Method for continuously preparing CGC ligand by coupling ultrasonic field with local mechanical vibration

Abstract

The invention provides a method for preparing a CGC ligand, which comprises the following steps: mixing tetra-substituted cyclopentadiene and n-butyllithium under a mechanical vibration condition, carrying out lithiation reaction under an ultrasonic condition, and then carrying out silicification reaction with a disubstituted dichlorosilane solution, the preparation method comprises the following steps: preparing a silicification product into a tetrahydrofuran solution of the silicification product by using tetrahydrofuran, mixing primary amine and n-butyllithium under a mechanical vibration condition, carrying out lithiation reaction under an ultrasonic condition, carrying out amination reaction on an obtained lithiation reaction solution and the prepared tetrahydrofuran solution of the silicification product, and carrying out post-treatment on the obtained amination reaction solution to obtain the CGC ligand. According to the method for preparing the CGC ligand, the CGC ligand is continuously prepared by coupling the ultrasonic microreactor with local mechanical vibration, the danger coefficient is low, the reaction efficiency is high, the cost is saved, the period is short, and meanwhile, the problem that an organic lithium intermediate generated by lithiation reaction is deposited in the microreactor is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a method for continuously preparing a CGC ligand by coupling an ultrasonic field with local mechanical vibration. Background Art

[0002] In 2021, the China Petroleum Industry Federation emphasized in the "Guidelines for the Development of the Petroleum and Chemical Industry" that it is necessary to vigorously enhance the industry's independent innovation capabilities and accelerate the development of the industrial new materials industry. Focus on breakthroughs in key raw materials such as high-end polyolefins, engineering plastics, high-carbon α-olefin comonomers, metallocene catalysts, and high-performance fluorosilicone materials, and promote some of the country's petrochemical industries to take the lead in entering the ranks of powerful countries. Polyolefin catalysts play an important role in polymerization, and the performance of polyolefin products will also be affected by the structure of the catalyst. Only by vigorously developing high-performance, high-stability, and high-value-added polyolefin catalysts can we achieve innovation in the industry, continuously narrow the gap with developed countries, and promote the further development of China's polyolefin industry.

[0003] Constrained geometry catalyst (CGC catalyst) is widely used to prepare various olefin polymers. Compared with traditional metallocene catalysts, the polymers obtained by CGC catalyst in olefin polymerization have the characteristics of long chain branching (LCB) and narrow relative molecular weight distribution, and thus have excellent processing performance and physical and mechanical properties. The CGC that has been studied more is dimethylsilyl tert-butylamine tetramethylcyclopentadiene titanium dichloride (referred to as CGC type dichlorotitanium complex catalyst or chlorotitanium complex catalyst). The important feature of the molecular structure of CGC catalyst is that a bridging substituent group (such as SiMe2) that restricts the spatial geometric configuration of the metal atom is introduced into the substituted cyclopentadiene, thereby making the active site of the metal atom in the complex more exposed, that is, it has a more "open" feature. This structural feature allows other olefins except ethylene to be inserted into the polyethylene chain during the catalytic olefin polymerization process. Therefore, the catalyst has excellent copolymerization catalytic performance.

[0004] However, although there have been many studies on restricted geometry catalysts in olefin homopolymerization and copolymerization, the synthesis process of this type of complex catalyst usually involves multiple steps such as lithiation and amination to synthesize ligands, dilithiation and salt elimination, which are carried out in a batch reactor. The synthesis process has the defects of complicated steps, low yield, high cost, long cycle and high safety risk, which greatly limits the application and development of this type of catalyst.

[0005] Therefore, there is an urgent need in the art for a method for preparing CGC ligands that is simple to operate, has high reaction efficiency, saves costs, has a short cycle, and has low safety risks. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a method for continuously preparing CGC ligands by coupling local mechanical vibrations with an ultrasonic microreactor. With the extremely high heat transfer rate of the microreactor, the reaction that requires extremely low temperatures in the kettle reactor can be carried out at a higher temperature, which greatly reduces the risk factor, improves the reaction efficiency, saves costs and shortens the cycle. At the same time, ultrasound coupled local mechanical vibration solves the problem of deposition of organic lithium intermediates generated by lithiation reactions in microreactors. Using the synthesis method of the present invention, the silanization reaction and amination reaction involved in the synthesis of CGC ligands can be completed within 10 minutes, and the reaction yield can reach 78.65%.

