JP6168227B2 - Purification method of acrylic acid derivatives - Google Patents

Description

  The present invention relates to a method for purifying an acrylic acid derivative, and more particularly to a method for purifying an acrylic acid derivative characterized in that the aldehyde is removed from a composition containing an acrylic acid derivative and an aldehyde having 2 to 6 carbon atoms.

Acrylic acid derivatives are (1) raw materials for water-absorbing polymers, (2) as substitutes for inorganic glass, window materials for buildings or vehicles, covers for lighting equipment, lantern signs, road signs, daily necessities, office supplies, crafts It is also widely used as a raw material for acrylic resins used for windshields of watches and (3) acrylic resin paints.
Among acrylic acid derivatives, fluorine-containing acrylic acid derivatives are synthetic intermediates for pharmaceuticals (for example, antibiotics), synthetic intermediates for optical fiber sheath materials, synthetic intermediates for coating materials, and semiconductor resist materials. It is useful as an intermediate and a monomer of a functional polymer.
As a method for producing an acrylic acid derivative, a method for producing an acrylic acid derivative by oxidizing isobutylene or propylene, or a method for producing an acrylic acid derivative using a transition metal catalyst from ethylene or propyne as a raw material is known.
As an acrylic acid derivative containing fluorine, for example, Patent Document 1 discloses a method of reacting 2-fluoropropionic acid ester with a brominating agent having a nitrogen-bromine bond in the presence of a radical initiator. Has been.
Patent Document 2 discloses that a 3-halo-2-fluoropropionic acid derivative is converted into a substituted 2-fluoroacrylic acid derivative in the presence of at least one base and in the presence of at least one polymerization inhibitor. A method of conversion is disclosed.

JP 2011-001340 A Special table 2012-530756 gazette

In the production of an acrylic acid derivative, an aldehyde may be mixed in the composition containing the target acrylic acid derivative.
The aldehyde is an acrylic acid derivative, as described above, a pharmaceutical intermediate (for example, antibiotic), a synthetic intermediate for optical fiber sheath materials, a synthetic intermediate for coating materials, and a synthetic intermediate for semiconductor resist materials. When used in applications such as monomers of functional polymers, etc., there is a risk of adversely affecting the desired reaction.
In such cases, it is necessary to remove the aldehyde from the acrylic acid derivative and the composition containing the aldehyde.
An object of the present invention is to provide a method for efficiently purifying an acrylic acid derivative, specifically, a method for efficiently removing an aldehyde from a composition containing an acrylic acid derivative and an aldehyde.

In general, as a method of removing impurities from useful compounds, for example, (1) a method of removing the impurities as they are, and (2) a method of removing the impurities by reacting them with other components to convert them into other compounds Can be considered.
However, in the method (1), the structure and physical properties of useful compounds and impurities are often similar, and thus the impurities may not be removed as they are by conventional methods such as distillation.
In the method (2), such a problem may be avoided, but there is a problem in that the other component itself and / or the other compound can become a new impurity. In particular, this problem is a big problem in fields where extremely high purity is required, such as the manufacture of pharmaceuticals or electronic materials, and in such a case, the method (2) tends to be avoided. Is strong.
Accordingly, an object of the present invention is to provide a new method for purifying an acrylic acid derivative, which is highly efficient and highly suppresses the introduction of such new impurities as described above.

As a result of intensive studies, the present inventors have
Formula (I):
[Where:
R ^a represents an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituents, or a hydrogen atom, and X represents an alkyl group, a fluoroalkyl group, a fluorine atom, or a hydrogen atom Represents. ]
An acrylic acid derivative (acrylic acid compound) represented by the formula (sometimes referred to herein as an acrylic acid derivative (I))
The purification method of
Acrylic acid derivative represented by the formula (I) and an aldehyde having 2 to 6 carbon atoms (sometimes referred to as aldehyde (II) in the present specification).
A composition A containing
It discovered that an aldehyde could be removed by making it contact with the compound or sulfite which has 1 or more amino groups, and completed this invention based on the said knowledge.

  The present invention includes the following aspects.

