阅读说明：本技术 一种硅醚烷基锂的制备方法 (Preparation method of silyl ether lithium alkyl ) 是由 周卫强 储鹏 史先桥 程力伟 蒋国群 朱爱军 曹沛栋 谢云良 董涛 戴玉明 吴晓 于 2021-09-02 设计创作，主要内容包括：本发明提供一种硅醚烷基锂的制备方法,属于聚合引发剂合成技术领域,通过气相沉积法,以本身具备催化活性的多孔纳米镍材料为基底,以吡啶为碳源和氮源,制备得到具有立体结构的掺氮少层石墨烯,再通过扩层处理增大层间距,将其沉积在碳纤维纸基底上得到具有高比表层次结构的薄膜载体,经熔融锂负载后与卤代硅醚在非极性溶剂中反应,反应产物经过滤制得所述硅醚烷基锂；本发明通过制备薄膜载体,将熔融锂金属均匀负载在所述薄膜载体上,具有良好的分散性,使得合成反应充分,具有高收率、低杂质、易分离的特点。(The invention provides a preparation method of silyl ether lithium alkyl, which belongs to the technical field of polymerization initiator synthesis, and is characterized in that a porous nano nickel material with catalytic activity is used as a substrate by a vapor deposition method, pyridine is used as a carbon source and a nitrogen source to prepare nitrogen-doped few-layer graphene with a three-dimensional structure, the interlayer distance is increased by layer expansion treatment, the graphene is deposited on a carbon fiber paper substrate to obtain a film carrier with a high-ratio surface substructure, the film carrier is loaded by fused lithium and then reacts with halogenated silyl ether in a nonpolar solvent, and a reaction product is filtered to prepare the silyl ether lithium alkyl; according to the invention, the film carrier is prepared, and the molten lithium metal is uniformly loaded on the film carrier, so that the film carrier has good dispersibility, full synthesis reaction, high yield, low impurity and easy separation.)

1. The preparation method of the silyl ether lithium alkyl is characterized by comprising the following steps:

s1 preparation of lithium metal

(1) Weighing nickel-manganese alloy powder, dispersing the nickel-manganese alloy powder in a hot ammonium sulfate solution, keeping the temperature and standing for 6-12h, filtering, dispersing the nickel-manganese alloy powder in a mixed solution of polyvinylpyrrolidone and glacial acetic acid again, filtering, washing the nickel-manganese alloy powder by deionized water and absolute ethyl alcohol in sequence, drying the nickel-manganese alloy powder in vacuum, placing the metal powder in an alumina ceramic boat, transferring the metal powder into the middle of a tubular furnace, closing the tubular furnace, pumping out air in the tube, filling argon, heating the metal powder to 900-1000 ℃ at the speed of 5-8 ℃/min under the argon atmosphere, keeping the temperature for 10-20min, annealing the metal powder in the argon-hydrogen mixed atmosphere with the volume ratio of (20-30):1, annealing the metal powder for 3-5min, and switching the atmosphere into the mixed atmosphere with the volume ratio of (12-18): (8-12): 1, performing growth deposition of few-layer graphene in argon-hydrogen-pyridine mixed atmosphere for 20-30min, cooling after deposition is finished, washing a deposition product with a hydrochloric acid solution, and drying to obtain a black-gray powder product;

wherein the concentration of the polyvinylpyrrolidone in the mixed solution of the polyvinylpyrrolidone and the glacial acetic acid is 1g/50 mL;

(2) respectively weighing the black-gray powder product and chromium trioxide, dispersing and dissolving the black-gray powder product and the chromium trioxide in the hydrochloric acid solution, stirring the mixture at room temperature for reaction for 1 to 2 hours, separating precipitates, adding the precipitates into 10 percent hydrogen peroxide for rinsing and soaking, separating the precipitates again, washing the precipitates with deionized water, dispersing the washed precipitates in the deionized water to obtain a dispersion liquid with the dispersion ratio of 4 to 8mg/ml, filtering the dispersion liquid on carbon fiber paper, soaking the carbon fiber paper in a hydriodic acid solution after freeze drying, leaching the carbon fiber paper to be neutral after soaking, and drying to obtain graphene paper;

the concentration of the hydrochloric acid solution is 2-10mol/L, and the mass ratio of the dark gray powder product to the chromium trioxide to the hydrochloric acid solution is 1: 8.5: (8.5-10), wherein the soaking concentration of the hydriodic acid solution is 10 wt.%, the soaking time is 1-5min, and the soaking temperature is 30-60 ℃;

