester represented by the formula (2) is preferably at least one compound selected from the group consisting of methyl α,β-dichloropropionate and methyl α,β-dibromopropionate. If the α,β-dihalogenopropionic acid alkyl ester represented by the formula (2) is at least one compound selected from the group consisting of methyl α,β-dichloropropionate and methyl α,β-dibromopropionate, since these compounds are relatively easy to synthesize, α,β-dihalogenopropionic acid fluoroalkyl ester can be produced more industrially advantageously.

[0015] In the method for producing α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention, the α,β-dihalogenopropionic acid fluoroalkyl ester represented by the formula (1) is preferably selected from the group consisting of 2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate, 2,2,3,3,4,4,4-heptafluorobutyl α,β-dichloropropionate, and 2,2,3,3,3-pentafluoropropyl α,β-dibromopropionate. If the α,β-dihalogenopropionic acid fluoroalkyl ester represented by the formula (1) is selected from the group consisting of 2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate, 2,2,3,3,4,4,4-heptafluorobutyl α,β-dichloropropionate or 2,2,3,3,3-pentafluoropropyl α,β-dibromopropionate, it can be more advantageously used as a raw material for obtaining a monomer used in the production of a polymer.

Advantages of the Invention

[0016] According to the present invention, there can be provided a method for industrially advantageously producing an α,β-dihalogenopropionic acid fluoroalkyl ester with good yield by a simple operation.

Brief Description of the Drawings

[0017]

Figure 1

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail. Here, the α,β-dihalogenopropionic acid fluoroalkyl ester produced by using the method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention can be advantageously used, for example, as a raw material for obtaining a monomer used in the production of a polymer. Specifically, it can be advantageously used as a raw material for obtaining an α-halogenoacrylic acid fluoroalkyl ester used in the production of a polymer that is preferably used as a main-chain cleavage type positive resist and whose main chain is cleaved by irradiation with ionizing radiation such as an electron beam or short-wavelength light such as ultraviolet light to reduce its molecular weight.

[0019] (Method for Producing α,β-Dihalogenopropionic Acid Fluoroalkyl Ester) The method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention includes a step of reacting an alkyl α,β-dihalogenopropionate represented by the following formula (2) and a fluoroalcohol represented by the following formula (3) in the presence of an acid catalyst and a fluorine-containing solvent.

[0020] <Alkyl α,β-dihalogenopropionate> The alkyl α,β-dihalogenopropionate used in the method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention is a compound represented by the following formula (2). [Chemical formula]

[0021] In formula (2), X and Y are the same as X and Y in formula (1) described below. That is, in formula (2), X and Y each independently represent a halogen atom selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Further, in formula (2), R represents a methyl group or an ethyl group. The alkyl α,β-dihalogenopropionate represented by formula (2) is a relatively stable compound and is easy to handle. Therefore, by using this as a raw material, an α,β-dihalogenopropionic acid fluoroalkyl ester can be produced by a simple operation and industrially advantageously. Examples of the alkyl α,β-dihalogenopropionate represented by the formula (2) include methyl α,β-dichloropropionate, methyl α,β-dibromopropionate, methyl α,β-difluoropropionate, methyl α-fluoro-β-chloropropionate, methyl α-bromo-β-chloropropionate, methyl α-chloro-β-iodopropionate and other methyl α,β-dihalogenopropionates; ethyl α,β-dichloropropionate, ethyl α,β-dibromopropionate, ethyl α,β-difluoropropionate, ethyl α-fluoro-β-chloropropionate, ethyl α-bromo-β-chloropropionate, ethyl α-chloro-β-iodopropionate and other ethyl α,β-dihalogenopropionates. Among these, since synthesis is relatively easy and as a result, fluoroalkyl α,β-dihalogenopropionate can be produced more advantageously industrially, it is preferable to use at least one compound selected from the group consisting of methyl α,β-dichloropropionate, methyl α,β-dibromopropionate, ethyl α,β-dichloropropionate and ethyl α,β-dibromopropionate, and it is more preferable to use at least one compound selected from the group consisting of methyl α,β-dichloropropionate and methyl α,β-dichloropropionate.

