JP6665459B2 - Method for producing ketimine compound of 2-aminoethyl methacrylate - Google Patents

Description

The present invention relates to a method for producing a ketimine compound of 2-aminoethyl methacrylate in high yield by reacting a ketimine compound of 2-aminoethanol with a methacrylic acid ester. The ketimine compound of 2-aminoethyl methacrylate provided by the present invention is a polymer coagulant, a coagulant, a fiber treatment agent, a paper modifier or a processing agent, a paint, an ink, a toner, an adhesive, an adhesive, a chelate. It is a useful compound as a raw material for resins, ion exchange resins, medical materials, hair care products, cosmetics, antibacterial agents, dispersants, surface treatment agents, antistatic agents, additives for lubricating oils and fuel oils, resists, and the like.

Conventionally, various methods have been proposed as a method for producing a ketimine compound of 2-aminoethyl methacrylate. In Patent Documents 1 and 4, 2-aminoethyl methacrylate methyl isobutyl ketimine or 2-aminoethyl is obtained by transesterifying a Schiff base obtained by reacting monoethanolamine with methyl isobutyl ketone and methyl methacrylate or methyl acrylate. Acrylate methyl isobutyl ketimine is being synthesized. Here, the Schiff base as an intermediate used is one purified by distillation under reduced pressure, and excess impurities including ketones have been removed. Therefore, the final yield of the target product is reduced by the intermediate purification step, and furthermore, equipment and cost for purification of the intermediate are required. In Patent Documents 1 and 4, sodium methoxide or tetraisopropyl titanate, which is easily deactivated with water and requires careful handling, is used as a catalyst. When these are used in the reaction, the water in the reaction system must be removed beforehand. There is a description in the embodiment that it is omitted. However, these documents do not specifically describe to what extent the water in the system needs to be reduced.

In Patent Documents 2 and 3, 2-aminoethyl methacrylate methyl ethyl ketimine is synthesized by charging a Schiff base obtained by reacting monoethanolamine and methyl ethyl ketone, methyl methacrylate, and a zinc acetylacetone complex as a catalyst, and heating. . These documents do not describe the necessity of removing water in the system before adding the catalyst. As the intermediate Schiff base, the one obtained by synthesizing monoethanolamine and methyl ethyl ketone and removing excess ketone is used. Regarding the reaction results, the yield of the intermediate Schiff base synthesis step was 95% based on monoethanolamine, and the yield of 2-aminoethyl methacrylate methyl ethyl ketimine in the transesterification step was based on the intermediate Schiff base. About 84%, and the yield of 2-aminoethyl methacrylate methyl ethyl ketimine based on monoethanolamine used as a raw material is about 80%, which cannot be said to be a sufficient reaction result.

In Patent Documents 5 and 6, a transesterification reaction is performed between dimethylaminoethanol and methyl methacrylate using a potassium titanium oxalate or zinc acetylacetone complex as a catalyst. No consideration is given to water during the reaction.

In Patent Document 7, N- (2-hydroxyethyl) morpholine and methyl acrylate are reacted using dibutyltin oxide or zirconia acetylacetonate as a catalyst. Since N- (2-hydroxyalkyl) morpholines are hydrophilic and easily absorb water, it is desirable to use a catalyst that is not deactivated by water.

U.S. Pat. No. 3,037,969 Japanese Patent No. 4031150 Japanese Patent No. 4221118 JP-A-38-8310 JP-A-2002-249471 JP-A-1-317700 JP 2006-290850 A

（式（１）中R¹およびR²は炭素数１〜１２のアルキル基もしくはアリール基を示す。）

（式（２）中R³は炭素数３〜１０の２価の炭化水素基であり、その一部に二重結合を有していてもよい。

（式（３）中R¹およびR²は炭素数１〜１２のアルキル基もしくはアリール基を示す。）

（式（４）中R³は炭素数３〜１０の２価の炭化水素基であり、その一部に二重結合を有していてもよい。

（式（５）中R¹およびR²は炭素数１〜１２のアルキル基もしくはアリール基を示す。）

（式（６）中R³は炭素数３〜１０の２価の炭化水素基であり、その一部に二重結合を有していてもよい。 Thus, in the above-mentioned prior art documents 1, 2, 3, and 4, the following formula (1) or (2) obtained by reacting monoethanolamine with a ketone represented by the following formula (5) or (6): A method for producing a ketimine compound represented by the formula (3) or (4) by reacting a compound represented by the formula (I), a so-called Schiff base, with a methacrylic acid ester is described. However, ketimine compounds represented by the following formula (1) or (2) having an imino group in the molecule or ketimine compounds which are the target compounds of the present invention represented by the following formulas (3) or (4) are exposed to heat and moisture. Although it is extremely sensitive to the compound and is easily decomposed, special consideration is required for the synthesis, but the above-mentioned prior art does not describe this point in detail.
The ketimine compound represented by the following formula (3) or (4) aimed at in the present invention is often required to have a certain level of purity or more in view of its use. However, in view of the boiling point, polymerizability, thermal stability, and hygroscopicity of this compound, once a by-product (impurity) is generated in the synthesis process, a separation and purification process for increasing the purity to the required level is required. Will be very difficult. Therefore, a method for obtaining a ketimine compound represented by the following formula (3) or (4) in a high yield while suppressing generation of impurities has been demanded.

(In the formula (1), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (2), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.

(In the formula (3), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (4), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.

(In the formula (5), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (6), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.

As a result of intensive studies to solve the above problems, a ketimine compound represented by the formula (1) or (2) is reacted with a methacrylic acid ester to produce a ketimine compound represented by the formula (3) or (4). In the step of performing, the present inventors have found that the ketimine compound represented by the formula (3) or (4) can be obtained in a high yield by controlling the water concentration in the reaction raw material liquid to a predetermined value or less, and have completed the invention. .