(3) under the protection of argon atmosphere, placing the polished lithium sheet in a stainless steel boat, heating to 300 ℃ to melt the lithium sheet, immersing the graphene paper into molten lithium, injecting the molten lithium into the graphene paper through a pore channel, changing the color from black to silver gray, and enabling the lithium loading to reach 4-8mg/cm²Obtaining lithium-loaded graphene paper;

wherein the content of water and oxygen in the argon atmosphere is less than 1 ppm;

s2 preparation of alkyl lithium

Under the protection of argon, adding halogenated silyl ether and the lithium-loaded graphene paper prepared in the step S1 into a nonpolar solvent with the volume 1-3 times that of the halogenated silyl ether, reacting at 20-50 ℃ for 2-5h, and filtering the reaction product to obtain silyl ether alkyl lithium;

wherein the molar ratio of the halogenated silyl ether to lithium in the lithium-loaded graphene paper is 1: (1-8).

2. The method for preparing the silyl ether lithium alkyl according to claim 1, wherein the method for preparing the halogenated silyl ether comprises the following steps:

reacting a halosilane with a halohydrin in a molar ratio (1-1.3): 1 is dissolved in a polar solvent, imidazole, pyridine or triethylamine with the molar weight 1-1.3 times that of the halogenated silane is added, the mixture is stirred and reacted for 4-8 hours at room temperature under the protection of argon, a non-polar solvent with the volume 2-5 times that of the polar solvent is added, the mixture is stirred and mixed, then the mixture is washed by sodium bicarbonate solution, a non-polar solvent layer is separated, and the halogenated silyl ether is obtained by chromatographic column separation after the solvent is evaporated.

3. The method for preparing silyl ether lithium alkyl according to claim 1, wherein the nonpolar solvent is n-hexane, cyclohexane or n-heptane.

4. The method for preparing silyl ether lithium alkyl according to claim 2, wherein the polar solvent is tetrahydrofuran or N, N-dimethylformamide.

5. The method for preparing the lithium silyl ether alkyl according to claim 2, wherein the halogenated silane is tert-butyldimethylsilyl chloride, and the halogenated alcohol is 3-chloropropanol.

6. The method for preparing the silyl ether lithium alkyl as claimed in claim 1, wherein the carbon fiber paper is pre-treated, specifically washed with 1 wt.% hydrochloric acid and deionized water sequentially.

7. The method for preparing silyl ether lithium alkyl according to claim 1, wherein the graphene paper further comprises silver electroplating treatment, the electrolyte is 0.2mol/L silver nitrate aqueous solution, and the pulse current is 20mA/cm²The pulse duty ratio is 1:1, and the total electroplating time is 140 s.

Technical Field

The invention relates to the technical field of polymerization initiator synthesis, and particularly relates to a preparation method of silyl ether lithium alkyl.

Background

The use of alkyllithium as an initiator for the production of lithium-based anionic polymers is a very important class of organic alkali metal compounds, the unique property of which is both covalent and ionic, which makes them soluble in both polar and non-polar solvents.

The lithium initiator for synthesizing hydroxyl-terminated polybutadiene liquid polymer is prepared through the reaction of monohalogenated or bihalogenated organic compound and metal lithium. The monohalogenated organic compound can synthesize an initiator with a protective group, and the bihalogenated organic compound can synthesize an organic dilithium initiator. The alkyl lithium with silyl ether to protect hydroxyl group is widely used as one kind of anionic olefin polymerization initiator with special function, and may be used in preparing functional star polymer and telechelic polymer, mainly for preparing liquid rubber.

The preparation of the silicon ether alkyl lithium is generally prepared by adopting halogenated alkane and a metal lithium block or lithium sand as raw materials, but the lithium block is used as the raw material, so that the reaction temperature is too high, the color of a product is darker, side reactions are more, and more impurities are caused. The lithium sand is used as a raw material to prepare the lithium alkyl, so that the reaction temperature is reduced, the occurrence of side reactions can be reduced to a certain extent, and the purity of the product is improved. At present, the method for preparing lithium sand by melting metal lithium and then dispersing the metal lithium by high-speed stirring is a mature and commonly applied method in the industry. Heating metal lithium in white oil to a temperature higher than a melting point to completely melt the metal lithium, stirring and dispersing at a high speed of 3000-15000 rpm for 10-30 min, cooling to a temperature below the melting point, stopping stirring, and continuously cooling to obtain the lithium sand. However, the lithium sand prepared by the method often contains more white oil. The white oil contains some impurities, has high treatment difficulty or high treatment cost, and is not generally treated, so that the prepared alkyl lithium has high impurity content, poor appearance color and limited application.