[0022] The alkyl α,β-dihalogenopropionate can be synthesized according to a conventionally known method. For example, Macromolecuels, Vol. 19, 1035 (1986) and JP-A-1-172356 disclose an example of synthesizing methyl α,β-dichloropropionate from methyl acrylate and chlorine gas. Polymer Chemistry, Vol. 9, 2082 (2018) discloses an example of synthesizing methyl α,β-dibromopropionate from methyl acrylate and copper(I) bromide. Furthermore, as another synthesis example, Japanese Patent Application Laid-Open No. 2014-214147 discloses that α-fluoro-β-hydroxypropionic acid is obtained from serine, which is one kind of amino acid, as a raw material, from pyridine-hydrogen fluoride salt and sodium nitrite, and then a solution obtained by reacting this with thionyl chloride is mixed with methanol to obtain methyl α-fluoro-β-chloropropionate. Also, by a similar method, Japanese Patent Application Laid-Open No. 2012-530756 discloses that ethyl α-fluoro-β-chloropropionate can be synthesized from ethyl α-fluoro-β-hydroxypropionate.

[0023] <fluoroalcohol> The fluoroalcohol used in the method for producing the fluoroalkyl ester of α,β-dihalogenopropionic acid of the present invention is a compound represented by the following formula (3). RfOH (3)

[0024] In formula (3), Rf is the same as Rf in formula (1) described below. That is, in formula (3), Rf represents a fluoroalkyl group having 3 to 6 carbon atoms. Since Rf is easily available, it is preferably a fluoroalkyl group having 3 to 5 carbon atoms. As the fluoroalcohol represented by the formula (3), those having a boiling point of 80°C or higher can be preferably used from the viewpoint of reaction conditions and the like. Specific examples of such fluoroalcohols include fluoroalcohols having 3 carbon atoms such as 2,2,3,3,3-pentafluoropropanol (boiling point: 80°C), 2,2,3,3-tetrafluoropropanol (boiling point: 109°C), 3,3,3-trifluoropropanol (boiling point: 100°C); fluoroalcohols having 4 carbon atoms such as 2,2,3,3,4,4,4-heptafluorobutanol (boiling point: 96°C), 2,2,3,4,4,4-hexafluorobutanol (boiling point: 114°C), 3,3,4,4,4-pentafluorobutanol (boiling point: 110°C), 3,3,4,4,4-pentafluorobutan-2-ol (boiling point: 83°C); fluoroalcohols having 5 carbon atoms such as 2,2,3,3,4,4,5,5-octafluoropentanol (boiling point: 140°C), 4,4,5,5,5-pentafluoropentanol (boiling point: 135°C), 1,1,1,2,2-pentafluoropentan-3-ol (boiling point: 97°C); fluoroalcohols having 6 carbon atoms such as 2,2,3,3,4,4,5,5,6,6,6-undecafluorohexanol (boiling point: 130°C) and the like. Among these, 2,2,3,3,3-pentafluoropropanol, 2,2,3,3-tetrafluoropropanol, 2,2,3,3,4,4,4-heptafluorobutanol, 2,2,3,3,4,4,5,5-octafluoropentanol are preferable because they are easily available, and 2,2,3,3,3-pentafluoropropanol and 2,2,3,3,4,4,4-heptafluorobutanol are more preferable.

[0025] The amount of the fluoroalcohol represented by the formula (3) used is usually 1 mol or more, preferably 1.5 mol or more, usually 5 mol or less, and preferably 3 mol or less per 1 mol of the alkyl α,β-dihalogenopropionate. If the amount of the fluoroalcohol represented by the formula (3) is not less than the above lower limit, the transesterification reaction easily proceeds, and the fluoroalkyl α,β-dihalogenopropionate can be produced in a higher yield. On the other hand, if the amount of the fluoroalcohol represented by the formula (3) is not more than the above upper limit, it is economically advantageous, and the purification operation after the reaction can be simplified.

[0026] <Fluorine-containing solvent> In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, a fluorine-containing solvent is used. By using a fluorine-containing solvent in the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, the fluoroalkyl α,β-dihalogenopropionate can be produced in a good yield with a simple operation and industrially advantageously. Specifically, it is possible to suppress the generation of a large amount of polymer in the reaction and the inability to recover the target fluoroalkyl α,β-dihalogenopropionate and the decrease in the yield. The reason is presumed as follows.

