JP2023046125A - Method for producing α,β-dihalogenopropionic acid fluoroalkyl ester - Google Patents

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

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

The α-halogenoacrylic acid fluoroalkyl ester is a useful compound as a raw material monomer for a polymer.
For example, α-chloroacrylic acid fluoroalkyl ester, which is one of the α-halogenoacrylic acid fluoroalkyl esters, is used as a raw material monomer for copolymers used as main chain scission type positive resists in fields such as semiconductor manufacturing. used (see, for example, Patent Document 1).

Such an α-halogenoacrylic acid fluoroalkyl ester can be produced, for example, by contacting an α,β-dihalogenopropionic acid fluoroalkyl ester with an organic amine or an inorganic alkali to dehalogenate it (see, for example, patent See Document 2 and Patent Document 3). Therefore, α,β-dihalogenolopropionic acid fluoroalkyl esters are important precursor compounds in the production of α-halogenoacrylic acid fluoroalkyl esters.

Here, in Patent Document 2, 2,2,2,3,3-pentafluoropropyl acrylate is synthesized from 2,2,2,3,3-pentafluoropropanol and acrylic acid, and chlorine gas is synthesized. Chlorination of this 2,2,2,3,3-pentafluoropropyl acrylate using disclosed.
Further, in Patent Document 3, 2-(perfluorobutyl)ethyl acrylate is chlorinated using chlorine gas to produce α,β-dichloropropionic acid-(1H,1H,2H,2H-nonafluorohexyl). A method is also disclosed.
Furthermore, in Patent Document 4, α,β-dichloropropionic acid-2 is obtained by dehydration condensation of 2,2,3,3-tetrafluoropropanol and α,β-dichloropropionic acid in the presence of concentrated sulfuric acid. , 2,3,3-tetrafluoropropyl are disclosed.

JP 2021-067811 A JP-A-57-118535 WO2006/54549 JP-A-63-201145

However, in the methods of Patent Documents 2 and 3, the electron density of the double bond portion of the raw material fluoroalkyl acrylate is reduced by the fluoroalkyl group having a strong electron-withdrawing property. The electrophilic chlorination reaction is more difficult to proceed than the acrylic acid alkyl ester of (1), and it takes a long time to complete the reaction, which is industrially disadvantageous.

Further, in the method of Patent Document 4, α,β-dichloropropionic acid as a raw material has a strong hygroscopic property, and stickiness occurs due to absorption of water, so there is a problem that it is difficult to handle from the viewpoint of operation. In addition, there is also a problem that the esterification reaction itself may not proceed due to this strong hygroscopicity.

The present invention has been made under such circumstances, and an object of the present invention is to produce a fluoroalkyl α,β-dihalogenopropionate by a simple operation with good yield and industrial advantage. The purpose is to provide a method.

The inventor of the present invention has made intensive studies in order to achieve the above object. Further, the present inventors have found that any method comprising the step of reacting a given α,β-dihalogenopropionic acid alkyl ester with a given fluoroalcohol in the presence of an acid catalyst and a fluorine-containing solvent, The present inventors have found that β-dihalogenopropionic acid fluoroalkyl ester can be produced in a simple operation with high yield and industrial advantage, and have completed the present invention.

［式（１）中、Ｘ及びＹは、それぞれ独立して、フッ素原子、塩素原子、臭素原子及びヨウ素原子からなる群から選択されるハロゲン原子を表し、Ｒｆは、炭素数３以上６以下のフルオロアルキル基を表す。］で表されるα，β－ジハロゲノプロピオン酸フルオロアルキルエステルの製造方法であって、下記式（２）：

［式（２）中、Ｘ及びＹは、式（１）中のＸ及びＹと同じであり、Ｒは、メチル基又はエチル基を表す。］で表されるα，β－ジハロゲノプロピオン酸アルキルエステルと、下記式（３）：
ＲｆＯＨ （３）
［式（３）中、Ｒｆは、式（１）のＲｆと同じである。］で表されるフルオロアルコールと、を酸触媒及び含フッ素溶媒の存在下で反応させる工程を含む、α，β－ジハロゲノプロピオン酸フルオロアルキルエステルの製造方法である。このようなα，β－ジハロゲノプロピオン酸フルオロアルキルエステルの製造方法であれば、α，β－ジハロゲノプロピオン酸フルオロアルキルエステルを、簡便な操作で収率良く、且つ、工業的に有利に製造できる。 That is, an object of the present invention is to advantageously solve the above-mentioned problems, and the present invention provides the following formula (1):

