Preparation method of dienyldichlorosilane

Abstract

The present invention belongs to the technical field of dienyldichlorosilane, and specifically relates to a method for preparing dienyldichlorosilane. The preparation method comprises reacting a diene and trichlorosilane in the presence of a first catalyst to obtain an alkenyltrichlorosilane; and reacting the alkenyltrichlorosilane with a haloolefin in the presence of a second catalyst to obtain the dienyldichlorosilane. The dienyldichlorosilane produced by this method has a high synthetic yield and a considerable yield, and has application value for large-scale synthesis.

Description

Technical Field

[0001] The present invention relates to the technical field of dienyldichlorosilane, and in particular to a method for preparing dienyldichlorosilane. Background Art

[0002] CN111138469A discloses an organic silane compound, the general formula of which is R 1 R 2 SiX2, where R 1 and R 2 The organosilane compound is a linear, branched, or isomerized olefin group having 4 to 20 carbon atoms and containing an α-olefin double bond at the end; X is a halogen, and X is F, Cl, Br, or I. This organosilane compound can be used to prepare polyolefin resins, improving the melt processing and mechanical properties of polyolefin resins. The organosilane compound is selected from one or more of di(3-butenyl)dichlorosilane, di(4-pentenyl)dichlorosilane, di(5-hexenyl)dichlorosilane, di(6-heptenyl)dichlorosilane, di(8-nonenyl)dichlorosilane, di(9-decenyl)dichlorosilane, and (5-hexenyl)(7-octenyl)dichlorosilane. This patent discloses a "Gentleman method" to obtain the organosilane compound by contacting a product containing a metal organic compound R1MX with trichloroorganosilane R2SiCl3 and silicon tetrachloride SiCl4. Furthermore, CN113683837A discloses an impact-resistant copolymer polypropylene and its preparation method. The impact-resistant copolymer polypropylene includes a propylene homopolymer as a continuous phase matrix and an ethylene-propylene random copolymer as a dispersed phase; the monomers of the ethylene-propylene random copolymer include: propylene, ethylene, di(7-octenyl)dichlorosilane, and α,ω-non-conjugated diene. A method for preparing di(7-octenyl)dichlorosilane is also disclosed, which comprises preparing 7-octenylmagnesium bromide and reacting 7-octenylmagnesium bromide with silicon tetrachloride to obtain di(7-octenyl)dichlorosilane. However, studies have found that the synthesis effects of these Grignard reagent methods are not ideal, with a large amount of unreacted bromoolefins and mono- or poly-substituted by-products, resulting in a low yield of the target compound in the product. For example, the product composition often contains by-products such as mono-substituted 7-octenyltrichlorosilane and poly-substituted tri(7-octenyl)chlorosilane, which are difficult to separate. In addition, studies have found that this method also has the disadvantage of side reactions such as self-coupling of the Grignard reagent to form ethers.

[0003] In addition, patent CN111138469A also discloses a "hydrosilylation method" to prepare an organosilane compound with the general formula R by reacting dichlorosilane SiH2Cl2 with α,ω-diolefin. 1 R 2SiX2. The traditional hydrosilylation method is used to prepare dienyldichlorosilane. This method has a higher yield than the traditional Grignard reagent method mentioned above, but the yield is still relatively low overall. In addition, this preparation method requires the use of a large amount of precious metal catalysts, which is costly. When dichlorosilane is used as a raw material, it is a flammable and explosive hazardous chemical and a highly toxic gas, making it difficult to use. During the experiment, the dichlorosilane that does not participate in the reaction is discharged through the exhaust gas, which is harmful to the environment.