（式（１）中R¹およびR²は炭素数１〜１２のアルキル基もしくはアリール基を示す。）

（式（２）中R³は炭素数３〜１０の２価の炭化水素基であり、その一部に二重結合を有していてもよい。

（式（３）中R¹およびR²は炭素数１〜１２のアルキル基もしくはアリール基を示す。）

（式（４）中R³は炭素数３〜１０の２価の炭化水素基であり、その一部に二重結合を有していてもよい。

（式（５）中R¹およびR²は炭素数１〜１２のアルキル基もしくはアリール基を示す。）

（式（６）中R³は炭素数３〜１０の２価の炭化水素基であり、その一部に二重結合を有していてもよい。

（式（７）中R⁴は炭素数１〜４のアルキル基を示す。）
２．式（１）におけるR１がメチル基であり、R２がエチル基または２−メチルプロピル基である、１に記載のケチミン化合物の製造方法。
３．式（７）におけるR４がメチル基である、１または２に記載のケチミン化合物の製造方法。
４．工程（Ａ）を、２−アミノエタノールと式（５）または式（６）で示されるケトンとの反応により生成する水を抜き出しながら実施することを特徴とする、１〜３のいずれかに記載のケチミン化合物の製造方法。
５．工程（Ｂ）において、反応開始時点から反応終了時点までの間、前記反応原料液および反応液の液温を１１０℃以下に維持することを特徴とする、１〜４のいずれかに記載のケチミン化合物の製造方法。
６．前記反応原料液がケトンを含有し、前記反応原料液中の式（１）または式（２）で示されるケチミン化合物に対する前記ケトンの割合が、当量比で０．６〜２．０当量であることを特徴とする、１〜５のいずれかに記載のケチミン化合物の製造方法。
７．前記ケトンが、工程（Ａ）において反応に供される式（５）または式（６）で示されるケトンと同一であることを特徴とする、６に記載のケチミン化合物の製造方法。
８．前記エステル交換反応触媒が、亜鉛アセチルアセトン錯体であることを特徴とする、１〜７のいずれかに記載のケチミン化合物の製造方法。
９．工程（Ａ）の反応において、２−アミノエタノールの反応転化率が９９%に到達した後に、前記亜鉛アセチルアセトン錯体を供給することを特徴とする、８に記載のケチミン化合物の製造方法。
１０．工程（Ａ）で得られた反応生成物（I）と前記亜鉛アセチルアセトン錯体を混合し、前記混合物中に含まれる水を抜き出した後、工程（Ｂ）の前記反応原料液に供することを特徴とする、８に記載のケチミン化合物の製造方法。
１１．工程（Ａ）で得られた反応生成物（I）中に含まれる式（１）または式（２）で示されるケチミン化合物を、蒸留により分離せずに、工程（Ｂ）の反応原料液に供することを特徴とする１〜１０のいずれかに記載のケチミン化合物の製造方法。 That is, the present invention is as follows.
1. Steps (A) and (B) shown below
Step (A): reacting 2-aminoethanol with a ketone represented by the following formula (5) or (6) to produce a reaction containing a ketimine compound represented by the following formula (1) or (2) A step of obtaining the product (I),
Step (B): a ketimine compound represented by the following formula (1) or (2) contained in the reaction product (I) obtained in the step (A), and a methacrylic acid represented by the following formula (7) Reacting with an ester to synthesize a ketimine compound represented by the following formula (3) or (4):
A method for producing a ketimine compound represented by the following formula (3) or (4) having:
The reaction product (I), a methacrylic acid ester represented by the following formula (7), and a water content in a reaction raw material liquid to be subjected to the step (B), wherein the water concentration is 400 ppm or less. A method for producing a ketimine compound represented by the following formula (3) or (4):

(In the formula (1), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (2), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.

(In the formula (3), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (4), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.

(In the formula (5), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (6), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.

(In the formula (7), R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)
2. 2. The method for producing a ketimine compound according to 1, wherein R1 in the formula (1) is a methyl group, and R2 is an ethyl group or a 2-methylpropyl group.
3. 3. The method for producing a ketimine compound according to 1 or 2, wherein R4 in the formula (7) is a methyl group.
4. 4. The process according to any one of 1 to 3, wherein the step (A) is carried out while extracting water generated by the reaction of 2-aminoethanol with the ketone represented by the formula (5) or (6). A method for producing a ketimine compound.
5. The ketimine according to any one of claims 1 to 4, wherein, in the step (B), the temperature of the reaction raw material liquid and the reaction liquid is maintained at 110 ° C or lower from the start of the reaction to the end of the reaction. A method for producing a compound.
6. The reaction raw material liquid contains a ketone, and the ratio of the ketone to the ketimine compound represented by the formula (1) or the formula (2) in the reaction raw material liquid is 0.6 to 2.0 equivalents in equivalent ratio. 7. The method for producing a ketimine compound according to any one of 1 to 5, wherein
7. The method for producing a ketimine compound according to 6, wherein the ketone is the same as the ketone represented by the formula (5) or (6) subjected to the reaction in the step (A).
8. 8. The method for producing a ketimine compound according to any one of 1 to 7, wherein the transesterification catalyst is a zinc acetylacetone complex.
9. 9. The method for producing a ketimine compound according to 8, wherein the zinc acetylacetone complex is supplied after the reaction conversion of 2-aminoethanol reaches 99% in the reaction of the step (A).
10. Mixing the reaction product (I) obtained in the step (A) with the zinc acetylacetone complex, extracting water contained in the mixture, and then supplying the water to the reaction raw material liquid in the step (B). 9. The method for producing a ketimine compound according to 8, wherein
11. The ketimine compound represented by the formula (1) or the formula (2) contained in the reaction product (I) obtained in the step (A) is separated into the reaction raw material liquid of the step (B) without separation by distillation. 11. The method for producing a ketimine compound according to any one of 1 to 10, which is provided.

From the ketimine compound represented by the formula (1) or (2) obtained by reacting ethanolamine with the ketone represented by the formula (5) or (6) by carrying out the present invention, the compound represented by the formula (3) or ( The conversion to the ketimine compound represented by 4) can proceed with almost no side reaction, and the ketimine compound represented by formula (3) or (4), which is the target compound of the present invention, can be obtained in high yield. It becomes possible to manufacture stably. When the target compound of the present invention (the ketimine compound represented by the formula (3) or (4)) is obtained in high purity and high yield, its industrial significance is extremely large in view of its various uses.

Hereinafter, the present invention will be described in detail. In the present invention, the step (A) of reacting 2-aminoethanol with a ketone represented by the formula (5) or (6) to synthesize a ketimine compound called a Schiff base represented by the formula (1) or (2) ) Will be described.

In the step (A), 2-aminoethanol and a ketone represented by the formula (5) or (6) are provided as raw materials. The ketone represented by the formula (5) or (6) to be subjected to the step (A) includes at least methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, diisobutyl ketone, cyclopentanone and cyclohexanone. It is preferable to use one type. Among the above compounds, methyl ethyl ketone or methyl isobutyl ketone is more preferable in consideration of the availability, the ease of synthesizing a Schiff base, and the ease of purification of the obtained compound.

The ratio of the total amount of the ketone represented by the formula (5) or (6) to the total amount of 2-aminoethanol subjected to the step (A) is in the range of 1.0 to 3.0 in equivalent ratio. Is preferred. When the equivalent ratio is less than 1.0, a part of 2-aminoethanol cannot necessarily be a ketimine compound represented by the formula (1) or the formula (2) and remains in the system. become. This is not only a waste of raw materials, but also when 2-aminoethanol is unreacted and mixed into the step (B) described below, it causes impurities to be generated during the reaction, and the formula (3) or the formula (3) This may cause a decrease in the yield and purity of the ketimine compound shown in 4). If the above equivalence ratio exceeds 3.0, the concentration of the compound of the formula (1) or the formula (2) in the reaction solution becomes low, which not only lowers the efficiency but also costs extra because of the extra cost. Disadvantaged.

The reaction of the step (A) is an equilibrium reaction, and usually, water produced by the reaction is discharged out of the system, thereby completely converting 2-aminoethanol as a raw material to a target product. Various methods can be considered as a method of discharging water generated by the reaction to the outside of the system.A method of forming an azeotropic mixture with water by coexisting a compound called an azeotropic solvent and extracting the water by azeotropic distillation is often used. Can be The azeotropic solvent often used in the step (A) in the present invention is one having an azeotropic point with water lower than the ketone represented by the formula (5) or the formula (6) used in the step (A). Any one can be used as long as it is present, and specific examples thereof include hexane, cyclohexane, benzene, and toluene. When the ketone represented by the formula (5) or (6) used as a raw material in the step (A) is a compound which forms an azeotropic mixture with water, such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. May be used as the azeotropic solvent.