[In the 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; represents a fluoroalkyl group. ] A method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester represented by the following formula (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. ] and an α,β-dihalogenopropionic acid alkyl ester represented by the following formula (3):
RfOH (3)
[In Formula (3), Rf is the same as Rf in Formula (1). ] with a fluoroalcohol represented by ] in the presence of an acid catalyst and a fluorine-containing solvent. According to such a method for producing a fluoroalkyl α,β-dihalogenopropionate, a fluoroalkyl α,β-dihalogenopropionate can be produced by a simple operation in a high yield and industrially advantageously. can.

In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, the acid catalyst is preferably 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 α,β-dihalogenopropionic acid fluoroalkyl ester can be produced with higher yield.

In the method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention, the reaction is performed under reflux, and 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). ] is preferably removed. With such a method for producing a fluoroalkyl α,β-dihalogenopropionate, the fluoroalkyl α,β-dihalogenopropionate can be produced in a simpler operation with a higher yield and is industrially more advantageous. can be manufactured to

In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, the zeolite is preferably at least one selected from the group consisting of type 4A synthetic zeolite and type 5A synthetic zeolite.
If the zeolite is at least one selected from the group consisting of type 4A synthetic zeolite and type 5A synthetic zeolite, these compounds are readily available, and thus α,β-dihalogenopropionic acid fluoroalkyl esters are industrially produced. can be produced in a more advantageous manner. Further, if the zeolite is at least one selected from the group consisting of 4A type synthetic zeolite and 5A type synthetic zeolite, it effectively adsorbs the alkyl alcohol represented by the formula (4), A halogenopropionic acid fluoroalkyl ester can be produced with a higher yield.

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

In the method for producing a fluoroalkyl α,β-dihalogenopropionic acid of the present invention, the fluoroalkyl α,β-dihalogenopropionic acid represented by the formula (1) is α,β-dichloropropionic acid-2 , 2,3,3,3-pentafluoropropyl, α,β-dichloropropionate-2,2,3,3,4,4,4-heptafluorobutyl or α,β-dibromopropionate-2,2 , 3,3,3-pentafluoropropyl.
The α,β-dihalogenopropionic acid fluoroalkyl ester represented by formula (1) is α,β-dichloropropionic acid-2,2,3,3,3-pentafluoropropyl, α,β-dichloropropionic acid. -2,2,3,3,4,4,4-heptafluorobutyl or -2,2,3,3,3-pentafluoropropyl α,β-dibromopropionate; It can be used more advantageously as a raw material for obtaining a monomer that is used in the manufacture of coalescence.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing a fluoroalkyl α,β-dihalogenopropionate by a simple operation, in a high yield, and with an industrial advantage.

It is a schematic diagram showing an example of a reflux vessel.

Hereinafter, embodiments of the present invention will be described in detail.
Here, the α,β-dihalogenopropionic acid fluoroalkyl ester produced by the method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention is, for example, a monomer used for polymer production. can be advantageously used as a raw material for obtaining Specifically, a polymer whose main chain is cut and reduced in molecular weight by irradiation with ionizing radiation such as an electron beam or light with a short wavelength such as ultraviolet rays, which can be suitably used as a main chain scission type positive resist. It can be advantageously used as a raw material or the like for obtaining the α-halogenoacrylic acid fluoroalkyl ester used in production.

(Method for producing α,β-dihalogenopropionic acid fluoroalkyl ester)
The method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention comprises an α,β-dihalogenopropionic acid alkyl ester represented by the formula (2) described later and an α,β-dihalogenopropionic acid alkyl ester represented by the formula (3) described later. with a fluoroalcohol in the presence of an acid catalyst and a fluorine-containing solvent.