Item 1.
Formula (I):
[Where:
R ^a represents an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituents, or a hydrogen atom, and X represents an alkyl group, a fluoroalkyl group, a fluorine atom, or a hydrogen atom Represents. ]
A method for purifying an acrylic acid derivative represented by
A composition A containing an acrylic acid derivative represented by the formula (I) and an aldehyde having 2 to 6 carbon atoms,
Contacting with a compound having one or more amino groups, or sulfite,
Step A for removing the aldehyde having 2 to 6 carbon atoms
A purification method comprising:
Item 2.
Item 2. The purification method according to item 1, wherein R ^a is a linear alkyl group having 1 to 20 carbon atoms.
Item 3.
Item 3. The purification method according to Item 1 or 2, wherein X is an alkyl group having 1 to 20 carbon atoms, a fluorine atom, or a hydrogen atom.
Item 4.
Item 4. The purification method according to any one of Items 1 to 3, wherein the aldehyde having 2 to 6 carbon atoms is normal butyraldehyde.
Item 5.
Formula (I):
[Where:
R ^a represents an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituents, or a hydrogen atom, and X represents an alkyl group, a fluoroalkyl group, a fluorine atom, or a hydrogen atom Represents. ]
A process for producing an acrylic acid derivative represented by:
The purification method according to any one of Items 1 to 4,
A production method comprising purifying an acrylic acid derivative represented by the formula (I).

  According to the present invention, a method for efficiently purifying an acrylic acid derivative (I), specifically, a composition containing the acrylic acid derivative (I) and an aldehyde having 2 to 6 carbon atoms, the carbon number 2 A method for efficiently removing -6 aldehydes is provided.

Terminology The symbols and abbreviations in this specification are understood to have the meanings usually used in the technical field to which the present invention belongs in accordance with the context of this specification, unless otherwise specified.
In this specification, the phrase “containing” is intended to encompass the phrase “consisting essentially of” and the phrase “consisting of”.

In this specification, room temperature means a temperature within the range of 10 to 40 ° C.
The steps, processes, or operations herein can be performed at room temperature unless specifically limited.

In the present specification, an “alkyl group” (the term “alkyl group” includes a part of “alkyl group” in “fluoroalkyl group” and the like) is cyclic, linear or branched. It can be an alkyl group.
In the present specification, the “alkyl group” is, for example, an alkyl group having 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms. it can.
In the present specification, the “alkyl group” specifically includes, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a neopentyl group. And linear or branched alkyl groups such as a hexyl group.
In the present specification, specifically, examples of the “alkyl group” include cyclic alkyl groups having 3 to 6 carbon atoms (cycloalkyl groups) such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

In the present specification, the “fluoroalkyl group” is an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
In the present specification, the “fluoroalkyl group” has 1 or more fluorine atoms (eg, 1 to 3, 1 to 6, 1 to 12, or the maximum number that can be substituted from 1). be able to.
In the present specification, the “fluoroalkyl group” is, for example, a fluoroalkyl group having 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms. be able to.
In the present specification, the “fluoroalkyl group” may be a linear or branched fluoroalkyl group.
In the present specification, the “fluoroalkyl group” specifically includes, for example, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a tetrafluoro group, and the like. Propyl group (eg, HCF ₂ CF ₂ CH ₂ —), Hexafluoropropyl group (eg, (CF ₃ ) ₂ CH—), Nonafluorobutyl group, Octafluoropentyl group (eg, HCF ₂ CF ₂ CF ₂ CF ₂₎ CH ₂ -), and tridecafluorohexyl group, and the like.

  In the present specification, examples of the “aryl group” include a phenyl group and a naphthyl group.

  In the present specification, examples of the “halogen atom” include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  In the present specification, the “alkoxy group” is an alkyl-O— group.

  In the present specification, examples of the “acyl group” include an alkanoyl group (that is, an alkyl-CO— group) and the like.

  In the present specification, examples of the “ester group” include an alkylcarbonyloxy group (that is, an alkyl-CO—O— group), an alkoxycarbonyl group (that is, an alkyl-O—CO— group), and the like.

  In the present specification, the “organic group” includes a hydrocarbon group such as an alkyl group.

Method for purifying acrylic acid derivative (I) The method for purifying the acrylic acid derivative (I) of the present invention will be described in detail below.
In the purification method of the present invention, the composition A (that is, the crudely purified acrylic acid derivative (I)) containing the acrylic acid derivative (I) as the main component and the aldehyde (II) as the impurity is converted into the aldehyde (II). Is removed to obtain a purified acrylic acid derivative (I).