Disclosure of Invention

In order to solve the problems, the invention provides a preparation method of silyl ether lithium alkyl.

The purpose of the invention is realized by adopting the following technical scheme:

a preparation method of silyl ether lithium alkyl comprises the following steps:

s1 preparation of lithium metal

(1) Weighing nickel-manganese alloy powder, dispersing the nickel-manganese alloy powder in a hot ammonium sulfate solution, keeping the temperature and standing for 6-12h, filtering, dispersing the nickel-manganese alloy powder in a mixed solution of polyvinylpyrrolidone and glacial acetic acid again, filtering, washing the nickel-manganese alloy powder by deionized water and absolute ethyl alcohol in sequence, drying the nickel-manganese alloy powder in vacuum, placing the metal powder in an alumina ceramic boat, transferring the metal powder into the middle of a tubular furnace, closing the tubular furnace, pumping out air in the tube, filling argon, heating the metal powder to 900-1000 ℃ at the speed of 5-8 ℃/min under the argon atmosphere, keeping the temperature for 10-20min, annealing the metal powder in the argon-hydrogen mixed atmosphere with the volume ratio of (20-30):1, annealing the metal powder for 3-5min, and switching the atmosphere into the mixed atmosphere with the volume ratio of (12-18): (8-12): 1, performing growth deposition of few-layer graphene in argon-hydrogen-pyridine mixed atmosphere for 20-30min, cooling after deposition is finished, washing a deposition product with a hydrochloric acid solution, and drying to obtain a black-gray powder product;

wherein the concentration of the polyvinylpyrrolidone in the mixed solution of the polyvinylpyrrolidone and the glacial acetic acid is 1g/50 mL;

(2) respectively weighing the black-gray powder product and chromium trioxide, dispersing and dissolving the black-gray powder product and the chromium trioxide in the hydrochloric acid solution, stirring the mixture at room temperature for reaction for 1 to 2 hours, separating precipitates, adding the precipitates into 10 percent hydrogen peroxide for rinsing and soaking, separating the precipitates again, washing the precipitates with deionized water, dispersing the washed precipitates in the deionized water to obtain a dispersion liquid with the dispersion ratio of 4 to 8mg/ml, filtering the dispersion liquid on carbon fiber paper, soaking the carbon fiber paper in a hydriodic acid solution after freeze drying, leaching the carbon fiber paper to be neutral after soaking, and drying to obtain graphene paper;

the concentration of the hydrochloric acid solution is 2-10mol/L, and the mass ratio of the dark gray powder product to the chromium trioxide to the hydrochloric acid solution is 1: 8.5: (8.5-10), wherein the soaking concentration of the hydriodic acid solution is 10 wt.%, the soaking time is 1-5min, and the soaking temperature is 30-60 ℃;

(3) under the protection of argon atmosphere, placing the polished lithium sheet in a stainless steel boat, heating to 300 ℃ to melt the lithium sheet, immersing the graphene paper into molten lithium, injecting the molten lithium into the graphene paper through a pore channel, changing the color from black to silver gray, and enabling the lithium loading to reach 4-8mg/cm²Obtaining lithium-loaded graphene paper;

wherein the content of water and oxygen in the argon atmosphere is less than 1 ppm;

s2 preparation of alkyl lithium

Under the protection of argon, adding halogenated silyl ether and the lithium-loaded graphene paper prepared in the step S1 into a nonpolar solvent with the volume 1-3 times that of the halogenated silyl ether, reacting at 20-50 ℃ for 2-5h, and filtering the reaction product to obtain silyl ether alkyl lithium;

wherein the molar ratio of the halogenated silyl ether to lithium in the lithium-loaded graphene paper is 1: (1-8).

Preferably, the preparation method of the halogenated silyl ether comprises the following steps:

reacting a halosilane with a halohydrin in a molar ratio (1-1.3): 1 is dissolved in a polar solvent, imidazole, pyridine or triethylamine with the molar weight 1-1.3 times that of the halogenated silane is added, the mixture is stirred and reacted for 4-8 hours at room temperature under the protection of argon, a non-polar solvent with the volume 2-5 times that of the polar solvent is added, the mixture is stirred and mixed, then the mixture is washed by sodium bicarbonate solution, a non-polar solvent layer is separated, and the halogenated silyl ether is obtained by chromatographic column separation after the solvent is evaporated.

