Synthesis method of triethyl silane

Abstract

The invention relates to the technical field of synthesis of triethyl silane, and discloses a synthesis method of triethyl silane, which comprises the following steps: taking tetrahydride and ethylene as starting materials, and generating triethyl silane on a fixed bed reactor under the catalytic action of a catalyst. The technical process is simple, the equipment investment is low, no solvent is needed, purification is convenient, the front fraction diethylsilane can be mechanically applied to the production process, the material use efficiency is improved to the maximum extent, and tetraethylsilane can also be sold as a byproduct after being purified.

Description

TECHNICAL FIELD

[0001] The present application relates to triethylsilane synthesis technical field, especially to a kind of synthesis method of triethylsilane. BACKGROUND

[0002] Triethylsilane is a very wide range of fine chemicals, in medicine, he is a high selectivity reducing agent, in the treatment of diabetes drugs such as dapagliflozin, engeli net, kan geli net, igli net, triethylsilane is used as reducing agent without exception, in the synthesis of antiviral drug oseltamivir phosphate, triethylsilane is also used;In chip manufacturing process, the product is also used.

[0003] The current industrial production of triethylsilane method is mainly with chloroethane and trichlorosilane as starting material Grignard method production: First, in ether solvent, chloroethane and magnesium or magnesium powder is generated by format reaction ethyl magnesium chloride Grignard reagent, then add trichlorosilane to generate triethylsilane and magnesium chloride, then through quenching, washing, concentration, rectification process to obtain triethylsilane.

[0004] Although the raw material of this method is cheap, but there are the following shortcomings: Chloroethane and Grignard reaction of magnesium is a dangerous reaction, in the initiation process, it is easy to cause material, explosion and other dangers, and generally uses ether as solvent, the boiling point is low, further aggravate the danger.

[0005] The second step reaction is very large, and every molecule of product generates three molecules of salt, the solid content is large in the reaction process, stirring is difficult, not conducive to heat transfer, reaction control difficulty is big.

[0006] Production steps are complicated, the atomic utilization rate is not high, the process is long, and the energy consumption is high.

[0007] A large amount of non-useful magnesium chloride is produced, and the environmental protection treatment is difficult. SUMMARY

[0008] The present application relates to triethylsilane synthesis technical field, especially to a kind of triethylsilane synthesis method.

[0009] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: A kind of synthesis method of triethylsilane, comprising the following steps: With tetrahydrogenated silicon and ethylene as starting material, triethylsilane is generated under the catalysis of catalyst in fixed bed reactor, and the reaction formula is as follows: .

[0010] Preferably, the tetrahydrogenated silicon and ethylene are respectively reduced in pressure by a pressure reducer before entering the fixed bed reactor, and then the tetrahydrogenated silicon and ethylene are respectively metered by a mass flow meter, the metered tetrahydrogenated silicon and ethylene are mixed to obtain a mixed reaction gas, and the mixed reaction gas enters the fixed bed reactor for reaction.

[0011] Preferably, the catalyst is a supported platinum-based catalyst.

[0012] Preferably, the tetrahydrogenated silicon and ethylene are in gaseous state, and the molar ratio of the tetrahydrogenated silicon gas to the ethylene gas is 3:1, and the mass ratio is 2.63:1.

[0013] Preferably, after the mixed reaction gas enters the fixed bed reactor for reaction, the mixture after reaction is cooled by a coil and then subjected to gas-liquid separation to obtain a mixed liquid containing triethylsilane, tetraethylsilane and diethylsilane, and the mixed liquid is subjected to rectification separation to obtain triethylsilane.

[0014] Preferably, the supported platinum-based catalyst is a platinum-based catalyst supported on a porous carrier, and the porous carrier includes one or more of alumina, silica or molecular sieve.

[0015] Preferably, the fixed bed reactor is subjected to heat exchange by a jacket oil bath.

[0016] Preferably, the cooling medium of the coil cooling is circulating water or cooling oil.

[0017] Preferably, the gas-liquid separation is performed in a gas-liquid separator.

[0018] Preferably, after the rectification separation, the following is obtained: a front fraction with a boiling point of 56℃, diethylsilane; a main fraction with a boiling point of 109℃, triethylsilane; and a rear fraction with a boiling point of 153℃, tetraethylsilane.

[0019] Compared with the prior art, the present application has the following beneficial effects: The process of the present application is simple, the equipment investment is low, no solvent is needed, the purification is convenient, the front fraction diethylsilane can be used in the production process, the material use efficiency is maximized, and the purified tetraethylsilane can also be sold as a byproduct. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A component schematic diagram of a device for triethylsilane synthesis according to the present application is shown.

[0021] In the figure: 1, a four hydrogenated silicon steel cylinder; 2, an ethylene steel cylinder; 3, a pressure reducer; 4, a gas mass flow meter; 5, a one-way valve; 6, a mixer; 7, a pre-column pressure gauge; 8, a fixed bed reactor; 9, a back pressure valve; 10, a pre-distillation column; 11, a column top condenser; 12, a pre-distillation receiving tank; 13, a delivery pump; 14, a finished product distillation column; 15, a finished product condenser; 16, a finished product receiving tank. DETAILED DESCRIPTION

[0022] In order to make the technical means and purposes of the present application easy to understand, the embodiments of the present application are described in detail below in combination with specific drawings.