[0007] To achieve its purpose, the present invention adopts the following technical solutions:

[0008] A method for preparing a CGC ligand, wherein the structural formula of the CGC ligand is as follows:

[0009]

[0010] Wherein, R1, R2, R3, R4, R5 and R6 are methyl or ethyl, and R7 is tert-butyl;

[0011] The method comprises the following steps:

[0012] (1) mixing the tetra-substituted cyclopentadiene solution with a nitrogen gas stream to form a plug flow, which is stream A;

[0013] (2) mixing and diluting the n-butyl lithium n-hexane solution with tetrahydrofuran to obtain stream B;

[0014] (3) Stream A and Stream B are premixed in a micromixer M1 and mechanical vibration is applied to the micromixer M1, and then enter the microreactor R1 for lithiation reaction and ultrasound is applied to the microreactor R1;

[0015] (4) mixing the lithiation reaction solution obtained in step (3) with the disubstituted dichlorosilane solution through a micromixer M2, and then entering the microreactor R2 for a silicidation reaction;

[0016] (5) subjecting the silicification reaction solution obtained in step (4) to rotary evaporation, and using tetrahydrofuran to prepare a tetrahydrofuran solution of the silicification product;

[0017] (6) mixing the primary amine solution with the nitrogen gas stream to form a plug flow, which is stream C;

[0018] (7) mixing and diluting the n-butyl lithium n-hexane solution with tetrahydrofuran to obtain stream D;

[0019] (8) Stream C and stream D are premixed in micromixer M3 and mechanical vibration is applied to micromixer M3, and then enter microreactor R3 for lithiation reaction and ultrasound is applied in microreactor R3;

[0020] (9) mixing the tetrahydrofuran solution prepared in step (5) and the lithiation reaction solution obtained in step (8) through a micromixer M4, and then entering a microreactor R4 for an amination reaction;

[0021] (10) The amination reaction liquid obtained in step (9) is subjected to rotary evaporation to collect the substrate, and then subjected to reduced pressure distillation by an oil pump to collect the 81-83° C. fraction, which is the CGC ligand with a purity of 97-99%.

[0022] According to the method of the present invention, in step (1),

[0023] The structural formula of tetrasubstituted cyclopentadiene is as follows:

[0024]

[0025] Wherein, R1, R2, R3, and R4 are as defined above; preferably, the tetrasubstituted cyclopentadiene is tetramethylcyclopentadiene or tetraethylcyclopentadiene;

[0026] The tetrasubstituted cyclopentadiene solution is a tetrasubstituted cyclopentadiene tetrahydrofuran solution, a tetrasubstituted cyclopentadiene ether solution, etc.;

[0027] The concentration of the tetrasubstituted cyclopentadiene solution is 0.1 to 2 mol / L, preferably 0.1 to 1 mol / L;

[0028] The volume flow ratio of the tetrasubstituted cyclopentadiene solution to nitrogen is 1:(0.5-5), preferably 1:1 to 1:3, and more preferably 1:1 to 1:2.

[0029] According to the method of the present invention, in step (2),

[0030] The concentration of n-butyl lithium in n-hexane solution is 1.6-2.7 mol / L;

[0031] The volume ratio of the n-butyl lithium n-hexane solution to the tetrahydrofuran used for dilution is 1:(4-10), preferably 1:8.

[0032] According to the method of the present invention, in step (3),

[0033] Stream A and stream B are premixed at -78 to 25°C, preferably -10 to 20°C, by a micromixer M1;

[0034] The reaction temperature of the lithiation reaction is -78 to 25°C, preferably -10 to 20°C, and the reaction time of the lithiation reaction is 1 to 360s, preferably 10 to 60s, more preferably 10 to 30s;

[0035] The molar ratio of tetrasubstituted cyclopentadiene to n-butyl lithium is 1:(1-2), preferably 1:(1.1-1.3);

[0036] The frequency of mechanical vibration applied to the micro mixer M1 is 10000 to 31000 times / minute, preferably 20000 to 31000 times / minute;

[0037] Ultrasound is applied to the microreactor R1, and an ultrasonic field is generated by an ultrasonic oscillator with a frequency of 20 to 80 KHz, preferably 40 to 60 KHz. The microreactor R1 is wound around the ultrasonic oscillator and immersed in the condensation circulating liquid.