Preferably, the non-polar solvent is n-hexane, cyclohexane or n-heptane.

Preferably, the polar solvent is tetrahydrofuran or N, N-dimethylformamide.

Preferably, the halogenated silane is tert-butyldimethylsilyl chloride, and the halogenated alcohol is 3-chloropropanol.

Preferably, the carbon fiber paper comprises a pretreatment, specifically a washing with 1 wt.% hydrochloric acid and deionized water in sequence.

Preferably, the graphene paper further comprises silver electroplating treatment, the electrolyte is 0.2mol/L silver nitrate water solution, and the pulse current is 20mA/cm²The pulse duty ratio is 1:1, and the total electroplating time is 140 s.

The invention has the beneficial effects that:

(1) in the preparation reaction of silicon ether alkyl lithium, the surface property of lithium metal has larger influence on the reaction process, the lithium metal is required to have larger lithium surface, inert organic fluid is generally used as a dispersion phase auxiliary agent to disperse the lithium metal to generate large lithium surface, solvent exchange is needed to remove the dispersion phase auxiliary agent after dispersion and cooling, and the processing difficulty is large. On one hand, a lithium metal load body with high dispersion characteristic is obtained through molten metal lithium loading, the lithium metal load body can directly react with halogenated silicon ether, the reaction process is fast, the synthesis yield is high, and meanwhile, the graphene paper carrier can be recycled; on the other hand, the carrier also has natural hydrophobic and air-barrier capacity, and can reduce the sensitivity of lithium metal to water and oxygen.

(2) According to the invention, a silver coating is electroplated between graphene layers on the graphene paper through silver electroplating treatment, so that the affinity of the graphene paper and lithium metal is further improved, liquid molten metal lithium can be rapidly absorbed into the graphene paper with the silver coating through siphoning, and the dispersibility of the lithium metal is further improved.

Detailed Description

The invention is further described with reference to the following examples.

Example 1

3- (tert-butyl-dimethylsilyloxy) -1-propyllithium (molecular formula C)₉H₂₁A method of making LiOSi, CAS No. 97057-70-0), comprising the steps of:

s1 preparation of lithium metal

(1) Weighing Ni30Mn70 alloy powder, dispersing the powder in hot ammonium sulfate solution of 1mol/L, preserving heat, standing for 10 hours for etching, filtering, dispersing the powder in mixed solution of 1g/50mL of polyvinylpyrrolidone and glacial acetic acid again, filtering after dispersing for several seconds, washing precipitates with deionized water and absolute ethyl alcohol in sequence, drying in vacuum, placing the obtained metal powder in an alumina ceramic boat, moving the metal powder into the middle of a tubular furnace, closing the tubular furnace, pumping out air in the tube, filling argon, heating to 950 ℃ at the speed of 5 ℃/min in the argon atmosphere, preserving heat for 12min, and then adding the mixture into a reactor with the volume ratio of 25: Ar-H of 1₂Annealing treatment is carried out in mixed atmosphere, the annealing time is 3-5min, and after the annealing is finished, the atmosphere is switched to 18: 8: 1, carrying out growth deposition on few-layer graphene in argon-hydrogen-pyridine mixed atmosphere for 24min, cooling after deposition is finished, washing a deposition product with 4mol/L hydrochloric acid solution, and drying to obtain a black and gray powder product;

(2) respectively weighing the dark grey powder product and the chromium trioxide, dispersing and dissolving the dark grey powder product and the chromium trioxide in a 4mol/L hydrochloric acid solution, wherein the mass ratio of the dark grey powder product to the chromium trioxide to the hydrochloric acid solution is 1: 8.5: 10, stirring and reacting for 1-2 hours at room temperature, separating precipitates, adding the precipitates into 10% hydrogen peroxide for rinsing and soaking, separating the precipitates again, washing with deionized water, dispersing the washed precipitates in the deionized water to obtain a dispersion liquid with the dispersion ratio of 5mg/ml, filtering the dispersion liquid on carbon fiber paper which is obtained by washing with 1 wt.% hydrochloric acid and deionized water in sequence, soaking the carbon fiber paper in 10 wt.% hydriodic acid solution for 23-min after freeze drying, soaking at the temperature of 50 ℃, leaching the carbon fiber paper to be neutral with the deionized water after soaking, and drying to obtain graphene paper;

