JP2005068077A - Method for producing (meth)acrylic esters - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for industrially, readily and efficiently producing (meth)acrylic esters while hardly forming byproducts. <P>SOLUTION: The method for producing the esters involves carrying out an esterification reaction of (meth)acrylic acid to the unsaturated bond of a cyclic compound having the unsaturated bond in the presence of a triflate of a group 3-13 metal in the periodic table. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing (meth) acrylic acid esters. Specifically, the esterification reaction of (meth) acrylic acid to the unsaturated bond of a cyclic compound having an unsaturated bond is performed in the presence of a metal triflate of Groups 3 to 13 of the periodic table (meth). The present invention relates to a method for producing acrylic acid esters. The (meth) acrylic acid esters obtained by the present invention are useful as fine chemicals such as pharmaceuticals, agricultural chemicals, and photoresist raw materials.

A method of esterifying a bridged cyclic hydrocarbon having an alkylidene group and (meth) acrylic acid in the presence of an acid catalyst is known (for example, see Patent Document 1).
However, when the present inventors performed a similar reaction on a cyclic compound having an internal olefin, oligomerization of acrylic acid itself, various secondary substances such as oligomers and polymers of (meth) acrylic acid ester as a product, etc. It was found that the product was made. In order to use such reaction products as fine chemicals, removal of by-products is important, but there is also a problem of stability of the esters, which are products, and the purification load due to distillation and the like increases. Therefore, a production method with fewer by-products is desired.
JP 2002-284739

  It is an object of the present invention to provide a method capable of producing (meth) acrylic acid esters efficiently by an industrially simple operation and with little production of by-products using a reagent that is easy to industrially use. And

  As a result of intensive studies, the present inventors have made a reaction in the presence of a specific metal triflate when esterifying a cyclic compound having an unsaturated bond with (meth) acrylic acid. It has been found that high-purity ester products can be obtained by suppressing side reactions such as oligomerization and polymerization of product esters, and the present invention has been completed. That is, the gist of the present invention is characterized in that the esterification reaction of (meth) acrylic acid to an unsaturated bond of a cyclic compound having an unsaturated bond is performed in the presence of a metal triflate of Groups 3 to 13 of the periodic table. It exists in the manufacturing method of ester to do.

  According to the present invention, (meth) acrylic acid esters can be produced efficiently and with little production of by-products by industrially simple operation using a reagent that is easy to use industrially.

Hereinafter, the present invention will be described in detail.
(Cyclic compound having an unsaturated bond)
The cyclic compound having an unsaturated bond in the present invention is a cyclic compound having an internal olefin, and the number of internal olefins in the compound is arbitrary depending on the purpose, but is usually 1 to 3, preferably 1. It is a piece.

Examples of the ring type of the cyclic compound having an unsaturated bond include unsaturated aliphatic monocyclic hydrocarbons such as cyclopentene and cyclohexene; unsaturated aliphatic condensed cyclic hydrocarbons such as norbornene; or cyclic condensed aromatic rings Examples include hydrocarbons.
These rings may optionally have a substituent within a range that does not adversely affect the esterification reaction, and specifically, an optionally substituted alkyl group or an optionally substituted aryl group. Examples of the substituent for the alkyl group and aryl group include a halogen atom, an alkyl group, and an aryl group. In addition, it may be a substituent having a polar group such as an ether group, an ester group, a ketone group, or a lactone group, but the polar substituent is bonded to a position away from the olefin to be esterified. Is preferred.

  Preferable specific examples of the cyclic compound having an unsaturated bond include those having a structure represented by the following general formula (1).

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, an optionally substituted alkyl group or an optionally substituted aryl group, each being the same; And R ¹ and R ² and / or R ³ and R ⁴ may be bonded to each other to form a ring)
Examples of the optionally substituted alkyl group and the optionally substituted aryl group include a substituent selected from the group consisting of a halogen atom, an alkyl group, and an aryl group, or an ether group, an ester group, a ketone group, and a lactone. Examples thereof include those having 20 or less carbon atoms which may be optionally substituted with a substituent having a polar group such as a group, preferably an alkyl group, an aralkyl group, an aryl group or an arylalkyl group, and more Preferably, an alkyl group having 1 to 6 carbon atoms such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-butyl group, i-butyl group, t-butyl group; benzyl group Aralkyl groups having 10 or less carbon atoms such as 2-phenylethyl group; phenyl or naphthyl groups; alkyl having 12 or less carbon atoms such as tolyl group and xylyl group And an aryl group.

