JP2005097293A - Organotin silane compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an organotin silane compound useful as a raw material for transesterification catalysts, provide a method for producing the organotin silane compound in high yield and high selectivity, and provide a method for producing a carboxylic acid ester by catalyst-reusable transesterification in which tin is hardly dissolved in the reaction solution and the catalyst is easily separated. <P>SOLUTION: The organic tin silane compound is expressed by formula (1). In formula (1) R<SP>1</SP>independently expresses a 1-10C alkyl, a 5-10C cycloalkyl, an aryl, F, Cl, Br, I or a 1-10C alkoxy; R<SP>2</SP>independently expresses F, Cl, Br, I or a 1-10C alkoxy; R<SP>3</SP>expresses a 1-10C alkylene, R<SP>3</SP>can bind with an arbitrary carbon of 2-6 positions in the benzene ring. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organotin silane compound and a method for producing the same, a silica gel-supported organotin compound and a method for producing the same, and a method for producing a carboxylic acid ester using the silica gel-supported organotin compound as a catalyst.

Patent Document 1 describes a general formula including many compounds as an organotin silane compound. In addition, a solid supported organotin silane, which is a reaction product of the organotin silane compound and a silica gel or other solid support with a hydroxyl group on the surface of the support, and the supported organotin silane is used as a catalyst for the transesterification reaction. It also describes what you can do.
JP 11-255782 A

  An object of this invention is to provide the organotin silane compound useful as a raw material of the catalyst for transesterification, and the method of manufacturing the organotin silane compound with a high yield and a high selectivity. In addition, high yields of silica gel-supported organotin compounds and silica gel-supported organotin compounds that can be used as catalysts for transesterification reactions, which have the advantages of low elution of tin into the reaction solution, easy separation from the reaction solution, and reusability. It aims at providing the method of manufacturing with high rate and high selectivity. Another object of the present invention is to provide a method for producing a carboxylic acid ester by a transesterification reaction in which the elution of tin into the reaction solution is small, the catalyst can be easily separated, and the catalyst can be reused.

  The present invention is an organotin silane compound represented by any one of formula (1), formula (2), formula (3) or formula (4).

（Ｒ^１は、それぞれ独立に、炭素数１〜１０のアルキル基、炭素数５〜１０のシクロアルキル基、アリール基、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^３は炭素数１〜１０のアルキレン基を表す。Ｒ^３はベンゼン環の２〜６位の任意の炭素と結合できる。）

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms, R ³ represents an alkylene group having 1 to 10 carbon atoms, and R ³ represents 2 of the benzene ring. It can be bonded to any carbon at the 6th position.)

（Ｒ^１は、それぞれ独立に、炭素数１〜１０のアルキル基、炭素数５〜１０のシクロアルキル基、アリール基、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。ケイ素はベンゼン環の２〜６位の任意の炭素と結合できる。）

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms, and silicon can be bonded to any carbon at positions 2 to 6 of the benzene ring.

（Ｒ^１は、それぞれ独立に、炭素数１〜１０のアルキル基、炭素数５〜１０のシクロアルキル基、アリール基、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^４は炭素数１〜１０のアルキレン基を表す。Ｒ^５は水素またはメチル基を表す。）

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² represents each independently fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms, R ⁴ represents an alkylene group having 1 to 10 carbon atoms, R ⁵ represents hydrogen or a methyl group Represents.)

（Ｒ^１は、それぞれ独立に、炭素数１〜１０のアルキル基、炭素数５〜１０のシクロアルキル基、アリール基、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。）

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms.)

  The second of the present invention is an organotin compound represented by formula (5) and at least one silane coupling agent selected from the group of silane coupling agents represented by formulas (6) to (9). It is a manufacturing method of the organotin silane compound of said Formula (1)-(4) reaction.

（Ｒ^６はそれぞれ独立に、水素、炭素数１〜１０のアルキル基、炭素数５〜１０のシクロアルキルまたはアリール基、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基から選択され、少なくともひとつのＲ^６は水素である。）

(R ⁶ is independently selected from hydrogen, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or aryl group having 5 to 10 carbon atoms, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. And at least one R ⁶ is hydrogen.)

（Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^３は炭素数１〜１０のアルキレン基を表す。Ｒ^３はベンゼン環の２〜６位の任意の炭素と結合できる。）

(R ² independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ³ represents an alkylene group having 1 to 10 carbon atoms. R ³ represents 2 of the benzene ring. It can be bonded to any carbon at the 6th position.)

（Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。ケイ素はベンゼン環の２〜６位の任意の炭素と結合できる。）

(R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. Silicon can be bonded to any carbon at positions 2 to 6 of the benzene ring.)

（Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。Ｒ^４は炭素数１〜１０のアルキレン基を表す。Ｒ^５は水素またはメチル基を表す。）

(R ² independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ⁴ represents an alkylene group having 1 to 10 carbon atoms. R ⁵ represents hydrogen or a methyl group. Represents.)

（Ｒ^２は、それぞれ独立に、フッ素、塩素、臭素、ヨウ素、または炭素数１〜１０のアルコキシ基を表す。）

(R ² represents each independently fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms.)

  According to a third aspect of the present invention, silicon (Si) of the organotin silane compounds of the formulas (1) to (4) is covalently bonded (Si—O—Si ′) through silicon (Si ′) and oxygen on the surface of the silica gel. Is an organotin compound supported on silica gel.

  4th of this invention is at least 1 sort (s) of silane coupling agent chosen from the group of the tin compound represented by said Formula (5), and the silane coupling agent represented by said Formula (6)-(9). And the obtained organotin silane compound of the formulas (1) to (4) and silica gel are reacted with each other.

A fifth aspect of the present invention is a silica gel-supported organotin compound obtained by reacting the organotin silane compound of the above formulas (1) to (4) with water or a mixed solvent containing water and alcohol, and supporting the product on silica gel. It is.
A sixth method of the present invention is a method for producing a carboxylic acid ester by a transesterification reaction between a carboxylic acid ester and an alcohol, wherein the third silica gel-supported organotin compound of the present invention is used as a catalyst. It is.

  The organotin silane compound of the present invention can be used as a raw material for a transesterification catalyst. Moreover, according to the manufacturing method of the organotin silane compound of this invention, an organotin silane compound can be manufactured with a high yield and a high selectivity.

  The silica gel-supported organotin compound of the present invention can be used as a catalyst for transesterification. Moreover, according to the method for producing a silica gel-supported organotin compound of the present invention, the silica gel-supported organotin compound can be produced with a high yield and a high selectivity.

  According to the method for producing a carboxylic acid ester of the present invention, the elution of tin into the reaction solution is small, the catalyst can be easily separated, and the catalyst can be reused.

  The organotin silane compound of the present invention is a compound represented by any one of the formulas (1) to (4).

In Formula (1), each R ¹ independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or 1 to 1 carbon atoms. 10 alkoxy groups are represented. When R ¹ is an alkyl group, the number of carbon atoms is preferably 1 to 5, but R ¹ is more preferably fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. From the viewpoint of reactivity, R ² is preferably an alkoxy group having 1 to 5 carbon atoms. R ³ represents an alkylene group having 1 to 10 carbon atoms. Among these, R ³ is preferably methylene or ethylene. R ³ can be bonded to any carbon at the 2-6 positions of the benzene ring. Specific examples of the preferred compound represented by the formula (1) include 4- (2-tributyltin ethyl) benzyltriethoxysilane and 3- (2-tributyltin ethyl) benzyltrimethoxysilane.

In the formula (2), R ¹ and R ² are the same as those in the formula (1). The silicon of the formula (2) can be bonded to any carbon at the 2-6 positions of the benzene ring. Specifically, preferred compounds represented by the formula (2) include 4- (2-tributyltin ethyl) phenyltrimethoxysilane, 4- (2-tributyltinethyl) phenyltriethoxysilane, and 3- (2-tributyltin). Ethyl) phenyltrimethoxysilane.

In the formula (3), R ¹ and R ² are the same as those in the formula (1). R ⁴ represents an alkylene group having 1 to 10 carbon atoms. Of these, R ⁴ is preferably ethylene or propylene. R ⁵ represents hydrogen or a methyl group. R ⁵ is preferably hydrogen because it is not necessary to use a radical initiator in the hydrostannation reaction. As a preferable compound represented by the formula (3), specifically, all of R ^{1 in} the formula (3) are butyl groups (—C ₄ H ₉ ) and all R ² are methoxy groups (—OCH). ₃ ), a compound in which R ⁴ is a propylene chain (—C ₃ H ₆ —), R ⁵ is a methyl group (—CH ₃ ), and all R ^{1 in} formula (3) are butyl groups (—C ₄ H ₉ ) , R ² is a methoxy group (—OCH ₃ ), R ⁴ is a propylene chain (—C ₃ H ₆ —), and R ⁵ is hydrogen (—H).

In the formula (4), R ¹ and R ² are the same as in the formula (1). Specific examples of the preferred compound represented by the formula (4) include 2-tributyltin ethyltrimethoxysilane and 2-trimethoxytin ethyltrimethoxysilane.

The organotin silane compound represented by any one of the formulas (1) to (4) includes, for example, a tin compound represented by the formula (5) and a silane represented by the formulas (6) to (9). It can be produced by reacting with at least one silane coupling agent selected from the group of coupling agents. Examples of such a reaction include a hydrostannation reaction between a trialkyltin hydride and the silane coupling agent, or adding hydrochloric acid to Sn or SnCl ₂ to form a carbon-carbon double bond (C = C) and the like.