In the step (A), the reaction conversion of 2-aminoethanol used as a raw material is preferably 99% or more. This is because, in the step (A), when the ester exchange reaction catalyst used in the step (B) is added to the reaction solution in the course of the reaction at a stage where the reaction conversion of 2-aminoethanol is less than 99%, it is an unreacted raw material. When 2-aminoethanol causes some reaction with the transesterification catalyst, the catalytic activity is reduced, and the yield of the ketimine compound represented by the formula (3) or (4) in the step (B) may be reduced. There is.

As a method for using the ketimine compound represented by the formula (1) or the formula (2) obtained through the step (A) as a raw material in the step (B), the formula (1) contained in the reaction product (I) is used. Alternatively, a method of separating the ketimine compound represented by the formula (2) by distillation, followed by subjecting the ketimine compound to a reaction raw material liquid in the step (B) described below, or the method represented by the formula (1) or the formula (2) contained in the reaction product (I) )), The ketimine compound may be used as a reaction raw material liquid in the step (B) described below without being separated by distillation. However, the ketimination reaction between 2-aminoethanol and the ketone represented by the formula (5) or (6) in the step (A) has a very high selectivity, and the transesterification reaction in the next step (B) is difficult. In addition to the formation of almost no inhibitory substances, the distillation of the reaction product (I) results in the addition of the ketimine compound represented by the formula (1) or (2) by heating at a high temperature for a long time. In the present invention, the reaction product (I) is subjected to distillation because the ketimine compound represented by the formula (1) or (2) is deteriorated and the recovery rate during the distillation purification is reduced. Preferably not.

Step (B) comprises the step of: reacting a ketimine compound represented by the formula (1) or (2) contained in the reaction product (I) obtained in the step (A) with a methacrylic acid ester represented by the formula (7) And synthesizing a ketimine compound represented by the formula (3) or (4).

The reaction raw material liquid supplied to the step (B) contains the reaction product (I) obtained in the step (A), the methacrylic acid ester represented by the formula (7), and a transesterification reaction catalyst.

It is important to reduce the water content in the reaction raw material liquid used for the reaction in the step (B) to a predetermined concentration or less. This is because the water in the reaction solution reacts with the ketimine compound represented by the formula (1) or (2) and the ketimine compound represented by the formula (3) or (4) to cause a deprotection reaction, Generates primary amine. This primary amine causes a 1,4-addition reaction or transesterification to methacrylate to generate impurities, and finally lowers the yield and purity of the ketimine compound represented by the formula (3) or (4). This is because such a problem may occur.

The water concentration in the reaction raw material liquid is preferably 400 ppm or less. When the water concentration exceeds 400 ppm, the influence of the above deprotection reaction appears, and the yield of the target ketimine compound represented by the formula (3) or (4) is significantly reduced.

Examples of the method for reducing the water content include a method of separating a ketimine compound represented by the formula (1) or the formula (2) from the reaction product (I) obtained through the step (A) by distillation, a reaction product After mixing (I) and the methacrylic acid ester represented by the formula (7), the mixture may be refluxed to remove water from the mixture, or a dehydrating agent may be added. When the ketimine compound represented by the formula (1) or the formula (2) contained in the reaction product (I) is separated by distillation, the yield of the ketimine compound represented by the formula (1) or the formula (2) decreases. This is not preferred. In the present invention, a method of distilling water by refluxing the reaction product (I) containing the ketimine compound represented by the formula (1) or (2) under heating is preferable.

It is preferable that a ketone coexist in the reaction raw material liquid. The reason is that in the step (B) of producing a ketimine compound represented by the formula (3) or (4) from a ketimine compound represented by the formula (1) or (2), a ketone is allowed to coexist in the system. This is because, even if water remains or is mixed in from the outside, the deprotection reaction of the ketimine compound by the water can be suppressed to some extent.

Specific examples of the type of ketone contained in the reaction raw material liquid include methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, diisobutyl ketone, cyclopentanone, and cyclohexanone. Among the above compounds, it is preferable that the compound is the same as the ketone represented by the formula (5) or (6) used for producing the ketimine compound represented by the formula (1) or (2).

The amount of the ketone contained in the reaction raw material liquid is preferably in the range of 0.6 to 2.0 equivalents in equivalent ratio to the ketimine compound represented by the formula (1) or the formula (2) in the reaction raw material liquid. . When the equivalent ratio exceeds 2.0, the concentration of the active ingredient such as the ketimine compound represented by the formula (1) or the formula (2) or the methacrylic acid ester represented by the formula (7) in the reaction solution decreases, Not only does the efficiency of the reaction decrease, but it also becomes economically disadvantageous because extra costs are required in subsequent steps such as ketone removal and purification of the target substance. When the equivalent ratio is less than 0.6, the effect of suppressing the reaction of deprotection of the ketimine compound by moisture decreases, and as a result, the yield of the ketimine compound represented by the formula (3) or (4) decreases.

As the methacrylate represented by the formula (7) to be subjected to the step (B), compounds having various structures can be used. Specifically, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate And the like. Considering availability and the like, methyl methacrylate is most preferred. The methacrylic acid ester represented by the formula (7) preferably has an equivalent ratio of 2.0 to 4.0 with respect to the total amount of the ketimine compound represented by the formula (1) or (2).

The reaction raw material liquid may include an organic compound such as hexane or cyclohexane, which forms an azeotrope with methanol generated by the reaction.

The transesterification reaction between the ketimine compound represented by the formula (1) or the formula (7) and the methacrylic acid ester represented by the formula (7), which is performed in the step (B), is an equilibrium reaction. Usually, the reaction is allowed to proceed to the end by withdrawing it from the system by a method such as distillation. When the methacrylic acid ester represented by the formula (7) used in the reaction is methyl methacrylate, methanol produced by the reaction may be removed from the system by distillation in the form of an azeotrope with methyl methacrylate. By refluxing the mixture with an organic compound that forms an azeotrope with methanol, etc. under heating to cause azeotropic distillation, methanol can be more efficiently extracted out of the system.

In the transesterification reaction of the ketimine compound represented by the formula (1) or the formula (2) and the methacrylic ester represented by the formula (7) performed in the step (B), the reaction is carried out while maintaining the reaction temperature within a certain range. It is important to do it. In this reaction, as the reaction proceeds, the ketimine compound represented by the formula (1) or the formula (2) and the methacrylic acid ester represented by the formula (7) are consumed, and the formula (3) or the boiling point higher than that is consumed. Since the ketimine compound represented by the formula (4) is formed and the alcohol having the lowest boiling point is extracted out of the system, the temperature of the kettle liquid usually rises gradually under the condition of constant pressure reflux. It is. However, the ketimine compound represented by the formula (3) or (4), which is the target compound of the present invention, is a very unstable compound, and under high temperature conditions, is transformed by various reactions such as a polymerization reaction and an addition reaction. Therefore, it is very important in the present invention to take care that the reaction temperature does not exceed a certain value.