[0004] Since compounds such as bis(3-butenyl)dichlorosilane, bis(4-pentenyl)dichlorosilane, bis(5-hexenyl)dichlorosilane, bis(6-heptenyl)dichlorosilane, bis(7-octenyl)dichlorosilane, bis(8-nonenyl)dichlorosilane and bis(9-decenyl)dichlorosilane(5-hexenyl)(7-octenyl)dichlorosilane (collectively referred to as dienyldichlorosilanes in the present invention, where the "dienyl" refers to two identical or different olefin groups) have great application prospects in preparing polyolefin resins, improving the melt processing performance and mechanical properties of polyolefin resins, and serving as raw materials for preparing impact-resistant copolymer polypropylene, it is particularly necessary to provide a method for synthesizing these dienyldichlorosilanes. Summary of the Invention

[0005] The present invention provides a method for preparing dienyldichlorosilane, which can better synthesize dienyldichlorosilane.

[0006] In a first aspect, embodiments disclose a method for preparing a dienyldichlorosilane, comprising: reacting a diene and trichlorosilane in the presence of a first catalyst to obtain an alkenyltrichlorosilane; and reacting the alkenyltrichlorosilane with a haloolefin in the presence of a second catalyst to obtain the dienyldichlorosilane.

[0007] In some embodiments, the dichlorodiphenylsilane is selected from the group consisting of bis(3-butenyl)dichlorosilane, bis(4-pentenyl)dichlorosilane, bis(5-hexenyl)dichlorosilane, bis(6-heptenyl)dichlorosilane, bis(7-octenyl)dichlorosilane, bis(8-nonenyl)dichlorosilane, bis(9-decenyl)dichlorosilane, and (3-butenyl)(4-pentenyl)dichlorosilane, (3-butenyl)(5-hexenyl)dichlorosilane. One of dichlorosilane, (3-butenyl)(7-octenyl)dichlorosilane, (3-butenyl)(9-decenyl)dichlorosilane, (4-pentenyl)(5-hexenyl)dichlorosilane, (4-pentenyl)(7-octenyl)dichlorosilane, (5-hexenyl)(7-octenyl)dichlorosilane, (5-hexenyl)(9-decenyl)dichlorosilane and (7-octenyl)(9-decenyl)dichlorosilane.

[0008] In some embodiments, the dialkenyldichlorosilane is selected from bis(5-hexenyl)dichlorosilane, (5-hexenyl)(7-octenyl)dichlorosilane, bis(7-octenyl)dichlorosilane, and (7-octenyl)(9-decenyl)dichlorosilane.

[0009] In some embodiments, the diene is selected from one or more of 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, and 1,9-decadiene.

[0010] In some embodiments, the halogenated olefin is selected from one or more of 4-chloro-1-butene, 4-bromo-1-butene, 5-chloro-1-pentene, 5-bromo-1-pentene, 6-chloro-1-hexene, 6-bromo-1-hexene, 7-chloro-1-heptene, 7-bromo-1-heptene, 8-chloro-1-octene, 8-bromo-1-octene, 9-chloro-1-nonene, 9-bromo-1-nonene, 10-chloro-1-decene, and 10-bromo-1-decene.

[0011] In some embodiments, the molar percentage of the total amount of the first catalyst, the diene, and the trichlorosilane is 10 ～5 ~10 ～1 :1, more preferably 10 ～4 ~10 ～2 :1.

[0012] In some embodiments, the molar ratio of the diene to the trichlorosilane is 10 to 1:1.

[0013] In some embodiments, the conditions for the first catalyst reaction include: a reaction temperature of 0 to 120° C. and a reaction time of 0.5 to 24 hours. In some embodiments, the conditions for the first catalyst reaction include: a reaction temperature of 30 to 80° C. and a reaction time of 2 to 24 hours.

[0014] In some embodiments, the first catalyst is selected from one or more industrial Speier catalysts, Willing catalysts, and Karstedt catalysts such as platinum, palladium, PtCl2, H2PtCl6, Na2PtCl4·4H2O, bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum, K{Pt(CH2=CH2)Cl3}H2O and Pt2(CH2=CH2)Cl4.

[0015] In some embodiments, the second catalyst is a Grignard reagent. The second catalyst is selected from magnesium, iodine, and combinations thereof.