[0027] First, in the alkyl α,β-dihalogenopropionate as a raw material and the fluoroalkyl α,β-dihalogenopropionate as a target product, the halogen atom at the β-position is easily eliminated by heating or the like. The fluorine-containing solvent used in the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention can dissolve the alkyl α,β-dihalogenopropionate represented by the formula (2) and the fluoroalcohol represented by the formula (3) well, so that when heated during the reaction, the generation of a locally high-temperature portion can be suppressed. As a result, it is possible to suppress the dehalogenation of the alkyl α,β-dihalogenopropionate and / or the fluoroalkyl α,β-dihalogenopropionate and the polymerization thereof. For the above reasons, it is considered that the fluoroalkyl α,β-dihalogenopropionate can be produced in a good yield with a simple operation and industrially advantageously.

[0028] The fluorine-containing solvent is not particularly limited as long as it can dissolve the raw materials, i.e., alkyl α,β-dihalogenopropionate and fluoroalcohol, well. The fluorine-containing solvent preferably has a solubility of the raw material alkyl α,β-dihalogenopropionate of 10 g or more, more preferably 20 g or more, per 100 g of the fluorine-containing solvent at 20°C. Further, the fluorine-containing solvent preferably has a solubility of fluoroalcohol of 20 g or more, more preferably 45 g or more, per 100 g of the fluorine-containing solvent at 20°C. Such a fluorine-containing solvent can effectively suppress the occurrence of locally high-temperature portions when heated during the reaction.

[0029] When the transesterification reaction of the present invention is carried out under reflux, since the fluorine-containing solvent can produce the fluoroalkyl α,β-dihalogenopropionate with a better yield, it is preferably a solvent that forms an azeotropic mixture with the alkyl alcohol represented by the following formula (4), or a solvent that can easily lead the alkyl alcohol out of the reaction system (for example, a solvent having a boiling point higher than that of the alkyl alcohol, etc.). Examples of such a fluorine-containing solvent include 1,1,2,2,3,3,4-heptafluorocyclopentane (boiling point: 82°C), nonafluorobutylethyl ether (boiling point: 76°C), 1,1,1,2,3,4,4,5,5,5-decafluoro-2-trifluoromethyl-3-methoxypentane (boiling point: 98°C), 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctane (boiling point: 114°C), etc. Among these, 1,1,2,2,3,3,4-heptafluorocyclopentane (boiling point 82°C) and nonafluorobutylethyl ether (boiling point 76°C), which form an azeotropic mixture with the alkyl alcohol represented by the following formula (4), are preferred.

[0030] The amount of the fluorine-containing solvent used is usually 0.5 times or more, preferably 1 time or more, and usually 3 times or less, preferably 2 times or less, based on the total mass of the alkyl α,β-dihalogenopropionate and fluoroalcohol. If the amount of the fluorine-containing solvent used is at least the above lower limit, generation of locally high-temperature portions can be suppressed, and dehalogenation of the alkyl α,β-dihalogenopropionate and the fluoroalkyl α,β-dihalogenopropionate can be suppressed. On the other hand, if the amount of the fluorine-containing solvent used is at most the above upper limit, the concentration of the raw materials becomes high, and the reaction rate of the transesterification reaction can be increased.

[0031] <acid catalyst> In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, an acid catalyst is used. Examples of the acid catalyst include protonic acids such as sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid; rare earth metal triflates such as scandium(III) trifluoromethanesulfonate, ytterbium(III) trifluoromethanesulfonate, and neodymium(III) trifluoromethanesulfonate, and Lewis acids such as hafnium(IV) trifluoromethanesulfonate; and the like. Among these, at least one selected from the group consisting of sulfuric acid, trifluoromethanesulfonic acid, and rare earth metal triflates is preferable because the fluoroalkyl α,β-dihalogenopropionate can be produced in a higher yield. Among the rare earth metal triflates, scandium(III) trifluoromethanesulfonate and ytterbium(III) trifluoromethanesulfonate are preferable, and scandium(III) trifluoromethanesulfonate is more preferable.