As a method for preventing the reaction temperature from exceeding a certain value, a method of lowering the reaction pressure to below atmospheric pressure, a method of gradually lowering the reaction pressure with the progress of the reaction, a methacrylic acid ester represented by the formula (7) as a raw material A method in which an organic compound forming an azeotrope with methanol, a low-boiling compound such as a ketone represented by the formula (5) or (6) is present in a large amount in the system, and the low-boiling compound reacts with the progress of the reaction. A method of adding an appropriate amount during the reaction to keep the temperature at or below a certain level can be considered, and any method is effective.

In the step (B), the temperature of the reaction raw material liquid and the reaction liquid is preferably maintained at 110 ° C. or lower from the start of the reaction to the end of the reaction. The reaction start point in the step (B) in the present invention is a point in time when the supply of the reaction raw material liquid to the reaction vessel is completed. At the reaction end point, the reaction liquid is analyzed by gas chromatography, and the formula (1) or ( This is the time when the disappearance of the ketimine compound shown in 2) was confirmed. When the temperature of the reaction raw material liquid or the reaction liquid exceeds 110 ° C., the polymerization reaction, the addition reaction, and the like may occur as described above.

In the step (B) of the present invention, a transesterification catalyst is required. As a catalyst used in carrying out this reaction, various catalysts known as transesterification catalysts can be used. For example, sodium alcoholate, titanium alcoholate, magnesium alcoholate, dialkyltin oxide, zinc acetylacetone complex and the like can be used. In consideration of ease of handling and reaction results, zinc acetylacetone complex is particularly preferable.

The amount of the transesterification catalyst used is such that the rate of the transesterification reaction between the ketimine compound represented by the formula (1) or the formula (2) and the methacrylic acid ester represented by the formula (7) becomes suitable. is important. If the amount used is too small, the reaction rate will not sufficiently increase, and the ketimine compound represented by the formula (3) or (4), which is the object of the present invention, will be exposed to an unnecessarily high temperature. The reaction performance decreases. If the amount used is too large, there is no particular problem in the reaction results itself, but this reaction is an equilibrium reaction as described below, and it is rate-limiting to withdraw by-produced alcohol out of the system. Speed increase is no longer expected. In view of the above circumstances, the amount of the transesterification catalyst with respect to the total amount of the ketimine compound represented by the formula (1) or (2) in the reaction raw material liquid is 0.001 to 0.05 in equivalent ratio. Is preferably within the range.

When the transesterification catalyst is a zinc acetylacetone complex, the timing of supplying the zinc acetylacetone complex is not particularly limited, and may be any time before the start of the reaction in step (B). Specifically, in the step (A), the reaction solution is charged together with the reaction raw material (2-aminoethanol, ketone represented by the formula (5) or (6)), or the reaction solution is added during the reaction in the step (A). Supply to the user. However, if the zinc acetylacetone complex is supplied after the reaction has proceeded and the residual amount of 2-aminoethanol has decreased in step (A), the reaction is represented by the formula (3) or (4) in the subsequent step (B). Since the yield of the ketimine compound tends to increase, it is preferable to supply the zinc acetylacetone complex used as the transesterification catalyst after the reaction conversion of 2-aminoethanol reaches 99% in step (A). . After the step (A), a zinc acetylacetone complex may be mixed with the reaction product (I).

The zinc acetylacetone complex itself absorbs moisture in the atmosphere and easily absorbs moisture. When the absorbed zinc acetylacetone complex is used, the moisture and the ketimine compound represented by the formula (1) or (2) and the formula (3) Alternatively, the ketimine compound represented by the formula (4) reacts to cause a deprotection reaction to generate a primary amine. The primary amine undergoes a 1,4-addition reaction or transesterification to methacrylate to generate impurities, and finally yields a 2-aminoethyl methacrylate ketimine compound represented by the formula (3) or (4). It lowers the rate and purity. Therefore, when a zinc acetylacetone complex is supplied or mixed to the reaction product (I) during or after the reaction of the step (A) as described above, a mixture of the reaction product (I) and the zinc acetylacetone complex It is preferable to perform an operation of extracting water contained therein. The method of extracting water from the mixture is not particularly limited, and examples thereof include a method of refluxing under heating and distilling off water.

It is effective to use a polymerization inhibitor in the transesterification reaction in which the ketimine compound represented by the formula (1) or the formula (2) is reacted with the methacrylic ester represented by the formula (7) in the step (B). is there. The type of the polymerization inhibitor is not particularly limited and known ones can be used. Specifically, hydroquinone, p-monomethylhydroquinone, di-t-butylphenol, diphenylamine, 2,2,6,6-tetramethylpiperidine, phenothiazine , 2,2,6,6-tetramethyl-1-piperidinoxy-4-ol, oxygen, nitric oxide and the like. Of these, hydroquinone and p-monomethylhydroquinone are preferred, and these may be used in combination. Although the timing of supplying the polymerization inhibitor is not particularly limited, it may be mixed with the reaction raw material liquid supplied to the step (B) or the reaction liquid during the reaction. In this case, the ratio of the polymerization inhibitor may be appropriately determined according to the type of the polymerization inhibitor used, and the concentration of the polymerization inhibitor in the reaction raw material liquid or the reaction liquid is preferably 0.0001 to 1 wt%.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the scope of the present invention is not limited by these examples.

In the examples and comparative examples, the definitions and measurement methods of the following physical properties are shown below. The reaction conversion rate and the reaction yield in the step (A) and the step (B) are determined by gas chromatography (GC system 7890A GC column: CP-Sil 8 manufactured by Agilent, Inc.) using the reaction solution during the reaction or the product after the reaction is completed. CB for Amines Length: 30 m Inner diameter: 0.25 mm Thickness: 0.25 μm) The components were analyzed and calculated by the following formula.
<Reaction conversion rate>
The reaction conversion in the step (A) is a ratio of the 2-aminoethanol consumed in the step (A) to the 2-aminoethanol charged before the reaction in the step (A). This is indicated by (8).
[Reaction conversion] = 1- [2-aminoethanol residual amount] / [2-aminoethanol charge amount] (8)
The reaction conversion in the step (B) is calculated based on the charged amount of 2-aminoethanol in the step (A), and is consumed in the step (B) with respect to the theoretical yield of the ketimine compound represented by the formula (1) or (2). This is the yield ratio of the ketimine compound represented by the formula (1) or (2), and is specifically represented by the formula (9).
[Reaction conversion] = 1- [residual molar amount of ketimine compound represented by formula (1) or formula (2)] / [molar amount of 2-aminoethanol charged in step (A)] (9)
<Reaction yield>
The yield of the ketimine compound represented by the formula (1) or (2) is determined by calculating the yield of the ketimine compound represented by the formula (1) or (2) calculated from the charged weight of 2-aminoethanol in the step (A). It refers to the weight fraction of the yield actually obtained in step (A) with respect to the theoretical yield, and is specifically represented by formula (10).
[Reaction yield] = [molar amount of ketimine compound represented by formula (1) or formula (2)] / [molar amount of 2-aminoethanol charged in step (A)] (10)
The yield of the ketimine compound represented by the formula (3) or the formula (4) is determined by calculating the yield of the ketimine compound represented by the formula (3) or the formula (4) calculated from the charged weight of 2-aminoethanol in the step (A). It indicates the weight fraction of the yield obtained in the step (B) with respect to the theoretical yield, and is specifically shown by the formula (11).
[Reaction yield] = [molar amount of ketimine compound represented by formula (3) or (4) obtained in step (B)] / [molar amount of 2-aminoethanol charged in step (A)] (11) )
<Moisture concentration in reaction raw material liquid in step (B)>
The moisture concentration in the reaction raw material liquid in the step (B) was measured by a Karl Fischer moisture meter (manufactured by Metrohm, Karl Fischer moisture meter, Tightland 852, one-pack cell type, measuring reagent: HYDRANAL-Coulomat AK, manufactured by Fluka).