[0016] In a second aspect, embodiments disclose a method for preparing bis(7-octenyl)dichlorosilane. The method comprises: reacting 1,7-octadiene and trichlorosilane in the presence of a first catalyst to obtain 7-octenyltrichlorosilane; and reacting 7-octenyltrichlorosilane with 8-bromo-1-octene in the presence of a second catalyst to obtain the bis(7-octenyl)dichlorosilane.

[0017] In some embodiments, the molar percentage of the total amount of the first catalyst, the 1,7-octadiene and the trichlorosilane is 10 ～4 ~10 ～2 :1.

[0018] In some embodiments, the molar ratio of the 1,7-octadiene to the trichlorosilane is 10 to 1:1.

[0019] In some embodiments, the molar ratio of the 7-octenyltrichlorosilane to the 8-bromo-1-octene is 10 to 1:1. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the following examples. It should be understood that the specific examples described herein are merely illustrative of the present invention and are not intended to limit the present invention. Reagents not described in detail herein are all conventional reagents and are commercially available; methods not specifically described in detail are all conventional experimental methods and are known in the art.

[0021] The present invention provides a method for preparing dienyldichlorosilane, which can effectively synthesize dienyldichlorosilane. The method comprises: reacting a diene and trichlorosilane in the presence of a first catalyst to obtain alkenyltrichlorosilane; and reacting the alkenyltrichlorosilane with a haloolefin in the presence of a second catalyst to obtain the dienyldichlorosilane.

[0022] In some embodiments, the dichlorodiphenylsilane is selected from the group consisting of bis(3-butenyl)dichlorosilane, bis(4-pentenyl)dichlorosilane, bis(5-hexenyl)dichlorosilane, bis(6-heptenyl)dichlorosilane, bis(7-octenyl)dichlorosilane, bis(8-nonenyl)dichlorosilane, bis(9-decenyl)dichlorosilane, and (3-butenyl)(4-pentenyl)dichlorosilane, (3-butenyl)(5-hexenyl)dichlorosilane. One of dichlorosilane, (3-butenyl)(7-octenyl)dichlorosilane, (3-butenyl)(9-decenyl)dichlorosilane, (4-pentenyl)(5-hexenyl)dichlorosilane, (4-pentenyl)(7-octenyl)dichlorosilane, (5-hexenyl)(7-octenyl)dichlorosilane, (5-hexenyl)(9-decenyl)dichlorosilane and (7-octenyl)(9-decenyl)dichlorosilane.

[0023] Example 1

[0024] Take 1 mol of 1,7-octadiene and 10 ～4 mol of H2PtCl6, 1 mol of trichlorosilane was slowly added dropwise to 1,7-octadiene at room temperature under magnetic stirring. After the addition was completed, the mixture was reacted at 50°C for 12 hours. After the reaction was completed, the mixture was distilled under reduced pressure and the 60°C (10 mmHg) fraction was taken, which contained 0.751 mol of 7-octenyltrichlorosilane.

[0025] 1 H-NMR (400MHz, CDCl3, ppm): δ: 1.00~1.04 (t, 2H, Si-CH2), 1.29~1.30 (m, 8H, CH2), 2.16~2.20 (m, 2H, CH2), 5.02~5.07 (q, 2H, =CH2), 5.80~5.83 (m, H, CH=).

