JPH08183755A - Production of alpha-hydroxymethyl acrylate compound - Google Patents

Abstract

PURPOSE: To readily obtain the subject high-purity compound without causing the formation of a bifunctional cross-linking monomer as a by-product by reacting an acrylate with formaldehyde in a solvent containing a tertiary amine present therein, extracting and purifying the organic phase. CONSTITUTION: An acrylate compound of formula I (R is a 1-20C alkyl, a 3-10C cycloalkyl, an aryl, a 1-16C hydroxyalkyl, etc.) is reacted with an aqueous solution of formaldehyde in an organic solvent (e.g. 1,2-dimethoxyethane) containing a tertiary amine (e.g. 1,4-diazabicyclo[2.2.2]octane) present therein at 0-120 deg.C. A reactional solution of a two-phase system is produced and the organic phase is then extracted and purified to afford an α-hydroxymethyl acrylate of formula II. The resultant compound of formula II is useful as a resin for coatings, a flocculant, a monomer for modifying wood or various resins, a synthetic intermediate, etc., for medicines and agrochemicals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an .alpha.-hydroxymethyl acrylate compound useful as a coating resin, a flocculant, a monomer for modifying wood or various resins, or an intermediate for pharmaceuticals and agricultural chemicals. .

[0002]

BACKGROUND ART α-Hydroxymethyl acrylate compounds have applications as resins for paints, flocculants, monomers for modifying wood or various resins, or as intermediates for pharmaceuticals and agricultural chemicals. Synthetic methods as described are known.

For example, in US Pat. No. 4,654,432, an acrylate compound represented by [Chemical Formula 3],
Α-hydroxy represented by [Chemical Formula 4] is obtained by reacting hydrated formaldehyde or a semi-acetal derived from an alcohol having 1 to 6 carbon atoms in the presence of a catalyst composed of a tertiary amine at 0 to 150 ° C. A method for obtaining a methyl acrylate compound is described.

[0004]

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[0005]

[Chemical 4]

In the method for producing an α-hydroxymethyl acrylate compound described in this US Pat. No. 4,654,432, the target compound is extracted with an organic solvent such as diethyl ether after the reaction is completed, and then 70 The target compound is obtained by carrying out distillation purification under extremely severe conditions such as ° C / 0.3 mmHg, and the operation for purification is not easy.

In addition, Macromolecules 1
987, 20 , 2039-2041 and Macromo.
rules 1991, 24 , 2043-2047
In the method for producing an α-hydroxymethyl acrylate compound in which a methyl acrylate and an aldehyde compound are reacted in the absence of a solvent, and excess methyl acrylate is distilled off after the reaction is completed, a heating step in the presence of a catalyst is performed. It is described that a crosslinkable monomer such as an ether body or an acetal body of an α-hydroxymethyl acrylate compound is by-produced.

Since the ethers and acetals of these α-hydroxymethyl acrylate compounds are all bifunctional crosslinkable monomers, they are the target compound α.
-It is not allowed to be mixed in the hydroxymethyl acrylate compound.

Therefore, in the above-mentioned method for producing an α-hydroxymethyl acrylate compound, an extraction operation and a distillation operation for removing the above ethers and acetals from the reaction solution are indispensable. It has problems such as being complicated.

Further, in JP-A-5-70408, as described in the above-mentioned US Pat. No. 4,654,432, an acrylate compound and an aldehyde in the presence of a catalyst composed of a tertiary amine are used. The reaction with the compound is carried out in an organic solvent compatible with water, and after the reaction is completed, the crude α-hydroxymethyl acrylate compound is dissolved in water, and impurities are extracted and removed with a specific solvent to remove α.
-A method of obtaining a hydroxymethyl acrylate compound is disclosed.

The method for producing an α-hydroxymethyl acrylate compound according to this method is as follows: (1) After adding the organic solvent which is not compatible with water to the reaction product solution obtained after the reaction is completed, the target product is subjected to solvent extraction. A first step of obtaining a crude α-hydroxymethyl acrylate compound by distilling an organic solvent from the extract,

(2) A second step in which the crude α-hydroxymethyl acrylate compound obtained in the first step is dissolved in water and impurities are extracted and removed using petroleum ether or a hydrocarbon having 5 to 8 carbon atoms. ,

(3) α from the aqueous phase obtained in the second step
-Isolating a hydroxymethyl acrylate compound
The process is complicated, and it is complicated to add an organic solvent to the reaction product solution.