Objective of Purification The objective of purification by the purification method of the present invention is the acrylic acid derivative (I).
Hereinafter, symbols in the formula (I) representing the acrylic acid derivative (I) will be described.
In formula (I),
R ^a represents an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituents, or a hydrogen atom, and X represents an alkyl group, a fluoroalkyl group, a fluorine atom, or a hydrogen atom Represents.
Preferred examples of the substituent in the “aryl group optionally having one or more substituents” represented by ^Ra include a fluorine atom, an alkyl group, an alkoxy group, an acyl group, an ester group, a cyano group, A nitro group and a fluoroalkyl group are mentioned, and a more preferred example is a fluorine atom.
The number of the “substituents” is preferably 0 (that is, unsubstituted), 1, 2, or 3.

R ^a preferably has 1 to 20 carbon atoms (preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, still more preferably 1 to 3 carbon atoms, particularly Preferably, it is a linear alkyl group having 1 or 2 carbon atoms or a linear fluoroalkyl group.

  X preferably has 1 to 20 carbon atoms (preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, still more preferably 1 to 3 carbon atoms, and particularly preferably 1 to 6 carbon atoms). Is an alkyl group having 1 or 2 carbon atoms, 1 to 20 carbon atoms (preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, still more preferably carbon numbers). 1 to 3, particularly preferably a fluoroalkyl group having 1 or 2 carbon atoms, a fluorine atom, or a hydrogen atom, and more preferably a fluorine atom.

In the formula (I), preferably,
R ^a is a methyl group or an ethyl group (more preferably, a methyl group), and X is a methyl group, a fluorine atom, or a hydrogen atom (more preferably, a methyl group or a fluorine atom).
It is.

Removal object of purification The removal object of the purification method of the present invention is aldehyde (II). By the purification method of the present invention, at least a part of the aldehyde (II) is removed. In the purification, it is preferable that more aldehyde (II) is removed.
Examples of the aldehyde (II) include acetaldehyde, propionaldehyde, normal butyraldehyde, isobutyraldehyde, and n-valeraldehyde.
In the present invention, the aldehyde (II) is preferably an aldehyde having 3 to 6 carbon atoms, more preferably an aldehyde having 4 to 6 carbon atoms, and particularly preferably normal butyraldehyde.
In the present invention, the aldehyde (II) may be a single type or a combination of two or more types.
In the purification method of the present invention, impurities other than this may be removed together with the aldehyde (II).

Object to be treated The object to be treated of the purification method of the present invention is the composition A containing the acrylic acid derivative (I) and the aldehyde (II) (that is, the crudely purified acrylic acid derivative (I)).

The manufacturing method and origin of the composition A, which is a treatment target of the purification method of the present invention, are not particularly limited.
The acrylic acid derivative (I) contained in the composition A can be, for example, a reaction product.
The aldehyde (II) contained in the composition A can be, for example, an additive in the production of the acrylic acid derivative (I) or a by-product in the production of the acrylic acid derivative (I).

  The content of the acrylic acid derivative (I) in the composition A can be, for example, in the range of 80 to 99 mass%, in the range of 85 to 99 mass%, or in the range of 90 to 99 mass%.

  The content of the aldehyde (II) in the composition A is, for example, in the range of 0.01 to 5% by mass, in the range of 0.01 to 1% by mass, or in the range of 0.05 to 0.5% by mass. Can be.

The content of the aldehyde (II) in the composition A can be, for example, 0.0001 parts by mass or more, or 0.0005 parts by mass or more with respect to 1 part by mass of the acrylic acid derivative (I).
The content of the aldehyde (II) in the composition A is, for example, 0.005 parts by mass or less, 0.05 parts by mass or less, or 0.01 parts by mass or less with respect to 1 part by mass of the acrylic acid derivative (I). Can be.
The content of the aldehyde (II) in the composition A is, for example, 0.0001 to 0.05 parts by weight, 0.0001 to 0.01 parts by weight, or 1 part by weight of the acrylic acid derivative (I). It can be 0.0005 to 0.005 parts by mass.