[0032] The amount of the acid catalyst used can be appropriately adjusted depending on the activity of the acid catalyst, but is usually 0.00001 mol or more, preferably 0.0001 mol or more, usually 0.5 mol or less, and preferably 0.3 mol or less per 1 mol of the alkyl α,β-dihalogenopropionate as the raw material. If the amount of the acid catalyst used is at least the above lower limit, the transesterification reaction proceeds smoothly, and the target product, α,β-dihalogenopropionic acid fluoroalkyl ester, can be produced in a higher yield. 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 easier, and α,β-dihalogenopropionic acid fluoroalkyl ester can be produced by a simpler operation. Further, if the amount of the acid catalyst used is at most the above upper limit, dehalogenation of the raw material α,β-dihalogenopropionic acid alkyl ester and the target product α,β-dihalogenopropionic acid fluoroalkyl ester is suppressed, and as a result, α,β-dihalogenopropionic acid fluoroalkyl ester can be produced in a higher yield.

[0033] <Reaction conditions> The heating temperature during the transesterification reaction is not particularly limited as long as the transesterification reaction occurs, but it is usually 100°C or higher, preferably 120°C or higher, usually 150°C or lower, and preferably 140°C or lower. If the heating temperature is at least the above lower limit, the transesterification reaction can proceed effectively. On the other hand, if the heating temperature is at most the above upper limit, an excessive increase in the reaction rate can be suppressed. Further, when the transesterification reaction of the present invention is carried out under reflux, if the heating temperature is at most the above upper limit, an excessive intensification of the reflux state can be suppressed.

[0034] The reaction time of the transesterification reaction can be appropriately determined depending on the heating temperature and the like, but it is usually 10 hours or longer, preferably 20 hours or longer, usually 5 days or shorter, and preferably 3 days or shorter. If the reaction time is at least the above lower limit, the remaining of the raw material can be suppressed. On the other hand, if the reaction time is at most the above upper limit, dehalogenation of α,β-dihalogenopropionic acid alkyl ester and / or α,β-dihalogenopropionic acid fluoroalkyl ester and their polymerization can be suppressed.

[0035] The transesterification reaction is preferably carried out under reflux. If the transesterification reaction is carried out under reflux, the reaction temperature can be maintained at a favorable temperature, so that the transesterification reaction proceeds effectively, and the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced with a simpler operation, a higher yield, and more industrially advantageously. In one embodiment, the reflux can be carried out using a reflux device including a reactor and a condenser (cooling pipe) located above the reactor. The reactor and the condenser may be connected by a connecting pipe. The connecting pipe is not particularly limited and may have only one path or two or more paths.

[0036] When the transesterification reaction is carried out under reflux, it is preferable to remove the alkyl alcohol represented by the following formula (4) from the reflux liquid during reflux. ROH (4)

[0037] In the formula (4), R is the same as R in the formula (2). That is, in the formula (4), R represents a methyl group or an ethyl group. If the alkyl alcohol represented by the formula (4) is removed from the reflux liquid, the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced with an even higher yield. The reason is presumed as follows.

[0038] In the transesterification reaction of the present invention using an acid catalyst, as the reaction proceeds, the target product α,β-dihalogenopropionic acid fluoroalkyl ester and the by-product alkyl alcohol represented by the formula (4) are generated. Here, since the transesterification reaction is an equilibrium reaction, as the production amount of the alkyl alcohol increases, the reaction rate decreases. When the alkyl alcohol is removed from the reflux liquid, the equilibrium state is disrupted, and the reaction easily proceeds in the direction of generating the target product α,β-dihalogenopropionic acid fluoroalkyl ester. For the above reasons, it is considered that the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced with an even higher yield.

[0039] The method for removing the alkyl alcohol represented by formula (4) is not particularly limited. For example, there are a method of adsorbing the alkyl alcohol (incorporated into the pores) onto an adsorbent such as zeolite, a method of removing using the boiling point difference of each component by using two or more capacitors having different refrigerant temperatures in series, and the like. In the method for removing the alkyl alcohol, it is preferable to use zeolite because the reflux operation becomes easy and the selectivity of the adsorbing substance is excellent. That is, in the method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention, it is particularly preferable to remove the alkyl alcohol by bringing the reflux liquid into contact with zeolite.