[0038] According to the method of the present invention, in step (4),

[0039] The molecular formula of the disubstituted dichlorosilane is R5R6SiCl2, wherein R5 and R6 are as defined above; preferably, the disubstituted dichlorosilane is dimethyldichlorosilane, or diethyldichlorosilane;

[0040] The lithiation reaction solution obtained in step (3) is mixed with the disubstituted dichlorosilane solution by a micro mixer M2 at a temperature of -10 to 60° C., preferably 10 to 40° C.;

[0041] The disubstituted dichlorosilane solution includes disubstituted dichlorosilane tetrahydrofuran solution, disubstituted dichlorosilane ether solution, etc.;

[0042] The concentration of the disubstituted dichlorosilane solution is 0.1 to 2 mol / L, preferably 0.1 to 1 mol / L;

[0043] The reaction temperature of the silicification reaction is -10 to 60°C, preferably 10 to 40°C, and the reaction time of the silicification reaction is 1 to 10 minutes, preferably 2 to 8 minutes; more preferably 2 to 5 minutes;

[0044] The molar ratio of tetrasubstituted cyclopentadiene to disubstituted dichlorosilane is 1:(1-3), preferably 1:(1-2).

[0045] According to the method of the present invention, in step (5),

[0046] The rotary evaporation temperature is 20-50°C and the pressure is 50-300 mbar. Preferably, the rotary evaporation temperature is 40°C and the pressure is 200 mbar.

[0047] The concentration of the silicification product in the tetrahydrofuran solution of the silicification product is 0.05 to 0.5 mol / L, preferably 0.1 to 0.3 mol / L.

[0048] According to the method of the present invention, in step (6),

[0049] The molecular formula of the primary amine is R7NH2, wherein R7 is as defined above;

[0050] The primary amine solution is a primary amine tetrahydrofuran solution, a primary amine ether solution, etc.;

[0051] The concentration of the primary amine solution is 0.1 to 2 mol / L, preferably 0.1 to 1 mol / L, more preferably 0.2 to 0.5 mol / L;

[0052] The volume flow ratio of the primary amine to the nitrogen is 1:(0.5-5), preferably 1:(1-3).

[0053] According to the method of the present invention, in step (7),

[0054] The concentration of n-butyl lithium in n-hexane solution is 1.6-2.7 mol / L;

[0055] The volume ratio of the n-butyl lithium n-hexane solution to the tetrahydrofuran used for dilution is 1:(4-10), preferably 1:9.

[0056] According to the method of the present invention, in step (8),

[0057] Stream C and stream D are premixed at a temperature of -78 to 25°C, preferably -10 to 20°C, by a micromixer M3;

[0058] The reaction temperature of the lithiation reaction is -78 to 25°C, preferably -10 to 20°C, and the reaction time of the lithiation reaction is 1 to 360s, preferably 10 to 60s, more preferably 25 to 45s;

[0059] The molar ratio of primary amine to n-butyl lithium is 1:(1-2), preferably 1:(1.1-1.3);

[0060] The frequency of mechanical vibration applied to the micro mixer M3 is 10000 to 31000 times / minute;

[0061] Ultrasound is applied to the microreactor R3, and an ultrasonic field is generated by an ultrasonic oscillator with a frequency of 20 to 80 KHz, preferably 40 to 60 KHz. The microreactor R3 is wound around the ultrasonic oscillator and immersed in the condensation circulating liquid.

[0062] According to the method of the present invention, in step (9), the reaction temperature of the amination reaction is -10 to 60°C, preferably 10 to 40°C, and the reaction time of the amination reaction is 1 to 10 min, preferably 2 to 8 min, and more preferably 3 to 5 min.

[0063] According to the method of the present invention, the inner diameter of the microreactors R1, R2, R3 and R4 is 1 mm.

[0064] Beneficial Effects

[0065] The method for preparing CGC ligand provided by the present invention, by virtue of the extremely high heat transfer rate of the microreactor, enables the reaction that requires extremely low temperature in the autoclave reactor to be carried out at a higher temperature, greatly reducing the risk factor, improving the reaction efficiency, saving costs and shortening the cycle. At the same time, ultrasonic coupling of local mechanical vibration solves the problem of deposition of organic lithium intermediates generated by the lithiation reaction in the microreactor. By adopting the synthesis method of the present invention, the silanization reaction and amination reaction involved in the synthesis of CGC ligand can be completed within 10 minutes, and the reaction yield can reach 78.65%. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 Schematic diagram of the process of silanization reaction in the continuous flow synthesis of CGC ligand.