[0026] Under nitrogen protection, 1.00 mol of magnesium powder and 1 mmol of iodine particles were added to 200 mL of anhydrous ether and magnetically stirred. Then, 0.25 mol of 8-bromo-1-octene was slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution faded, 0.75 mol of 8-bromo-1-octene was slowly added dropwise. The reaction temperature was controlled at 10°C±1°C. After the dropwise addition was completed, the mixture was refluxed for 8 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder to obtain an ether solution containing 7-octenylmagnesium bromide. The above solution containing 7-octenylmagnesium bromide was added dropwise to the fraction containing 0.751 mol of 7-octenyltrichlorosilane. The reaction temperature was 10°C. After the dropwise addition was completed, the mixture was refluxed for 4 hours. After the reaction was completed, the product was distilled under reduced pressure. A fraction at 160°C (10 mmHg) was collected to yield 0.691 mol of di(7-octenyl)dichlorosilane, with a yield of 69.1% (the yield is the molar percentage of the product di(7-octenyl)dichlorosilane and the starting material 8-bromo-1-octene). Its NMR data are shown below:

[0027] 1 H-NMR (400MHz, CDCl3, ppm): δ: 1.00~1.04 (t, 4H, Si-CH2), 1.29~1.30 (m, 16H, CH2), 2.16~2.20(m, 4H, CH2), 5.02~5.07(q, 4H, =CH2), 5.80~5.83(m, 2H, CH=).

[0028] Example 2

[0029] Take 1 mol of 1,7-octadiene and 10～4 1 mol of trichlorosilane was slowly added dropwise to 1,7-octadiene under magnetic stirring at room temperature. After the addition was completed, the mixture was reacted at 50°C for 18 hours. After the reaction was completed, the mixture was distilled under reduced pressure and the fraction at 60°C (10 mmHg) was taken, which contained 0.94 mol of 7-octenyltrichlorosilane.

[0030] Under nitrogen protection, 1.00 mol of magnesium powder and 1 mmol of iodine particles were added to 200 mL of anhydrous tetrahydrofuran and magnetically stirred. Then, 0.25 mol of 8-bromo-1-octene was slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution faded, 0.75 mol of 8-bromo-1-octene was slowly added dropwise. The reaction temperature was controlled at 50°C±1°C. After the dropwise addition was completed, the mixture was refluxed for 8 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder to obtain a tetrahydrofuran solution containing 7-octenylmagnesium bromide. The above tetrahydrofuran solution containing 7-octenylmagnesium bromide was added dropwise to the fraction containing 0.94 mol of 7-octenyltrichlorosilane. The reaction temperature was 30°C. After the dropwise addition was completed, the mixture was refluxed for 8 hours. After the reaction was completed, the product was distilled under reduced pressure and a fraction at 160° C. (10 mmHg) was taken to obtain 0.868 mol of a product fraction containing di(7-octenyl)dichlorosilane with a yield of 86.8% (the yield was the molar percentage of the product di(7-octenyl)dichlorosilane and the raw material 8-bromo-1-octene).

[0031] Example 3

[0032] Take 1 mol of 1,7-octadiene and 0.03 mol of H2PtCl6, and slowly add 1 mol of trichlorosilane to 1,7-octadiene at room temperature under magnetic stirring. After the addition is completed, react at 50°C for 12 hours. After the reaction is completed, distill under reduced pressure and take the 60°C (10 mmHg) fraction, which contains 0.841 mol of 7-octenyltrichlorosilane.

[0033] Under nitrogen protection, 100 mol of magnesium powder and 1 mmol of iodine particles are added to a mixed solvent of 100 ml of anhydrous ether and 100 ml of tetrahydrofuran, and magnetic stirring is performed. Then, 0.25 mol of 8-bromo-1-octene is slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution fades, 0.75 mol of 8-bromo-1-octene is slowly added dropwise. The reaction temperature is controlled at 70°C±1°C. After the dropwise addition is completed, the mixture is refluxed for 8 hours, and then the unreacted magnesium powder is filtered to remove the unreacted magnesium powder to obtain a mixed solvent solution of ether and tetrahydrofuran containing 7-octenylmagnesium bromide. The mixed solvent solution of ether and tetrahydrofuran containing 7-octenylmagnesium bromide is added dropwise to a fraction containing 0.841 mol of 7-octadienyltrichlorosilane. The reaction temperature is 70°C. After the dropwise addition is completed, the mixture is refluxed for 48 hours. After the reaction was completed, the product was distilled under reduced pressure and a fraction at 160° C. (10 mmHg) was taken to obtain 0.682 mol of a product fraction containing di(7-octenyl)dichlorosilane with a yield of 68.2% (the yield was the molar percentage of the product di(7-octenyl)dichlorosilane and the raw material 8-bromo-1-octene).