  Specific examples of the hydrostannation reaction include a reaction between 4-vinylphenyltrimethoxysilane and tributyltin hydride using a radical generator. Examples of radical generators that can be used include 2,2'-azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvaleronitrile). In the hydrostannation reaction, in order to prevent radical deactivation by oxygen, it is preferable to replace oxygen in the reaction system with an inert gas. Examples of the inert gas include nitrogen and argon. The reaction temperature is preferably 0 to 150 ° C., and more preferably 20 to 100 ° C. from the viewpoint of promoting the reaction and suppressing side reactions. The reaction may be solventless or a solvent may be added. As the reaction solvent, n-pentane, n-hexane and n-heptane are preferable.

  The organotin silane compound represented by any one of the formulas (1) to (4) itself has a catalytic activity for the transesterification reaction, but a silica gel-supported organotin compound (supported catalyst) supported and immobilized on silica gel is also used. Similarly, it has catalytic activity. The supported catalyst is preferable as a catalyst for transesterification that is repeatedly used because the catalyst can be easily separated after the reaction.

The method of supporting the organotin silane compound on silica gel is not particularly limited, and examples thereof include a method of heating the organotin silane compound and silica gel in a solvent. Examples of the solvent include toluene, xylene, n-hexane, n-heptane, ethyl acetate, 2-butanone and the like. The heating temperature is preferably 0 to 200 ° C, and more preferably 20 to 150 ° C from the viewpoint of promoting the reaction and suppressing side reactions. The silica gel is not particularly limited, but it is preferable to use a silica gel produced for a catalyst carrier having a relatively high strength in order to suppress pulverization when used in the transesterification reaction.
Surprisingly, the silica gel-supported organotin compound obtained by hydrolyzing and dehydrating and condensing the organotin silane compounds of formulas (1) to (4) onto silica gel does not undergo a reaction with water. Compared with the catalyst synthesized in step 1, the catalytic activity of the transesterification reaction is increased several times. The reason is estimated as follows.
Silane compounds such as the organotin silane compound and the silane coupling agent are hydrolyzed to silanol (Si—OH) compounds when reacted with water. Silanol groups are unstable, and partially dehydrated and condensed with time to form siloxane bonds (—O—Si—O—) to become oligomers. For this reason, it is speculated that tin atoms exist close to each other, and the interaction between tin atoms brings about an increase in activity.
In the hydrolysis reaction, the concentration of the aqueous solution of the silane compound is preferably 0.1 to 2 wt%, and the hydrolysis is usually completed by stirring for 30 to 60 minutes at room temperature. If hydrolysis is performed in a weakly acidic region using acetic acid or the like, the hydrolysis rate is accelerated.
When the organotin silane compounds of the above formulas (1) to (4) are reacted with water, water may be added directly, or a mixed solvent obtained by mixing water-soluble organic solvent such as alcohol and water may be added. Although many of the organotin silane compounds are not water-soluble, the use of alcohols such as methanol, ethanol, propanol, and isopropanol increases solubility and allows the reaction to proceed rapidly. Of these, ethanol and isopropanol are more preferable. The ratio of alcohol is preferably 10 to 70 wt%, more preferably 20 to 40 wt%, based on the entire aqueous solution. The ratio of water to be reacted is preferably 10 to 30 times (weight ratio) with respect to the organotin silane compound.
The pH of the water to be reacted is preferably an acidic region (pH ≦ 7), more preferably a weakly acidic region (pH = 3 to 5). Although the reaction with water may be carried out at room temperature, it is preferable to heat to 60 ° C. or higher, and more preferable to heat to 70 ° C. or higher because the reaction rate with water increases. The reaction time with water is generally preferably 1 to 60 hours, more preferably 3 to 24 hours.

In the thus prepared silica-supported organotin compound, silica (Si) in the organotin silane compounds of the formulas (1) to (4) is replaced with at least one of R ² , and the surface of the silica gel via oxygen. The silicon (Si ′) and the covalent bond (Si—O—Si ′) are formed. Formula (10) represents a silica gel-supported organotin compound in which silicon of the organotin silane compound of formula (4) is bonded to silicon on the surface of the silica gel through two covalent bonds via oxygen.

  A series of operations from the synthesis of the organotin silane compound to the production of the silica gel-supported organotin compound can be performed in a separate reactor for each stage, but from the viewpoint of improving the yield of the organotin silane compound on the silica gel carrier, It is preferable to carry out in one reactor.