On the other hand, when the present inventors carry out the reaction between the acrylate compound and formaldehyde using an aqueous formaldehyde solution in the presence of a specific solvent, the reaction solution becomes a two-phase system at the end of the reaction, and Attention is paid to the fact that almost no crosslinkable monomer such as an ether or acetal is produced at the end of the reaction, and if such a reaction system is used, the organic phase containing the target compound is extracted and purified. As a result of confirming that the target compound, an α-hydroxymethyl acrylate compound, was obtained by itself, the present invention was completed.

[0015]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to prevent a difunctional crosslinkable monomer as a by-product from being produced in the treatment stage and to carry out a purification operation by distillation under severe conditions. It is an object of the present invention to provide a method for easily obtaining a highly pure α-hydroxymethyl acrylate compound without carrying out the above.

[0016]

The above problems can be solved by the present invention described below. That is, the present invention prepares a two-phase system reaction solution by charging an acrylate compound represented by the following [Chemical formula 5] and an aqueous formaldehyde solution, and reacting them in an organic solvent containing a tertiary amine. Then, the method is for producing an α-hydroxymethyl acrylate compound represented by the following [Chemical Formula 6] in which the organic phase is extracted and purified.

[0017]

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[0018]

[Chemical 6]

Examples of the acrylate compound represented by [Chemical Formula 5] used in the method for producing an α-hydroxymethyl acrylate compound of the present invention include: (a) R = alkyl group having 1 to 20 carbon atoms: methyl acrylate, Ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, etc.,

(B) R = cycloalkyl group having 3 to 10 carbon atoms: cyclopentyl acrylate, cyclohexyl acrylate, etc.

(C) R = aryl group: phenyl acrylate, o-methoxyphenyl acrylate, p-methoxyphenyl acrylate, p-nitrophenyl acrylate, o-methylphenyl acrylate, p-methylphenyl acrylate, p-tert-butylphenyl Acrylate, etc.

(D) R = hydroxyalkyl group having 1 to 16 carbon atoms: 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, etc.

(E) R = group represented by the following [Chemical formula 7]:

[0024]

[Chemical 7]

Glycidyl acrylate, 3,4-epoxybutyl acrylate, 10,11-epoxyundecyl acrylate, etc.

(F) R =-(CH ₂ ) _m -CH = CH ₂
(M represents an integer of 1 to 18) Allyl acrylate, 3-butenyl acrylate, 10
-Undecenyl acrylate, etc.

(G) R = group represented by the following [Chemical formula 8]:

[0028]

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Benzyl acrylate, etc.

(H) R = group represented by the following [Chem. 9]:

[0031]

[Chemical 9]

N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N,
N-dimethylaminopropyl acrylate, N, N-dimethylaminobutyl acrylate, N, N-diethylaminobutyl acrylate, N, N-dimethylaminoneopentyl acrylate, N, N-diethylaminoneopentyl acrylate, etc.,

(I) R = group represented by the following [Chemical Formula 10]:

[0034]

[Chemical 10]

Neutralized or quaternized N, N-dialkylaminoalkyl acrylates, etc.

(J) R =-(C ₂ H ₄ O) _p R ¹ (p represents an integer of 1 to 80, R ¹ represents an alkyl group having 1 to 8 carbon atoms) methoxyethyl acrylate, ethoxyethyl Acrylate, lauryloxytrioxyethyl acrylate,
Examples thereof include methoxypolyoxyethylene acrylate having 1 to 80, preferably 3 to 30 oxyethylene groups. In addition, R ¹ and R of the above compound are
^The alkyl groups represented by ² and R ³ may be linear or branched.

Among the above-mentioned acrylate compounds, especially methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-
Hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 4-hydroxybutyl acrylate are preferred.

An aqueous formaldehyde solution is used as the aldehyde compound reacted with the acrylate compound. Formaldehyde aqueous solution has 1 to 1 carbon atoms
The alcohol of 8 may be contained in the range of 20% by weight or less as a stabilizer, and usually, a commercially available formalin aqueous solution containing 30% by weight or more of formaldehyde and about 5 to 15% by weight of methanol is used. Is practical.

As an organic solvent which is prepared by charging an acrylate compound and an aqueous formaldehyde solution and reacting the acrylate compound with formaldehyde in an organic solvent containing a tertiary amine, a two-phase reaction solution is formed. An organic solvent having an ether bond is preferable.

An acrylate compound and an aqueous formaldehyde solution were charged in an organic solvent having an ether bond,
The reaction between the acrylate compound and formaldehyde is characterized in that a uniform and easy reaction state is formed at the time of charging each raw material, and a two-phase system is formed when the reaction progresses to some extent.

As the organic solvent having an ether bond,
Dimethoxymethane and 1,2-dimethoxyethane are preferred, and cyclic ethers such as tetrahydrofuran can also be used.