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

X and Y in formula (2) 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. Moreover, in Formula (2), R represents a methyl group or an ethyl group. The α,β-dihalogenopropionic acid alkyl ester represented by formula (2) is a relatively stable compound and is easy to handle. Fluoroalkyl esters of acids can be produced in a simple and industrially advantageous manner.
Examples of α,β-dihalogenopropionic acid alkyl esters represented by formula (2) include methyl α,β-dichloropropionate, methyl α,β-dibromopropionate, methyl α,β-difluoropropionate, Methyl α,β-dihalogenopropionate such as methyl α-fluoro-β-chloropropionate, methyl α-bromo-β-chloropropionate, methyl α-chloro-β-iodopropionate; α,β-dichloropropionate ethyl acetate, α,β-ethyl dibromopropionate, ethyl α,β-difluoropropionate, ethyl α-fluoro-β-chloropropionate, ethyl α-bromo-β-chloropropionate, α-chloro-β-iodine Examples include ethyl α,β-dihalogenopropionate such as ethyl propionate. Among these, methyl α,β-dichloropropionate and α,β-dibromo are relatively easy to synthesize, and as a result, the fluoroalkyl α,β-dihalogenopropionate can be produced industrially more advantageously. It is preferable to use at least one compound selected from the group consisting of methyl dipropionate, ethyl α,β-dichloropropionate and ethyl α,β-dibromopropionate, methyl α,β-dichloropropionate and More preferably, at least one compound selected from the group consisting of methyl α,β-dichloropropionate is used.

An α,β-dihalogenopropionic acid alkyl ester can be synthesized according to a conventionally known method. See, for example, Macromolecules, Vol. 19, 1035 (1986) and JP-A-1-172356 disclose an example of synthesizing α,β-methyl dichloropropionate from methyl acrylate and chlorine gas. Also, 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, in JP-A-2014-214147, α-fluoro-β-hydroxypropionic acid is prepared from pyridine-hydrogen fluoride and sodium nitrite, using serine, which is one of amino acids, as a raw material. It is disclosed that methyl α-fluoro-β-chloropropionate can be obtained by obtaining and further reacting this with thionyl chloride and mixing the resulting solution with methanol. Further, JP-A-2012-530756 discloses that ethyl α-fluoro-β-chloropropionate can be synthesized from ethyl α-fluoro-β-hydroxypropionate by a similar method.

<Fluoroalcohol>
The fluoroalcohol used in the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention is a compound represented by the following formula (3).
RfOH (3)

In addition, in Formula (3), Rf is the same as Rf of Formula (1) demonstrated below. That is, in formula (3), Rf represents a fluoroalkyl group having 3 or more and 6 or less carbon atoms. Rf is preferably a fluoroalkyl group having 3 or more and 5 or less carbon atoms because it is easily available.
As the fluoroalcohol represented by formula (3), one having a boiling point of 80° C. or higher can be suitably used from the viewpoint of reaction conditions and the like. Specific examples of such fluoroalcohols include 2,2,3,3,3-pentafluoropropanol (boiling point: 80°C) and 2,2,3,3-tetrafluoropropanol (boiling point: 109°C). , 3,3,3-trifluoropropanol (boiling point: 100° C.) and other fluoroalcohols having 3 carbon atoms; 2,2,3,3,4,4,4-heptafluorobutanol (boiling point: 96° C.); , 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 - fluoroalcohols having 4 carbon atoms such as pentafluorobutan-2-ol (boiling point: 83°C), 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), etc. fluoroalcohols; fluoroalcohols having 6 carbon atoms such as 2,2,3,3,4,4,5,5,6,6,6-undecafluorohexanol (boiling point: 130° C.); . 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 preferred, 2,2,3,3,3-pentafluoropropanol, 2,2,3,3 ,4,4,4-heptafluorobutanol is more preferred.

The amount of the fluoroalcohol represented by formula (3) to be used is usually 1 mol or more, preferably 1.5 mol or more, usually 5 mol or less, preferably 3 mol or less per 1 mol of α,β-dihalogenopropionic acid alkyl ester.
When the amount of the fluoroalcohol represented by the formula (3) used is at least the above lower limit, the transesterification reaction proceeds easily, and the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced at a higher yield. On the other hand, if the amount of the fluoroalcohol represented by formula (3) used is equal to or less than the above upper limit, it is economically advantageous, and the purification operation after completion of the reaction can be simplified.

<Fluorine-containing solvent>
In the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, a fluorine-containing solvent is used. The method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention uses a fluorine-containing solvent to produce a fluoroalkyl α,β-dihalogenopropionate in a simple operation with a high yield, and It can be produced industrially advantageously. Specifically, it is possible to prevent the production of a large amount of polymer in the reaction, which makes it impossible to recover the target α,β-dihalogenopropionic acid fluoroalkyl ester, and the decrease in yield. The reason is presumed to be as follows.

