JPH09157279A - Production of organomonoalkoxysilane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organomonoalkoxysilane in high yield under mild conditions, useful as a silylation agent by allowing a specific organodisiloxane, an orthocarboxylate ester, a catalyst and a compound bearing a group containing active hydrogen atoms. SOLUTION: An organodisiloxane of the formula (R<1> -R<6> are each a monofunctional hydrocarbon, a monosubstituted hydrocarbon, H), for example, hexamethyldisiloxane, an orthocaboxylate ester such as trimethyl orthoformate, a catalyst such as sulfuric acid and a compound bearing a group containing active hydrogens, for example, methanol are allowed to react using a reflux condenser in a nitrogen atmosphere at room temperature to produce the objective organo-monoalkoxysilane in high yield, through a halogen-free process, cleanly under mild conditions with increased safety in low costs.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an organomonoalkoxysilane. More specifically, it relates to a novel method for producing an organomonoalkoxysilane, which is one of important intermediates for silylating agents and other various organosilicon compounds.

[0002]

As a technique for obtaining an organomonoalkoxysilane by reacting an organodisiloxane and an orthocarboxylic acid ester compound, a reaction of obtaining trimethylethoxysilane from hexamethyldisiloxane and triethyl orthoformate in the presence of an acid catalyst is ． P. Zhurkin
a et al. (Metalloorg. K).
him. , 3,1283 (1990)). Further, as a related technique, a method of obtaining an organomonochlorosilane from an organodisiloxane is disclosed in JP-A-52-65226 and JP-A-5-222062.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
P. The reaction reported by Zhurkina et al. Has a drawback that the reaction rate, the reaction rate, and the yield are low because there is no substance having a reaction promoting effect. That is, in the reaction of hexamethyldisiloxane and triethyl orthoformate, the conversion rate of hexamethyldisiloxane is 5
It was as low as 2%, and the yield of the product trimethylethoxysilane was about 40%. Further, no study has been made on a compound having a hydrogen atom as a substituent on a silicon atom.

The method disclosed in JP-A-52-65226 is a method in which an organodisiloxane and a dialkyldichlorosilane are reacted with hexamethylphosphoric triamide as a catalyst, but a viscous polysiloxane is used. In addition to being a by-product, there was a problem that the catalyst hexamethylphosphoric triamide had a strong carcinogenic property, and it was difficult to industrialize it. Further, in the technique disclosed in JP-A-5-222062, there is a problem that a sulfurous acid gas is produced as a by-product because an organodisiloxane is reacted with thionyl chloride. Further, when the organomonochlorosilane obtained by such a reaction is subjected to the reaction as an intermediate of various organosilicon compounds, hydrogen chloride is produced as a by-product, and there are problems in terms of safety, economy, and device corrosion. . For this reason, a more stable and safer alkoxy compound is desirable when used as an intermediate of an organosilicon compound, but if an attempt is made to alkoxylate an organomonochlorosilane, an additional step is required, resulting in a cost reduction. There was a problem in terms of yield.

An object of the present invention is to solve the problems of the prior art and to provide a method for producing an organomonoalkoxysilane cleanly under mild conditions and in a high yield.

[0006]

Means for Solving the Problems The method for producing an organomonoalkoxysilane of the present invention, which was made in order to achieve this object, comprises:

[0007]

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The organodisiloxane represented by and the orthocarboxylic acid ester compound are reacted in the presence of a catalyst and an active hydrogen group-containing compound. In the above formula,
R ¹ to R ⁶ are the same or different monovalent hydrocarbon groups, monovalent substituted hydrocarbon groups, or hydrogen atoms. In the case of a monovalent hydrocarbon group, it may be a saturated group or an unsaturated group, and may be acyclic or cyclic. Examples thereof include various alkyl groups, alkenyl groups, vinyl groups, allyl groups, aryl groups and aralkyl groups. In the case of a monovalent substituted hydrocarbon group, examples of the substituent include a halogen atom, a cyano group, a carboxyl group and a silyl group. Further, these hydrocarbon groups may be bonded to each other to form a ring-shaped body containing a silicon atom. Various substituents may be bonded to the cyclic hydrocarbon group, an unsaturated bond may be contained, or the aromatic ring may be condensed.