(3) under the protection of argon atmosphere, placing the polished lithium sheet in a stainless steel boat, heating to 300 ℃ to melt the lithium sheet, immersing the graphene paper into molten lithium, injecting the molten lithium into the graphene paper through a pore channel, changing the color from black to silver gray, and controlling the contact time of the molten lithium and the graphene paper to enable the lithium loading to reach 6.18mg/cm²And the contact time is 20s, and the lithium-loaded graphene paper is obtained;

wherein the content of water and oxygen in the argon atmosphere is less than 1 ppm;

s2 preparation of alkyl lithium

A 1L four-mouth round-bottom flask is used as a reaction kettle, the reaction kettle is placed in a magnetic stirring heating sleeve, a mercury thermometer is inserted into a left port, a reflux condenser (cooled by tap water) is inserted into a middle port, the top of the condenser is connected with argon gas for purging and maintaining argon seal, a 250mL dropping funnel is inserted into a right port, and a magnet and magnetic stirring are used; the flask, the dropping funnel, the weighing beaker, the sampling glass bottle, the syringe and other instruments are cleaned and dried;

under the protection of argon, 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane and the lithium-loaded graphene paper prepared in the step S1 are mixed and added into a n-hexane solvent with the volume 2 times that of the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane, wherein the molar ratio of the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane to lithium in the lithium-loaded graphene paper is 1: 4.8, reacting for 3 hours at the temperature of 40 ℃, and filtering a reaction product to obtain the 3- (tert-butyl-dimethylsilyloxy) -1-propyl lithium;

the yield of the finished product was 96.8%, the impurity content was 3.1 wt.%, and the chlorine content was less than 0.1 wt.%.

The preparation method of the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane comprises the following steps:

tert-butyldimethylsilyl chloride and 3-chloropropanol were mixed in a molar ratio of 1.1: 1, dissolving in tetrahydrofuran, adding imidazole or pyridine with the molar weight 1.1 times that of the tert-butyldimethylsilyl chloride, stirring and reacting for 6 hours at room temperature under the protection of argon, adding an n-hexane solvent with the volume 4 times that of the tetrahydrofuran, stirring and mixing, washing with a sodium bicarbonate solution, separating out an n-hexane solvent layer, evaporating the solvent, and separating by a chromatographic column to obtain the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane.

Example 2

3- (tert-butyl-dimethylsilyloxy) -1-propyllithium (molecular formula C)₉H₂₁A method of making LiOSi, CAS No. 97057-70-0), comprising the steps of:

s1 preparation of lithium metal

(1) Weighing Ni30Mn70 alloy powder, dispersing the powder in hot ammonium sulfate solution of 1mol/L, preserving heat, standing for 10 hours for etching, filtering, dispersing the powder in mixed solution of 1g/50mL of polyvinylpyrrolidone and glacial acetic acid again, filtering after dispersing for several seconds, washing precipitates with deionized water and absolute ethyl alcohol in sequence, drying in vacuum, placing the obtained metal powder in an alumina ceramic boat, moving the metal powder into the middle of a tubular furnace, closing the tubular furnace, pumping out air in the tube, filling argon, heating to 950 ℃ at the speed of 5 ℃/min in the argon atmosphere, preserving heat for 12min, and then adding the mixture into a reactor with the volume ratio of 25: Ar-H of 1₂Annealing treatment is carried out in mixed atmosphere, the annealing time is 3-5min, and after the annealing is finished, the atmosphere is switched to 18: 8: 1, carrying out growth deposition on few-layer graphene in argon-hydrogen-pyridine mixed atmosphere for 24min, cooling after deposition is finished, washing a deposition product with 4mol/L hydrochloric acid solution, and drying to obtain a black and gray powder product;

(2) respectively weighing the dark grey powder product and the chromium trioxide, dispersing and dissolving the dark grey powder product and the chromium trioxide in a 4mol/L hydrochloric acid solution, wherein the mass ratio of the dark grey powder product to the chromium trioxide to the hydrochloric acid solution is 1: 8.5: 10, stirring and reacting for 1-2 hours at room temperature, separating precipitates, adding the precipitates into 10% hydrogen peroxide for rinsing and soaking, separating the precipitates again, washing with deionized water, dispersing the washed precipitates in the deionized water to obtain a dispersion liquid with the dispersion ratio of 5mg/ml, filtering the dispersion liquid on carbon fiber paper which is obtained by washing with 1 wt.% hydrochloric acid and deionized water in sequence, soaking the carbon fiber paper in 10 wt.% hydriodic acid solution for 23-min after freeze drying, soaking at the temperature of 50 ℃, leaching the carbon fiber paper to be neutral with the deionized water after soaking, and drying to obtain graphene paper;