The tertiary amine used as a catalyst is, for example, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tributylamine, triisobutylamine, tri-n-pentylamine, N-methyldiisopropylamine, N. , N-diethylisopropylamine, N, N-dimethylethylamine, N, N-dimethylisopropylamine, tri-2-
Ethylhexylamine, N-methyldiethylamine,
N, N-dimethyl-n-propylamine, N, N-dimethyl-n-butylamine, N, N-dimethyl-isobutylamine, N, N-dimethyl- (2-ethylhexyl)
Amine, N, N-diisopropyl- (2-ethylhexyl) amine, N, N-di-n-butyl- (2-ethylhexyl) amine, N-methyl-di (2-ethylhexyl) amine, Nn-butyl- Di (2-ethylhexyl) amine, N-isobutyl-di (2-ethylhexyl) amine, pyrocholine, quinolidine, 1,4-diazabicyclo [2.2.2] octane, hexamethylenetetramine, and the like, particularly 1,4 -Diazabicyclo [2.2.2] octane and hexamethylenetetramine are preferred.

The amount of the tertiary amine used as a catalyst is 0.1 to 3 with respect to 100.0 mol of the acrylate compound.
The amount is 0.0 mol, preferably 3.0 to 15.0 mol.
The reaction temperature is preferably 0 to 120 ° C.

The reaction time varies depending on the reaction temperature, the amount of the catalyst used, the molar ratio of the acrylate compound to the aldehyde compound, the kind of the acrylate compound, etc., but is 8 to 240 at the reaction temperature of 0 to 50 ° C. time,
At 50 ° C or higher, about 4 to 72 hours is sufficient.

The charging ratios of the acrylate compound and the aldehyde compound are usually equimolar ratios, but it may be industrially necessary to use one of them in excess.

That is, in the case of having a facility for recovering an acrylate compound, it is possible to increase the amount of the acrylate compound used relative to the aldehyde compound.
If you have a formaldehyde recovery facility,
It is preferable to use an excess amount of the aldehyde compound with respect to the acrylate compound.

[0047]

EXAMPLES The specific constitution of the method for producing an .alpha.-hydroxymethyl acrylate compound of the present invention will be described below based on examples. In this example, the α-hydroxymethyl acrylate compound was identified by H-NMR, and the quantification of this compound was performed by high performance liquid chromatography.

Example 1 A 3 liter flask was charged with a 37% formalin aqueous solution 29.
5 g (3.6 mol) and ethyl acrylate 360 g
(3.6 mol) and 1,4-diazabicyclo [2.2.
2] Octane (15.2 g, 0.13 mol) and 1 liter of 1,2-dimethoxyethane were charged, and the mixture was stirred at room temperature for 40
The reaction was allowed to stir for hours. In this reaction, the reaction system was uniform at the time of charging each raw material, and an aqueous phase appeared at the end of the reaction, and it was a two-phase system of an organic phase and an aqueous phase.

After completion of the reaction, 1700 ml of the organic phase was separated from the reaction solution having two phases and washed with 400 ml of 1N-HCl (10% ammonium sulfate solution). Subsequently, the organic phase is separated and the 30% ammonium sulfate solution 40
It was washed with 0 ml and further with 400 ml of 40% ammonium sulfate solution, and the organic phase was separated.

The separated organic phase is dried over magnesium sulfate and the organic solvent is distilled off to give a crude α
222 g of ethyl hydroxymethyl acrylate were obtained.
88 g of this crude ethyl α-hydroxymethyl acrylate was dissolved in 880 ml of water, washed with 528 ml of n-hexane to remove impurities, and 190 g of ammonium sulfate was added to 950 ml of the obtained aqueous phase, followed by extraction with 1500 ml of ethyl acrylate. .

After that, the organic phase was separated, dried over magnesium sulfate, and the ethyl acrylate was distilled off to obtain 49.2 g of ethyl α-hydroxymethylacrylate as a colorless transparent liquid.

Α-based on the charged ethyl acrylate
The yield of ethyl hydroxymethyl acrylate was 27% and the HPLC purity was 90%. Almost no crosslinkable monomer was produced as an impurity.

Example 2 In a 500 ml flask, 37% formalin aqueous solution 41
g (0.5 mol) and 75 g of ethyl acrylate (0.
75 mol) and 10.5 g of hexamethylenetetramine
(0.0075 mol) and 140 ml of 1,2-dimethoxyethane were charged and reacted at a bath temperature of 50 ° C. for 42 hours with stirring. In this reaction, the reaction system was uniform at the time of charging each raw material, and an aqueous phase appeared at the end of the reaction, and it was a two-phase system of an organic phase and an aqueous phase.