[0034] Example 4

[0035] Take 1 mol of 1,5-hexadiene and 0.03 mol of H2PtCl6, and slowly add 1 mol of trichlorosilane dropwise to the 1,5-hexadiene at room temperature under magnetic stirring. After the addition is complete, the mixture is reacted at 10°C for 12 hours. After the reaction is complete, vacuum distillation is performed and the 45°C (10 mmHg) fraction is taken, which contains 0.88 mol of 5-hexenyltrichlorosilane. Its NMR data are shown below:

[0036] 1H-NMR (400MHz, CDCl3, ppm): δ: 1.00~1.04 (t, 2H, Si-CH2), 1.29~1.30 (m, 4H, CH2), 2.18 (m, 2H, CH2), 5.02~5.07 (q, 2H, =CH2), 5.80~5.83 (m, H, CH=).

[0037] Under nitrogen protection, 1.00 mol of magnesium powder and 1 mmol of iodine particles were added to 300 ml of anhydrous ether and magnetically stirred. Then, 0.25 mol of 6-chloro-1-hexene was slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution faded, 0.75 mol of 6-chloro-1-hexene was slowly added dropwise. The reaction temperature was controlled at 10°C±1°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder to obtain an ether solution containing 5-hexenylmagnesium chloride. The above ether solution containing 5-hexenylmagnesium chloride was added dropwise to the fraction containing 0.88 mol of 5-hexenyltrichlorosilane. The reaction temperature was 10°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours. After the reaction was completed, the product was distilled under reduced pressure and a fraction at 80° C. (10 mmHg) was taken to obtain 0.743 mol of a product fraction containing di(5-hexenyl)dichlorosilane with a yield of 74.3% (the yield was the molar percentage of the product di(5-hexenyl)dichlorosilane and the raw material 6-chloro-1-hexene).

[0038] Its NMR data are as follows:

[0039] 1 H-NMR (400MHz, CDCl3, ppm): δ: 1.02 (t, 4H, Si-CH2), 1.29~1.30 (m, 8H, CH2), 2.16~2.18 (m, 4H, CH2), 5.02~5.07 (q, 4H, =CH2), 5.80~5.83 (m, 2H, CH=).

[0040] Example 5

[0041] Take 1 mol of 1,9-decadiene and 0.03 mol of H2PtCl6, and slowly add 1 mol of trichlorosilane dropwise to the 1,9-decadiene at room temperature under magnetic stirring. After the addition is complete, react at 10°C for 12 hours. After the reaction is complete, distill under reduced pressure and take the 70°C (10 mmHg) fraction, which contains 0.75 mol of 9-decenyltrichlorosilane. Its NMR data are shown below:

[0042] 1 H-NMR (400MHz, CDCl3, ppm): δ: 1.02 (t, 2H, Si-CH2), 1.29~1.30 (m, 12H, CH2), 2.16~2.18 (m, 2H, CH2), 5.02~5.05 (m, 2H, =CH2), 5.75~5.82 (m, H, CH=).