[0067] Figure 2 Schematic diagram of the process of amination reaction in the continuous flow synthesis of CGC ligand.

[0068] Figure 3 This is the NMR spectrum for purity analysis of CGC ligand. DETAILED DESCRIPTION

[0069] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0070] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0071] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0072] The following is the information about the instruments used:

[0073] The microreactor, with an inner diameter of 1 mm, was made of polytetrafluoroethylene (PFA) and was purchased from IDEX Health & Science. The length of the microreactor used for the lithiation reaction can be changed according to the residence time requirement, and its value is 0.5 to 2 meters. The length of the microreactor used for the silanization reaction and the amination reaction is 8 to 20 meters.

[0074] The syringe pump, model LSP02-1B, was purchased from Lange Constant Flow Pump Co., Ltd.

[0075] The micromixer, namely a T-type micromixer with an inner diameter of 1 mm, was purchased from IDEX Health & Science.

[0076] The low temperature circulating water bath, model SB-5200, was purchased from Xinzhi Biological Co., Ltd.

[0077] The mechanical vibration generator is a Mijia electric toothbrush rod T200, model MES606, purchased from JD.com.

[0078] The ultrasonic generator, product model JLT-1003, with a maximum power of 150W, was purchased from Shenzhen Jielite Ultrasonic Cleaning Equipment Co., Ltd.

[0079] The GC chromatograph was Agilent 7890B, purchased from Agilent.

[0080] The nuclear magnetic resonance spectrometer, model NMR Bruker 400, purchased from Bruker Corporation, was used to determine the purity and structure of the CGC ligand.

[0081] The rotary evaporator, model RV10 control, was purchased from AiKa Instruments Co., Ltd.

[0082] The nitrogen mass flow meter, model CS200-A, with a range of 0-5 SCCM, was purchased from Beijing Sevenstar Huachuang Electronics Co., Ltd.

[0083] Test method:

[0084] GC chromatography test conditions: the chromatographic column is HP-5column, 30m×0.32mm×0.25μm, argon is the carrier gas, the initial column temperature is set to 50°C, the heating rate is 30°C / min, the final temperature is 300°C, and the retention time is 3min.

[0085] NMR spectrometer test conditions:

[0086] The ligand NMR test used deuterated chloroform, the NMR conditions were temperature 298K, pulse condition ZG30, and scan times 8 times.

[0087] Example 1

[0088] Prepare 0.1 mol / L tetramethylcyclopentadiene THF solution, 1 mol / L dimethyldichlorosilane THF solution and 0.2 mol / L tert-butylamine THF solution respectively and set aside.

[0089] Step (1): Mix the prepared tetramethylcyclopentadiene THF solution (concentration of 0.1 mol / L) with nitrogen in a microreactor to form a plug flow, which is stream A;

[0090] Step (2): a n-hexane solution of n-butyl lithium (concentration of 1.6 mol / L, purchased from Titan Corporation) was mixed and diluted with tetrahydrofuran, the volume ratio of the n-hexane solution to tetrahydrofuran being 1:7.9, and the concentration after dilution being 0.18 mol / L, which is stream B;

[0091] Step (3): Stream A and Stream B are premixed through a micromixer M1 and mechanical vibration is applied to the micromixer M1 at a vibration frequency of 31,000 times / minute, and then enter the microreactor R1 for lithiation reaction. The reaction temperature is 10° C. and the reaction residence time is 19 s (the corresponding length of the microreactor R1 is 1 m). During the reaction, ultrasound is continuously applied to the microreactor R1. The frequency of the ultrasonic oscillator is set to 40 KHz. The microreactor R1 is wound around the ultrasonic oscillator and immersed in the condensation circulating liquid.