Examples of such organodisiloxane include 1,1,3,3-tetramethyldisiloxane, 1,3-dimethyl-1,1,3,3-tetraphenyldisiloxane and 1,3- Bis (2-cyanoethyl)-
1,1,3,3-tetramethyldisiloxane, 1,3-
Bis (2-phenylethyl) -1,1,3,3-tetraphenyldisiloxane, 1,3-di-tert-butyl-1,3-dimethyldisiloxane, tert-butyl-
Pentamethyldisiloxane, hexamethyldisiloxane, 1,3-diisopropyl-1,1,3,3-tetramethyldisiloxane, 1,3-dicyclohexyl-1,
1,3,3-tetramethyldisiloxane, 1,3-divinyl-1,1,3,3-tetraethyldisiloxane,
1,3-diallyl-1,3-diethyl-1,3-dimethyldisiloxane, 1,3-di (3-trifluoropropyl) -1,1,3,3-tetramethyldisiloxane, di (silacyclo) Butyl) ether (formula 2),

[0010]

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Examples thereof include, but are not limited to: These organodisiloxanes may be reacted alone or in combination of two or more compounds. The orthocarboxylic acid ester compound which is the composition of the present invention, trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, tributyl orthoformate, orthoformate compounds such as trioctyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, Examples thereof include orthoacetic acid ester compounds such as tripropyl orthoacetate, tributyl orthoacetate, and trioctyl orthoacetate, but are not limited thereto. These orthocarboxylic acid ester compounds may be used alone or in combination of two or more kinds. Among these orthocarboxylic acid ester compounds, the orthocarboxylic acid methyl ester or the orthocarboxylic acid ethyl ester is preferable in that the alkoxy group of the resulting organomonoalkoxysilane is a highly versatile methoxy group or an ethoxy group. Orthoformate is preferable in terms of high reactivity. Further, trimethyl orthoformate is particularly preferable in that it easily produces a low-boiling point methyl formate that is easily separated and is easily available.

The amount of orthocarboxylic acid ester compound used is not particularly limited, but is preferably 10 to 100,000 mol, and most preferably 50 to 10,000 mol per 100 mol of organodisiloxane. The active hydrogen group-containing compound which is the composition of the present invention, a compound containing a hydroxyl group, a carboxyl group, a mercapto group, an amino group and the like in the molecule, and a hydroxyl group in the molecule by reacting with an orthocarboxylic acid ester compound, a carboxyl group , A compound that produces a compound containing a mercapto group, an amino group, and the like. Specific examples thereof include water, alcohol compounds, carboxylic acid compounds, thiol compounds, amine compounds, and the like, and water and alcohol compounds are preferable in that the reaction rate is high. The active hydrogen group-containing compound also includes, for example, water and alcohol contained as impurities in the starting material.

When an alcohol compound is used as the active hydrogen group-containing compound, the alcohol compound is
Examples are monohydric aliphatic alcohols such as methanol, ethanol, isopropanol, n-propanol and n-butanol, aromatic alcohols such as benzyl alcohol, phenol and naphthyl alcohol, and polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin. However, the present invention is not limited to these. It is preferable to use an alcohol having the same organic group moiety as the orthocarboxylic acid ester compound used in these, because the resulting organomonoalkoxysilane has a single alkoxy group, and for example, as an orthocarboxylic acid ester compound, trimethyl orthoformate is used. When is used, methanol is preferred.

When a carboxylic acid compound is used as the active hydrogen group-containing compound, examples of the carboxylic acid compound include, but are not limited to, formic acid, acetic acid, propanoic acid, acrylic acid and benzoic acid. . When using a thiol compound as an active hydrogen group-containing compound,
Examples of the thiol compound include methanethiol, ethanethiol, 1-propanethiol, 2-propanethiol, 1-butanethiol, thiophenol, and 1,2-ethanedithiol, but are not limited thereto. .

When an amine compound is used as the active hydrogen group-containing compound, examples of the amine compound include ammonia, methylamine, dimethylamine, ethylamine, diethylamine, aniline and ammonium chloride, but are not limited thereto. is not. These active hydrogen group-containing compounds may be used alone or in combination of two or more. The amount of the active hydrogen group-containing compound used in the present invention is not particularly limited, but since the reaction rate increases as the amount of use increases, it is 0.1 mol or more based on 100 active hydrogen groups per 100 mol of organodisiloxane. The amount is preferable, and the amount of 1 mol or more is particularly preferable. When no active hydrogen group-containing compound is used, the reaction does not proceed or is extremely slow,
Further, the reaction rate of the organodisiloxane becomes low, and the yield of the organomonoalkoxysilane becomes low. However, if the amount used is too large, it becomes difficult to separate the product, so 10 parts based on active hydrogen groups per 100 mol of organodisiloxane.
An amount of 0000 mol or less is preferable, and an amount of 10,000 mol or less is particularly preferable. Regarding the active hydrogen group-containing compound, the concentration in the solution depends on the reaction rate. Therefore, the concentration of the active hydrogen group-containing compound used in the reaction solution is preferably 0.1 to 80% by weight, particularly preferably 1 to 50% by weight.

Examples of the catalyst used in the present invention include hydrochloric acid, sulfuric acid, fuming sulfuric acid, nitric acid, acetic acid, phosphoric acid, phosphoric acid ester, sulfurous acid, nitrous acid, hypochlorous acid, perchloric acid, hydrogen peroxide and benzoic acid. Acid, salicylic acid, boric acid, trifluoroacetic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, p-phenolsulfonic acid, trialkylsilyltrifluoromethanesulfonic acid, trialkylsilylperchlorate, bistrimethylsilyl sulfate,
Examples thereof include strong acid ion exchange resins (for example, Nafion (trade name)), chloroplatinic acid, aluminum chloride, iron chloride, boron trifluoride, activated clay and the like, but are not limited thereto. These catalysts may be used alone or in combination of two or more. Acid catalysts are preferred in terms of reactivity, and sulfonic acid compounds such as sulfuric acid, trifluoromethanesulfonic acid and p-toluenesulfonic acid are particularly preferred.

The amount of the catalyst used in the present invention is not particularly limited, but 0.001 to 20 parts is preferable, and 0.01 to 5 parts is particularly preferable, relative to 100 parts of the organodisiloxane. Regarding the catalyst, since the concentration in the reaction solution depends on the reaction rate, the concentration of the catalyst used in the present invention is not particularly limited, but 0.0001 to 20% by weight.
Is preferred, and 0.01 to 5% by weight is particularly preferred.

A solvent may be used in the practice of the present invention. As the solvent, a compound that is inert to the orthocarboxylic acid ester compound and the monoalkoxysilane and is liquid at the reaction temperature can be used. For example,
Aliphatic hydrocarbon compounds such as pentane, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, ethylbenzene, naphthalene, biphenyl and diphenylmethane. Hydrogen compounds, organic halides such as dichloromethane, chloroform, methyl chloride, 1,2-dichloroethane, dibromomethane, bromoform and methyl bromide, diethyl ether, diphenyl ether, 1,4
Examples thereof include ether compounds such as dioxane and tetrahydrofuran, ketone compounds such as acetone and methyl ethyl ketone, and carbon disulfide, but are not limited thereto. Further, an orthocarboxylic acid ester compound or an active hydrogen group-containing compound which is the composition of the present invention, or an organodisiloxane which is a raw material may be used as a solvent. These solvents may be used alone,
Alternatively, a mixture of two or more kinds may be used.

The amount of the solvent used in the present invention is not particularly limited, but is preferably 0.1 to 100,000 parts by volume with respect to 100 parts by weight of organodisiloxane, and 10 to 10 parts.
000 parts by volume is particularly preferred. An organomonoalkoxysilane is obtained by reacting the above-mentioned organodisiloxane and an orthocarboxylic acid ester compound in the presence of the above-mentioned active hydrogen group-containing compound and a catalyst. A reaction formula (Formula 3) is shown.

[0020]

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In the above formula, R ¹ to R ⁶ and R ′ are the same or different monovalent hydrocarbon groups, monovalent substituted hydrocarbon groups, or hydrogen atoms, and R is the same or different monovalent hydrocarbon groups. Or a monovalent substituted hydrocarbon group.
In the case of a monovalent hydrocarbon group, it may be a saturated group or an unsaturated group, and may be acyclic or cyclic. For example, various alkyl groups, alkenyl groups, vinyl groups, allyl groups,
Examples thereof include an aryl group and an aralkyl group. In the case of a monovalent substituted hydrocarbon group, examples of the substituent include a halogen atom, a cyano group, a carboxyl group and a silyl group. Regarding R ¹ to R ⁶ , these hydrocarbon groups may be bonded to each other to form a ring-shaped body containing a silicon atom. Various substituents may be bonded to the cyclic hydrocarbon group, an unsaturated bond may be contained, or the aromatic ring may be condensed.

Specific examples of the organomonoalkoxysilane obtained by the above reaction formula include dimethylmethoxysilane, diphenylmethylmethoxysilane and (2-
(Cyanoethyl) dimethylmethoxysilane, (2-phenylethyl) diphenylmethoxysilane, tert-butylmethylmethoxysilane, tert-butyldimethylethoxysilane, trimethylmethoxysilane, isopropyldimethylmethoxysilane, cyclohexyldimethylmethoxysilane, diethylvinylethoxysilane, allyl Examples thereof include ethylmethylmethoxysilane, dimethyltrifluoropropylmethoxysilane, 1-methoxysilacyclobutane, dimethylethoxysilane, trimethylpropoxysilane, and triphenylethoxysilane.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The reaction procedure for producing a monoalkoxysilane according to the present invention may be carried out, for example, as follows. The organodisiloxane is charged into a reaction vessel, and the inside of the reaction vessel is stirred while adding an orthocarboxylic acid ester compound, an active hydrogen group-containing compound and a catalyst. The orthocarboxylic acid ester compound, the active hydrogen group-containing compound and the catalyst may be mixed in advance or may be added separately.
Alternatively, there is no problem even if the reaction vessel is charged with the organodisiloxane. A solvent can be used in order to effectively mix the raw materials and the reaction. If the solution is well mixed, the reaction will proceed without stirring. Since the reaction proceeds rapidly even at room temperature, there is no particular need for heating, but there is no problem even if heating is performed to increase the reaction rate. The amount of the orthocarboxylic acid ester compound used is not particularly limited, but is preferably 10 to 100,000 mol per 100 mol of organodisiloxane,
An amount of 50 to 10,000 mol is particularly preferable. The amount of the active hydrogen group-containing compound used is not particularly limited, but it is 0. 0 based on the active hydrogen group per 100 mol of organodisiloxane.
An amount of 1 to 10000 mol is preferable, and an amount of 1 to 500 mol is particularly preferable. The concentration of the active hydrogen group-containing compound in the reaction solution is not particularly limited, but is preferably 0.1 to 80% by weight, particularly preferably 1 to 50% by weight. The amount of the catalyst used in the present invention is not particularly limited, but 0.001 to 20 parts is preferable, and 0.01 to 5 parts is particularly preferable, relative to 100 parts of the organodisiloxane. The concentration of the catalyst used in the present invention in the reaction solution is not particularly limited, but is preferably 0.0001 to 20% by weight, and 0.01 to 20% by weight.
5% by weight is particularly preferred. The amount of the solvent used in the present invention is not particularly limited, but organodisiloxane 100
1 to 100,000 parts by volume is preferable with respect to parts by weight, and 1
0 to 10000 parts by volume is particularly preferred. The reaction temperature is not particularly limited, but is preferably 0 to 500 ° C., and 10 to 20.
0 ° C. is particularly preferred.

A crude product of the organomonoalkoxysilane is obtained by the above reaction. To obtain a high-purity monoalkoxysilane from the obtained crude product, the crude product may be distilled. Unreacted orthocarboxylic acid ester compound, active hydrogen group-containing compound, catalyst, and solvent can be returned to the reaction vessel and recycled.
These may be separated and purified and reused, or may be used without being particularly separated.

According to the organomonoalkoxysilane production method of the present invention, the reaction proceeds rapidly even at room temperature. The reaction can be performed under mild conditions without using a dangerous reaction product, hydrogen chloride or chlorosilane is not produced as a by-product, and an undesirable compound is hardly formed. No complicated fractional distillation operation is required in the reaction step. That is, according to the method of the present invention, it is possible to produce an organomonoalkoxysilane cleanly and in a high yield by a halogen-free process under relatively mild conditions.

[0026]

EXAMPLES The present invention will be specifically described with reference to Examples and Comparative Examples below. (Examples 1 to 5) Hexamethyldisiloxane 61.6 g
(0.38 mol) and trimethyl orthoformate 40.5 g
(0.38 mol) was mixed to prepare a liquid A. About 10 g of each A solution was weighed in a 50 mL eggplant-shaped flask, and 0.6 mol% of sulfuric acid was added to hexamethyldisiloxane.
About 5 mol% of active hydrogen group-containing compound was added to hexamethyldisiloxane, and the mixture was stirred at room temperature under a nitrogen atmosphere with a reflux condenser attached. As an active hydrogen group-containing compound,
Water (Example 1), methanol (Example 2), ethanol (Example 3), 1-butanol (Example 4), and acetic acid (Example 5) were used. 1H-NMR measurement was performed and the yield of methoxytrimethylsilane was determined on the basis of hexamethyldisiloxane. Table 1 shows the amount of raw material charged and the yield of methoxytrimethylsilane.

[0027]

[Table 1]

Comparative Example 1 The reaction was carried out in exactly the same manner as in Examples 1 to 5 except that the active hydrogen group-containing compound was not added. 1H-NMR measurement was performed and the yield of methoxytrimethylsilane was determined on the basis of hexamethyldisiloxane. Table 1 shows the results. (Examples 6 to 8) 10.0 g of hexamethyldisiloxane
(61.6 mmol) and 0.196 g of methanol (6.
11 mmol) was mixed to obtain a liquid B. This solution B is about 1.
2 g was placed in three 5 mL volumetric flasks, and trimethyl orthoformate (Example 6), triethyl orthoformate (Example 7), and trimethyl orthoacetate (Example 8) were added to prepare a mixed solution. After adding chloroform to each flask to make a 5 mL solution, sulfuric acid 21 m
g (0.21 mmol) was added and the mixture was allowed to stand at room temperature. 1H
-NMR measurement was performed and the yield of methoxytrimethylsilane was determined on the basis of hexamethyldisiloxane. Table 2 shows the amount of raw material charged and the yield of methoxytrimethylsilane.

[0029]

[Table 2]

(Comparative Example 2) 1.23 g of solution B used in Examples 6 to 8 (1.21 g of hexamethyldisiloxane)
(7.42 mmol) + methanol 24 mg (0.74
mmol)) was placed in a 5 mL volumetric flask, and chloroform was added to make a total solution of 5 mL. 21 mg of sulfuric acid
(0.21 mmol) was added and 5 hours later, 1H-NMR was added.
It was measured, but hexamethyldisiloxane was 100%
It remained. (Example 9) 1,1,3,3-tetramethyldisiloxane 10.0 g (74.5 mmol), trimethyl orthoformate 7.90 g (74.5 mmol), methanol 1.
10 g (34.3 mmol) was charged with a magnetic stir bar 50
Weigh in a mL 2-necked flask, attach a reflux condenser, and add 20 mg (0.20 mmol) of sulfuric acid while stirring in a nitrogen atmosphere.
Was added. After stirring at room temperature for 30 minutes, 1 H-NMR measurement was performed, it was found that dimethylmethoxysilane was 1,1,
It was produced in a yield of 98% based on 3,3-tetramethyldisiloxane.

[0031]

As described above in detail, by using the method for producing an organomonoalkoxysilane of the present invention, it is possible to obtain an organomonoalkoxysilane in a high yield and a high purity by a halogen-free process, and it is safe. High, and separation and purification are easy. In addition, since the reaction proceeds even at room temperature, equipment costs and manufacturing costs can be kept low.

Claims (9)

[Claims] 1. A compound of the general formula (1) (R1 to R6 are the same or different monovalent hydrocarbon groups, monovalent substituted hydrocarbon groups, or hydrogen atoms), an orthocarboxylic acid ester compound, a catalyst and an active hydrogen group-containing compound. A method for producing an organomonoalkoxysilane, which comprises reacting in the presence of 2. The organodisiloxane is at least 1
The method for producing an organomonoalkoxysilane according to claim 1, wherein each hydrogen atom is contained as a substituent on the silicon atom. 3. The method for producing an organomonoalkoxysilane according to claim 1, wherein orthocarboxylic acid methyl ester is used as the orthocarboxylic acid ester compound. 4. An orthoformate ester is used as an orthocarboxylic acid ester compound.
The method for producing an organomonoalkoxysilane according to 1. 5. The method for producing an organomonoalkoxysilane according to claim 1, wherein an acid catalyst is used as the catalyst. 6. The method for producing an alkoxysilane according to claim 1, wherein a compound that reacts with an orthocarboxylic acid ester compound to produce an alcohol is used as the active hydrogen group-containing compound. 7. The water and / or alcohol is used as the active hydrogen group-containing compound, according to claim 1.
The method for producing an organomonoalkoxysilane according to 1. 8. The method for producing an organomonoalkoxysilane according to claim 1, wherein the reaction is carried out in the presence of a solvent. 9. A method for producing an organomonoalkoxysilane, which comprises decomposing an organodisiloxane with trimethyl orthoformate, methanol, and an acid catalyst.