After completion of the reaction, 270 ml of the organic phase was separated from the reaction solution having two phases and washed with 65 ml of 1N-HCl (10% ammonium sulfate solution). continue,
The organic phase is separated and 65 ml of 25% ammonium sulfate solution
Washed with 40% ammonium sulfate solution 65
Wash with ml and separate the organic phase.

The separated organic phase was dried over magnesium sulfate and the organic solvent was distilled off to obtain 21.7 g of crude ethyl α-hydroxymethyl acrylate. After dissolving 21.7 g of the obtained crude ethyl α-hydroxymethyl acrylate in 300 ml of water and washing with 120 ml of n-hexane to remove impurities, 137 g of ammonium sulfate was added to 320 ml of the obtained aqueous phase to obtain ethyl acrylate. Two
Extracted with 25 ml.

After that, the organic phase was separated, dried over magnesium sulfate, and ethyl acrylate was distilled off to obtain 16.6 g of ethyl α-hydroxymethyl acrylate as a colorless transparent liquid.

Α-based on the charged ethyl acrylate
The yield of ethyl hydroxymethyl acrylate was 26% and the HPLC purity was 97%. Almost no crosslinkable monomer was produced as an impurity.

Example 3 A 30% reaction vessel was charged with 3% 37% formalin aqueous solution.
813 g (46.7 mol) and ethyl acrylate 51
15 g (51.2 mol), 1,4-diazabicyclo [2.2.2] octane 188 g (1.68 mol),
Charge with 12.5 kg of 1,2-dimethoxyethane,
The reaction was stirred at room temperature for 4 days. In the reaction, the reaction system was uniform at the time of charging each raw material, and an aqueous phase appeared at the end of the reaction, which was a two-phase system of an organic phase and an aqueous phase.

After completion of the reaction, the organic phase was separated from the reaction solution having two phases and washed with 1N-HCl (10% ammonium sulfate solution). Subsequently, the organic phase is separated and 3
Washed with 0% ammonium sulphate solution, 27% more
It was washed with ammonium sulfate solution and the organic phase was separated.

The separated organic phase was dried over magnesium sulfate and the organic solvent was distilled off to obtain 4.58 kg of crude ethyl α-hydroxymethyl acrylate. The obtained crude ethyl α-hydroxymethyl acrylate was dissolved in water, washed with n-hexane three times to remove impurities, and
Ammonium sulfate was added to the obtained aqueous phase, and the mixture was extracted with ethyl acetate.

After that, the organic phase was separated, dried over magnesium sulfate, ethyl acetate was distilled off, and α-hydroxymethylethyl acrylate 216 consisting of a colorless transparent liquid was obtained.
7 g were obtained.

Α-based on the charged ethyl acrylate
The yield of ethyl hydroxymethyl acrylate was 36% and the HPLC purity was 99%. Almost no crosslinkable monomer was produced as an impurity.

Example 4 In a 50 ml flask, a 37% formalin aqueous solution 4.1 was added.
g (0.05 mol) and methyl acrylate 4.3 g
(0.05 mol) and 1,4-diazabicyclo [2.
2.2] 0.21 g (0.0018 mol) of octane,
14 ml of dimethoxymethane was charged, and the mixture was reacted by stirring at room temperature for 22 hours. In the reaction, the reaction system was uniform at the time of charging each raw material, and an aqueous phase appeared at the end of the reaction, which was a two-phase system of an organic phase and an aqueous phase.

After completion of the reaction, the organic phase is separated from the two-phase reaction solution, and the same treatment as that of the corresponding step in Example 1 is carried out to obtain α-hydroxymethylacryl composed of a colorless transparent liquid. 1.45 g of methyl acidate was obtained.

Α-based on the charged methyl acrylate
The yield of methyl hydroxymethyl acrylate was 25% and the HPLC purity was 91%. Almost no crosslinkable monomer was produced as an impurity.

[0066]

According to the method for producing an α-hydroxymethyl acrylate compound of the present invention, the objective compound α-
Production of high-purity α-hydroxymethyl acrylate compounds without by-products of cross-linking monomers consisting of ethers or acetals of hydroxymethyl acrylate compounds, and without performing purification operation by distillation under severe conditions can do.

Therefore, the method for producing an α-hydroxymethyl acrylate compound of the present invention has a very easy purification step, and has the practical effect of producing an α-hydroxymethyl acrylate compound on an industrial scale. .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07C 211/62 8517-4H C07D 303/16 // C07B 61/00 300

Claims (1)

[Claims] 1. A two-phase reaction solution is produced by charging an acrylate compound represented by the following [Chemical formula 1] and an aqueous formaldehyde solution and reacting them in an organic solvent containing a tertiary amine. After that, the organic phase is extracted and purified, and α-displayed in [Chemical Formula 2] below
Process for producing hydroxymethyl acrylate compound. Embedded image Embedded image