JPH08301817A - Production of alpha-hydroxymethyl acrylate compound - Google Patents

Abstract

PURPOSE: To produce an α-hydroxyethyl acrylate compound useful for a coating resin, etc., in high conversion and selectivity through an extremely simple purification process by charging a raw material into an organic solvent containing a specified amount of water. CONSTITUTION: (A) An acrylate compound of formula I R is a 1-20C alkyl, a 3-10C cycloalkyl, an aryl, a 1-16C hydroxyalkyl, formula II [(m) is 1-18], etc.} (e.g. ethyl acrylate) and (B) a formaldehyde aqueous solution (e.g. a 37wt.% formalin aqueous solution) are charged into an organic solvent (e.g. 1,4-dioxane) capable of dissolving >=5% of water and containing 0.5-2.0 times of the maximum amount of water which can exist in a reaction liquid without separating into two phases at the start of reaction. Then, the components A and B are made to react with each other in the presence of (C) a tertiary amine (e.g. 1,4-diazabicyclo[2.2.2]octane) to obtain a compound of formula III.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the production of α-hydroxymethyl acrylate compounds useful as monomers for resins for paints, flocculants, resins for modifying wood or various resins, or as intermediates for pharmaceuticals and agricultural chemicals. The present invention relates to a method, especially a method for producing an α-hydroxymethyl acrylate compound with high conversion and selectivity.

[0002]

2. Description of the Related Art α-Hydroxymethyl acrylate compounds have uses as resins for paints, flocculants, monomers for resins for modifying wood or various resins, or as intermediates for pharmaceuticals and agricultural chemicals. A synthesis method as described below is known.

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

[0004]

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[0005]

[Chemical 4]

However, this US Pat.
The production method of the α-hydroxymethyl acrylate compound described in Japanese Patent No. 2 is described in Macromolecule.
s1987, 20 , 2039-2041 and Macro
molecules 1991, 24 , 2043-20
47, a large amount of a bifunctional crosslinking monomer such as an ether body or an acetal body is by-produced in addition to the target α-hydroxymethyl acrylate compound, so that the yield of the target compound is at most 30. %,
An extraction operation and a distillation operation for removing the above ethers and acetals from the reaction solution are indispensable, and there is a drawback that the operations for this are complicated.

Further, JP-A-6-135896 discloses a method for producing an α-hydroxymethyl acrylate compound using a basic ion exchange resin as a catalyst. Compared with the conventional method using a tertiary amine as a catalyst, this method has a considerably higher reaction rate and conversion rate, but since there is still a by-product of a bifunctional crosslinking monomer, the target compound There is a drawback that the yield is low.

On the other hand, the present inventors have found that the method using a basic ion exchange resin is more suitable for the α-hydroxymethyl acrylate compound than the above method using a tertiary amine as a catalyst. The cause of the high conversion rate is
As a result of confirming that it is due to the influence of water surrounding the basic ion exchange resin, and by confirming that the reaction rate can be remarkably increased by adding water in a specific range to the reaction system. The present invention has been completed.

[0009]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for obtaining α-hydroxymethyl acrylate compounds with high conversion and high selectivity.

[0010]

According to the present invention, an acrylate compound represented by the following [Chemical formula 5] and an aqueous formaldehyde solution can dissolve 5% by weight or more of water and a reaction solution at the start of the reaction. Of the maximum amount of water that can be contained without separation into two phases, 0.5-2.
The following [Chemical Formula 6] is characterized in that the reaction is carried out in the presence of a tertiary amine by charging in an organic solvent added with 0 times water.
The method for producing an α-hydroxymethyl acrylate compound represented by

[0011]

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[0012]

[Chemical 6]

Examples of the acrylate compound represented by [Chemical Formula 5] that can be 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: for example, 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: for example, cyclopentyl acrylate, cyclohexyl acrylate, etc.

(C) R = aryl group: for example, 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: for example, 2-hydroxyethyl acrylate,
2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, etc.,

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

[Chemical 7] For example, 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] For example, allyl acrylate, 3-butenyl acrylate, 10-undecenyl acrylate, etc.

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

Embedded image For example, benzyl acrylate,

(H) R = group represented by the following [Chemical formula 9]:

[Chemical 9] For example, 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]:

[Chemical 10] For example, neutralized or quaternized N, N-dialkylaminoalkyl acrylate, 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] For example, methoxyethyl acrylate, ethoxy Mention may be made of ethyl acrylate, lauryloxytrioxyethyl acrylate, methoxypolyoxyethylene acrylate having 1 to 80, preferably 3 to 30 oxyethylene groups.

It should be noted that R ¹ , R ² and R of the above compound are
^The alkyl group represented by ³ may be linear or branched.

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

In the method for producing an α-hydroxymethyl acrylate compound of the present invention, the aqueous formaldehyde solution to be reacted with the above acrylate compound contains an alcohol having 1 to 8 carbon atoms as a stabilizer in an amount of 20% by weight or less. However, it is usually practical to use commercially available formalin containing 37% by weight or more formaldehyde and about 5 to 15% by weight methanol.