[0023] It should be noted that all the terms for indicating direction and position in the present application, such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inner", "outer", "top", "low", "transverse", "longitudinal", "center", etc., are only used to explain the relative positional relationship, connection condition, etc. between the components in a certain specific state (as shown in the drawings), and are only for the convenience of describing the present application, and thus cannot be understood as a limitation on the present application. In addition, the description of "first", "second", etc. in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features.

[0024] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0025] The present application provides a production process of triethylsilane, comprising the following steps: Ethylene and tetrahydrogenated silicon gas pass through the pressure reducer 3 respectively, and are metered by the mass flow meter in a proportion of 3:1 by mol and a mass ratio of 2.63:1. The two gas streams enter the mixer, are fully mixed, and then enter the fixed bed reactor 8. The fixed bed reactor 8 is filled with a supported platinum catalyst and is heat exchanged by a jacket oil bath. The reaction mixture is cooled by a coil, and after gas-liquid separation, the main component in the mixed liquid is triethylsilane, a small amount of tetraethylsilane and diethylsilane. The mixture is then separated by rectification. The pre-distillation is mainly diethylsilane with a boiling point of 56℃, the main distillation is triethylsilane with a boiling point of 109℃, and the post-distillation is tetraethylsilane with a boiling point of 153℃.

[0026] The reaction conversion rate is 99%, the proportion of triethylsilane in the reaction solution is 87%, the proportion of diethylsilane is 8%, and the proportion of tetraethylsilane is 4%, and the separation yield of triethylsilane is about 80%.

[0027] Among them, one silicon atom and three ethyl groups in the triethylsilane molecule can add ethylene to form ethyl under the condition of the presence of a catalyst, and as long as the reasonable ratio is controlled, the generated product can be made of triethylsilane in an absolute proportion. Therefore, a new production process is designed to generate triethylsilane from silicon tetrahydride and ethylene as starting materials in a fixed bed reactor under the catalysis of a platinum catalyst.

[0028] Silicon tetrahydride is a commonly used gas raw material in the chip industry, and ethylene is a bulk chemical raw material with low price. Both materials are gases and are suitable for continuous flow production. The platinum catalyst mainly refers to metal palladium, platinum, ruthenium, etc., and the carrier is activated carbon, aluminum oxide, molecular sieve, diatomite, etc.

[0029] This production process is simple, the equipment investment is low, no solvent is needed, the purification is convenient, the front fraction diethylsilane can be used in the production process, the material use efficiency is maximized, and the purified tetraethylsilane can also be sold as a byproduct.

[0030] The present application adopts a new route for the synthesis of triethylsilane, which has the following advantages compared with the traditional route: 1. The traditional route uses Grignard reagent preparation and Grignard reaction two reaction steps, while the new process only one step reaction generates triethylsilane.

[0031] 2. The new process has excellent atom economy, all atoms in the raw materials are reacted to form components in the product, and no atoms become unnecessary substances. In the traditional process, a large amount of magnesium chloride is generated, and the weight is much larger than the product weight, and the atom economy is very low.

[0032] 3. High production efficiency, no solvent is used, the new process is free of solvent system, the reactants are directly reacted, not only in the form of the highest concentration, but also avoids unnecessary solvent separation, recovery and other processes, greatly improving the production efficiency.

[0033] 4. The new process avoids the dangerous process of Grignard reagent preparation. The process initiated by Grignard reagent in the traditional process is very dangerous, often causing accidents such as material fire. The new process adopts a new route to avoid the dangerous process.

[0034] Therefore, the following conclusions can be drawn: the new process engineering investment cost is greatly reduced, the new process production process is very simple, which means that the process is less, and the investment cost is greatly reduced; the traditional process is complex, not only the reaction process is two steps, but also the subsequent quenching, extraction, washing, multi-stage distillation, solvent water removal, the process is very complex, the corresponding equipment investment and automation investment is greatly increased, compared with the new process, the new process has obvious advantages.