[0092] Step (4): the outlet of microreactor R1 is connected to micromixer M2, mixed with dimethyldichlorosilane THF solution with a concentration of 1 mol / L through micromixer M2, and then enters microreactor R2 for silicidation reaction, the reaction temperature is 40°C, and the residence time is 180s (the corresponding length of microreactor R2 is 10m);

[0093] Step (5): After the silicification reaction liquid collected by the microreactor R2 is purified by rotary evaporation, a silicification product (P2) is obtained, and a tetrahydrofuran solution of the silicification product is prepared with tetrahydrofuran at a concentration of 0.1 mol / L; the rotary evaporation temperature is 40° C. and the pressure is 200 mbar;

[0094] Step (6): mixing the prepared tert-butylamine THF solution (with a concentration of 0.2 mol / L) with nitrogen in a microreactor to form a plug flow, which is stream C;

[0095] Step (7): a n-hexane solution of n-butyl lithium (concentration of 1.6 mol / L, purchased from Titan Corporation) was mixed and diluted with tetrahydrofuran, the volume ratio of the n-hexane solution to tetrahydrofuran being 1:9, and the concentration after dilution being 0.16 mol / L, which is stream D;

[0096] Step (8): Stream C and stream D are premixed through a micromixer M3 and mechanical vibration is applied to the micromixer M3 at a vibration frequency of 30,000 times / minute, and then enter the microreactor R3 for lithiation reaction. The reaction temperature is 10° C. and the reaction residence time is 28 s (the corresponding length of the microreactor R3 is 1 m). During the reaction, ultrasound is continuously applied to the microreactor R3. The frequency of the ultrasonic oscillator is set to 40 KHz. The microreactor R3 is wound around the ultrasonic oscillator and immersed in the condensation circulating liquid.

[0097] Step (9): the outlet of the microreactor R3 is connected to a micromixer M4, and after mixing with the tetrahydrofuran dilution of the silanized product obtained in the microreactor R2, an amination reaction is carried out in the microreactor R4, the reaction temperature is 40° C., and the residence time is 198 s (the corresponding length of the microreactor R4 is 10 m);

[0098] Step (10): After the amination reaction liquid obtained in step (9) is subjected to rotary evaporation, the substrate is collected, and then vacuum distillation is performed by an oil pump to collect the fraction at 81-83° C., which is the CGC ligand (P3). The purity thereof is 98% according to nuclear magnetic resonance analysis; the conversion rate of tetramethylcyclopentadiene is 82.38% according to GC analysis, and the yield of CGC ligand is 78.09% according to weight analysis.

[0099] In the lithiation reaction and silication reaction of steps (1) to (5), the molar ratio of tetramethylcyclopentadiene:n-butyllithium:dimethyldichlorosilane is n(tetramethylcyclopentadiene):n(nBuLi):n(Me2SiCl2)=1:1.1:2; the volume flow ratio of tetramethylcyclopentadiene solution to nitrogen is V(tetramethylcyclopentadiene solution):V(N2)=1:1; the above lithiation reaction and subsequent silication reaction can be carried out safely and smoothly, especially the lithiation reaction does not need to adopt the deep cold operation process of the kettle process, which significantly reduces energy consumption and ensures process safety;

[0100] In the lithiation reaction and amination reaction of steps (6) to (10), the molar ratio of tert-butylamine:n-butyllithium:silicide product is n(tert-butylamine):n(nBuLi):n(silicide product)=1:1.1:0.9; the volume flow ratio of tert-butylamine to nitrogen is V(tert-butylamine):V(N2)=1:2; the above lithiation reaction and subsequent amination reaction can be carried out safely and smoothly, especially the lithiation reaction does not need to adopt the deep cold operation process of the autoclave process, which significantly reduces energy consumption and ensures process safety.

[0101] The process schematic diagram of the silanization reaction during the continuous flow synthesis of CGC ligand in Example 1 is as follows Figure 1 As shown; the process schematic diagram of the amination reaction during the continuous flow synthesis of CGC ligand is as shown Figure 2As shown; the nuclear magnetic resonance spectrum of the purity analysis of the CGC ligand prepared in Example 1 is as shown Figure 3 shown.

[0102] Example 2

[0103] The ether in step (1) was used as a solvent to prepare the tetramethylcyclopentadiene ether solution, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 81.52%, the yield of CGC ligand was 77.5%, and the purity was 98.5%.

[0104] Example 3

[0105] The concentration of tetramethylcyclopentadiene THF solution in step (1) was changed to 0.2 mol / L, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 81.2%, the yield of CGC ligand was 77.8%, and the purity was 98.5%.

[0106] Example 4

[0107] The frequency of the ultrasonic oscillator for applying ultrasound to the microreactor R1 in step (3) was changed to 50 KHz, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 81.6%, the yield of CGC ligand was 78.3%, and the purity was 98.6%.