First, the raw material α,β-dihalogenopropionic acid alkyl ester and the target product α,β-dihalogenopropionic acid fluoroalkyl ester easily eliminate the halogen atom at the β-position by heating or the like. . The fluorine-containing solvent used in the method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention includes the α,β-dihalogenopropionic acid alkyl ester represented by formula (2) and the α,β-dihalogenopropionic acid alkyl ester represented by formula (3). Since the fluoroalcohol to be used is dissolved satisfactorily, it is possible to suppress the occurrence of locally high temperature portions when heated during the reaction. As a result, dehalogenation and polymerization of α,β-dihalogenopropionic acid alkyl ester and/or α,β-dihalogenopropionic acid fluoroalkyl ester can be suppressed.
For the above reasons, it is believed that the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced in a simple operation with good yield and with industrial advantages.

The fluorine-containing solvent is not particularly limited as long as it can satisfactorily dissolve the raw materials, α,β-dihalogenopropionic acid alkyl ester and fluoroalcohol. The fluorine-containing solvent preferably dissolves 10 g or more, more preferably 20 g or more, of α,β-dihalogenopropionic acid alkyl ester as a raw material per 100 g of the fluorine-containing solvent at 20°C. more preferred. The fluorine-containing solvent preferably dissolves 20 g or more, more preferably 45 g or more, of fluoroalcohol per 100 g of the fluorine-containing solvent at 20°C. With such a fluorine-containing solvent, it is possible to effectively suppress the occurrence of localized high-temperature portions when heated during the reaction.

When the transesterification reaction of the present invention is carried out under reflux, the fluorine-containing solvent can produce α,β-dihalogenopropionic acid fluoroalkyl ester in a higher yield, and is represented by the formula (4) described later. A solvent that forms an azeotropic mixture with the alkyl alcohol or a solvent that easily guides the alkyl alcohol out of the reaction system (for example, a solvent having a boiling point higher than that of the alkyl alcohol) is preferable. Examples of such fluorine-containing solvents include 1,1,2,2,3,3,4-heptafluorocyclopentane (boiling point: 82°C), nonafluorobutyl ethyl 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.) and the like. Among these, 1,1,2,2,3,3,4-heptafluorocyclopentane (boiling point 82° C.) and nonafluoro, which form an azeotrope with the alkyl alcohol represented by formula (4) described later Butyl ethyl ether (boiling point 76° C.) is preferred.

The amount of fluorine-containing solvent used is usually 0.5 times or more, preferably 1 time or more, usually 3 times or less, preferably 2 times the total mass of α,β-dihalogenopropionic acid alkyl ester and fluoroalcohol. are the following quantities:
If the amount of the fluorine-containing solvent used is at least the above lower limit, it suppresses the occurrence of localized high temperature parts, and α,β-dihalogenopropionate alkyl ester and α,β-dihalogenopropionate fluoroalkyl ester Ester dehalogenation can be suppressed. On the other hand, if the amount of the fluorine-containing solvent used is equal to or less than the above upper limit, the concentration of the starting material will be high, and the reaction rate of the transesterification reaction can be increased.

<Acid catalyst>
An acid catalyst is used in the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention. Examples of acid catalysts include protonic acids such as sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid; scandium trifluoromethanesulfonate (III), ytterbium trifluoromethanesulfonate (III), trifluoromethanesulfonic acid Rare earth metal triflates such as neodymium (III), Lewis acids such as hafnium trifluoromethanesulfonate (IV); 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, since the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced with higher yield. Among the rare earth metal triflates, scandium trifluoromethanesulfonate (III) and ytterbium trifluoromethanesulfonate (III) are preferred, and scandium trifluoromethanesulfonate (III) is more preferred.

The amount of the acid catalyst used can be appropriately adjusted depending on the activity of the acid catalyst. It is 0.5 mol or less, preferably 0.3 mol or less.
When 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, when the amount of the acid catalyst used is not more than the above upper limit, separation operation during post-treatment becomes easy, and α,β-dihalogenopropionate fluoroalkyl ester can be produced by simpler operation. When the amount of the acid catalyst used is equal to or less than the above upper limit, the starting α,β-dihalogenopropionic acid alkyl ester and the target product α,β-dihalogenopropionic acid fluoroalkyl ester suppress dehalogenation. As a result, α,β-dihalogenopropionic acid fluoroalkyl ester can be produced in a higher yield.

