A process for the preparation of a benzylsilane

Abstract

This invention relates to the field of organic synthesis technology, specifically to a process for preparing benzylsilane. The invention employs a one-step nucleophilic substitution reaction, where an aminosilane reacts directly with a benzyl halide to generate the target product. This route has fewer steps, is simpler to operate, avoids the cumbersome process and cumulative losses associated with multi-step synthesis, and significantly improves production efficiency. Furthermore, the entire reaction is carried out under reflux conditions, eliminating the need for precious metal catalysts or extreme reaction conditions. By precisely controlling the molar ratio of aminosilane, benzyl halide, and acid-binding agent, and by selecting a suitable solvent system, the nucleophilic substitution of the amino group for the benzyl halogen is effectively promoted, while suppressing side reactions such as silane hydrolysis, benzyl elimination, or excessive alkylation. This ensures high selectivity and high yield. In addition, this invention eliminates complex purification steps such as column chromatography, making it highly suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to a process for preparing benzylsilane. Background Technology

[0002] Benzylsilanes are an important class of organosilicon compounds with benzyl functional groups attached to silicon atoms. Due to the simultaneous presence of silane groups and benzyl aromatic rings in their molecular structure, they exhibit broad application prospects in materials science, polymer chemistry, and surface treatment. For example, they can serve as excellent surface modifiers to improve the interfacial adhesion between inorganic materials (such as glass and metal oxides) and organic polymers (such as epoxy resins and polyurethanes); they can also serve as intermediates in organic synthesis to prepare more complex silane derivatives.

[0003] Currently, while methods for synthesizing benzylsilanes have been reported, most have limitations. Some methods involve reacting highly reactive silane reagents (such as hydrides) with benzyl halides under catalysis; however, such routes may be sensitive to water and oxygen, require stringent operating conditions, and involve expensive catalysts. Other methods may involve multiple reaction steps, resulting in long process flows, low overall yields, and the generation of difficult-to-separate byproducts, leading to low purity of the final product and difficulty in meeting the stringent performance requirements of high-end applications.

[0004] Based on the above, the present invention provides a process for preparing benzylsilane to solve the technical problems mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a preparation process for benzylsilane, which has the characteristics of high yield and high purity, effectively ensuring its grade. Furthermore, the preparation process provided by this invention has few steps and side reactions, mild conditions, and simple operation, eliminating complex purification steps such as column chromatography, effectively saving production costs, and is very suitable for industrial production.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A process for preparing benzylsilane includes the following steps: under the protection of an inert gas, aminosilane is added to an organic solvent at a dosage ratio of 0.2-0.3 mol / L, and the mixture is stirred at a speed of 300-500 r / min until homogeneous. Then, halobenzyl is added in molar amounts of 1-2 times that of aminosilane and 3-4 times that of an acid-binding agent. After stirring until homogeneous, the mixture is refluxed for 15-25 h. After the reaction is complete, the product is naturally cooled to room temperature, filtered, and extracted with ethyl acetate. Then, it is subjected to vacuum distillation to remove ethyl acetate and halobenzyl. The final product is benzylsilane.

[0008] Furthermore, the aminosilane is selected from monoaminosilane or diaminosilane; wherein the monoaminosilane is selected from either γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane; and the diaminosilane is selected from either N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane or N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

[0009] Furthermore, the halobenzyl is selected from either benzyl chloride or benzyl bromide.

[0010] Furthermore, the inert gas is any one of nitrogen, helium, or argon.

[0011] Furthermore, the acid-binding agent is triethylamine.

[0012] Furthermore, the organic solvent is selected from any one of N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, and toluene.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. This invention employs a one-step nucleophilic substitution reaction, directly reacting aminosilane with benzyl halide to generate the target product. This route has fewer steps, is simpler to operate, avoids the cumbersome process and cumulative losses associated with multi-step synthesis, and significantly improves production efficiency. Furthermore, the entire reaction is carried out under reflux conditions, eliminating the need for precious metal catalysts or extreme reaction conditions (such as ultra-low temperature and high pressure). By precisely controlling the molar ratio of aminosilane, benzyl halide, and acid-binding agent, and by optimizing a suitable solvent system, the nucleophilic substitution of the amino group with the benzyl halogen is effectively promoted, while suppressing side reactions such as silane hydrolysis, benzyl elimination, or excessive alkylation, thereby ensuring high selectivity and high yield.