[0040] Zeolite is a general term for crystalline aluminosilicates, and there are natural products and synthetic products. The zeolite that can be used in the production method of the α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention is not particularly limited as long as it can adsorb the alkyl alcohol represented by formula (4). For example, zeolites such as 4A type, 5A type, and 13X type can be mentioned. Zeolite is easily available, can more advantageously produce the α,β-dihalogenopropionic acid fluoroalkyl ester industrially, and can effectively adsorb the alkyl alcohol and produce the α,β-dihalogenopropionic acid fluoroalkyl ester with a higher yield. Therefore, it is preferably at least one selected from the group consisting of 4A type synthetic zeolite and 5A type synthetic zeolite. Specific examples of 4A type synthetic zeolite and 5A type synthetic zeolite include molecular sieves 4A and molecular sieves 5A. Note that the zeolite may be subjected to an activation treatment such as calcination before use.

[0041] The shape of the zeolite is preferably bead-shaped or pellet-shaped because the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced by a simpler operation.

[0042] The amount of zeolite used is not particularly limited as long as it can sufficiently adsorb the alkyl alcohol represented by the formula (4), but is preferably 50 times or more, more preferably 80 times or more, preferably 200 times or less, and more preferably 150 times or less on a mass basis with respect to the theoretical maximum amount of the alkyl alcohol produced from the alkyl α,β-dihalogenopropionate as a raw material. If the amount of zeolite used is equal to or more than the above lower limit, the alkyl alcohol can be effectively adsorbed, and the fluoroalkyl α,β-dihalogenopropionate can be produced in a higher yield. On the other hand, if the amount of zeolite used is equal to or less than the above upper limit, an excessive amount of zeolite can be suppressed, and the fluoroalkyl α,β-dihalogenopropionate can be produced more industrially advantageously.

[0043] The zeolite may be present in the fluorine-containing solvent as long as it does not adversely affect the transesterification reaction. However, since it is not necessary to separate it after the reaction is completed, and as a result, the fluoroalkyl α,β-dihalogenopropionate can be produced by a simpler operation, it is preferable to use the zeolite filled in the connecting pipe. That is, the connecting pipe is preferably a packed pipe filled with zeolite. The packed pipe may have only one path or two or more paths, but those having two or more paths are preferable. When the packed pipe has two or more paths, it is preferable that the zeolite is filled in at least the path through which the reflux liquid passes. With such a shape of the packed pipe, the alkyl alcohol can be effectively adsorbed, and the fluoroalkyl α,β-dihalogenopropionate can be produced in a higher yield.

[0044] Hereinafter, an example of a reflux operation will be described by exemplifying a refluxer 10 including a reactor 11 and a condenser 13 located above the reactor 11 as shown in FIG. 1, wherein the reactor 11 and the condenser 13 are connected by a packed pipe 12, and the packed pipe 12 has two paths. When the mixed liquid 14 containing the raw materials and products in the reactor 11 is heated, low-boiling components such as alkyl alcohol, fluoroalcohol, and fluorine-containing solvent contained in the mixed liquid 14 vaporize to become vapor. The vapor passes through the side tube of the filling tube 12 (the left path in FIG. 1) and is cooled by the condenser 13 at the upper part to become the reflux liquid 15. Here, in the condenser 13, the refrigerant circulates in the direction of the arrow. The reflux liquid 15 passes through the main body part of the filling tube 12 filled with the zeolite 16 (the right path in FIG. 1), and the alkyl alcohol contained in the reflux liquid 15 is adsorbed by the zeolite 16, and the remaining reflux liquid 15 is returned into the reactor 11. This is continuously repeated to perform reflux. Incidentally, as shown in FIG. 1, an intake and exhaust pipe 17 may be connected to the upper part of the condenser 13 in the reflux device 10.

[0045] In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, after the completion of the transesterification reaction, for example, a step of removing an acid catalyst by alkali washing, filtration, etc., a step of distilling off and concentrating a fluorine-containing solvent and unreacted substances, a step of purifying the concentrated solution by distillation, or any other step may be performed.

[0046] <fluoroalkyl α,β-dihalogenopropionate> The fluoroalkyl α,β-dihalogenopropionate obtained by the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention is a compound represented by the following formula (1).

Chemical formula

[0047] In formula (1), X and Y each independently represent a halogen atom selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and Rf represents a fluoroalkyl group having 3 to 6 carbon atoms. The α,β-dihalogenopropionic acid fluoroalkyl ester represented by the formula (1) can be more advantageously used as a raw material for obtaining a monomer used in the production of a polymer. Therefore, it is preferably selected from the group consisting of 2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate, 2,2,3,3,4,4,4-heptafluorobutyl α,β-dichloropropionate, or 2,2,3,3,3-pentafluoropropyl α,β-dibromopropionate.