<Reaction conditions>
The heating temperature for the transesterification reaction is not particularly limited as long as it is a temperature at which the transesterification reaction occurs.
If the heating temperature is at least the above lower limit, the transesterification reaction can be effectively advanced. On the other hand, if the heating temperature is equal to or lower than the above upper limit, excessive acceleration of 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 equal to or lower than the above upper limit, it is possible to prevent the reflux state from becoming too vigorous.

The reaction time of the transesterification reaction can be appropriately determined depending on the heating temperature and the like, and is usually 10 hours or more, preferably 20 hours or more, and usually 5 days or less, preferably 3 days or less.
When the reaction time is at least the above lower limit, it is possible to suppress the raw material from remaining. On the other hand, if the reaction time is equal to or less than the above upper limit, the α,β-dihalogenopropionic acid alkyl ester and/or the α,β-dihalogenopropionic acid fluoroalkyl ester are dehalogenated and polymerized. can be suppressed.

The transesterification reaction is preferably carried out under reflux. If the transesterification reaction is carried out under reflux, the reaction temperature is maintained at a favorable temperature, so that the transesterification reaction proceeds effectively, and the α,β-dihalogenopropionic acid fluoroalkyl ester can be processed more easily. can be produced in a higher yield and industrially more advantageously.
In one embodiment, the reflux can be performed using a reflux vessel comprising a reactor and a condenser (cooling tube) located at the top of the reactor. The reactor and condenser may be connected by a connecting pipe. The connecting pipe is not particularly limited, and may have only one route or two or more routes.

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

In formula (4), R is the same as R in formula (2). That is, in 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 in a higher yield. The reason is presumed to be as follows.

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 produced. is generated. Here, since the transesterification reaction is an equilibrium reaction, the reaction rate decreases as the amount of alkyl alcohol produced increases. When the alkyl alcohol is removed from the reflux liquid, the equilibrium state is disturbed, and the reaction tends to proceed toward the production of the target product, α,β-dihalogenopropionic acid fluoroalkyl ester.
For the above reasons, it is believed that α,β-dihalogenopropionic acid fluoroalkyl esters can be produced with higher yields.

The method for removing the alkyl alcohol represented by the formula (4) is not particularly limited, but for example, a method of adsorbing the alkyl alcohol to an adsorbent such as zeolite (incorporation into pores), a method of using two refrigerants with different temperatures. A method of using the above capacitors in series and removing the components by utilizing the difference in boiling point of each component can be used.
In the method for removing alkyl alcohol, it is preferable to use zeolite because it facilitates the reflux operation and is excellent in selectivity of adsorbed substances. That is, in the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention, it is particularly preferable to bring the reflux liquid into contact with zeolite to remove the alkyl alcohol.

Zeolite is a general term for crystalline aluminosilicates, and may be natural or synthetic. The zeolite that can be used in the method for producing 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). , 5A type and 13X type zeolites. Zeolite is easily available, and it is possible to industrially more advantageously produce fluoroalkyl At least one selected from the group consisting of type 4A synthetic zeolite and type 5A synthetic zeolite is preferable, since the alkyl ester can be produced with higher yield. Specific examples of type 4A synthetic zeolite and type 5A synthetic zeolite include molecular sieves 4A and molecular sieves 5A.
The zeolite may be subjected to an activation treatment such as calcination before use.

The zeolite is preferably in the form of beads or pellets because the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced by a simpler operation.

The amount of zeolite to be used is not particularly limited as long as it is an amount that can sufficiently adsorb the alkyl alcohol represented by formula (4). It is preferably 50 times or more, more preferably 80 times or more, preferably 200 times or less, and more preferably 150 times or less of the maximum amount on a mass basis.
When the amount of zeolite used is at least the above lower limit, alkyl alcohol can be effectively adsorbed, and α,β-dihalogenopropionic acid fluoroalkyl ester can be produced at a higher yield. On the other hand, if the amount of zeolite used is equal to or less than the above upper limit, excessive use of zeolite can be suppressed, and the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced industrially more advantageously.

The zeolite may be present in the fluorine-containing solvent as long as it does not adversely affect the transesterification reaction. It is preferable to use zeolite by filling it in the connecting pipe, since the alkyl ester can be produced by a simpler operation. That is, the connecting pipe is preferably a filled pipe filled with zeolite.
The fill tube may have only one passageway or two or more passageways, preferably two or more passageways. If the packed tube has two or more paths, at least the path through which the reflux liquid passes is preferably filled with zeolite. With such a packed tube shape, the alkyl alcohol can be effectively adsorbed, and the α,β-dihalogenopropionic acid fluoroalkyl ester can be produced at a higher yield.