An organic solvent having a property of dissolving 5% by weight or more of water is used when the acrylate compound and the aqueous formaldehyde solution are charged. Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol and propylene glycol, dimethoxymethane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, tetrahydrofuran, 1,4-dioxane, 1, Examples thereof include 3-dioxolane, and tetrahydrofuran, 1,4-dioxane, and 1,3-dioxolane are particularly preferable.

In the method for producing an α-hydroxymethyl acrylate compound of the present invention, the conversion rate and selectivity with respect to the acrylate compound as a raw material may differ depending on the type of organic solvent used.

The amount of the organic solvent used is about 100 to 1000% by weight of the amount of the acrylate compound charged in the organic solvent. For example, 1,4-dioxane or 1,3-dioxolane is preferably 300 to 700% by weight. 200 to 60 for dimethoxymethane and 1,2-dimethoxyethane
0% by weight is preferable, and tetrahydrofuran is 100-
500% by weight is preferred.

The amount of water added to the organic solvent is 0.5 to 2 times the maximum amount of water that can be contained in the reaction solution at the start of the reaction without separation into two phases. Since most of the formaldehyde aqueous solution charged in the organic solvent exists in the form of trihydroxymethane, the water of the formaldehyde aqueous solution is not added to the amount of water added to the organic solvent.

The optimum amount of water added to the organic solvent depends on the type of organic solvent. For example, as shown in Comparative Examples 2 to 4, the reaction rate decreases when the amount of water added to the organic solvent is too large or too small. In terms of conversion and reaction rate, the maximum amount of water that can be contained in the reaction solution at the start of the reaction without separating into two phases is 0.5%.
The amount of water is most preferably 1.0 to 1.2 times the amount of the maximum amount of water that can be contained in the reaction solution without separation into two phases at the start of the reaction from the viewpoint of selectivity. Most preferred is an eightfold amount.

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 in the present invention is 0.1 to 30 mol, preferably 3 to 15 mol, based on 100 mol of the acrylate compound.

The reaction temperature is 20 to 120 ° C., preferably 4
It is 0 to 80 ° C. The reaction time varies depending on the reaction temperature, the amount of the catalyst used, the molar ratio of the acrylate compound and formaldehyde, the type of the acrylate compound, and the like, but about 2 to 72 hours is sufficient.

The charge ratio of the acrylate compound and the aqueous formaldehyde solution is usually an equimolar ratio with respect to the ratio of the acrylate compound and formaldehyde, but it may be industrially necessary to use one of them in excess. That is, if the facility for recovering acrylate compounds is used, the amount of acrylate compound used relative to formaldehyde should be excessive. Is preferred.

[0035]

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 In a 50 ml flask, 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 4.3 of ethyl acrylate.
g (0.043 mol), 1,4-diazabicyclo-
0.52 g (0.005 mol) of [2,2,2] -octane, 14 ml of 1,4-dioxane (336% by weight of the amount of ethyl acrylate charged), 8 ml of water (the reaction solution was in two phases at the start of the reaction). Charge 1.0 times the maximum amount of water that can be contained without separation, and
The reaction was allowed to stir for 8 hours.

After completion of the reaction, the reaction solution was analyzed by high performance liquid chromatography and calculated by the corrected percentage method. As a result, the conversion rate to the charged ethyl acrylate was 85%,
It was confirmed that α-hydroxymethyl acrylate was produced at a selectivity of 84%.

Example 2 A 50 ml flask was charged with 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 4.3 parts of ethyl acrylate.
g (0.043 mol), 1,4-diazabicyclo-
0.56 g (0.005 mol) of [2,2,2] -octane, 14 ml of 1,4-dioxane (336% by weight of the amount of ethyl acrylate charged), 4 ml of water (the reaction solution was in two phases at the start of the reaction). Charge 0.5 times the maximum amount of water that can be contained without separation, and
The reaction was allowed to stir for 8 hours.

After the completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion of 89% with respect to the charged ethyl acrylate and a selectivity of 78%. It was

Example 3 A 50 ml flask was charged with 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 4.3 parts of ethyl acrylate.
g (0.043 mol), 1,4-diazabicyclo-
0.52 g of [2,2,2] -octane (0.005 mol), 14 ml of 1,4-dioxane (336% by weight of the amount of ethyl acrylate charged), 14 ml of water (the reaction solution was in two phases at the start of the reaction). 1.75 times the maximum amount of water that can be contained without separation) was charged and reacted at room temperature with stirring for 18 hours.

After the completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion rate of 71% with respect to the charged ethyl acrylate and a selectivity of 92%. It was

Example 4 In a 50 ml flask, 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 5.0 parts of ethyl acrylate.
g (0.05 mol), 1,4-diazabicyclo- [2,
2,2] -octane 0.56 g (0.005 mol),
14 ml of 1,4-dioxane (336 wt% of the amount of ethyl acrylate charged) and 14 ml of water (1.8 of the maximum amount of water that the reaction solution can contain at the start of the reaction without separation into two phases). Double), bath temperature 60
The reaction was carried out by stirring at ℃ for 7 hours.

After completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion of 86% with respect to the charged ethyl acrylate and a selectivity of 90%. It was

Example 5 A 50 ml flask was charged with 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 5.0 parts of ethyl acrylate.
g (0.05 mol), 1,4-diazabicyclo- [2,
2,2] -Octane 0.56 g (0.005 mol), tetrahydrofuran 20 ml (356 wt% of the amount of charged ethyl acrylate), water 0.5 ml (the reaction solution does not separate into two phases at the start of reaction) (1.0 times the maximum amount of water that can be used) was charged, and the reaction was carried out by stirring at room temperature for 18 hours.

After completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was formed at a conversion of 51% with respect to the charged ethyl acrylate and a selectivity of 94%. It was

Example 6 In a 50 ml flask, 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 4.3 of ethyl acrylate.
g (0.043 mol), 1,4-diazabicyclo-
0.52 g of [2,2,2] -octane (0.005 mol), 18 ml of 1,3-dioxolane (447 wt% of the amount of ethyl acrylate charged), 1.5 ml of water (the reaction solution was 2 at the start of the reaction). A phase was charged with 1.0 times the maximum amount of water that can be contained without separation, and the reaction was allowed to stir at room temperature for 18 hours.

After completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion of 69% with respect to the charged ethyl acrylate and a selectivity of 84%. It was

Comparative Example 1 In a 50 ml flask, 4.1 g (0.05 mol) of 37% by weight aqueous formalin solution and 4.3 methyl acrylate were added.
g (0.05 mol), 1,4-diazabicyclo- [2,
2,2] -octane 0.21 g (0.0018 mol),
14 ml of 1,4-dioxane (336 wt% of the amount of methyl acrylate charged) was charged, and the mixture was stirred at room temperature for 22 hours for reaction.

After completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion of 45% with respect to the charged ethyl acrylate and a selectivity of 84%. It was

Comparative Example 2 In a 50 ml flask, 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 4.3 of ethyl acrylate were added.
g (0.043 mol), 1,4-diazabicyclo-
0.52 g of [2,2,2] -octane (0.005 mol), 14 ml of 1,4-dioxane (90% by weight of the amount of ethyl acrylate charged), 2 ml of water (the reaction solution was in two phases at the start of the reaction). The maximum amount of water that can be contained without separation is 4.0 times), and the mixture is allowed to stand at room temperature for 24 hours.
The reaction was allowed to stir for hours.

After completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion of 60% with respect to the charged ethyl acrylate and a selectivity of 82%. It was

Comparative Example 3 In a 50 ml flask, 2.45 g (0.03 mol) of 37% by weight aqueous formalin solution and ethyl acrylate 2.
5 g (0.025 mol), 1,4-diazabicyclo-
0.22 g (0.0025 mol) of [2,2,2] -octane, 23 ml of tetrahydrofuran (819 wt% of the amount of ethyl acrylate charged), 2 ml of water (without the reaction solution separating into two phases at the start of the reaction) Charge 0.3 times the maximum amount of water that can be contained, and
The mixture was reacted for 9 hours with stirring.

After completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion rate of 42% with respect to the charged ethyl acrylate and a selectivity of 70%. It was

Comparative Example 4 In a 50 ml flask, 4.9 g (0.06 mol) of 37% by weight aqueous formalin solution and 4.3 ethyl acrylate were added.
g (0.043 mol), 1,4-diazabicyclo-
0.56 g (0.005 mol) of [2,2,2] -octane, 14 ml of 1,3-dioxolane (348 wt% of the amount of ethyl acrylate charged), 140 ml of water (the reaction solution was in two phases at the start of the reaction) Charge 12.0 times the maximum amount of water that can be contained without separation)
The reaction was allowed to stir at room temperature for 18 hours.

After the completion of the reaction, the reaction solution was analyzed and calculated in the same manner as in Example 1. As a result, it was confirmed that α-hydroxymethyl acrylate was produced at a conversion of 39% with respect to the charged ethyl acrylate and a selectivity of 89%. It was

[0057]

According to the method for producing an α-hydroxymethyl acrylate compound of the present invention, an α-hydroxymethyl acrylate compound can be produced with a high conversion and a high selectivity. 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.

Claims (1)

[Claims] 1. An acrylate compound represented by the following [Chemical formula 1] and an aqueous formaldehyde solution can dissolve 5% by weight or more of water, and the reaction solution does not separate into two phases at the start of the reaction. The following chemical formula characterized in that the reaction is carried out in the presence of a tertiary amine by charging in an organic solvent added with 0.5 to 2.0 times the amount of water which can be contained. [2] A method for producing an α-hydroxymethyl acrylate compound represented by [2]. Embedded image Embedded image