[0043] Under nitrogen protection, 1.00 mol of magnesium powder and 1 mmol of iodine particles were added to 200 ml of anhydrous ether and magnetically stirred. Then, 0.25 mol of 10-chloro-1-decene was slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution faded, 0.75 mol of 10-chloro-1-decene was slowly added dropwise. The reaction temperature was controlled at 10°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder to obtain an ether solution containing 9-decenylmagnesium chloride. The above ether solution containing 9-decenylmagnesium chloride was added dropwise to the fraction containing 0.75 mol of 9-decenyltrichlorosilane. The reaction temperature was 10°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours. After the reaction was completed, distillation was performed under reduced pressure, and the 180°C (10 mmHg) fraction was collected to obtain 0.657 mol of a product fraction containing di(9-decenyl)dichlorosilane, with a yield of 65.7% (the yield is the molar percentage of the product di(9-decenyl)dichlorosilane and the starting material 10-chloro-1-decene). Its NMR data are shown below:

[0044] 1 H-NMR (400MHz, CDCl3, ppm): δ: 1.02 (t, 4H, Si-CH2), 1.29~1.30 (m, 24H, CH2), 2.16~2.18 (m, 4H, CH2), 5.02~5.05 (m, 4H=CH2), 5.75~5.82 (m, 2H, CH=).

[0045] Example 6

[0046] Take 1 mol of 1,7-octadiene and 0.03 mol of H2PtCl6, and slowly add 1 mol of trichlorosilane to 1,7-octadiene at room temperature under magnetic stirring. After the addition is completed, react at 10°C for 12 hours. After the reaction is completed, distill under reduced pressure and take the 60°C (10 mmHg) fraction, which contains 0.79 mol of 7-octenyltrichlorosilane.

[0047] Under nitrogen protection, 1.00 mol of magnesium powder and 1 mmol of iodine particles were added to 200 ml of anhydrous ether and magnetically stirred. Then, 0.25 mol of 6-chloro-1-hexene was slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution faded, 0.75 mol of 6-chloro-1-hexene was slowly added dropwise. The reaction temperature was controlled at 10°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder to obtain an ether solution containing 5-hexenylmagnesium chloride. The above ether solution containing 5-hexenylmagnesium chloride was added dropwise to the fraction containing 0.79 mol of 7-octenyltrichlorosilane. The reaction temperature was 10°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours. After the reaction was completed, the product was distilled under reduced pressure at 155°C (10 mmHg) to obtain 0.728 mol of a product fraction containing (5-hexenyl)(7-octenyl)dichlorosilane, with a yield of 72.8% (the yield is the molar percentage of the product (5-hexenyl)(7-octenyl)dichlorosilane and the starting material 6-chloro-1-hexene). Its NMR data are shown below:

[0048] 1 H-NMR (400MHz, CDCl3, ppm): δ: 1.02 (t, 4H, Si-CH2), 1.29~1.30 (m, 14H, CH2), 2.16~2.18 (m, 4H, CH2), 5.02~5.07 (q, 4H, =CH2), 5.80~5.83 (m, 2H, CH=).

[0049] Example 7

[0050] Take 1 mol of 1,5-hexadiene and 0.03 mol of H2PtCl6, and slowly add 1 mol of trichlorosilane to 1,5-hexadiene at room temperature under magnetic stirring. After the addition is completed, react at 10°C for 12 hours. After the reaction is completed, distill under reduced pressure and take the 45°C (10 mmHg) fraction, which contains 0.81 mol of 5-hexenyltrichlorosilane.

[0051] Under nitrogen protection, 1.00 mol of magnesium powder and 1 mmol of iodine particles were added to 200 ml of anhydrous ether and magnetically stirred. Then, 0.25 mol of 8-bromo-1-octene was slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution faded, 0.75 mol of 8-bromo-1-octene was slowly added dropwise. The reaction temperature was controlled at 10°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder to obtain an ether solution containing 7-octenylmagnesium bromide. The above ether solution containing 7-octenylmagnesium bromide was added dropwise to the fraction containing 0.81 mol of 5-hexenyltrichlorosilane at a reaction temperature of 10°C. After the dropwise addition was completed, the mixture was refluxed for 48 hours. After the reaction was completed, the product fraction was distilled under reduced pressure at 155°C (10 mmHg) to obtain 0.724 mol of (5-hexenyl)(7-octenyl)dichlorosilane in a yield of 72.4% (the yield was the molar percentage of the product (5-hexenyl)(7-octenyl)dichlorosilane and the raw material 8-bromo-1-octene).