[0035] As shown in Figure 1 The application also provides a device for synthesizing triethylsilane, which is used to realize the production process of the triethylsilane and has the working principle as follows. A silicon tetrahydride cylinder 1 and an ethylene cylinder 2 store silicon tetrahydride gas and ethylene gas respectively, and a pressure reducer 3 is installed to control the output pressure; the pressure reducer 3 is connected with a gas mass flow meter 4 through a pipeline, the gas mass flow meter 4 has the function of controlling the flow according to the set requirements, and the purpose is to control the equivalent of the two kinds of gas raw materials, and the accurate equivalent control is beneficial to the improvement of the proportion of the main product; the outlet of the gas mass flow meter 4 is connected with a one-way valve 5 to prevent the gas or liquid from flowing back to damage the gas mass flow meter 4 under pressure fluctuation; the pipelines of the silicon tetrahydride gas and the ethylene gas are merged into a mixer 6, and the two kinds of gas are mixed uniformly under the gas flow state; the mixed gas is measured by a pre-column pressure gauge 7; the pipeline is connected with a fixed bed reactor 8, the fixed bed reactor 8 is provided with a jacket, and an oil bath or a steam heat source can be used to provide the required temperature for the reaction; the fixed bed reactor 8 is filled with granular catalyst, and the gas contacts the catalyst surface to react under a certain pressure and temperature to generate the required substance; the outlet end of the fixed bed reactor 8 is connected with a back pressure valve 9, which is used to maintain the specific reaction pressure in the fixed bed reactor 8; the back pressure valve 9 is connected to a front distillation column 10, and since the reaction process produces diethylsilane, the boiling point of the diethylsilane is 56℃, which is lower than the boiling point 109℃ of the product, so the diethylsilane is separated at the top of the front distillation column 10, and the triethylsilane and the by-product tetraethylsilane are left in the column still; the front distillation column 10 is provided with 30 plates, and the feed plate number is 15; the top of the front distillation column 10 is connected with a front distillation condenser 11, which is used to condense the gas phase components at the top; the condensed liquid enters a front distillation receiver tank 12 through a pipeline; the column still material enters a product distillation column 14 through a delivery pump 13, and the product distillation column 14 is provided with 30 plates, and the feed height is 25 plates to ensure the purity of the triethylsilane; the gas phase is cooled by a product condenser 15 and collected in a product receiver tank 16.

[0036] Test example: The silane steel cylinder and the ethylene steel cylinder decompression device are respectively adjusted to 1.2 mPa, and the mass flow meter flow is respectively 1 g / min for silane and 2.63 g / min for ethylene, the fixed bed oil bath is set to 80 DEG C, the catalyst is a Pd / C supported catalyst with a particle size of 1 mm, the bed residence time is 1.5 min, and the back pressure valve pressure is adjusted to 1 mPa. The reaction liquid is collected, and the reaction conversion rate is detected by gas chromatography to be 99%, the triethylsilane in the reaction liquid accounts for 87%, the diethylsilane accounts for 8%, and the tetraethylsilane accounts for 4%.

[0037] A rectifying device is built, the rectifying column height is 70 cm, the filler is a stainless steel theta ring, the model is 3*3, and the number of tower plates is about 15. The above reaction liquid is transferred to the tower cauldron rectifying bottle, the oil bath is warmed, the tower top reflux ratio is set to 3, the 55-100 DEG C fraction is collected, the main component is diethylsilane, the 107-110 DEG C fraction is collected, the main component is triethylsilane, the purity is 98.5%, and the yield is about 80%.

[0038] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method for synthesizing triethylsilane, characterized in that: The following steps are involved: Using tetrahydrosilane and ethylene as starting materials, triethylsilane is produced in a fixed bed reactor under the catalytic action of a catalyst. The reaction formula is as follows: 。 2. A method for synthesizing triethylsilane according to claim 1, characterized in that: Before entering the fixed bed reactor, the tetrahydrogen silicon and ethylene are respectively depressurized by a pressure reducer, and the tetrahydrogen silicon and ethylene are respectively measured by a mass flow meter. The measured tetrahydrogen silicon and ethylene are mixed to obtain a mixed reaction gas, and the mixed reaction gas enters the fixed bed reactor for reaction.

3. A method for synthesizing triethylsilane according to claim 2, characterized in that: The catalyst is a supported platinum catalyst.

4. A method for synthesizing triethylsilane according to claim 3, characterized in that: The silicon tetrahydride and ethylene are in gaseous state, and the molar ratio of the silicon tetrahydride gas to the ethylene gas is 3:1, and the mass ratio is 2.63:

1.

5. A method for synthesizing triethylsilane according to claim 4, characterized in that: After the mixed reaction gas enters the fixed bed reactor for reaction, the reaction mixture is cooled through a coil and then subjected to gas-liquid separation to obtain a mixed liquid containing triethylsilane, tetraethylsilane and diethylsilane. The mixed liquid is subjected to rectification and separation to obtain triethylsilane.

6. A method for synthesizing triethylsilane according to claim 5, characterized in that: The supported platinum catalyst is a platinum-based catalyst supported on a porous carrier, and the porous carrier includes one or more of alumina, silica or molecular sieve.

7. A method for synthesizing triethylsilane according to claim 6, characterized in that: The fixed bed reactor is heat exchanged by a jacketed oil bath.

8. A method for synthesizing triethylsilane according to claim 7, characterized in that: The cooling medium for the coil cooling is circulating water or cooling oil.

9. A method for synthesizing triethylsilane according to claim 8, characterized in that: The gas-liquid separation is carried out in a gas-liquid separator.

10. The method for synthesizing triethylsilane according to claim 9, wherein: After the distillation separation, the following is obtained: The front fraction with a boiling point of 56°C is diethylsilane; the main fraction with a boiling point of 109°C is triethylsilane; the rear fraction with a boiling point of 153°C is tetraethylsilane.

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