[0108] Example 5

[0109] The concentration of dimethyldichlorosilane THF solution in step (4) was changed to 0.5 mol / L, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 81.8%, the yield of CGC ligand was 77.9%, and the purity was 98.8%.

[0110] Example 6

[0111] The molar ratio of the amination reaction in step (9) was changed to n(tert-butylamine):n(nBuLi):n(siliconized product)=1:1.2:0.9, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 81.82%, the yield of CGC ligand was 77.5%, and the purity was 97.8%.

[0112] Example 7

[0113] At the same time, the concentration of the n-butyl lithium n-hexane solution in step (2) and step (7) was changed (referring to the concentration of the purchased solution), and its value was 2 mol / L. The residence time and the molar ratio of the reactants were kept unchanged by adjusting the flow rate and the tube length, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 80.25%, the yield of CGC ligand was 77.21%, and the purity was 98%.

[0114] Example 8

[0115] At the same time, the volume ratio of the n-butyl lithium solution to tetrahydrofuran in the dilution process of the n-butyl lithium n-hexane solution in step (2) and step (7) was changed to 1:6, and the residence time and the molar ratio of the reactants were kept unchanged by adjusting the flow rate and the tube length, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 81%, the CGC ligand yield was 78.2%, and the purity was 98.5%.

[0116] Example 9

[0117] The mechanical vibration frequency applied by the micro mixer M1 in step (3) was changed to 20,000 times / min, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 83.1%, the yield of CGC ligand was 77.8%, and the purity was 98%.

[0118] Example 10

[0119] The tetrahydrofuran solution prepared in step (5) to obtain the silanized product was changed to a concentration of 0.2 mol / L, and the residence time and the molar ratio of the reactants were kept unchanged by adjusting the flow rate and the tube length, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 82.2%, the yield of CGC ligand was 78.8%, and the purity was 98.6%.

[0120] Embodiment 11

[0121] The mechanical vibration frequency applied by the micro mixer M3 in step (8) was changed to 25,000 times / min, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 82.5%, the yield of CGC ligand was 77.5%, and the purity was 98.2%.

[0122] Example 12

[0123] The concentration of the tert-butylamine THF solution in step (6) was changed to 0.5 mol / L, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 83%, the yield of CGC ligand was 78.5%, and the purity was 99%.

[0124] Embodiment 13

[0125] The volume flow ratio of step (6) was changed to V(tert-butylamine):V(N2)=1:3, and the residence time was kept unchanged by adjusting the tube length, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 83.2%, the yield of CGC ligand was 77.58%, and the purity was 99%.

[0126] Embodiment 14

[0127] The reaction temperature of the lithiation reaction in step (3) and the lithiation reaction in step (8) was adjusted to -10°C, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 82.35%, the yield of CGC ligand was 78.65%, and the purity was 99%.

[0128] Embodiment 15

[0129] In step (3), the lithiation reaction in the microreactor R1 was carried out at -10°C and with a residence time of 10 s, that is, the residence time was changed by adjusting its length to 0.52 m, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 81.12%, the yield of CGC ligand was 76.78%, and the purity was 97.2%.

[0130] Example 16

[0131] The residence time of the lithiation reaction in step (3) and the residence time of the lithiation reaction in step (8) were adjusted to 28.5 s and 42 s, respectively, that is, the lengths of R1 and R3 were both adjusted to 1.5 m, and the rest were the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 83.62%, the yield of CGC ligand was 77.5%, and the purity was 98.8%.

[0132] Embodiment 17

[0133] The reaction temperature of the silylation reaction in step (4) and the amination reaction in step (9) was adjusted to 30° C., and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 80.9%, the yield of CGC ligand was 76.95%, and the purity was 97%.

[0134] Embodiment 18

[0135] The residence time of the silicidation reaction in step (4) and the amination reaction in step (9) were adjusted to 210 s and 230 s respectively, that is, the lengths of R2 and R4 were both adjusted to 11.7 m, and the rest were the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 83.52%, the yield of CGC ligand was 77.05%, and the purity was 98.3%.

[0136] Embodiment 19

[0137] The rotary evaporation temperature in step (5) was adjusted to 50° C. and the pressure was adjusted to 100 mbar, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 82.1%, the yield of CGC ligand was 77.8%, and the purity was 98.5%.