Process A
In step A, the composition A is contacted with a compound having one or more amino groups (ie, —NH ₂ groups) or a sulfite to remove the aldehyde (II).

In the present invention, the composition A may be used in combination with a compound having one or more amino groups and a sulfite. Specifically, for example, (1) contacting the composition A with a compound having one or more amino groups to remove the aldehyde (II); and (2) converting the composition A into a sulfite. The contact and removal of the aldehyde (II) may be performed sequentially and in combination.
Moreover, you may implement the method of this invention in combination with the method of removing other aldehyde (II).

  In the present invention, the aldehyde (II) to be removed is a part or all of the aldehyde (II) contained in the composition A.

Suitable examples of the “compound having one or more amino groups” used in the present invention include
(1) amino acids,
(2) a compound having one or more amino groups and one or more sulfhydryl groups (ie, —SH groups), and (3) one or more amino groups and one or more hydroxyl groups (ie, —OH). A compound having a group).
The “(1) amino acid” used in the present invention can be D-form, L-form, or a mixture of D-form and L-form (eg, racemate).
The number of amino groups possessed by the “compound having one or more amino groups” used in the present invention is preferably one.
The number of sulfhydryl groups possessed by the “(2) compound having one or more amino groups and one or more sulfhydryl groups” is preferably one.
The number of hydroxyl groups that the “(3) compound having one or more amino groups and one or more hydroxyl groups” has is preferably one.
The “(2) compound having one or more amino groups and one or more sulfhydryl groups” is preferably one or more (preferably one) hydroxyl group and one (preferably one) or more. In which a sulfhydryl group is linked via a linker.
The linker is preferably a linker having 1 to 3 carbon atoms.
The linker is also preferably alkylene which may have one or more substituents, or arylene which may have one or more substituents.
The number of carbon atoms of “alkylene” in the “alkylene optionally having one or more substituents” is preferably 1 to 3.
Suitable examples of the “substituent” in the “alkylene optionally having one or more substituents” include a nitro group, a cyano group, a tosyl group, a halogen atom, a phenyl group, an acyl group, and a carboxy group. Include.
The “arylene” in the “arylene optionally having one or more substituents” preferably has 6 to 8 carbon atoms.
Suitable examples of the “substituent” in the “arylene optionally having one or more substituents” include a nitro group, a cyano group, a tosyl group, a halogen atom, a phenyl group, an acyl group, and a carboxy group. Include.

  A particularly preferred example of a compound having one or more amino groups used in the present invention is cysteine. Cysteine can be D-form, L-form, or a mixture of D-form and L-form (eg, racemate).

  The compound which has 1 or more amino groups may be used individually by 1 type, and may be used in combination of 2 or more type.

  Although the form of the compound having one or more amino groups used in the present invention is not particularly limited, for example, a compound having one or more amino groups in the form of powder is preferably used. However, the compound having one or more amino groups in the form of the powder can be used in the form of a liquid by being used with a solvent described later.

Examples of anions constituting “sulfite” used in the present invention include sulfite anions and pyrosulfite anions.
Examples of cations constituting “sulfite” used in the present invention include alkali metal ions such as sodium ion and potassium ion; tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, benzyl Ammonium ions such as trimethylammonium ion, benzyltriethylammonium ion, and phenyltrimethylammonium ion; and phosphonium ions such as ethyltriphenylphosphonium ion and propyltriphenylphosphonium ion.
Examples of “sulfite” used in the present invention are sodium pyrosulfite (ie, sodium disulfite), potassium pyrosulfite, sodium hydrogenbisulfite, potassium hydrogenbisulfite, sodium hydrogensulfite, potassium hydrogensulfite, tetramethylammonium. Pyrosulfite, tetraethylammonium pyrosulfite, tetrapropylammonium pyrosulfite, tetrabutylammonium pyrosulfite, benzyltrimethylammonium pyrosulfite, benzyltriethylammonium pyrosulfite, phenyltrimethylammonium pyrosulfite, ethyltriphenylphosphonium pyro Sulfite, propyltriphenylphosphonium pyrosulfite, tetramethylammonium pyrobisulfite, tetraethylammonium pyrobisulfite, Trapropylammonium pyrobisulfite, tetrabutylammonium pyrobisulfite, benzyltrimethylammonium pyrobisulfite, benzyltriethylammonium pyrobisulfite, phenyltrimethylammonium pyrobisulfite, ethyltriphenylphosphonium pyrobisulfite, propyl Triphenylphosphonium pyrobisulfite, tetramethylammonium hydrogensulfite, tetraethylammonium hydrogensulfite, tetrapropylammonium hydrogensulfite, tetrabutylammonium hydrogensulfite, benzyltrimethylammonium hydrogensulfite, benzyltriethylammonium hydrogensulfite, phenyl Trimethylammonium bisulfite, ethyltriphenylphosphonium bisulfite, and pro Including Le triphenylphosphonium bisulfite.