(Example 1) Synthesis of 2-aminoethyl methacrylate methyl ethyl ketimine
Ketimine- forming step A three-necked flask with an inner volume of 1000 ml equipped with a magnetic stirrer, a rectification column with an inner diameter of 25 mmφ filled with a McMahon packing of size 6 mm up to a height of 300 mm, a Dean-Stark trap, and a reflux condenser. Were charged with 49.0 g (0.80 mol) of 2-aminoethanol, 173 g (2.4 mol) of methyl ethyl ketone, and 162 g (1.9 mol) of hexane, and the mixture was heated under reflux at a kettle liquid temperature of 63.7 to 69.8 ° C. The ketimine synthesis was carried out while extracting water accumulated in the Dean Stark trap outside the system. After 6 hours, the reaction solution was analyzed by gas chromatography, and the conversion of 2-aminoethanol was 100% and the yield of 2-aminoethanol methylethylketimine was 99%.
Transesterification Step 10.7 g of zinc acetylacetone complex and 0.32 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the kettle solution, and Dean-Stark trap was added. Was replaced with a normal distillation head (controllable reflux amount), and the mixture was heated under reflux to extract 47.5 g of an azeotropic mixture of water-hexane. To the remaining kettle solution, 323 g (3.2 mol) of methyl methacrylate was added. At this time, the water concentration in the reaction raw material liquid was 200 ppm. Subsequently, the mixture was heated and refluxed at a tank liquid temperature of 79.5 to 87.3 ° C., and transesterification was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and hexane. As a polymerization preventive measure, a 4% -p-methoxyphenol-methyl methacrylate solution was supplied at a rate of 2 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 10 ml / min. After 7.5 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylethylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl ethyl ketimine based on the charged 2-aminoethanol was 88%.

Example 2 Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine formation process Magnetic stirrer, 3-mm rectifier with inner diameter of 25 mmφ filled with a 6 mm-size McMahon packing to a height of 300 mm, a Dean-Stark trap, and a reflux condenser. A flask was charged with 100.0 g (1.6 mol) of 2-aminoethanol and 409.8 g (4.1 mol) of methyl isobutyl ketone, and heated to reflux at a kettle liquid temperature of 76.0 to 99.0 ° C. and a pressure of 33.6 kPa. Then, ketimine synthesis was performed while extracting the water accumulated in the Dean Stark trap outside the system. Two hours later, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%.
Transesterification step 4.32 g of zinc acetylacetone complex and 0.41 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the kettle solution, and Dean-Stark trap was added. Is replaced with a normal distillation head (a reflux amount can be adjusted), and the mixture is heated under reflux to obtain 153 g of an azeotropic mixture of water and methyl isobutyl ketone under the conditions of a kettle liquid temperature of 91.0 ° C. and a reduced pressure of normal pressure to 18.7 kPa. Distilled off. 409.7 g (4.1 mol) of methyl methacrylate was added to the remaining kettle solution. Here, the water concentration in the reaction raw material liquid after adding methyl methacrylate was 370 ppm. Subsequently, the mixture was heated and refluxed at a kettle liquid temperature of 84.7 to 94.2 ° C. and a pressure of 41.7 kPa, and transesterification was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and methyl methacrylate. As a polymerization preventing measure, a 1% -p-methoxyphenol-methyl methacrylate solution was supplied at a rate of 0.8 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 8 ml / min. After 6.5 hours, the reaction mixture was analyzed by GC. As a result, the conversion of 2-aminoethanolmethylisobutylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 96%.

Example 3 Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine formation process Magnetic stirrer, 3-mm rectifier with inner diameter of 25 mmφ filled with a 6 mm-size McMahon packing to a height of 300 mm, a Dean-Stark trap, and a reflux condenser. A flask was charged with 100.0 g (1.6 mol) of 2-aminoethanol and 409.8 g (4.1 mol) of methyl isobutyl ketone, and heated to reflux at a kettle liquid temperature of 76.0 to 99.0 ° C. and a pressure of 33.6 kPa. Then, ketimine synthesis was performed while extracting the water accumulated in the Dean Stark trap outside the system. Two hours later, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%.
Transesterification Step 2.16 g of zinc acetylacetone complex and 0.41 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the kettle solution, and Dean-Stark trap was added. Was replaced with a normal distillation head (a reflux amount can be adjusted), and the mixture was heated and refluxed, and excess methyl isobutyl ketone was distilled off under reduced pressure of normal pressure to 4 kPa. 409.7 g (4.1 mol) of methyl methacrylate was added to the remaining kettle solution. After adding methyl methacrylate, the water concentration in the reaction raw material liquid was 340 ppm. Subsequently, the mixture was heated and refluxed at a pressure of 41.7 kPa and a kettle liquid temperature of 82.8 to 94.0 ° C., and a transesterification reaction was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and methyl methacrylate. As a polymerization prevention measure, a 1% -p-methoxyphenol-methyl methacrylate solution was added at a rate of 0.8 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 8 ml / minute. After 7 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylisobutylketimine was 99.3%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 93%.

(Example 4) Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine formation process Magnetic stirrer, 3-mm rectifier with inner diameter of 25 mmφ filled with a 6 mm-size McMahon packing to a height of 300 mm, a Dean-Stark trap, and a reflux condenser. A flask was charged with 100.0 g (1.6 mol) of 2-aminoethanol and 409.8 g (4.1 mol) of methyl isobutyl ketone, and heated to reflux at a kettle liquid temperature of 76.0 to 99.0 ° C. and a pressure of 33.6 kPa. Then, ketimine synthesis was performed while extracting the water accumulated in the Dean Stark trap outside the system. Two hours later, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%.
Transesterification Step 2.16 g of zinc acetylacetone complex was added to the kettle solution, and the Dean-Stark trap was replaced with a normal distillation head (controlling the amount of reflux), and the excess methyl isobutyl ketone was reduced in pressure from normal pressure to 4 kPa. Under the same conditions. To the remaining kettle solution, 409.7 g (4.1 mol) of methyl methacrylate and 0.41 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added. At this time, the water concentration in the reaction raw material liquid was 350 ppm. Subsequently, the mixture was heated and refluxed at a pressure of 51.3 kPa and a kettle liquid temperature of 90.6 to 111.2 ° C., and transesterification was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol-methyl methacrylate. As a polymerization prevention measure, a 1% -p-methoxyphenol-methyl methacrylate solution was added at a rate of 0.8 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 8 ml / minute. After 7 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylisobutylketimine was 99.3%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 89%.