Example

[0048] Hereinafter, the present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited by the following examples. Unless otherwise specified, “%” represents “mass %”.

[0049] The analysis conditions for gas chromatography analysis (GC analysis) performed in the examples and comparative examples are as follows.

[0050] Apparatus: Agilent-7890 (manufactured by Agilent Technologies) Column: Inert Cap-1 (manufactured by GL Sciences, length 60 m, inner diameter 0.25 mm, film thickness 1.5 μm) Column temperature: Held at 60°C for 10 minutes, then heated to 260°C at a heating rate of 20°C / min, and then held at 260°C for 10 minutes Injection temperature: 250°C Detector temperature: 250°C Carrier gas: Nitrogen Split ratio: 100 / 1 Detector: FID

[0051] [Example 1] A dropping funnel with a side tube and a stir bar were attached. Further, a Dimroth condenser was attached to the upper part of the dropping funnel with a side tube. 15.7 g (0.1 mol, manufactured by Alpha Aesar) of methyl α,β-dichloropropionate, 30 g (0.2 mol) of 2,2,3,3,3-pentafluoropropanol, 60 g of heptafluorocyclopentane as a solvent, and 2.94 g (0.03 mol) of concentrated sulfuric acid as an acid catalyst were charged into a 100 ml round-bottomed flask. The main body part of the dropping funnel with a side tube was filled with 30 g of pelletized molecular sieves 5A (diameter: 1 / 16 inch). A refrigerant at 0 °C was circulated through the condenser. The round-bottomed flask was immersed in an oil bath heated to 130 °C, and reflux was continued for 30 hours. During that time, the reflux liquid (condensate) passing through the main body part was brought into contact with the molecular sieves. After 30 hours, heating was stopped and it was cooled to room temperature. The contents were washed successively with 30 ml of water, 30 ml of saturated sodium bicarbonate solution, and 30 ml of saturated brine, and the organic phase was dried over magnesium sulfate. The organic phase was concentrated using an evaporator, and 26.49 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid 2,2,3,3,3-pentafluoropropyl as a standard substance, 19.25 g of α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl was contained (yield: 70.0%).

[0052] [Example 2] In Example 1, various operations were carried out in the same manner as in Example 1 except that 2.94 g (0.03 mol) of concentrated sulfuric acid as the acid catalyst was changed to 1.5 g (0.01 mol) of trifluoromethanesulfonic acid, and 25.37 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid 2,2,3,3,3-pentafluoropropyl as a standard substance, 18.92 g of α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl was contained (yield: 68.8%).

[0053] [Example 3] In Example 1, except that 60 g of the solvent heptafluorocyclopentane was changed to 60 g of nonafluorobutyl ethyl ether and the temperature of the oil bath was changed to 125°C, various operations were performed in the same manner as in Example 1, and 24.08 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid 2,2,3,3,3-pentafluoropropyl as a standard substance, 18.53 g of α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl was contained (yield: 67.4%).

[0054] [Example 4] In Example 1, except that 30 g of pellet-shaped molecular sieves 5A (diameter: 1 / 16 inch) was changed to 30 g of pellet-shaped molecular sieves 4A (diameter: 1 / 16 inch), various operations were performed in the same manner as in Example 1, and 25.37 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid 2,2,3,3,3-pentafluoropropyl as a standard substance, 18.81 g of α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl was contained (yield: 68.6%).

[0055] [Example 5] In Example 1, except that 30 g (0.2 mol) of 2,2,3,3,3-pentafluoropropanol was reduced to 22.5 g (0.15 mol) and 2.94 g (0.03 mol) of concentrated sulfuric acid as an acid catalyst was changed to 1.5 g (0.01 mol) of trifluoromethanesulfonic acid, various operations were performed in the same manner as in Example 1, and 23.30 g of a liquid was recovered. When this liquid was analyzed by gas chromatography, 17.0 g of α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl was contained (yield: 61.9%).

[0056] [Example 6] In Example 1, various operations were carried out in the same manner as in Example 1, except that 30 g (0.2 mol) of 2,2,3,3,3-pentafluoropropanol was changed to 40 g (0.2 mol) of 2,2,3,3,4,4,4-heptafluorobutanol, and 28.66 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl as a standard substance, 22.13 g of α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl was contained (yield: 68.1%).