R ^{1 to} R ⁴ are particularly preferably a hydrogen atom or an alkyl group, and most preferably R ¹
This is the case when all of R ⁴ are hydrogen atoms.
Here, when the cyclic compound having an unsaturated bond has a bridged condensed ring structure, there are exo and endo stereoisomers, but this reaction can be applied to either stereo. is there.

(Metal triflate)
The metal triflate used in the method of the present invention is a metal triflate of Groups 3 to 13 of the periodic table. A triflate of a metal of Group 3, 4, 11 or 13 of the periodic table is preferable, and a triflate of aluminum, scandium, copper, silver, a lanthanoid, zirconium or hafnium is more preferable. These triflates may be those added with aromatic hydrocarbons such as benzene and toluene.

The amount of metal triflate used is usually 0.0005 times mol or more, preferably 0.001 with respect to the number of moles in terms of unsaturated bonds to be esterified of the cyclic compound having an unsaturated bond.
It is used in a range of more than double mole. On the other hand, if the amount of the metal triflate used is too large, a problem arises in terms of catalyst removal, etc., so usually the amount is less than equimolar amount, preferably 0.5 times or less, more preferably 0.2 times. It is used in the range of not more than mol, more preferably not more than 0.1 times mol.

((Meth) acrylic acid)
In the present invention, the amount of (meth) acrylic acid used is not particularly limited, and is usually 0.8 times mol or more, preferably equimolar amount or more, more preferably 2 times mol or more. You can also However, these are unstable compounds, and impurities may be mixed in during storage due to oligomerization or polymerization. Therefore, it is preferable to keep the necessary minimum amount. That is, it is used in a range of usually 20 times mole or less, preferably 10 times mole or less, more preferably 6 times mole or less relative to the number of moles of the cyclic compound having an unsaturated bond.

(solvent)
In the present invention, there is no particular limitation as long as it does not adversely affect the action of the metal triflate. Specifically, in addition to acrylic acid and methacrylic acid, which are also reaction reagents, aliphatic hydrocarbons such as hexane, heptane, and octane; aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; chlorobenzene, fluorobenzene, and the like Halogenated aromatic hydrocarbons; aromatic hydrocarbons having nitrogen-containing substituents such as nitrobenzene and benzonitrile; diethyl ether, dipropyl ether, dibutyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diglyme, Ethers such as triglyme and tetraglyme; esters such as ethyl acetate and butyl acetate; lactones such as γ-butyrolactone and δ-valerolactone; halogenated aliphatic hydrocarbons such as dichloromethane, chloroform and 1,2-dichloroethane Etc. are illustrated That.

The amount of the solvent used in the present invention is not particularly limited and is arbitrary, but is generally 0.01 times or more, preferably 0.1 times or more, and 1000 times or less, by weight based on the cyclic compound having an unsaturated bond, Preferably it is 500 times or less.
(Reaction method)
There is no restriction | limiting in particular in the reaction method in this invention. There are no particular restrictions on the method and sequence for adding the reagent, and it can be added in any method and sequence. The reaction is started when the inside of the reactor reaches a predetermined temperature. Among these, as a specific preferable reaction mode, for example, a cyclic compound having an unsaturated bond, a metal triflate, (meth) acrylic acid, and a solvent as required are charged in a batch reactor, and the reaction is preferably carried out with stirring. The

Further, if necessary, other additives such as an additive for suppressing polymerization of (meth) acrylic acid can coexist in any amount. Examples of the additive include polymerization inhibitors such as hydroquinone, 4-methoxyphenol, and 2,6-di-t-butyl-4-methylphenol.
The reaction temperature is usually 0 ° C. or higher, preferably 20 ° C. or higher, more preferably 40 ° C. or higher. The reaction temperature may be increased stepwise. Moreover, as an upper limit of reaction temperature, it is 200 degrees C or less normally, Preferably it is 150 degrees C or less.

While the reaction time depends on the reaction scale and temperature, etc., it is usually carried out for 0.01 hour or longer, preferably 0.1 hour or longer, and the reaction is usually completed within 48 hours, preferably within 24 hours.
(Esterification product)
The product can be confirmed by analyzing the reaction solution by gas chromatography, size exclusion chromatography or the like, if necessary.