[0138] Embodiment 20

[0139] The volume flow ratio of the tetrasubstituted cyclopentadiene solution to nitrogen in step (1) was 1:2, and the residence time and the molar ratio of the reactants were kept constant by adjusting the flow rate and the tube length, and the rest was the same as in Example 1. Finally, the conversion rate of tetramethylcyclopentadiene was 83.1%, the yield of CGC ligand was 79.8%, and the purity was 98.2%.

[0140] Embodiment 21

[0141] Tetraethylcyclopentadiene was used to replace tetramethylcyclopentadiene, and the rest was the same as in Example 1. Finally, the conversion rate of tetraethylcyclopentadiene was 80.5%, the yield of CGC ligand was 75.5%, and the purity was 97%.

[0142] Embodiment 22

[0143] No nitrogen was introduced into the reaction, and the rest was the same as in Example 1. Finally, during the lithiation, silication and amination reactions, the stability of the system was poor, the solid was unevenly distributed in the microreactor, and repeatable experimental results could not be obtained.

[0144] Embodiment 23

[0145] No ultrasound or mechanical vibration was applied during the reaction, and the rest was the same as in Example 1. Finally, during the lithiation, silicification and amination reactions, the stability of the system was poor, solids were deposited and blocked in the microreactor, and no repeatable experimental results could be obtained.

Claims

1. A method for preparing a CGC ligand, wherein: The structural formula of the CGC ligand is as follows: Wherein, R1, R2, R3, R4, R5 and R6 are methyl or ethyl, and R7 is tert-butyl; The method comprises the following steps: (1) mixing the tetra-substituted cyclopentadiene solution with a nitrogen gas stream to form a plug flow, which is stream A; (2) mixing and diluting the n-butyl lithium n-hexane solution with tetrahydrofuran to obtain stream B; (3) Stream A and Stream B are premixed in a micromixer M1 and mechanical vibration is applied to the micromixer M1, and then enter the microreactor R1 for lithiation reaction and ultrasound is applied to the microreactor R1; (4) mixing the lithiation reaction solution obtained in step (3) with the disubstituted dichlorosilane solution through a micromixer M2, and then entering the microreactor R2 for a silicidation reaction; (5) subjecting the silicification reaction solution obtained in step (4) to rotary evaporation, and using tetrahydrofuran to prepare a tetrahydrofuran solution of the silicification product; (6) mixing the primary amine solution with the nitrogen gas stream to form a plug flow, which is stream C; (7) mixing and diluting the n-butyl lithium n-hexane solution with tetrahydrofuran to obtain stream D; (8) Stream C and stream D are premixed in micromixer M3 and mechanical vibration is applied to micromixer M3, and then enter microreactor R3 for lithiation reaction and ultrasound is applied in microreactor R3; (9) mixing the tetrahydrofuran solution prepared in step (5) and the lithiation reaction solution obtained in step (8) through a micromixer M4, and then entering a microreactor R4 for an amination reaction; (10) The amination reaction liquid obtained in step (9) is subjected to rotary evaporation to collect the substrate, and then subjected to reduced pressure distillation by an oil pump to collect the 81-83° C. fraction, which is the CGC ligand with a purity of 97-99%.

2. The method according to claim 1, wherein: In step (1), The structural formula of tetrasubstituted cyclopentadiene is as follows: Wherein, R1, R2, R3, and R4 are as defined in claim 1; preferably, the tetrasubstituted cyclopentadiene is tetramethylcyclopentadiene or tetraethylcyclopentadiene; The tetrasubstituted cyclopentadiene solution is a tetrasubstituted cyclopentadiene tetrahydrofuran solution or a tetrasubstituted cyclopentadiene ether solution; The concentration of the tetrasubstituted cyclopentadiene solution is 0.1 to 2 mol / L, preferably 0.1 to 1 mol / L; The volume flow ratio of the tetrasubstituted cyclopentadiene solution to nitrogen is 1:(0.5-5), preferably 1:1 to 1:3, and more preferably 1:1 to 1:

2.

3. The method according to claim 1 or 2, wherein: In step (2), The concentration of n-butyl lithium in n-hexane solution is 1.6-2.7 mol / L; The volume ratio of the n-butyl lithium n-hexane solution to the tetrahydrofuran used for dilution is 1:(4-10), preferably 1:

8.