[0057] [Example 7] In Example 6, various operations were carried out in the same manner as in Example 6, except that 60 g of heptafluorocyclopentane as the solvent was changed to 60 g of nonafluorobutylethyl ether, the temperature of the oil bath was changed to 125 °C, and the reflux time was changed to 35 hours, and 31.09 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl as a standard substance, 24.41 g of α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl was contained (yield: 75.1%).

[0058] [Example 8] In Example 7, various operations were carried out in the same manner as in Example 7, except that the amount of 2,2,3,3,4,4,4-heptafluorobutanol was reduced from 40 g (0.2 mol) to 30 g (0.15 mol), and 28.09 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl as a standard substance, 20.80 g of α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl was contained (yield: 64.0%).

[0059] [Example 9] In Example 1, except that 30 g (0.2 mol) of 2,2,3,3,3-pentafluoropropanol was changed to 26 g (0.2 mol) of 2,2,3,3-tetrafluoropentanol and the temperature of the oil bath was changed to 125 °C, various operations were carried out in the same manner as in Example 1, and 29.16 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid-2,2,3,3-tetrafluoropropyl as a standard substance, 19.92 g of α,β-dichloropropionic acid-2,2,3,3-tetrafluoropropyl was contained (yield: 78.8%).

[0060] [Example 10] A 100 ml round-bottomed flask equipped with a dropping funnel with a side tube and a stirrer, and further equipped with a Dimroth condenser on the upper part of the dropping funnel with a side tube, was charged with 15.7 g (0.1 mol, manufactured by Alpha Aesar) of methyl α,β-dichloropropionate, 40 g (0.2 mol) of 2,2,3,3,4,4,4-heptafluorobutanol, 60 g of nonafluorobutylethyl ether as a solvent, and 1.47 g (0.003 mol) of scandium(III) tris(trifluoromethanesulfonate) as an acid catalyst. The main body part of the dropping funnel with a side tube was filled with 30 g of pelletized molecular sieves 5A (diameter: 1 / 16 inch). A refrigerant at 0 °C was circulated through the condenser. The round-bottomed flask was immersed in an oil bath heated to 125 °C, and reflux was continued for 30 hours. During that time, the reflux liquid (condensate) passing through the main body part was brought into contact with the molecular sieves. After 30 hours, heating was stopped and the mixture was cooled to room temperature. The contents were filtered to remove the solid matter, and the filtrate was washed successively with 30 ml of water, 30 ml of saturated aqueous sodium bicarbonate, and 30 ml of saturated brine, and the organic phase was dried over magnesium sulfate. The organic phase was concentrated using an evaporator, and 29.16 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl as a standard substance, 18.91 g of α,β-dichloropropionic acid-2,2,3,3,4,4,4-heptafluorobutyl was contained (yield: 58.1%).

[0061] [Example 11] In Example 10, 15.7 g (0.1 mol, manufactured by Alpha Esser) of methyl α,β-dichloropropionate was changed to 24.6 g (0.1 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) of methyl α,β-dibromopropionate, and 40 g (0.2 mol) of 2,2,3,3,4,4,4-heptafluorobutanol was changed to 30 g (0.2 mol) of 2,2,3,3,3-pentafluoropropanol. Various operations were carried out in the same manner as in Example 10, and 27.95 g of a liquid was recovered. When this liquid was analyzed by gas chromatography using methyl α,β-dibromopropionate-2,2,3,3,3-pentafluoropropyl as a standard substance, 21.37 g of methyl α,β-dibromopropionate-2,2,3,3,3-pentafluoropropyl was contained (yield: 58.7%).