Example 5 Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine step <br/> magnetic stirrer, rectification column, Dean Stark trap, three-necked flask having an inner volume of 1000ml, equipped with a reflux condenser 2-aminoethanol 49.6 g (0.81 mol), methyl isobutyl 243 g (2.4 mol) of ketone and 162 g (1.9 mol) of hexane were charged, and the mixture was heated under reflux at a kettle liquid temperature of 81.1 to 83.0 ° C., and while the water accumulated in the Dean-Stark trap was being drawn out of the system, the ketimine was removed. Synthesis was performed. After 6.5 hours, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%.
Transesterification step 10.6 g of zinc acetylacetone complex and 0.16 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the kettle solution, and Dean-Stark trap was added. Was replaced with an ordinary distillation head (a reflux amount can be adjusted), and the mixture was heated to reflux to distill off 21.2 g of an azeotropic mixture of water and hexane at a kettle liquid temperature of 83.1 to 85.2 ° C. 167 g (1.7 mol) of methyl methacrylate was added to the remaining pot liquid, and the water concentration in the reaction raw material liquid at this time was 119 ppm. Subsequently, the mixture was heated and refluxed at a kettle liquid temperature of 85.2 to 101.3 ° C., and transesterification was carried out while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and hexane. As a polymerization prevention measure, a 3.7% -p-methoxyphenol-methylisobutylketone solution was added at a rate of 2.9 g / hour from the top of the rectification tower, and air was supplied to the kettle at a rate of 10 ml / minute. After 5 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylisobutylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 95%.

Example 6 Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine formation step 50.4 g (0.83 mol) of 2-aminoethanol and methyl isobutyl were placed in a 1000 ml three-necked flask equipped with a magnetic stirrer, a rectifier, a Dean Stark trap, and a reflux condenser. 241 g (2.4 mol) of ketone, 10.7 g of zinc acetylacetone complex and 162 g (1.9 mol) of hexane were charged, and the mixture was heated under reflux at a bath liquid temperature of 75.5 to 84.6 ° C., and water accumulated in a Dean-Stark trap. Was extracted from the system to synthesize ketimine. After 6 hours, the reaction solution was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%.
Transesterification step 0.17 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) was added to the kettle solution, and the Dean-Stark trap was placed in a normal distillation head (returned). The mixture was heated and refluxed, and 8.2 g of an azeotropic mixture of water-hexane was distilled off at a kettle liquid temperature of 84.0 to 84.3 ° C. 165 g (1.7 mol) of methyl methacrylate was added to the remaining kettle solution, and the water concentration in the reaction material solution at this time was 116 ppm. Subsequently, the mixture was heated and refluxed at a kettle liquid temperature of 84.0 to 105.3 ° C., and transesterification was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and hexane. As a polymerization prevention measure, a 3.7% -p-methoxyphenol-methylisobutylketone solution was added at a rate of 2.9 g / hour from the top of the rectification tower, and air was supplied to the kettle at a rate of 10 ml / minute. After 7 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylisobutylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 89%.

Example 7 Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine step <br/> magnetic stirrer, rectification column, Dean Stark trap, three-necked flask having an inner volume of 1000ml, equipped with a reflux condenser 2-aminoethanol 49.6 g (0.81 mol), methyl isobutyl 243 g (2.4 mol) of ketone and 162 g (1.9 mol) of hexane were charged, and the mixture was heated under reflux at a kettle liquid temperature of 81.1 to 83.0 ° C., and while the water accumulated in the Dean-Stark trap was being drawn out of the system, the ketimine was removed. Synthesis was performed. After 2.5 hours, the reaction solution was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 86%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 86%.
Transesterification step 10.6 g of zinc acetylacetone complex and 0.16 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the kettle solution, and Dean-Stark trap was added. Was replaced with an ordinary distillation head (one capable of adjusting the reflux amount), and the mixture was heated under reflux to distill off 21.2 g of an azeotropic mixture of water and hexane at a kettle liquid temperature of 83.1 to 85.1 ° C. 167 g (1.7 mol) of methyl methacrylate was added to the remaining kettle solution, and the water concentration in the reaction material solution at this time was 186 ppm. Subsequently, the mixture was heated and refluxed at a kettle liquid temperature of 85.2 to 101.3 ° C., and transesterification was carried out while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and hexane. As a polymerization preventing measure, a 4.4% -p-methoxyphenol-methyl isobutyl ketone solution was added at 2.1 g / hour from the top of the rectification column, and air was supplied to the kettle at 10 ml / minute. After 5.5 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylisobutylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 93%.

(Comparative Example 1) Synthesis of 2-aminoethyl methacrylate methyl ethyl ketimine
Ketimine step <br/> magnetic stirrer, rectification column, Dean Stark trap, 2-aminoethanol 49.6 g (0.81 mol) in a three-neck flask having an inner volume of 1000ml, equipped with a reflux condenser, methyl ethyl ketone 173g (2.4 mol) and 101 g (1.2 mol) of hexane were heated and refluxed at a kettle liquid temperature of 64.8-72.0 ° C., and ketimine synthesis was carried out while extracting water accumulated in the Dean-Stark trap outside the system. went. After 4 hours, the conversion of 2-aminoethanol was 100% and the yield of 2-aminoethanol methyl ethyl ketimine was 99%.
Transesterification step The Dean-Stark trap is replaced with a normal distillation head (a reflux amount can be adjusted), and 11.2 g of zinc acetylacetone complex, 323 g (3.2 mol) of methyl methacrylate, 4-hydroxy- 0.32 g of 2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) was added. Here, the water concentration in the reaction raw material liquid before the start of the reaction was 0.1%. Subsequently, the mixture was heated and refluxed at a kettle liquid temperature of 72.1 to 91.5 ° C., and transesterification was performed while methanol produced as a by-product was extracted out of the system as an azeotropic mixture of methanol and hexane. As a polymerization preventive measure, a 4% -p-methoxyphenol-methyl methacrylate solution was supplied at a rate of 2 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 10 ml / min. After 7 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylethylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl ethyl ketimine based on the charged 2-aminoethanol was 84%.

(Comparative Example 2) Synthesis of 2-aminoethyl methacrylate methyl ethyl ketimine
Ketimination step 24.9 g (0.41 mol) of 2-aminoethanol, methyl ethyl ketone 88 in a 500-ml three-necked flask equipped with a magnetic stirrer, a rectifier, a Dean-Stark trap, and a reflux condenser. 2.0 g (1.2 mol) and 27.1 g (0.32 mol) of cyclohexane were charged and heated to reflux at a tank liquid temperature of 73.8 to 82.6 ° C., and water accumulated in the Dean-Stark trap was drawn out of the system. While performing ketimine synthesis. After 6 hours, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanolmethylethylketimine was 99%.
Transesterification step The Dean-Stark trap is replaced with a normal distillation head (a reflux amount can be adjusted), and cyclohexane and excess methyl ethyl ketone remaining in the kettle are distilled under normal pressure to 26.7 kPa under reduced pressure. I left. 5.58 g of zinc acetylacetone complex, 172 g (1.7 mol) of methyl methacrylate, 0.18 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the remaining kettle solution. 91.6 g of hexane was added. At this time, the water concentration in the reaction raw material liquid was 0.1%. Subsequently, the mixture was heated to reflux at a kettle liquid temperature of 75.8 to 84.7 ° C., and transesterification was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and hexane. As a polymerization preventive measure, a 4% -p-methoxyphenol-methyl methacrylate solution was supplied at a rate of 2 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 10 ml / min. After 8 hours, the reaction solution was analyzed by gas chromatography (GC), and the conversion of 2-aminoethanolmethylethylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl ethyl ketimine based on the charged 2-aminoethanol was 71%.