  When the cyclic compound having an unsaturated bond is a compound represented by the above general formula (I), the esterification product obtained by this reaction is represented by the following general formulas (II) and (II ′).

Wherein R ¹ , R ² , R ³ and R ⁴ are the same as those in the general formula (I), and R is a hydrogen atom or a methyl group, and It becomes a mixture of plural isomers such as endo / exo isomer by bridged condensed ring structure and endo / exo isomer of ester group substitution site, but these can be used as they are, or they can be used in column chromatography. It can also be used for the intended purpose after being separated by a conventional method such as extraction or extraction.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to the following Example.
Example 1
Into a 50 mL flask equipped with a Dimroth condenser and a thermometer, 5.00 g (33.3 mmol) of exo-3-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-8-ene was added.
), 9.60 g (133.3 mmol) of acrylic acid, 0.158 g (0.333 mmol) of aluminum trifluoromethanesulfonate (aluminum triflate), 5 mg of p-methoxyphenol and 9 mL of toluene as a polymerization inhibitor. The temperature was raised to 100 ° C. with an oil bath, and the mixture was stirred at the same temperature for 5.5 hours. A solution obtained by diluting 40 mL of toluene to the reaction solution cooled to room temperature while stirring was gradually added to 100 mL of a saturated aqueous solution of sodium bicarbonate at room temperature. After confirming that the pH of the aqueous layer was 8 or more, the precipitated white precipitate was filtered off, and the resulting two-layer solution was separated. The organic layer was washed once with 50 mL of a saturated aqueous sodium hydrogen carbonate solution and twice with 50 mL of water, and then dried over anhydrous magnesium sulfate. The desiccant was filtered off and concentrated to obtain 7.27 g of a pale yellow oil. As a result of quantification by an internal standard method (internal standard substance n-docosane) using a gas chromatograph, the target ester was 3-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ] decane. An endo / exo isomer mixture of -8-yl acrylate and 5-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-8-yl acrylate is obtained in 88% yield. It was confirmed. Moreover, in the product analysis by size exclusion chromatography (SEC), the target ester body was 92.2 area%.

Example 2
In Example 1, instead of 0.158 g (0.333 mmol) of aluminum trifluoromethanesulfonate (aluminum triflate), 0.604 g (1.67 mmol) of copper (II) trifluoromethanesulfonate (copper (II) triflate) was used. The same operation and analysis as in Example 1 were performed except that the reaction time was 4 hours. As a result, the yield of the target ester in GC analysis was 86.2%. Moreover, in the product analysis by size exclusion chromatography (SEC), the target ester body was 87.5 area%.

Example 3
In Example 1, instead of 0.158 g (0.333 mmol) of aluminum trifluoromethanesulfonate (aluminum triflate), 1.639 g (3.33 mmol) of scandium trifluoromethanesulfonate (scandium triflate) was used, and the reaction time was 4 hours. The same operations and analysis as in Example 1 were conducted except that As a result, the yield of the target ester in GC analysis was 83.9%. Moreover, in the product analysis by size exclusion chromatography (SEC), the target ester body was 83.6 area%.

Example 4
In Example 1, instead of 9.60 g (133.3 mmol) of acrylic acid, 11.47 g (133.3 mmol) of methacrylic acid was used, and the addition amount of aluminum trifluoromethanesulfonate (aluminum triflate) was 0.039 g (0.003 g). 083 mmol), the reaction temperature was 110 ° C., the reaction time was 4 hours, and the same operation and analysis as in Example 1 were performed except that the reaction was performed without using a solvent. As a result, the yield of the target ester in GC analysis was 89%. Moreover, in the product analysis by size exclusion chromatography (SEC), the target ester body was 95.3 area%.

Example 5
In Example 1, exo-3-oxo-4-oxatricyclo [5.2.1.0 ^2,6
] Instead of 5.00 g (33.3 mmol) of decan-8-ene 5.00 g (33 of endo-3-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-8-ene .3mm
ol), instead of 9.60 g (133.3 mmol) of acrylic acid, 11.47 g (133.3 mmol) of methacrylic acid, 9 mL of chlorobenzene instead of 9 mL of toluene, a reaction temperature of 125 ° C., and a reaction time of 4.5 hours The same operations and analysis as in Example 1 were conducted except that As a result, the yield of the target ester in GC analysis was 91.9%. Moreover, in the product analysis by size exclusion chromatography (SEC), the target ester body was 97.4 area%.