  A sulfite may be used individually by 1 type, and may be used in combination of 2 or more type.

  Although the form of sulfite used in the present invention is not particularly limited, for example, sulfite in the form of powder is preferably used. However, the sulfite in the form of the powder can be preferably used together with the solvent described later to be in a liquid form.

The amount of the compound having one or more amino groups and / or sulfite used in Step A is preferably 0.00002 to 100 parts by mass of aldehyde (II) contained in Composition A, for example. It can be in the range of 20 parts by mass, more preferably in the range of 0.001 to 10 parts by mass, and still more preferably in the range of 0.001 to 5 parts by mass.
The amount of the compound having one or more amino groups used in the step A is, for example, preferably in the range of 80 to 500 parts by mass with respect to 100 parts by mass of the aldehyde (II) contained in the composition A. Preferably it is 90-300 mass parts, More preferably, it can be in the range of 90-150 mass parts.
The amount of sulfite used in Step A is, for example, preferably in the range of 40 to 250 parts by mass, more preferably 45 to 150 parts by mass with respect to 100 parts by mass of aldehyde (II) contained in Composition A. More preferably, it can be in the range of 45 to 75 parts by mass.
As described above, (1) contacting composition A with a compound having one or more amino groups to remove said aldehyde (II); and (2) contacting composition A with sulfite. When the removal of the aldehyde (II) is sequentially performed in combination, these amounts can be appropriately reduced.

The contact in step A can be preferably carried out in the presence of a solvent.
As the solvent, for example,
water;
Alcohol solvents such as methanol and ethanol;
Non-aromatic hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclohexane, decahydronaphthalene, n-decane, isododecane, tridecane;
Aromatic hydrocarbon solvents such as benzene, toluene, xylene, tetralin, veratrol, diethylbenzene, methylnaphthalene, nitrobenzene, o-nitrotoluene, mesitylene, indene, diphenyl sulfide;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, propiophenone, diisobutyl ketone, isophorone;
Halogenated hydrocarbon solvents such as dichloromethane, chloroform, chlorobenzene;
Ether solvents such as diethyl ether, tetrahydrofuran, diisopropyl ether, methyl t-butyl ether, dioxane, dimethoxyethane, diglyme, phenetole, 1,1-dimethoxycyclohexane, diisoamyl ether;
Ester solvents such as ethyl acetate, isopropyl acetate, diethyl malonate, 3-methoxy-3-methylbutyl acetate, γ-butyrolactone, ethylene carbonate, propylene carbonate, dimethyl carbonate, α-acetyl-γ-butyrolactone;
Nitrile solvents such as acetonitrile and benzonitrile;
Sulfoxide solvents such as dimethyl sulfoxide and sulfolane; and N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, N, N-dimethylacrylamide, N , N-dimethylacetoacetamide, N, N-diethylformamide, amide solvents such as N, N-diethylacetamide, and combinations of two or more thereof.
Suitable examples of such solvents include (1) water, and (2) water, and combinations of other solvents.
The solvent may be contained in Composition A; it may be used as a compound having one or more amino groups, or a sulfite solvent or suspending medium; or Composition A, and one or more The compound having an amino group and sulfite may be added separately to the system of Step A.
When a solvent is used in the present invention, the amount thereof is preferably in the range of 0.1 to 3 parts by weight, more preferably in the range of 0.3 to 2 parts by weight with respect to 1 part by weight of the composition A. And more preferably in the range of 0.5 to 1.2 parts by weight.
In the solvent, the compound having one or more amino groups and the sulfite may be in a free form, a salt, or an ion.
In addition, the compound having one or more amino groups and the sulfite may be changed depending on the presence of the solvent as long as it corresponds to the compound having one or more amino groups and the sulfite described above. Of course, this case is also within the scope of the present invention.