(Comparative Example 3) Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine formation process Magnetic stirrer, 3-mm rectifier with inner diameter of 25 mmφ filled with a 6 mm-size McMahon packing to a height of 300 mm, a Dean-Stark trap, and a reflux condenser. A flask was charged with 100.0 g (1.6 mol) of 2-aminoethanol and 409.8 g (4.1 mol) of methyl isobutyl ketone, and heated to reflux at a kettle liquid temperature of 76.0 to 99.0 ° C. and a pressure of 33.6 kPa. Then, ketimine synthesis was performed while extracting the water accumulated in the Dean Stark trap outside the system. Two hours later, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%.
Transesterification step The Dean-Stark trap was replaced with a normal distillation head (controllable reflux amount), and the excess methyl isobutyl ketone remaining in the kettle was distilled off under reduced pressure of normal pressure to 4 kPa. . 5.58 g of zinc acetylacetone complex, 409.8 g (4.1 mol) of methyl methacrylate, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the remaining kettle solution. 41 g and 252.9 g of hexane were added. Here, the water concentration in the reaction raw material liquid was 0.1%. Subsequently, the mixture was heated to reflux at a pot liquid temperature of 80.8 to 97.3 ° C., and transesterification was carried out while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and hexane. As a polymerization preventing measure, a 0.1% -p-methoxyphenol-methyl methacrylate solution was added at 2 g / hour from the top of the rectification column, and air was supplied to the kettle at 10 ml / minute. After 5.5 hours, the reaction mixture was analyzed by GC, and the conversion of 2-aminoethanolmethylisobutylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 77%.

(Comparative Example 4) Synthesis of 2-aminoethyl methacrylate methyl ethyl ketimine
Ketimination step 24.9 g (0.41 mol) of 2-aminoethanol, methyl ethyl ketone 88 in a 500-ml three-necked flask equipped with a magnetic stirrer, a rectifier, a Dean-Stark trap, and a reflux condenser. 2.0 g (1.2 mol) and 27.1 g (0.32 mol) of cyclohexane were charged and heated to reflux at a tank liquid temperature of 73.8 to 82.6 ° C., and water accumulated in the Dean-Stark trap was drawn out of the system. While performing ketimine synthesis. After 6 hours, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanolmethylethylketimine was 99%.
Transesterification step The Dean-Stark trap is replaced with a normal distillation head (a reflux amount can be adjusted), and cyclohexane and excess methyl ethyl ketone remaining in the kettle are distilled off under the condition of normal pressure to a reduced pressure of 26.7 kPa. did. 5.58 g of zinc acetylacetone complex, 82.0 g (0.8 mol) of methyl methacrylate, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the remaining kettle solution. 08 g was added. Here, the water concentration in the reaction raw material liquid was 0.1%. Subsequently, the mixture was heated to reflux at a kettle liquid temperature of 99.1 to 117.2 ° C., and transesterification was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and methyl methacrylate. As a polymerization preventing measure, a 4% -p-methoxyphenol-methyl methacrylate solution was added at a rate of 2 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 10 ml / minute. After 4.5 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylethylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl ethyl ketimine based on the charged 2-aminoethanol was 58%.

(Comparative Example 5) Synthesis of 2-aminoethyl methacrylate methyl ethyl ketimine
Ketimination step 24.9 g (0.41 mol) of 2-aminoethanol, methyl ethyl ketone 88 in a 500-ml three-necked flask equipped with a magnetic stirrer, a rectifier, a Dean-Stark trap, and a reflux condenser. 2.0 g (1.2 mol) and 27.1 g (0.32 mol) of cyclohexane were charged and heated to reflux at a tank liquid temperature of 73.8 to 82.6 ° C., and water accumulated in the Dean-Stark trap was drawn out of the system. While performing ketimine synthesis. After 6 hours, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanolmethylethylketimine was 99%.
Transesterification step The Dean-Stark trap is replaced with a normal distillation head (a reflux amount can be adjusted), and cyclohexane and excess methyl ethyl ketone remaining in the kettle are distilled under normal pressure to 26.7 kPa under reduced pressure. I left. 5.58 g of zinc acetylacetone complex, 82.0 g (0.8 mol) of methyl methacrylate, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) were added to the remaining kettle solution. 08 g was added. At this time, the water concentration in the reaction raw material liquid was 0.1%. Subsequently, the mixture was heated and refluxed at a kettle liquid temperature of 83.9 to 99.0 ° C. and a pressure of 62.7 kPa, and a transesterification reaction was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol and methyl methacrylate. As a polymerization preventing measure, a 4% -p-methoxyphenol-methyl methacrylate solution was added at a rate of 2 g / hour from the top of the rectification column, and air was supplied to the kettle at a rate of 10 ml / minute. After 5.5 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylethylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl ethyl ketimine based on the charged 2-aminoethanol was 72%.

(Comparative Example 6) Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimine formation process Magnetic stirrer, 3-mm rectifier with inner diameter of 25 mmφ filled with a 6 mm-size McMahon packing to a height of 300 mm, a Dean-Stark trap, and a reflux condenser. A flask was charged with 100.0 g (1.6 mol) of 2-aminoethanol and 409.8 g (4.1 mol) of methyl isobutyl ketone, and heated to reflux at a kettle liquid temperature of 76.0 to 99.0 ° C. and a pressure of 33.6 kPa. Then, ketimine synthesis was performed while extracting the water accumulated in the Dean Stark trap outside the system. Two hours later, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%. Excess hexane and methyl isobutyl ketone were first distilled off from the obtained reaction solution by vacuum distillation, and then 2-aminoethanol methyl isobutyl ketimine was separated. The yield of 2-aminoethanol methyl isobutyl ketimine was 182.9 (78% recovery).
Transesterification step: Purification by distillation in the above ketimine-forming step in a 1000 ml three-necked flask equipped with a magnetic stirrer, a rectification column, a distillation head (controllable reflux amount), and a reflux condenser. 180 g (1.3 mol) of 2-aminoethanol methyl isobutyl ketimine obtained by the above, 1.76 g of zinc acetylacetone complex, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4H-TEMPO) 0.34 g and 203 g (2.0 mol) of methyl isobutyl ketone were added, and the mixture was refluxed with heating, and methyl isobutyl ketone was distilled off under reduced pressure of normal pressure to 4 kPa. 338.0 g (3.4 mol) of methyl methacrylate was added to the remaining kettle solution. Here, the water concentration in the reaction raw material liquid after adding methyl methacrylate was 300 ppm. Subsequently, the mixture was heated and refluxed at a pressure of 41.7 kPa and a kettle liquid temperature of 82.8 to 94.0 ° C. to carry out transesterification. The by-product methanol was extracted out of the system as an azeotropic mixture of methanol-methyl methacrylate. As a polymerization preventive measure, a 1% -p-methoxyphenol-methyl methacrylate solution was supplied from the top of the rectification column at 0.8 g / hour and air was supplied to the kettle at 8 ml / minute. After 7 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion of 2-aminoethanolmethylisobutylketimine was 99.3%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 72%.