[0062] [Comparative Example 1] A dropping funnel with a side tube and a stir bar were attached, and 15.7 g (0.1 mol, manufactured by Alpha Aesar) of methyl α,β-dichloropropionate, 30 g (0.2 mol) of 2,2,3,3,3-pentafluoropropanol, and 2.94 g (0.03 mol) of concentrated sulfuric acid as an acid catalyst were added to a 100 ml round-bottomed flask with a Dimroth condenser attached to the upper part of the dropping funnel with a side tube. The main body part of the dropping funnel with a side tube was filled with 30 g of pellet-shaped molecular sieves 5A (diameter: 1 / 16 inch). A refrigerant at 0 °C was circulated through the condenser. The round-bottomed flask was immersed in an oil bath heated to 120 °C, and reflux was continued for 10 hours. During that time, the liquid condensed in the side tube of the dropping funnel and the condenser part was brought into contact with the molecular sieves. After 10 hours, heating was stopped and it was cooled to room temperature. When the contents were washed with 30 ml of water, a large amount of polymer precipitated, and the target product, α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl, could not be recovered. In this reaction, since there was no solvent, when heated, a locally high-temperature part occurred, and as a result, the starting material methyl α,β-dichloropropionate or the target product α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl underwent dehalogenation to form methyl α-chloroacrylate and / or α-chloroacrylate-2,2,3,3,3-pentafluoropropyl, and it is presumed that these polymerized by heat.

[0063] [Comparative Example 2] In Example 1, various operations were carried out in the same manner as in Example 1, except that 60 g of heptafluorocyclopentane as the solvent was changed to 40 g of toluene. As a result, 24.03 g of a gel-like substance was recovered. When this gel-like substance was analyzed by gas chromatography using α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl as a standard substance, 5.30 g of α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl was contained (yield: 19.3%). In this reaction, since toluene could not dissolve methyl α,β-dichloropropionate and 2,2,3,3,3-pentafluoropropanol well, when heated, local high-temperature parts occurred. As a result, the raw material methyl α,β-dichloropropionate or the target product α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl underwent dehalogenation to form methyl α-chloroacrylate and / or α-chloroacrylate-2,2,3,3,3-pentafluoropropyl, and it is presumed that these polymerized by heat.

[0064] As is clear from the results of the above Examples and Comparative Examples, it can be seen that the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention is a method for producing a fluoroalkyl α,β-dihalogenopropionate with a simple operation, a good yield, and industrially advantageously.

Industrial Applicability

[0065] According to the present invention, a method for producing a fluoroalkyl α,β-dihalogenopropionate with a simple operation, a good yield, and industrially advantageously can be provided.

Explanation of Symbols

[0066] 10 Refluxer 11 Reactor 12 Filling Tube 13 Condenser 14 Mixed Liquid 15 Reflux Liquid 16 Zeolite 17 Suction and exhaust pipe

Claims

1. The following formula (1): 【Chemical 1】 [In formula (1), X and Y each independently represent a halogen atom selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and Rf represents a fluoroalkyl group having 3 to 6 carbon atoms.] A method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester represented by the formula: The following formula (2): [Chemical 2] [In formula (2), X and Y are the same as X and Y in formula (1), and R represents a methyl group or an ethyl group.] An alkyl α,β-dihalogenopropionate represented by the formula: The following formula (3): RfOH (3) [In formula (3), Rf is the same as Rf in formula (1).] A fluoroalcohol represented by the formula: Reacting in the presence of an acid catalyst and a fluorine-containing solvent capable of dissolving the alkyl α,β-dihalogenopropionate and the fluoroalcohol, the method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester comprising this step.

2. The method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester according to claim 1, wherein the acid catalyst is at least one selected from the group consisting of sulfuric acid, trifluoromethanesulfonic acid, and rare earth metal triflates.

3. The reaction is carried out under reflux, During the reflux, the reflux liquid is brought into contact with zeolite to obtain the following formula (4): ROH (4) [In formula (4), R is the same as R in formula (2).] The method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester according to claim 1 or 2, wherein the alkyl alcohol represented by the formula is removed.

4. The method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester according to claim 3, wherein the zeolite is at least one selected from the group consisting of 4A type synthetic zeolite and 5A type synthetic zeolite.

5. The method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester according to any one of claims 1 to 4, wherein the alkyl α,β-dihalogenopropionate represented by the formula (2) is at least one compound selected from the group consisting of methyl α,β-dichloropropionate and methyl α,β-dibromopropionate.

6. The α,β-dihalogenopropionic acid fluoroalkyl ester represented by the formula (1) is selected from the group consisting of 2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate, 2,2,3,3,4,4,4-heptafluorobutyl α,β-dichloropropionate, or 2,2,3,3,3-pentafluoropropyl α,β-dibromopropionate. A method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester according to any one of claims 1 to 5.

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