[0052] Comparative Example 1

[0053] Under a nitrogen atmosphere, 1.00 mol of magnesium chips and 0.25 mol of 8-bromo-1-octene were weighed and placed in a 500 mL three-necked flask. 200 mL of dry tetrahydrofuran (THF) was added to the flask and stirring was started. 1 mmol of iodine was added to the reaction solution and stirred at room temperature for 30 minutes. Subsequently, approximately 0.75 mol of 8-bromo-1-octene was slowly added dropwise to the reaction system over 1 hour. The reaction was refluxed for 6 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder. The mixture was filtered under nitrogen to obtain a solution of 7-octenylmagnesium bromide. The above metal organic compound solution was added dropwise to 1 mol of silicon tetrachloride, and the mixture was stirred at room temperature for 12 hours. The mixture was then distilled under reduced pressure and the 160°C (10 mmHg) fraction was taken to obtain 0.247 mol of a product containing di(7-octenyl)dichlorosilane, with a yield of 24.7% (the yield is the molar percentage of the product di(7-octenyl)dichlorosilane and the raw material 8-bromo-1-octene).

[0054] Comparative Example 2

[0055] Under nitrogen protection, 0.22 mol of magnesium powder and 1 mmol of iodine particles were added to 200 mL of anhydrous ether and magnetically stirred. Then, 0.025 mol of 6-chloro-1-hexene was slowly added dropwise to the above solution at a reaction temperature of 10°C. After the purple-red color of the solution faded, 0.25 mol of 6-chloro-1-hexene was slowly added dropwise. The reaction temperature was controlled at 10°C±1°C. After the addition was complete, the mixture was refluxed for 8 hours, and then the unreacted magnesium powder was filtered to remove the unreacted magnesium powder to obtain an ether solution of the metal organic compound (5-hexenylmagnesium chloride). The above metal organic compound solution was added dropwise to 0.1 mol of silicon tetrachloride at a reaction temperature of 10°C. After the addition was complete, the mixture was refluxed for 48 hours. After the reaction was completed, the product was distilled under reduced pressure and a fraction at 60° C. (10 mmHg) was taken to obtain a product containing 0.09 mol of di(5-hexenyl)dichlorosilane with a yield of 32.7% (the yield was the molar percentage of the product di(5-hexenyl)dichlorosilane and the raw material 6-chloro-1-hexene).

[0056] Comparative Example 3

[0057] Take 2 mol of 1,5-hexadiene and 0.03 mol of H2PtCl6, and slowly add 1 mol of dichlorosilane to the 1,5-hexadiene at room temperature under magnetic stirring. After the addition is completed, react at 50°C for 48 hours. After the reaction is completed, distill under reduced pressure and take the 60°C (10 mmHg) fraction to obtain 0.405 mol of product fraction containing di(5-hexenyl)dichlorosilane, with a yield of 40.5% (the yield is the molar percentage of the product di(5-hexenyl)dichlorosilane to the raw material dichlorosilane).

[0058] Comparative Example 4

[0059] Take 2 mol of 1,9-decadiene and 0.03 mol of H2PtCl6, and slowly add 1 mol of dichlorosilane to 1,9-decadiene at room temperature under magnetic stirring. After the addition is completed, react at 50°C for 48 hours. After the reaction is completed, distill under reduced pressure and take the 180°C (10 mmHg) fraction to obtain 0.158 mol of product containing di(9-decenyl)dichlorosilane, with a yield of 15.8% (the yield is the molar percentage of the product di(9-decenyl)dichlorosilane to the raw material dichlorosilane).