  In the method of the present invention, the method in which the composition A is contacted with a compound having one or more amino groups or a sulfite includes contacting the composition A with a compound having one or more amino groups or a sulfite. However, there is no particular limitation as long as possible. The method may be a batch method or a continuous method. Examples of the batch-type method include a method in which a compound having one or more amino groups or a sulfite is added to the composition A contained in a container and stirred as desired.

In the method of the present invention, the temperature at which the composition A is contacted with a compound having one or more amino groups or sulfite is, for example, in the range of 0 to 40 ° C, or in the range of 10 to 30 ° C. Can be.
In the method of the present invention, the temperature when the composition A is contacted with a compound having one or more amino groups or sulfite can be room temperature.

  In the method of the present invention, the time for which the composition A is contacted with the compound having one or more amino groups or sulfite is appropriately set to a necessary and sufficient length capable of removing the desired aldehyde (II). That's fine. Specifically, for example, in the case of a batch type, the time can be within a range of 15 minutes to 5 hours, or within a range of 30 minutes to 3 hours.

  The content of the aldehyde (II) in the composition A treated by the purification method of the present invention (that is, the purified acrylic acid derivative (I)) is preferably 1 part by weight of the acrylic acid derivative (I). Is less than 0.003 parts by weight, more preferably 0.002 parts by weight or less, still more preferably 0.001 parts by weight or less, still more preferably 0.0005 parts by weight or less, and particularly preferably 0.0004 parts by weight. The amount is not more than parts by weight, more preferably not more than 0.0002 parts by weight, and most preferably 0.0000 parts by weight.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this.

In Examples, the following were used as L-cysteine and sodium disulfite, respectively.
L-cysteine: manufactured by Tokyo Chemical Industry Co., Ltd., purity> 98%
Sodium disulfite: Showa Chemical Co., Ltd., purity> 95%

In the examples, methyl methacrylate is sometimes referred to as Compound A.
In the examples, 2-fluoroacrylic acid methyl ester may be referred to as Compound B.
In the examples, normal butyraldehyde is sometimes referred to as butyraldehyde.

Example 1
To 2.0 g of the composition consisting of (1) compound A or B, (2) methanol, and (3) butyraldehyde, 1.6 g of water and L-cysteine in the amount shown in Table 1 are added, and then at room temperature for 1 hour. Stir. The composition ratio (weight ratio) of compound A or B and butyraldehyde before and after stirring is shown below. The composition was calculated from GC measurement.

Example 2
To 2.0 g of the composition consisting of (1) compound A or B, (2) methanol, and (3) butyraldehyde, 1.6 g of water and the amount of Na ₂ S ₂ O ₅ described in Table 2 were added, and For 1 hour. The composition ratio (weight ratio) of compound A and butyraldehyde before and after stirring is shown below. The composition was calculated from GC measurement.

Claims (4)

Formula (I):
[Where:
R ^a represents an alkyl group, fluoroalkyl group, one or more aryl group which may have a substituent, or a hydrogen atom, and X represents a full Tsu MotoHara child. ]
A method for purifying an acrylic acid derivative represented by
A composition A containing an acrylic acid derivative represented by the formula (I) and an aldehyde having 2 to 6 carbon atoms,
Contacting with a compound having one or more amino groups, or sulfite,
Step A for removing the aldehyde having 2 to 6 carbon atoms
A purification method comprising: The purification method according to claim 1, wherein R ^a is a linear alkyl group having 1 to 20 carbon atoms. Aldehydes of the 2 to 6 carbon atoms is, the purification method according to any one of claims 1-2 is n-butyl aldehyde. Formula (I):
[Where:
R ^a represents an alkyl group, fluoroalkyl group, one or more aryl group which may have a substituent, or a hydrogen atom, and X represents a full Tsu MotoHara child. ]
A process for producing an acrylic acid derivative represented by:
A production method comprising purifying the acrylic acid derivative represented by the formula (I) by the purification method according to any one of claims 1 to 3 .