[0015] 2. In this invention, the hydrogen halide generated in the reaction is promptly neutralized by excess acid-binding agent, forming a salt insoluble in the reaction system, which can be removed by simple filtration. Subsequent ethyl acetate extraction and vacuum distillation effectively separate and recover excess benzyl halide and solvent, ultimately yielding a high-purity benzylsilane product. This eliminates complex purification steps such as column chromatography, making it highly suitable for industrial production. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1

[0018] A process for preparing benzylsilane includes the following steps: Under nitrogen protection, γ-aminopropyltriethoxysilane is added to N,N-dimethylformamide at a molar ratio of 0.2 mol / L, and the mixture is stirred at 300 r / min until homogeneous. Then, benzyl chloride and triethylamine are added in molar amounts equal to 1 times that of γ-aminopropyltriethoxysilane and 3 times that of γ-aminopropyltriethoxysilane, respectively. After stirring until homogeneous, the mixture is refluxed for 15 h. After the reaction is complete, the product is naturally cooled to room temperature, filtered, and extracted with ethyl acetate. Then, it is subjected to vacuum distillation to remove ethyl acetate and benzyl chloride. The final product is benzylsilane.

[0019] Example 2

[0020] A process for preparing benzylsilane includes the following steps: Under helium protection, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane is added to N,N-dimethylacetamide at a molar ratio of 0.2 mol / L. After mixing and stirring at 400 r / min, benzyl bromide and triethylamine are added in molar amounts of 1.5 times and 3 times respectively of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane. After stirring and stirring, the mixture is refluxed for 20 h. After the reaction is complete, the product is naturally cooled to room temperature, filtered and extracted with ethyl acetate, and then subjected to vacuum distillation to remove ethyl acetate and benzyl bromide. The final product is benzylsilane.

[0021] Example 3

[0022] A process for preparing benzylsilane includes the following steps: Under argon protection, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane is added to acetonitrile at a molar ratio of 0.3 mol / L. After mixing and stirring at 500 r / min, benzyl chloride and triethylamine are added in molar amounts of 2 times and 4 times respectively, respectively. After stirring and stirring, the mixture is refluxed for 25 h. After the reaction is completed, the product is naturally cooled to room temperature, filtered and extracted with ethyl acetate, and then subjected to vacuum distillation to remove ethyl acetate and benzyl chloride. The final product is benzylsilane.

[0023] Performance testing: The yield and purity of the benzylsilane samples prepared in Examples 1-3 were tested, and the test data are recorded in the table below:

[0024]

[0025] By comparing and analyzing the data in the table, it can be seen that the benzylsilane prepared by this invention has the characteristics of high yield and high purity, effectively ensuring its grade. Furthermore, the preparation process provided by this invention involves few steps and side reactions, mild conditions, and simple operation, eliminating complex purification steps such as column chromatography, effectively saving production costs and making it very suitable for industrial production. Therefore, this indicates that the benzylsilane preparation process provided by this invention has a broader market prospect and is more suitable for widespread application.

[0026] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0027] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A process for preparing benzylsilane, characterized in that, Includes the following steps: Under the protection of an inert gas, aminosilane is added to an organic solvent at a dosage ratio of 0.2-0.3 mol / L. After mixing and stirring at a speed of 300-500 r / min, 1-2 times the molar amount of benzyl halide and 3-4 times the molar amount of acid-binding agent are added. After stirring and stirring, the mixture is refluxed for 15-25 h. After the reaction is complete, the product is naturally cooled to room temperature, filtered and extracted with ethyl acetate, and then subjected to vacuum distillation to remove ethyl acetate and benzyl halide. The final product is benzylsilane.

2. The preparation process of benzylsilane according to claim 1, characterized in that: The aminosilane is selected from monoaminosilane or diaminosilane; wherein the monoaminosilane is selected from either γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane; and the diaminosilane is selected from either N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane or N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

3. The preparation process of benzylsilane according to claim 1, characterized in that: The halobenzyl is selected from either benzyl chloride or benzyl bromide.

4. The preparation process of benzylsilane according to claim 1, characterized in that: The inert gas is any one of nitrogen, helium, or argon.

5. The preparation process of benzylsilane according to claim 1, characterized in that: The acid-binding agent is triethylamine.

6. The preparation process of benzylsilane according to claim 1, characterized in that: The organic solvent is selected from any one of N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, and toluene.

Images