Hereinafter, as shown in FIG. 1, a reactor 11 and a condenser 13 located above the reactor 11 are provided, the reactor 11 and the condenser 13 are connected by a filling pipe 12, and the filling pipe 12 provides two paths. An example of the reflux operation will be described by exemplifying the reflux device 10.
When the mixed liquid 14 containing the raw material and the product in the reactor 11 is heated, the low boiling point components such as alkyl alcohol, fluoroalcohol and fluorine-containing solvent contained in the mixed liquid 14 are vaporized into vapor. The vapor passes through the side tube (the left-hand path in FIG. 1) of the filling tube 12 and is cooled by the condenser 13 located above 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 body portion of the packed tube 12 (the right path in FIG. 1) filled with zeolite 16, the alkyl alcohol contained in the reflux liquid 15 is adsorbed by the zeolite 16, and the remaining reflux liquid 15 is returned into reactor 11 . This is continuously repeated to effect reflux. In addition, as shown in FIG. 1, the reflux device 10 may have an intake/exhaust pipe 17 connected to the upper part of the condenser 13 .

In the method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention, after completion of the transesterification reaction, for example, a step of removing the acid catalyst by alkali washing or filtration, a fluorine-containing solvent and unreacted substances are removed. An arbitrary step such as a step of distilling off and concentrating, a step of distilling and purifying the concentrated solution, and the like may be performed.

<α,β-dihalogenopropionic acid fluoroalkyl ester>
The α,β-dihalogenopropionic acid fluoroalkyl ester obtained by the method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester of the present invention is a compound represented by the following formula (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 has 3 to 6 carbon atoms. represents a fluoroalkyl group.
The α,β-dihalogenopropionic acid fluoroalkyl ester represented by the formula (1) can be used more advantageously as a raw material for obtaining a monomer used in polymer production. 2,2,3,3,3-pentafluoropropyl propionate, α,β-dichloropropionate-2,2,3,3,4,4,4-heptafluorobutyl or α,β-dibromopropionic acid It is preferably selected from the group consisting of -2,2,3,3,3-pentafluoropropyl.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited by the following examples. In addition, "%" represents "% by mass" unless otherwise specified.

Analysis conditions for gas chromatography analysis (GC analysis) performed in Examples and Comparative Examples are as follows.

Apparatus: Agilent-7890 (manufactured by Agilent)
Column: Inert Cap-1 (manufactured by GL Sciences, length 60 m, inner diameter 0.25 mm, film thickness 1.5 μm)
Column temperature: Hold at 60°C for 10 minutes, then heat up to 260°C at a heating rate of 20°C/min, then hold at 260°C for 10 minutes Injection temperature: 250°C
Detector temperature: 250°C
carrier gas: nitrogen split ratio: 100/1
Detector: FID

[Example 1]
15.7 g (0.1 mol, alpha Acer), 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 are added. bottom. The body of the dropping funnel with a side tube is filled with 30 g of pelletized molecular sieves 5A (diameter: 1/16 inch). A refrigerant of 0° C. was circulated in the condenser. The round bottom 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 body portion was contacted with the molecular sieves. After 30 hours, the heating was stopped and the mixture was allowed to cool to room temperature. The contents were washed with 30 ml of water, 30 ml of saturated aqueous sodium bicarbonate and 30 ml of saturated brine in that order, and the organic phase was dried over magnesium sulfate. The organic phase was concentrated by an evaporator to recover 26.49 g of liquid. Gas chromatography analysis of this liquid using 2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate as a standard revealed 19.25 g of α,β-dichloropropionate- It contained 2,2,3,3,3-pentafluoropropyl (yield: 70.0%).

[Example 2]
In Example 1, various operations were performed 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, 25.37 g of liquid was recovered. Gas chromatography analysis of this liquid using 2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate as a standard revealed 18.92 g of α,β-dichloropropionate- It contained 2,2,3,3,3-pentafluoropropyl (yield: 68.8%).

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

[Example 4]
Various operations were performed in the same manner as in Example 1, except that 30 g of pelletized molecular sieves 5A (diameter: 1/16 inch) were changed to 30 g of pelleted molecular sieves 4A (diameter: 1/16 inch). was performed and 25.37 g of liquid was recovered. Gas chromatography analysis of this liquid using 2,2,3,3,3-pentafluoropropyl α,β-dichloropropionate as a standard revealed 18.81 g of α,β-dichloropropionate- It contained 2,2,3,3,3-pentafluoropropyl (yield: 68.6%).