4. The method according to any one of claims 1 to 3, wherein: In step (3), Stream A and stream B are premixed at -78 to 25°C, preferably -10 to 20°C, by a micromixer M1; The reaction temperature of the lithiation reaction is -78 to 25°C, preferably -10 to 20°C, and the reaction time of the lithiation reaction is 1 to 360s, preferably 10 to 60s, more preferably 10 to 30s; The molar ratio of tetrasubstituted cyclopentadiene to n-butyl lithium is 1:(1-2), preferably 1:(1.1-1.3); The frequency of mechanical vibration applied to the micro mixer M1 is 10000 to 31000 times / minute, preferably 20000 to 31000 times / minute; Ultrasound is applied to the microreactor R1, and an ultrasonic field is generated by an ultrasonic oscillator with a frequency of 20 to 80 KHz, preferably 40 to 60 KHz. The microreactor R1 is wound around the ultrasonic oscillator and immersed in the condensation circulating liquid.

5. The method according to any one of claims 1 to 4, wherein: In step (4), The molecular formula of the disubstituted dichlorosilane is R5R6SiCl2, wherein R5 and R6 are as defined in claim 1; preferably, the disubstituted dichlorosilane is dimethyldichlorosilane or diethyldichlorosilane; The lithiation reaction solution obtained in step (3) is mixed with the disubstituted dichlorosilane solution by a micro mixer M2 at a temperature of -10 to 60° C., preferably 10 to 40° C.; The disubstituted dichlorosilane solution is a disubstituted dichlorosilane tetrahydrofuran solution or a disubstituted dichlorosilane ether solution; The concentration of the disubstituted dichlorosilane solution is 0.1 to 2 mol / L, preferably 0.1 to 1 mol / L; The reaction temperature of the silicification reaction is -10 to 60°C, preferably 10 to 40°C, and the reaction time of the silicification reaction is 1 to 10 minutes, preferably 2 to 8 minutes; more preferably 2 to 5 minutes; The molar ratio of tetrasubstituted cyclopentadiene to disubstituted dichlorosilane is 1:(1-3), preferably 1:(1-2).

6. The method according to any one of claims 1 to 5, wherein: In step (5), The rotary evaporation temperature is 20-50°C and the pressure is 50-300 mbar. Preferably, the rotary evaporation temperature is 40°C and the pressure is 200 mbar. The concentration of the silicification product in the tetrahydrofuran solution of the silicification product is 0.05 to 0.5 mol / L, preferably 0.1 to 0.3 mol / L.

7. The method according to any one of claims 1 to 6, wherein: In step (6), The molecular formula of the primary amine is R7NH2, wherein R7 is as defined in claim 1; The primary amine solution is a tetrahydrofuran solution of the primary amine or an ether solution of the primary amine; The concentration of the primary amine solution is 0.1 to 2 mol / L, preferably 0.1 to 1 mol / L, more preferably 0.2 to 0.5 mol / L; The volume flow ratio of the primary amine to the nitrogen is 1:(0.5-5), preferably 1:(1-3).

8. The method according to any one of claims 1 to 7, wherein: In step (7), The concentration of n-butyl lithium in n-hexane solution is 1.6-2.7 mol / L; The volume ratio of the n-butyl lithium n-hexane solution to the tetrahydrofuran used for dilution is 1:(4-10), preferably 1:

9.

9. The method according to any one of claims 1 to 8, wherein: In step (8), Stream C and stream D are premixed at a temperature of -78 to 25°C, preferably -10 to 20°C, by a micromixer M3; The reaction temperature of the lithiation reaction is -78 to 25°C, preferably -10 to 20°C, and the reaction time of the lithiation reaction is 1 to 360s, preferably 10 to 60s, more preferably 25 to 45s; The molar ratio of primary amine to n-butyl lithium is 1:(1-2), preferably 1:(1.1-1.3); The frequency of mechanical vibration applied to the micro mixer M3 is 10000 to 31000 times / minute; Ultrasound is applied to the microreactor R3, and an ultrasonic field is generated by an ultrasonic oscillator with a frequency of 20 to 80 KHz, preferably 40 to 60 KHz. The microreactor R3 is wound around the ultrasonic oscillator and immersed in the condensation circulating liquid.

10. The method according to any one of claims 1 to 9, wherein: In step (9), the reaction temperature of the amination reaction is -10 to 60°C, preferably 10 to 40°C, and the reaction time of the amination reaction is 1 to 10 min, preferably 2 to 8 min, and more preferably 3 to 5 min; preferably, the inner diameter of the microreactors R1, R2, R3 and R4 is 1 mm.

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