Novel preparation method of tetra (dimethylamino) tin

Abstract

The invention relates to a novel preparation method of tetra (dimethylamino) tin. The method comprises the following steps: in a nitrogen atmosphere, pumping an n-hexane solution of n-butyllithium and an n-hexane solution of dimethylamine into a pipeline through a propeller, mixing through a T-shaped joint, and reacting through a flow reactor 1 and a flow reactor 2 to obtain a lithium dimethylamide mixed solution; the method comprises the following steps: pumping a lithium dimethylamino mixed solution and a n-hexane solution of tin tetrachloride into a pipeline through a propeller, mixing through a T-shaped joint, and reacting through a flow reactor 3 and a flow reactor 4 to obtain a crude tetra (dimethylamino) tin product; and centrifuging and filtering the tetra (dimethylamino) tin crude product, adsorbing impurities by adopting a resin column, and carrying out reduced pressure distillation to remove the solvent, thereby obtaining the tetra (dimethylamino) tin. The adsorption resin column adopts modified macroporous adsorption resin, and is obtained by reacting, filtering and drying D190 macroporous styrene sulfydryl resin, dichloroethane, tetramethylguanidine, 5-allylpyrimidine-4, 6-diol and an ethylene boric anhydride pyridine complex.

Description

Technical Field

[0001] The invention relates to the technical field of tetrakis(dimethylamino)tin, in particular to a new preparation method of tetrakis(dimethylamino)tin. Background Art

[0002] Atomic layer deposition (ALD) is a technology that achieves precise thin film growth at the atomic level by alternately pulsing precursors into the reaction chamber. Compared with other thin film deposition technologies, ALD has low substrate temperature requirements, can accurately control film thickness, uniformly deposit thin films over large areas, and has excellent three-dimensional conformality. In addition, due to the full compatibility of ALD technology with flexible substrates / devices, this technology has received increasing attention and research in recent years. In today's integrated circuit manufacturing field, silicon dioxide (SiO2) is widely used as a gate dielectric material in electronic devices. However, as semiconductor memory and devices gradually tend to be miniaturized, the thickness of traditional silicon dioxide (SiO2) used as a gate dielectric layer material has approached the physical limit. This reduction has led to a significant increase in device power consumption, making it difficult to meet the strict requirements of the microelectronics industry for device stability.

[0003] In order to solve this challenge, one of the effective technical means is to find materials with higher dielectric constants (high-K materials) to replace the SiO2 that has been used. By using high-K materials, the actual thickness of the dielectric layer can be increased, thereby effectively reducing the phenomenon of electrons penetrating the dielectric layer and improving the stability and reliability of electronic devices. The applicability of the precursor will directly affect the functional performance and durability of future electronic devices. Therefore, exploring high-K materials and metal gate material precursors suitable for atomic layer deposition (ALD) and chemical vapor deposition (CVD) technologies has become a hot topic in research and development work.

[0004] Tin oxide (SnO2) has become the focus of the field of transparent conductive materials due to its excellent conductivity, high transmittance and outstanding chemical stability, and has attracted a lot of research work. It has broad application prospects in many fields such as gas sensors, fuel cells, photodetectors, light-emitting diodes, transparent electronic devices, thin film transistors (TFTs) and solar cells. Tetrakis(dimethylamino)tin (CAS: 1066-77-9), as a metal organic precursor, can be prepared by CVD or ALD technology to obtain tin oxide thin films. It not only has good stability and high vapor pressure, but also shows a very high reactivity. Therefore, the synthesis of tetrakis(dimethylamino)tin has become a focus in the field of ALD research.

[0005] At present, the traditional synthesis method of tetrakis(dimethylamino)tin is to first dilute butyl lithium with n-hexane solution, slowly introduce a certain amount of dimethylamine gas, and react to generate a dimethylamino lithium intermediate. Slowly add tin tetrachloride solution to the solution to react to obtain a product. Further separation, after distillation and purification, an organic aminotin precursor of a certain purity is obtained. There are many problems in the traditional method: 1. The raw material n-butyl lithium is extremely active and has harsh conditions for use. If a kettle reactor is selected, a large number of reactants are in contact, the reaction temperature is difficult to control, and the risk factor is relatively large; 2. In the preparation process of the traditional process, the preparation of dimethylamino lithium will be accompanied by a large number of large particles that are difficult to stir. This will not only reduce the reaction rate, but also may cause incomplete reaction of the raw material n-butyl lithium due to insufficient stirring, thereby affecting the yield and increasing the risk factor.

[0006] Chinese patent CN116925130A: relates to a method for preparing tetrakis(dimethylamino)tin, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: S1: adding a solvent to a metal hydride to obtain a suspension; S2: dropping anhydrous tin tetrachloride into the suspension to react and obtain a reaction liquid; S3: introducing dimethylamine into the reaction liquid, stirring the reaction and obtaining a mixture; S4: decompressing the mixture to remove low boiling points, decompressing distillation and rectifying to obtain the tetrakis(dimethylamino)tin.

[0007] