JPH08119978A - Method for jointly producing dimethylsilane and triorganochlorosilane - Google Patents

Abstract

PURPOSE: To provide a method for jointly producing dimethylsilane and a triorganochlorosilane, capable of simultaneously inexpensively and simply synthesizing dimethylsilane and a triorganochloro-silane in good yield without accompanying danger. CONSTITUTION: This method for jointly producing dimethylsilane and a triorganochlorosilane expressed by the formula, R<1> R<2> R<3> SiCl comprises reacting dimethyldichlorosilane with a SiH bond containing silane compound expressed by the general formula, R<1> R<2> R<3> SiH (R<1> , R<2> and R<3> are each mutually same or different monovalent hydrocarbon group) in the presence of a Lewis acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing and producing dimethylsilane and triorganochlorosilane together.

[0002]

BACKGROUND OF THE INVENTION Dimethylsilane is a monomer raw material that occupies an important position in the silicone industry, and is used as a raw material for addition modification of an organic compound having a double bond. Or
It is known as a raw material for synthesizing useful synthetic intermediates of organosilicon compounds such as silylating agents by redistribution reaction with various chlorosilanes.

On the other hand, triorganochlorosilanes such as trimethylchlorosilane and its derivatives are widely used as silylating agents, and also used for hydrophobizing inorganic substances and introducing terminal block units into organopolysiloxane chains. be able to.

Particularly, t-butyldimethylchlorosilane is an important compound as a silylating agent for the synthesis of drugs such as antibiotics and organic synthesis.

Conventionally, as a method for producing dimethylsilane, for example, when dimethyldichlorosilane is obtained by a direct method, a method in which dimethyldichlorosilane is isolated from a by-product obtained together with hydrocarbons in a low boiling point component by rectification is known. However, this method has a disadvantage that dimethylsilane can be obtained in a small amount although the process time is long.

Further, a method of synthesizing dimethylsilane using dichlorosilane as a raw material and a Grignard reagent of methyl chloride can be considered. However, the raw material dichlorosilane is a substance that is easily ignited and difficult to handle, and a large amount of solvent Therefore, there is a problem that productivity is poor and magnesium as a raw material is expensive.

As another method, a method of hydrolyzing chlorine of silicon-chlorine bond of chlorosilane with a hydrogenolysis reagent such as lithium aluminum hydride can be considered, but there is a risk of using a pyrophoric hydrogenolysis reagent. Yes, it is not industrially common.

On the other hand, t-butyldimethylchlorosilane is synthesized by chlorinating t-butyldimethylsilane with chlorine. But in this case,
Hydrogen atoms were lost as hydrogen chloride and were not effectively utilized.

The present invention has been made in view of the above circumstances.
It is an object of the present invention to provide a co-production method of dimethylsilane and triorganochlorosilane, which can simultaneously synthesize dimethylsilane and triorganochlorosilane inexpensively and easily and in good yield without danger.

[0010]

Means and Actions for Solving the Problems As a result of extensive studies conducted by the present inventor to achieve the above object, the general formula R
Si-H represented by ¹ R ² R ³ SiH (R ¹ , R ² , and R ³ are the same or different monovalent hydrocarbon groups).
By reacting a silane compound containing a group with dimethyldichlorosilane in the presence of a Lewis acid catalyst, both Si-Cl bonds of dimethyldichlorosilane are converted to Si-H bonds, and dimethylsilane can be obtained,
The triorganochlorosilane represented by the general formula R ¹ R ² R ³ SiCl (R ¹ , R ² and R ³ are the same as above) can be obtained in good yield, at low cost, easily and safely. In particular, it was found that this method effectively utilizes the hydrogen atom of t-butyldimethylsilane and enables simultaneous provision of dimethylsilane and t-butyldimethylchlorosilane, which led to the present invention. It is a thing.

Accordingly, the present invention is directed to dimethyldichlorosilane and the general formula R ¹ R ² R ² SiH in the presence of a Lewis acid catalyst.
(R ¹ , R ² , and R ³ have the same meanings as described above.) A silane compound containing SiH bond represented by the formula ( ¹ ) is reacted with dimethylsilane and R ¹ R ² R ³ SiCl.
And a method for co-producing triorganochlorosilane.

The present invention will be described in more detail below. The SiH bond-containing silane compound used in the method of the present invention is represented by the general formula R ¹ R ² R ³ SiH.
Examples of R ¹ , R ² , and R ³ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a cyclohexyl group, a cyclopentyl group, and an n-octyl group. A monovalent hydrocarbon group having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, such as an alkyl group or an aryl group such as a phenyl group can be used, and these may be the same or different from each other. Good. Specific examples thereof include trimethylsilane, triethylsilane, t-butyldimethylsilane, phenyldimethylsilane, isopropyldimethylsilane, dicyclohexylmethylsilane, normal octyldimethylsilane, normal butyldimethylsilane, and cyclopentyldimethylsilane.