(Comparative Example 7) Synthesis of 2-aminoethyl methacrylate methyl isobutyl ketimine
Ketimination Step 100.0 g (1.6 mol) of 2-aminoethanol and methyl isobutyl were placed in a 1000 ml three-necked flask equipped with a magnetic stirrer, a rectifier, a Dean Stark trap, and a reflux condenser. 409.8 g (4.10 mol) of ketone was charged, the mixture was heated to reflux at a temperature of 76.0 to 98.5 ° C. and a pressure of 33.5 kPa, and ketimine synthesis was performed while extracting water accumulated in the Dean-Stark trap outside the system. went. Two hours later, the reaction mixture was analyzed by gas chromatography. As a result, the conversion of 2-aminoethanol was 100%, and the yield of 2-aminoethanol methyl isobutyl ketimine was 100%.
Transesterification step The Dean-Stark trap is replaced with a normal distillation head (a reflux amount can be adjusted), and 6.48 g of zinc acetylacetone complex and 4-hydroxy-2,2,6,6-tetrahedral solution are added to the kettle solution. 0.41 g of methyl piperidine-1-oxyl (4H-TEMPO) was added, and the mixture was heated to reflux, and excess methyl isobutyl ketone was distilled off under reduced pressure of normal pressure to 4 kPa. 409.7 g (4.10 mol) of methyl methacrylate was added to the remaining kettle solution. Here, the water concentration in the reaction raw material liquid after adding methyl methacrylate was 600 ppm. Subsequently, the mixture was heated and refluxed at a pressure of 42.1 kPa and a kettle liquid temperature of 82.8 to 96.0 ° C., and a transesterification reaction was performed while methanol produced as a by-product was taken out of the system as an azeotropic mixture of methanol-methyl methacrylate. As a polymerization preventing measure, a 1% -p-methoxyphenol-methyl methacrylate solution was supplied from the top of the rectification column at 0.8 g / hour, and air was supplied to the kettle at 10 ml / min. After 7 hours, the reaction solution was analyzed by GC, and the conversion of 2-aminoethanolmethylisobutylketimine was 100%. The yield of 2-aminoethyl methacrylate methyl isobutyl ketimine based on the charged 2-aminoethanol was 83%.

Claims (10)

Steps (A) and (B) shown below
Step (A): reacting 2-aminoethanol with a ketone represented by the following formula (5) or (6) to produce a reaction containing a ketimine compound represented by the following formula (1) or (2) A step of obtaining the product (I),
Step (B): a ketimine compound represented by the following formula (1) or (2) contained in the reaction product (I) obtained in the step (A) and methacrylic acid represented by the following formula (7) Reacting with an ester to synthesize a ketimine compound represented by the following formula (3) or (4):
A method for producing a ketimine compound represented by the following formula (3) or (4) having:
Is supplied to step (B), the reaction product (I), Ri water concentration der less 400ppm of reactant solution containing methacrylic acid ester and a transesterification reaction catalyst is represented by the following formula (7),
The reaction raw material liquid contains a ketone, and the ratio of the ketone to the ketimine compound represented by the formula (1) or (2) in the reaction raw material liquid is 0.6 to 2.0 equivalents in equivalent ratio. A method for producing a ketimine compound represented by the following formula (3) or (4):

(In the formula (1), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (2), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond. )

(In the formula (3), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (4), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond. )

(In the formula (5), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (6), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond. )

(In the formula (7), R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.) The method for producing a ketimine compound according to claim 1, wherein R ¹ in the formula (1) is a methyl group, and R ² is an ethyl group or a 2-methylpropyl group. The method for producing a ketimine compound according to claim 1, wherein R ⁴ in the formula (7) is a methyl group.   4. The process according to claim 1, wherein the step (A) is carried out while extracting water produced by the reaction between 2-aminoethanol and the ketone represented by the formula (5) or (6). 3. The method for producing a ketimine compound according to item 1.   The method according to any one of claims 1 to 4, wherein, in the step (B), the liquid temperatures of the reaction raw material liquid and the reaction liquid are maintained at 110 ° C or lower from the reaction start point to the reaction end point. A method for producing a ketimine compound. The ketimine compound according to any one of claims 1 to 5 , wherein the ketone is the same as the ketone represented by the formula (5) or the formula (6) subjected to the reaction in the step (A). Manufacturing method. The method for producing a ketimine compound according to any one of claims 1 to 6 , wherein the transesterification reaction catalyst is a zinc acetylacetone complex. The method for producing a ketimine compound according to claim 7 , wherein in the reaction of the step (A), the zinc acetylacetone complex is supplied after the reaction conversion of 2-aminoethanol reaches 99%. Steps (A) and (B) shown below
Step (A): reacting 2-aminoethanol with a ketone represented by the following formula (5) or (6) to produce a reaction containing a ketimine compound represented by the following formula (1) or (2) A step of obtaining the product (I),
Step (B): a ketimine compound represented by the following formula (1) or (2) contained in the reaction product (I) obtained in the step (A) and methacrylic acid represented by the following formula (7) Reacting with an ester to synthesize a ketimine compound represented by the following formula (3) or (4):
A method for producing a ketimine compound represented by the following formula (3) or (4) having:
A reaction product (I), a methacrylic acid ester represented by the following formula (7), and a water content in a reaction raw material liquid containing a transesterification catalyst, which are subjected to the step (B), are 400 ppm or less;
The transesterification catalyst is a zinc acetylacetone complex,
Mixing the reaction product (I) obtained in the step (A) with the zinc acetylacetone complex, extracting water contained in the mixture, and then supplying the water to the reaction raw material liquid in the step (B). A method for producing a ketimine compound represented by the following formula (3) or (4):

(In the formula (1), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (2), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.)

(In the formula (3), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (4), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.)

(In the formula (5), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (6), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.)

(In the formula (7), R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.) Steps (A) and (B) shown below
Step (A): reacting 2-aminoethanol with a ketone represented by the following formula (5) or (6) to produce a reaction containing a ketimine compound represented by the following formula (1) or (2) A step of obtaining the product (I),
Step (B): a ketimine compound represented by the following formula (1) or (2) contained in the reaction product (I) obtained in the step (A) and methacrylic acid represented by the following formula (7) Reacting with an ester to synthesize a ketimine compound represented by the following formula (3) or (4):
A method for producing a ketimine compound represented by the following formula (3) or (4) having:
A reaction product (I), a methacrylic acid ester represented by the following formula (7), and a water content in a reaction raw material liquid containing a transesterification catalyst, which are subjected to the step (B), are 400 ppm or less;
The ketimine compound represented by the formula (1) or (2) contained in the reaction product (I) obtained in the step (A) is supplied to the reaction raw material liquid in the step (B) without being separated by distillation. A method for producing a ketimine compound represented by the following formula (3) or (4):

(In the formula (1), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (2), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.)

(In the formula (3), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (4), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.)

(In the formula (5), R ¹ and R ² represent an alkyl group or an aryl group having 1 to 12 carbon atoms.)

(In the formula (6), R ³ is a divalent hydrocarbon group having 3 to 10 carbon atoms, and a part thereof may have a double bond.)

(In the formula (7), R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)