In a reaction in which a tin compound and a silane coupling agent are reacted to synthesize an organotin silane compound, a tin compound in which R ¹ is an alkyl group having 1 to 10 carbon atoms and a silane coupling agent are used in order to suppress side reactions. It is preferable to react. In order to increase the catalytic activity, the alkyl group is preferably substituted with a halogen or an alkoxy group after the reaction, and more preferably substituted with an alkoxy group. Examples of a method for substituting a tin substituent from an alkyl group to a halogen include a method of reacting tin halide and a method of directly reacting with a halogen molecule. When the organotin compound is reacted with water or a mixed solvent containing water and alcohol (Step A), and then the product is supported on silica gel (Step B) to obtain a silica gel-supported organotin compound, tin halide and halogen Since many substituted organotin compounds are unstable to water, it is preferable to act on the tin halide after the step A, and to act after the steps A and B in terms of ease of handling. Is more preferable. Examples of the method for substituting the tin substituent from an alkyl group to an alkoxy group include a method of reacting an alkali metal alkoxide after halogenation.

  As described above, the silica gel-supported organotin compound of the present invention thus produced is effective as a catalyst for producing a carboxylic acid ester by a transesterification reaction between the carboxylic acid ester and an alcohol. In particular, this catalyst is preferred for the transesterification reaction of (meth) acrylic acid ester and alcohol.

  The conditions for the transesterification reaction may be appropriately selected depending on the type of the reaction substrate and the like, and are not particularly limited. From the balance of productivity, 1-10 times mole is more preferable. The amount of silica gel-supported organotin compound used as a catalyst is preferably 0.1 to 100% by mass of the raw material alcohol, and preferably 0.5 to 50% by mass in view of cost and reactivity. The reaction temperature is preferably 0 to 150 ° C., and the higher the temperature, the faster the reaction rate, and the lower the temperature, the side reaction can be suppressed.

  When the raw material carboxylic acid ester of the transesterification reaction is a polymerizable compound such as (meth) acrylic acid ester, it is preferable to use a polymerization inhibitor during the reaction. The polymerization inhibitor may be used alone or in combination of two or more. Examples of the polymerization inhibitor include phenolic compounds such as hydroquinone and paramethoxyphenol, N, N′-diisopropylparaphenylenediamine, N, N′-di-2-naphthylparaphenylenediamine, and N-phenyl-N′-. Amine compounds such as (1,3-dimethylbutyl) paraphenylenediamine and phenothiazine, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzoyloxy-2,2,6 Examples include N-oxyl compounds such as 6-tetramethylpiperidine-N-oxyl, and N-oxyl compounds exemplified by the following formula (11).

（式中、ｎ＝１〜１８であり、Ｒ^７＝Ｒ^８＝Ｈ、もしくは、Ｒ^７、Ｒ^８の一方が水素原子であり、他方がメチル基である。また、Ｒ^９、Ｒ^１０、Ｒ^１１、Ｒ^１２は直鎖状あるいは分岐状のアルキル基である。さらに、Ｒ^１３＝Ｈ又は（メタ）アクリロイル基である。）

(In the formula, n = 1 to 18, R ⁷ = R ⁸ = H, or one of R ⁷ and R ⁸ is a hydrogen atom and the other is a methyl group. Also, R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are linear or branched alkyl groups, and R ¹³ = H or a (meth) acryloyl group.

  The transesterification reaction is preferably carried out by distilling by-product alcohol by distillation and shifting the equilibrium.

  The reaction apparatus for performing the transesterification reaction may be a continuous apparatus such as a fluidized bed or a fixed bed, or a batch apparatus. In the case of a batch apparatus, the supported catalyst after the transesterification reaction can be easily separated from the product ester by filtration. When the reaction is carried out in a batch apparatus, the catalyst can be filtered off from the reaction end solution, and the recovered catalyst can be transesterified again to produce a carboxylic acid ester. Further, when the reaction is carried out in a column (fixed bed) packed with a catalyst, a carboxylic acid ester can be produced by supplying a reaction raw material and continuously performing a transesterification reaction.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. In the examples, the purity of the organotin silane compound and the raw materials and products of the transesterification reaction were determined by gas chromatography (hereinafter referred to as GC) analysis, and the tin element contained in the silica gel-supported organotin compound was determined by ICP emission analysis. Quantitative determination of elemental chlorine contained in silica gel-supported organotin compound was performed by ion chromatography analysis, determination of tin element in the transesterification reaction completed liquid was performed by atomic absorption analysis, and organotinsilane compound was confirmed by ¹ H-NMR. , ¹³ C-NMR analysis.

The conversion rate of the raw alcohol was calculated by the following formula.
Conversion rate of raw alcohol (%) = B / (A + B) × 100
Here, A is the number of moles of the raw material alcohol, and B is the number of moles of the produced ester.
The purity was calculated as an area percentage of GC.

[Example 1] Reaction of introducing tin into styrene-based silane coupling agent 100 ml of 5.39 g of 4-vinylphenyltrimethoxysilane, 7.0 g of tributyltin hydride, 0.01 g of 2,2'-azobisisobutyronitrile After putting into a three-necked flask and bubbling with nitrogen gas for 15 minutes, when heated at 80 ° C. for 8 hours, hydrostannation proceeds, and 12.97 g of 4- (2-tributyltinethyl) phenyltrimethoxysilane having a purity of 95.0% was obtained. Obtained.

[Example 2] Reaction of introducing tin into a methacrylate silane coupling agent 5.96 g of 3-methacryloxypropyltrimethoxysilane, 7.0 g of tributyltin hydride, 0.01 g of 2,2'-azobisisobutyronitrile. After putting into a 100 ml three-necked flask and bubbling with nitrogen gas for 15 minutes, when heated at 60 ° C. for 10 hours, hydrostannation proceeds, and all R ¹ of formula (3) having a purity of 86.8% is a butyl group (—C ₄ H ₉ ), a compound in which all R ² are methoxy groups (—OCH ₃ ), R ⁴ is a propylene chain (—C ₃ H ₆ —), and R ⁵ is a methyl group (—CH ₃ ) was obtained.

[Example 3] Introduction reaction of tin into acrylate-based silane coupling agent When 3-acryloxypropyltrimethoxysilane (5.63 g) and tributyltin hydride (7.0 g) are placed in a 100 ml three-necked flask and heated at 60 ° C for 10 hours. As the hydrolysis proceeds, all of R ^{1 in} formula (3) having a purity of 87.2% are butyl groups (—C ₄ H ₉ ), all R ² are methoxy groups (—OCH ₃ ), and R ⁴ is a propylene chain ( A compound in which —C ₃ H ₆ —) and R ⁵ are hydrogen (—H) was obtained.

[Example 4] Reaction of introducing tin into vinyl-based silane coupling agent 3.5 ml of vinyltrimethoxysilane, 7.0 g of tributyltin hydride, and 0.01 ml of 2,2'-azobisisobutyronitrile in 100 ml After putting into a flask and bubbling with nitrogen gas for 15 minutes, when heated at 80 ° C. for 30 hours, hydrostannation progressed, and 2-tributyltin ethyltrimethoxysilane having a purity of 88.5% was obtained.

[Example 5] Redistribution reaction and silane coupling reaction of substituents on tin of 4- (2-tributyltinethyl) phenyltrimethoxysilane (organotin silane compound obtained in Example 1) using tin tetrachloride 1000 ml After setting the dropping funnel in the four-necked flask and replacing with nitrogen, 12.97 g of 4- (2-tributyltinethyl) phenyltrimethoxysilane obtained in Example 1 was put in the four-necked flask, and the dropping funnel was filled with four. 9 ml of tin chloride was added. When the four-necked flask was immersed in an ice bath and tin tetrachloride was slowly added dropwise with stirring, the reaction solution changed from colorless and transparent to a pale yellow turbid solution. After completion of the dropwise addition, the reaction solution changed from pale yellow to dark brown when heated at 70 ° C. for 4 hours. After returning the reaction solution to room temperature, 400 ml of toluene and 100 g of silica gel were added, and the mixture was heated to reflux for 20 hours. Then, the reaction liquid was returned to room temperature and the solid substance was separated by suction filtration. The obtained solid was washed with toluene and vacuum dried at 100 ° C. overnight to obtain 107.74 g of a white solid. Elemental analysis of the solid (silica gel-supported tin compound) revealed tin of 4.8 wt% and chlorine of 1.7 wt%.

[Example 6] Sn-OCH ₃ of Sn-Cl bond of silica gel supported tin compound obtained in Example 5 107.74 g of silica gel supported tin compound obtained in Example 5 in a 1000 ml four-necked flask, 400 ml of methanol and 4.2 g of sodium methoxide were added and heated under reflux for 6 hours. After refluxing, the reaction solution was returned to room temperature, and the solid matter was separated by suction filtration. The obtained solid was vacuum-dried at 100 ° C. overnight to obtain 106.29 g of a white solid. Elemental analysis of the solid (silica gel-supported organotin compound) revealed that tin was 4.3 wt% and chlorine was 0.09 wt%.

[Example 7] Redistribution reaction and silane coupling reaction of substituents on tin of organotin silane compound obtained in Example 2 using tin tetrachloride A dropping funnel was set in a 1000 ml four-necked flask and purged with nitrogen. Thereafter, 13.32 g of the organotin silane compound obtained in Example 2 was placed in a four-necked flask, and 9 ml of tin tetrachloride was placed in a dropping funnel. The four-necked flask was immersed in an ice bath, and tin tetrachloride was slowly added dropwise with stirring. After completion of the addition, the mixture was heated at 70 ° C. for 4 hours. After returning the reaction solution to room temperature, 400 ml of toluene and 100 g of silica gel were added, and the mixture was heated to reflux for 20 hours. Then, the reaction liquid was returned to room temperature and the solid substance was separated by suction filtration. The obtained solid was washed with toluene and vacuum dried at 100 ° C. overnight to obtain 109.92 g of a white solid. Elemental analysis of the solid (silica gel-supported tin compound) revealed that it was 4.2 wt% tin and 1.4 wt% chlorine.