[Example 5]
In Example 1, 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 added. Various operations were performed in the same manner as in Example 1, except that 1.5 g (0.01 mol) of trifluoromethanesulfonic acid was used, and 23.30 g of liquid was recovered. When this liquid was analyzed by gas chromatography, it contained 17.0 g of α,β-dichloropropionate-2,2,3,3,3-pentafluoropropyl (yield: 61.9%). .

[Example 6]
In Example 1, 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. Various operations were carried out in the same manner as in Example 1, except that 28.66 g of liquid was recovered. Gas chromatography analysis of this liquid using α,β-dichloropropionate-2,2,3,3,4,4,4-heptafluorobutyl as a standard revealed 22.13 g of α,β -2,2,3,3,4,4,4-heptafluorobutyl dichloropropionate (yield: 68.1%).

[Example 7]
In Example 6, 60 g of heptafluorocyclopentane as a solvent was changed to 60 g of nonafluorobutyl ethyl ether, the temperature of the oil bath was changed to 125 ° C., and the reflux time was changed to 35 hours. Various operations were performed in the same manner, and 31.09 g of liquid was recovered. Gas chromatography analysis of this liquid using α,β-dichloropropionate-2,2,3,3,4,4,4-heptafluorobutyl as a standard revealed 24.41 g of α,β -2,2,3,3,4,4,4-heptafluorobutyl dichloropropionate (yield: 75.1%).

[Example 8]
In Example 7, various preparations were made in the same manner as in Example 7, except that 40 g (0.2 mol) of 2,2,3,3,4,4,4-heptafluorobutanol was reduced to 30 g (0.15 mol). The operation was performed and 28.09 g of liquid was recovered. Gas chromatography analysis of this liquid using α,β-dichloropropionate-2,2,3,3,4,4,4-heptafluorobutyl as a standard revealed 20.80 g of α,β -2,2,3,3,4,4,4-heptafluorobutyl dichloropropionate (yield: 64.0%).

[Example 9]
In Example 1, 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 oil bath was Various operations were performed in the same manner as in Example 1 except that the temperature was changed to 125° C., and 29.16 g of liquid was recovered. Gas chromatography analysis of this liquid using α,β-dichloropropionate-2,2,3,3-tetrafluoropropyl as a standard revealed 19.92 g of α,β-dichloropropionate-2. , 2,3,3-tetrafluoropropyl (yield: 78.8%).

[Example 10]
15.7 g (0.1 mol, alpha Acer), 40 g (0.2 mol) of 2,2,3,3,4,4,4-heptafluorobutanol, 60 g of nonafluorobutyl ethyl ether as a solvent, and tris (trifluoromethanesulfonic acid) as an acid catalyst. 1.47 g (0.003 mol) of scandium (III) was added. The body of the dropping funnel with a side tube is filled with 30 g of pelletized molecular sieves 5A (diameter: 1/16 inch). A refrigerant of 0° C. was circulated in the condenser. The round bottom 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 body portion was contacted with the molecular sieves. After 30 hours, the heating was stopped and the mixture was allowed to cool to room temperature. The contents were filtered to separate solids, the filtrate was washed with 30 ml of water, 30 ml of saturated aqueous sodium bicarbonate and 30 ml of saturated brine in that order, and the organic phase was dried over magnesium sulfate. The organic phase was concentrated by an evaporator to recover 29.16 g of liquid. Gas chromatography analysis of this liquid using α,β-dichloropropionate-2,2,3,3,4,4,4-heptafluorobutyl as a standard revealed 18.91 g of α,β -2,2,3,3,4,4,4-heptafluorobutyl dichloropropionate (yield: 58.1%).

[Example 11]
In Example 10, 15.7 g (0.1 mol, manufactured by Alpha Eisa) of methyl α,β-dichloropropionate was changed to 24.6 g (0.1 mol, manufactured by Tokyo Kasei Kogyo) of methyl α,β-dibromopropionate. , except that 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 performed in the same manner as in Example 10, and 27.95 g of liquid was recovered. Gas chromatography analysis of this liquid using α,β-dibromopropionate-2,2,3,3,3-pentafluoropropyl as a standard revealed 21.37 g of α,β-dibromopropionate. -2,2,3,3,3-pentafluoropyropyr (yield: 58.7%).