On the other hand, specific examples of the Lewis acid catalyst include aluminum chloride, iron chloride, boron trichloride, zinc chloride, cesium chloride, cobalt chloride, nickel chloride, titanium tetrachloride, tin chloride, rhodium chloride and cadmium chloride. ,
Copper acetylacetonate and the like are mentioned, and it is particularly preferable to use aluminum chloride.

The amount of the SiH bond-containing silane compound used is 0.8 with respect to 1 mol of dimethyldichlorosilane.
˜5.0 mol, especially 1.0 to 2.0 mol is preferred.
When the amount of the silane compound used is less than 0.8 mol or more than 5.0 mol, a large amount of unreacted raw material may remain.

The amount of the Lewis acid used is 0.001 to 0.5 mol, based on 1 mol of dimethyldichlorosilane.
In particular, it is preferably 0.02 to 0.1 mol. When the amount of the Lewis acid used is less than 0.001 mol, the reaction rate may decrease remarkably, and when it exceeds 0.5 mol, Si-C
Undesired disproportionation reactions such as bond cleavage may occur.

In the above reaction, the Lewis acid catalyst is usually dissolved in dimethyldichlorosilane, and then the general formula R ¹ R ² R is used.
It can be carried out by adding a Si—H bond-containing silane compound represented by ³ SiH (R ¹ , R ² and R ³ have the same meanings as described above) and stirring. In this case, the reaction temperature is preferably 0 to 90 ° C, particularly preferably 20 to 60 ° C. The reaction time is usually 10 minutes to 2 hours.

The general formula R ¹ R ² R ³ SiH (R ¹ ,
R ² and R ³ have the same meaning as above. ) Si
-Dissolving a Lewis acid catalyst in a silane compound containing an H bond,
Then, dimethyldichlorosilane may be added and stirred. In this case, in particular, dimethylsilane can be distilled off during the reaction.

A solvent may be used in the method for producing dimethyldichlorosilane of the present invention, and a solvent that does not react with dimethyldichlorosilane and / or SiH bond-containing silane is preferably used as the solvent.
Examples of such a solvent include toluene, ethyl acetate, decane, o-xylene and the like.

When the triorganochlorosilane is distilled and isolated from the reaction solution, it is desirable to deactivate the Lewis acid contained therein. Specific examples include a method in which ether such as anisole, diphenyl ether, o-dimethoxybenzene and p-dimethoxybenzene is added in an amount of 1 to 5 times the moles of the Lewis acid used.

[0020]

The co-production method of dimethylsilane and triorganochlorosilane of the present invention is an inexpensive and simple method, and it is possible to obtain dimethylsilane and triorganochlorosilane at the same time with high yield and high safety. This method is very effective as a method for simultaneously providing dimethylsilane and t-butyldimethylchlorosilane.

[0021]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to the following examples.

[Example 1] 12.9 g (0.10 mol) of dimethyldichlorosilane and 0.27 g (0.002) of aluminum chloride were placed in a four-necked flask equipped with a cooling tube, a thermometer, a dropping tube and a stirrer. Mol), and stirred with a stirrer. Next, 23.2 g (0.20 mol) of t-butyldimethylsilane was added dropwise thereto over 30 minutes at room temperature, and then the mixture was stirred for 1 hour while keeping the temperature at 30 ° C. After completion of the reaction, the reaction solution was distilled. As a result, 4.8 g of dimethylsilane having a boiling point of -20.1 ° C (yield 80%) and 29.5 g of t-butyldimethylchlorosilane having a boiling point of 125 ° C (yield 98
%)was gotten.

Example 2 In a four-necked flask equipped with a cooling tube, a thermometer, a dropping tube and a stirrer, t-butyldimethylsilane 123.2 (0.20 mol) and aluminum chloride 0.27 g (0 (.002 mol) was added and the mixture was stirred with a stirrer. Then, while distilling 12.9 g (0.10 mol) of dimethyldichlorosilane over 30 minutes at an internal temperature of 60 ° C. to distill off the distillate, the boiling point was −20.1.
5.7 g (yield 95%) of dimethylsilane at 0 ° C. were obtained. Furthermore, after adding 0.2 g of o-dimethoxybenzene and stirring for 1 hour, t-butyldimethylchlorosilane was isolated by distillation, and 29.4 g (yield 97%) of t-butyldimethylchlorosilane was obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasufumi Kubota 28-1 Nishifukushima, Kubiki Village, Nakakubiki District, Niigata Prefecture Shin-Etsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. Dimethylchlorosilane and the general formula R ¹ R ² R ³ SiH (R ¹ , R ² , R ^{3 in} the presence of a Lewis acid catalyst.
Are the same or different monovalent hydrocarbon groups. ) And a SiH bond-containing silane compound represented by the formula (1) are reacted with dimethylsilane and R ¹ R ² R ³ SiCl.
(R ¹ , R ² , and R ³ have the same meanings as described above.) A method of co-producing triorganochlorosilane. 2. A method for co-producing dimethylsilane and t-butyldimethylchlorosilane, which comprises reacting dimethylchlorosilane and t-butyldimethylsilane in the presence of a Lewis acid catalyst.