[Example 8] Sn-OCH ₃ of Sn-Cl bond of silica gel supported tin compound obtained in Example 7 109.92 g of silica gel supported tin compound obtained in Example 7 in a 1000 ml four-necked flask, 400 ml of methanol and 4.2 g of sodium methoxide were added and heated under reflux for 6 hours. After refluxing, the reaction solution was returned to room temperature, and the solid matter was separated by suction filtration. The obtained solid was vacuum-dried at 100 ° C. overnight to obtain 109.83 g of a white solid. Elemental analysis of the solid (silica gel-supported organotin compound) revealed tin of 3.8 wt% and chlorine of 0.07 wt%.

[Example 9] Redistribution reaction and silane coupling reaction of substituents on tin of 2-tributyltin ethyltrimethoxysilane using tin tetrachloride A dropping funnel was set in a 1000 ml four-necked flask and purged with nitrogen. 10.61 g of 2-tributyltin ethyltrimethoxysilane obtained in Example 4 was placed in the necked flask, and 9 ml of tin tetrachloride was placed in the dropping funnel. The four-necked flask was immersed in an ice bath, and tin tetrachloride was slowly added dropwise with stirring. After completion of the addition, the mixture was heated at 70 ° C. for 4 hours. After returning the reaction solution to room temperature, 400 ml of toluene and 100 g of silica gel were added, and the mixture was heated to reflux for 20 hours. Then, the reaction liquid was returned to room temperature and the solid substance was separated by suction filtration. The obtained solid was washed with toluene and vacuum dried at 100 ° C. overnight to obtain 106.72 g of a white solid. Elemental analysis of this solid (silica gel-supported tin compound) revealed that it was 3.7 wt% tin and 1.1 wt% chlorine.

Example 10 Example 9 obtained in silica gel supported tin compound Sn-Cl bonds of Sn-OCH ₃ of 1000ml four necked silica supported tin compound obtained in Example 9 in a flask 106.72G, 400 ml of methanol and 4.2 g of sodium methoxide were added and heated under reflux for 6 hours. After refluxing, the reaction solution was returned to room temperature, and the solid matter was separated by suction filtration. The obtained solid was vacuum-dried at 100 ° C. overnight to obtain 106.12 g of a white solid. Elemental analysis of the solid (silica gel-supported organotin compound) revealed 3.5 wt% tin and 0.06 wt% chlorine.

[Example 11] Transesterification reaction using silica-tin-supported organotin compound obtained in Example 6 Hydroquinone 0.37 g, n-butanol 194 g (2.62 mol) in a 1000 ml four-necked flask equipped with a 20-stage Oldershaw, Methyl methacrylate (MMA) 451 g (4.50 mol) was added, and total reflux was performed to dehydrate the water in the system to 100 ppm or less. After cooling the system to room temperature, 100 g of the silica-tin-supported organotin compound (catalyst) obtained in Example 6 was added, and the flask was heated in an oil bath to initiate a transesterification reaction. The place where total reflux was applied was set to reaction time 0, and the reaction was allowed to proceed while extracting methanol as a by-product. After 6 hours, the n-butanol conversion reached 99.31%, and the reaction was completed. It was 0.55 ppm when the tin content rate in the filtrate (reaction liquid) which filtered the catalyst by suction filtration from the reaction completion liquid was analyzed.
Using the catalyst separated by filtration, the second to fifth reactions were carried out under the same conditions. Table 1 shows the reaction time until the completion of the reaction, the conversion rate of n-butanol, and the elution concentration of tin in the reaction end solution.

Example 12 Transesterification Reaction Using Silica Gel-Supported Organotin Compound Obtained in Example 8 Hydroquinone 0.37 g, n-butanol 194 g (2.62 mol) in a 1000 ml four-necked flask equipped with a 20-stage Oldershaw, Methyl methacrylate (MMA) 451 g (4.50 mol) was added, and total reflux was performed to dehydrate the water in the system to 100 ppm or less. After cooling the system to room temperature, 100 g of the silica-tin-supported organotin compound (catalyst) obtained in Example 8 was added, and the flask was heated in an oil bath to initiate the transesterification reaction. The place where total reflux was applied was set to reaction time 0, and the reaction was allowed to proceed while extracting methanol as a by-product. After 10 hours, the n-butanol conversion reached 99.17%, and the reaction was completed. It was 440 ppm when the tin content rate in the filtrate (reaction liquid) which filtered the catalyst by suction filtration from the reaction completion liquid was analyzed.
Using the catalyst separated by filtration, the second to fifth reactions were carried out under the same conditions. Table 2 shows the reaction time until the completion of the reaction, the conversion rate of n-butanol, and the elution concentration of tin in the reaction end solution.