[0060] As can be seen from the above examples and comparative examples, the purity and yield of Examples 1 to 7 are significantly higher than those of the comparative examples. Furthermore, the yield of Example 2 is significantly higher than that of Examples 1, 3, 4, 5, 6, and 7, indicating that Example 2 uses bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum as a catalyst to produce more 7-octenyltrichlorosilane, thereby obtaining a higher yield of bis(7-octenyl)dichlorosilane.

[0061] In addition, although Comparative Examples 1 and 2 respectively produced di(7-octenyl)dichlorosilane and di(5-hexenyl)dichlorosilane, and the final distillate product yields were relatively low (less than 40%), they were still lower than the yields (approximately 70%) of the preparation methods of this scheme (Examples 1-3 of di(7-octenyl)dichlorosilane and Example 4 of di(5-hexenyl)dichlorosilane). This is mainly because the reaction liquid before distillation contains not only the target product, divinyldichlorosilane, and unreacted bromoolefin raw material, but also easily produces byproducts such as monosubstituted alkenyltrichlorosilane and trivinylchlorosilane, which are difficult to separate. The product of Comparative Example 2 contains a large amount of unreacted bromoolefin and mono- or polysubstituted byproducts, resulting in a low yield of the target compound in the product. In addition, research has found that this method also has the disadvantage of side reactions such as self-coupling of the Grignard reagent to form an ether.

[0062] Comparative Examples 3 and 4 utilize a traditional hydrosilylation process to prepare dienyldichlorosilane. While Comparative Example 3 demonstrates improved yield compared to the comparative examples, side reactions typically result in only monosubstituted alkenyldichlorosilanes. However, the yield is significantly lower than the 74.1% observed in Example 4 of this scheme. Furthermore, this preparation method requires the use of a large amount of precious metal catalyst, resulting in high costs. The raw material, dichlorosilane, is a flammable, explosive, hazardous chemical and highly toxic gas, making it difficult to use. During the experiment, unreacted dichlorosilane is discharged through the tail gas, posing a hazard to the environment.

[0063] In addition, the traditional Grignard reagent method and the traditional hydrosilylation method can usually only be used to prepare dichlorosilane compounds with the same alkenyl group, and it is rare to directly prepare dichlorosilanes with different alkenyl groups.

[0064] The method provided by the present invention utilizes trichlorosilane, a non-flammable and explosive raw material, in the first step. Its molecular structure contains only one hydrogen atom, making it more susceptible to hydrosilylation reactions with α,ω-dienes. This method utilizes a small amount of precious metal catalyst, resulting in low cost and high yield. Furthermore, it avoids the production of polysubstituted byproducts. The high-purity alkenyltrichlorosilane in the first-step reaction solution is distilled, which also facilitates the second-step reaction. In the second step, the high-purity alkenyltrichlorosilane after distillation is reacted with a high-purity olefin metal halide raw material. By controlling the monosubstitution reaction, dienyldichlorosilane compounds with different or identical alkenyl groups are prepared. This further reduces the production of byproducts such as polysubstituted silanes, resulting in a higher yield of the prepared dienyldichlorosilane.

[0065] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing bis(7-octenyl)dichlorosilane, comprising: 1,7-octadiene and trichlorosilane react in the presence of a first catalyst to obtain 7-octenyltrichlorosilane, wherein the first catalyst is bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum; 7-octenyltrichlorosilane and 8-bromo-1-octene are reacted in anhydrous tetrahydrofuran under the action of a second catalyst to obtain the di(7-octenyl)dichlorosilane, wherein the second catalyst is a combination of magnesium and iodine.

2. The preparation method according to claim 1, wherein The molar percentage of the total amount of the first catalyst, the 1,7-octadiene and the trichlorosilane is 10 -5 ~10 -1 :

1.

3. The preparation method according to claim 1, wherein The molar ratio of the 1,7-octadiene to the trichlorosilane is 10 to 1:

1.

4. The preparation method according to any one of claims 1 to 3, wherein the conditions for the first catalyst to participate in the reaction include: The reaction temperature is 50~120℃, and the reaction time is 0.5~24 hours.