Comparative Example 1
Into a 50 mL flask equipped with a Dimroth condenser and a thermometer, 5.00 g (33.3 mmol) of exo-3-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-8-ene was added.
), 1.375 g (13.3 mmol) of 95% concentrated sulfuric acid, 9.60 g (133.3 mmol) of acrylic acid, 5 mg of p-methoxyphenol and 9 mL of toluene as a polymerization inhibitor. The temperature was raised to 100 ° C. with an oil bath, and the mixture was stirred at the same temperature for 4 hours. A solution obtained by diluting 40 mL of toluene to the reaction solution cooled to room temperature while stirring was gradually added to 100 mL of a saturated aqueous solution of sodium bicarbonate at room temperature. After confirming that the pH of the aqueous layer was 8 or more, the precipitated white precipitate was filtered off, and the resulting two-layer solution was separated. The organic layer was washed once with 50 mL of a saturated aqueous sodium hydrogen carbonate solution and twice with 50 mL of water, and then dried over anhydrous magnesium sulfate. The desiccant was filtered off and concentrated to obtain 7.38 g of pale yellow oil. When analysis similar to Example 1 was conducted, the yield of the target ester body by GC analysis was 61.2%. Moreover, in the product analysis by size exclusion chromatography (SEC), the target ester body was 70.5 area%, and 29.5 area% of other high molecular weight by-products of unknown structure were detected.

Comparative Example 2
In Example 1, it replaces with 0.158 g (0.333 mmol) of aluminum trifluoromethanesulfonate (aluminum triflate), and is the same as Example 1 except for using 1.950 g (13.7 mmol) of boron trifluoride diethyl ether complex. When the reaction was started by the above operation, the precipitation of cream-insoluble matter was observed after 3 hours, and after 4 hours it became a large lump and could not be stirred. When the remaining liquid layer was analyzed by gas chromatograph in the same manner as in Example 1, the production of the target ester was confirmed, but the production amount was very small.

Comparative Example 3
In Example 1, instead of 0.158 g (0.333 mmol) of aluminum trifluoromethanesulfonate (aluminum triflate), 0.519 g (3.33 mmol) of lithium trifluoromethanesulfonate (lithium triflate)) was used. When the reaction was started in the same manner as in No. 1, the entire reactor was solidified at 1 hour later and became impossible to stir. When the liquid layer part which remained very little was analyzed by the gas chromatograph similarly to Example 1, the target ester body was not detected.

Comparative Example 4
In Example 1, instead of 0.158 g (0.333 mmol) of aluminum trifluoromethanesulfonate (aluminum triflate), 1.074 g (3.33 mmol) of magnesium trifluoromethanesulfonate (magnesium triflate)) was used. The target ester was not detected and the reaction substrate was exo-3-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ].
Only decan-8-ene was confirmed.

Comparative Example 5
In Example 1, instead of 0.158 g (0.333 mmol) of aluminum trifluoromethanesulfonate (aluminum triflate), Example 1 except that 0.740 g (3.33 mmol) of trimethylsilyl trifluoromethanesulfonate (trimethylsilyl triflate) was used. When the reaction was started in the same manner as in Example 1, the entire reactor solidified at 1 hour later, and stirring became impossible. When the liquid layer part which remained very little was analyzed by the gas chromatograph similarly to Example 1, the target ester body was not detected.

Claims (4)

Esterification reaction of (meth) acrylic acid to the unsaturated bond of a cyclic compound having an unsaturated bond is carried out in the presence of a metal triflate of Groups 3 to 13 of the periodic table. . 2. The production method according to claim 1, wherein the cyclic compound having an unsaturated bond is a norbornene derivative. The cyclic compound having an unsaturated bond is represented by the following general formula (I)

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, an optionally substituted alkyl group or an optionally substituted aryl group, each being the same; And R ¹ and R ² , and / or R ³ and R ⁴ may be bonded to each other to form a ring). The manufacturing method of Claim 1 or 2. 4. The method according to claim 1, wherein the metal triflate is a metal triflate belonging to Group 3, 4, 11 or 13 of the periodic table.