Example 13 Transesterification Reaction Using Silica Gel-Supported Organotin Compound Obtained in Example 10 Hydroquinone 0.37 g, n-butanol 194 g (2.62 mol) in a 1000 ml four-necked flask equipped with a 20-stage Oldershaw, Methyl methacrylate (MMA) 451 g (4.50 mol) was added, and total reflux was performed to dehydrate the water in the system to 100 ppm or less. After cooling the system to room temperature, 100 g of the silica-tin-supported organotin compound (catalyst) obtained in Example 10 was added, and the flask was heated in an oil bath to initiate the transesterification reaction. The place where total reflux was applied was set to reaction time 0, and the reaction was allowed to proceed while extracting methanol as a by-product. After 2 hours, the n-butanol conversion reached 100% and the reaction was completed. It was 440 ppm when the tin content rate in the filtrate (reaction liquid) which filtered the catalyst by suction filtration from the reaction completion liquid was analyzed.
Using the catalyst separated by filtration, the second to fifth reactions were carried out under the same conditions. Table 3 shows the reaction time until the completion of the reaction, the conversion rate of n-butanol, and the elution concentration of tin in the reaction end solution.

表１〜３で示されるように、本発明のシリカゲル担持有機スズ化合物はエステル交換反応用触媒として利用でき、短時間で反応を完了させることができた。また、反応液へのスズの溶出が少なく、触媒の分離が容易で、触媒の再使用が可能であった。

As shown in Tables 1 to 3, the silica gel-supported organotin compound of the present invention can be used as a catalyst for transesterification, and the reaction could be completed in a short time. Moreover, the elution of tin into the reaction solution was small, the catalyst could be easily separated, and the catalyst could be reused.

[Example 14] Reaction of 4- (2-tributyltinethyl) phenyltrimethoxysilane (organotin silane compound obtained in Example 1) with water 4- (2-tributyltinethyl) phenyltrimethoxysilane in a 1000 ml eggplant flask 12 g, 240 ml of isopropanol and 120 ml of aqueous acetic acid (pH = 4) were added, and the mixture was heated to reflux in an oil bath at about 80 ° C. for 5 hours. The reaction-terminated liquid was put into a 1000 ml four-necked flask containing 100 g of silica gel and 400 ml of toluene, heated in an oil bath (set temperature 100 ° C.) at about 80 ° C. for 2 hours, and alcohol (methanol, isopropanol) in the system and After almost distilling off water, 400 ml of toluene was added, and the mixture was heated to reflux for 1 hour using a Dean-Stark apparatus. After refluxing, the reaction solution was returned to room temperature, and the solid matter was separated by suction filtration. The obtained solid was vacuum-dried at 100 ° C. overnight to obtain 110.4 g of a white solid.

  Into a 1000 ml four-necked flask, 110.4 g of the silica-supported organotin compound obtained in the above reaction and 400 ml of toluene were placed. After nitrogen substitution in the system, 12 ml of tin tetrachloride was added, and an oil bath temperature of 70.degree. Heating was performed for hours. Thereafter, the reaction solution was returned to room temperature, and solid matter was separated by suction filtration.

  In a 1000 ml four-necked flask, 5.6 g of sodium methoxide and the above solid matter were added, 400 ml of methanol was added, and the mixture was heated to reflux for 3 hours. The reaction solution was returned to room temperature, filtered, and vacuum dried at 100 ° C. overnight to obtain 112.2 g of a white solid. Elemental analysis of this white solid (silica gel-supported organotin compound) revealed tin of 2.7 wt% and chlorine of 0.06 wt%.

[Example 15] Reaction of 2-tributyltin ethyltrimethoxysilane (organotin silane compound obtained in Example 4) with water Add 12 g of 2-tributyltin ethyltrimethoxysilane and 240 ml of isopropanol to a 1000 ml eggplant flask, and then stir. 120 ml of acetic acid aqueous solution (pH = 4) was added and heated in an oil bath (100 ° C.) for 5 hours. The reaction-terminated liquid was put into a 1000 ml four-necked flask containing 100 g of silica gel and 400 ml of toluene, heated at 100 ° C. to almost distill off alcohol (methanol, isopropanol) and water in the system, and then 400 ml of toluene was added. The mixture was heated to reflux for 1 hour using a Dean-Stark apparatus. After refluxing, the reaction solution was returned to room temperature, and the solid matter was separated by suction filtration. The obtained solid was vacuum-dried at 100 ° C. overnight to obtain 110.4 g of a white solid.
Into a 1000 ml four-necked flask, 110.4 g of the silica-supported organotin compound obtained in the above reaction and 400 ml of toluene were placed. After nitrogen substitution in the system, 12 ml of tin tetrachloride was added, and an oil bath temperature of 70.degree. Heating was performed for hours. Thereafter, the reaction solution was returned to room temperature, and solid matter was separated by suction filtration.
In a 1000 ml four-necked flask, 5.6 g of sodium methoxide and the above solid matter were added, 400 ml of methanol was added, and the mixture was heated to reflux for 3 hours. The reaction solution was returned to room temperature, filtered, and vacuum dried at 100 ° C. overnight to obtain 112.2 g of a white solid. Elemental analysis of this white solid (silica gel-supported organotin compound) revealed tin of 2.7 wt% and chlorine of 0.06 wt%.