[Comparative Example 1]
15.7 g (0.1 mol, alpha Acer), 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. The body of the dropping funnel with a side tube is filled with 30 g of pelletized molecular sieves 5A (diameter: 1/16 inch). A refrigerant of 0° C. was circulated in the condenser. The round-bottomed flask was immersed in an oil bath heated to 120° C., and reflux was continued for 10 hours. During this time, the side tube of the dropping funnel and the liquid condensing in the condenser section were brought into contact with the molecular sieves. After 10 hours, the heating was stopped and the mixture was allowed to cool to room temperature. When the contents were washed with 30 ml of water, a large amount of polymer precipitated, and the target α,β-dichloropropionate-2,2,3,3,3-pentafluoropropyl could not be recovered. In this reaction, since there is no solvent, when heated, a portion of the temperature rises locally to a high temperature. , β-dichloropropionate-2,2,3,3,3-pentafluoropropyl undergoes dehalogenation to form methyl α-chloroacrylate and/or α-chloroacrylate-2,2,3,3, It is presumed that 3-pentafluoropropyl was produced and polymerized by heat.

[Comparative Example 2]
Various operations were carried out in the same manner as in Example 1, except that 40 g of toluene was used instead of 60 g of heptafluorocyclopentane as a solvent, and 24.03 g of a gel-like material was recovered. This gel was analyzed by gas chromatography using α,β-dichloropropionate-2,2,3,3,3-pentafluoropropyl as a standard substance, and 5.30 g of α,β-dichloropropionate was analyzed. It contained 2,2,3,3,3-pentafluoropropyl propionate (yield: 19.3%). In this reaction, toluene could not dissolve methyl α,β-dichloropropionate and 2,2,3,3,3-pentafluoropropanol well, so when heated, the temperature was locally high. As a result, the starting material, methyl α,β-dichloropropionate, or the target product, α,β-dichloropropionate-2,2,3,3,3-pentafluoropropyl, is dehalogenated. It is presumed that methyl α-chloroacrylate and/or 2,2,3,3,3-pentafluoropropyl α-chloroacrylate were produced and polymerized by heat.

As is clear from the results of the above Examples and Comparative Examples, the method for producing a fluoroalkyl α,β-dihalogenopropionate of the present invention is capable of producing a fluoroalkyl α,β-dihalogenopropionate by a simple operation. It can be seen that the production method has a good yield and is industrially advantageous.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing a fluoroalkyl α,β-dihalogenopropionate in a simple operation, in a high yield, and in an industrially advantageous manner.

10 reflux vessel 11 reactor 12 filling tube 13 condenser 14 mixed liquid 15 reflux liquid 16 zeolite 17 intake and exhaust pipe

Claims (6)

Formula (1) below:

[In the 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; represents a fluoroalkyl group. ]
A method for producing an α,β-dihalogenopropionic acid fluoroalkyl ester represented by
Formula (2) below:

[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. ]
α, β-dihalogenopropionic acid alkyl ester represented by
Formula (3) below:
RfOH (3)
[In Formula (3), Rf is the same as Rf in Formula (1). ]
A fluoroalcohol represented by
in the presence of an acid catalyst and a fluorine-containing solvent. 2. The method for producing a fluoroalkyl α,β-dihalogenopropionic acid 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. the reaction is carried out under reflux,
During the reflux, the reflux liquid is brought into contact with zeolite, and 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 is removed. 4. The method for producing a fluoroalkyl α,β-dihalogenopropionic acid according to claim 3, wherein the zeolite is at least one selected from the group consisting of type 4A synthetic zeolite and type 5A synthetic zeolite. At least one compound wherein the α,β-dihalogenopropionic acid alkyl ester represented by the formula (2) is selected from the group consisting of methyl α,β-dichloropropionate and methyl α,β-dibromopropionate The method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester according to any one of claims 1 to 4, wherein The α,β-dihalogenopropionic acid fluoroalkyl ester represented by the formula (1) is α,β-dichloropropionate-2,2,3,3,3-pentafluoropropyl, α,β-dichloropropionate. selected from the group consisting of acid-2,2,3,3,4,4,4-heptafluorobutyl or α,β-dibromopropionate-2,2,3,3,3-pentafluoropropyl Item 6. A method for producing the α,β-dihalogenopropionic acid fluoroalkyl ester according to any one of Items 1 to 5.

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