(3) the graphene paper is subjected to silver electroplating treatment, the electrolyte is 0.2mol/L silver nitrate water solution, and the pulse current is 20mA/cm²The pulse duty ratio is 1:1, and the total electroplating time is 140 s;

(4) under the protection of argon atmosphere, placing the polished lithium sheet in a stainless steel boat, heating to 300 ℃ to melt the lithium sheet, immersing the graphene paper into molten lithium, injecting the molten lithium into the graphene paper through a pore channel, changing the color from black to silver gray, and controlling the contact time of the molten lithium and the graphene paper to enable the lithium loading to reach 6.21mg/cm²And the contact time is 18s, so that the lithium-loaded graphene paper is obtained;

wherein the content of water and oxygen in the argon atmosphere is less than 1 ppm;

s2 preparation of alkyl lithium

A 1L four-mouth round-bottom flask is used as a reaction kettle, the reaction kettle is placed in a magnetic stirring heating sleeve, a mercury thermometer is inserted into a left port, a reflux condenser (cooled by tap water) is inserted into a middle port, the top of the condenser is connected with argon gas for purging and maintaining argon seal, a 250mL dropping funnel is inserted into a right port, and a magnet and magnetic stirring are used; the flask, the dropping funnel, the weighing beaker, the sampling glass bottle, the syringe and other instruments are cleaned and dried;

under the protection of argon, 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane and the lithium-loaded graphene paper prepared in the step S1 are mixed and added into a n-hexane solvent with the volume 2 times that of the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane, wherein the molar ratio of the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane to lithium in the lithium-loaded graphene paper is 1: 4.8, reacting for 3 hours at the temperature of 40 ℃, and filtering a reaction product to obtain the 3- (tert-butyl-dimethylsilyloxy) -1-propyl lithium;

the yield of the finished product was 97.7%, the impurity content was 3.3 wt.%, and the chlorine content was less than 0.1 wt.%.

The preparation method of the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane comprises the following steps:

tert-butyldimethylsilyl chloride and 3-chloropropanol were mixed in a molar ratio of 1.1: 1, dissolving in tetrahydrofuran, adding imidazole or pyridine with the molar weight 1.1 times that of the tert-butyldimethylsilyl chloride, stirring and reacting for 6 hours at room temperature under the protection of argon, adding an n-hexane solvent with the volume 4 times that of the tetrahydrofuran, stirring and mixing, washing with a sodium bicarbonate solution, separating out an n-hexane solvent layer, evaporating the solvent, and separating by a chromatographic column to obtain the 3- (tert-butyl-dimethylsilyloxy) -1-chloropropane.

Example 3

A 1L four-mouth round-bottom flask is used as a reaction kettle, the reaction kettle is placed in a magnetic stirring heating sleeve, a mercury thermometer is inserted into a left port, a reflux condenser (cooled by tap water) is inserted into a middle port, the top of the condenser is connected with argon gas for purging and maintaining argon seal, a 250mL dropping funnel is inserted into a right port, and a magnet and magnetic stirring are used; the flask, the dropping funnel, the weighing beaker, the sampling glass bottle, the syringe and other instruments are cleaned and dried;

placing 17-23g of lithium sand (excessive) and 400-450mL of mixed solvent of cyclopentane and n-hexane into a round-bottom flask in sequence in an argon-sealed glove box, maintaining the reaction temperature at 51-70 ℃, and adding 140-150g of 3- (tert-butyl-dimethylsiloxy) -1-chloropropane (85-90%) into a dropping funnel.

After the reaction system is connected, replacing the atmosphere with argon, putting the flask into a magnetic stirring heating sleeve, heating to 50-60 ℃, then stopping heating and maintaining magnetic stirring, dripping at the speed of about 1 drops every 2s, starting reaction after dripping for about 20min, raising the temperature to the boiling temperature (51-70 ℃) of the solvent, removing the reaction heat mainly by solvent evaporation and condensation in a reflux condenser, keeping the temperature (51-60 ℃) and stirring for 120min after stopping dripping.

The yield of the finished product was 84.8%, the impurity content was 3.7 wt.%, and the chlorine content was 0.11 wt.%.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.