  [Example 16] Comparison of transesterification activity

  The catalyst activity comparison experiment was performed as follows.

A raw material (BuOH: MMA = 1.172 (containing hydroquinone 0.00057 wt%)) was continuously flowed at a space velocity SV≈1.6 h ⁻¹ in a U-shaped glass tube packed with 25 ml (12 g) of catalyst. The transesterification was carried out in an oil bath at ℃. Sampling was performed at 16 hours after the start of heating, GC analysis was performed, and the conversion rate of BuOH per 0.1 g of tin contained in the catalyst was calculated. The larger this value, the more the transesterification reaction has progressed.
Table 3 shows the results of reaction using the catalyst synthesized in each Example.

実施例６および１４は下記式（１２）で表される共通の構成単位を有するが、触媒活性は大きく異なった。実施例１４で示されるように、有機スズシラン化合物を水または水及びアルコールを含む混合溶媒と反応させてシリカゲルに担持することで、得られるシリカゲル担持有機スズ化合物の活性は増大した。同様に、実施例１０および１５も下記式（１３）で表される共通の構成単位を有するが、触媒活性は実施例１５の方が大きかった。

Examples 6 and 14 have a common structural unit represented by the following formula (12), but their catalytic activities differed greatly. As shown in Example 14, the activity of the resulting silica-supported organotin compound was increased by reacting the organotin silane compound with water or a mixed solvent containing water and alcohol and supporting it on silica gel. Similarly, Examples 10 and 15 also have a common structural unit represented by the following formula (13), but the catalytic activity of Example 15 was greater.

Claims (6)

An organotin silane compound represented by any one of formula (1), formula (2), formula (3) or formula (4).

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms, R ³ represents an alkylene group having 1 to 10 carbon atoms, and R ³ represents 2 of the benzene ring. It can be bonded to any carbon at the 6th position.)

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms, and silicon can be bonded to any carbon at positions 2 to 6 of the benzene ring.

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² represents each independently fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms, R ⁴ represents an alkylene group having 1 to 10 carbon atoms, R ⁵ represents hydrogen or a methyl group Represents.)

(R ¹ each independently represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms.) The formula (1) in which the organotin compound represented by the formula (5) is reacted with at least one silane coupling agent selected from the group of silane coupling agents represented by the formulas (6) to (9). )-(4) description of the manufacturing method of the organotin silane compound.

(R ⁶ is independently selected from hydrogen, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or aryl group having 5 to 10 carbon atoms, fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. And at least one R ⁶ is hydrogen.)

(R ² independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ³ represents an alkylene group having 1 to 10 carbon atoms. R ³ represents 2 of the benzene ring. It can be bonded to any carbon at the 6th position.)

(R ² each independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. Silicon can be bonded to any carbon at positions 2 to 6 of the benzene ring.)

(R ² independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms. R ⁴ represents an alkylene group having 1 to 10 carbon atoms. R ⁵ represents hydrogen or a methyl group. Represents.)

(R ² independently represents fluorine, chlorine, bromine, iodine, or an alkoxy group having 1 to 10 carbon atoms.)   Silica gel support in which silicon (Si) of the organotin silane compound of the formulas (1) to (4) forms a covalent bond (Si—O—Si ′) via silicon (Si ′) and oxygen on the surface of the silica gel Organotin compounds.   It is obtained by reacting the tin compound represented by the formula (5) with at least one silane coupling agent selected from the group of silane coupling agents represented by the formulas (6) to (9). 4. The method for producing a silica gel-supported organotin compound according to claim 3, wherein the organotin silane compound of the formulas (1) to (4) is reacted with silica gel.   A silica gel-supported organotin compound obtained by reacting the organotin silane compound of the above formulas (1) to (4) with water or a mixed solvent containing water and alcohol and supporting the product on silica gel. A process for producing a carboxylic acid ester by transesterification of a carboxylic acid ester with an alcohol, wherein the silica gel-supported organotin compound according to claim 3 or 5 is used as a catalyst. .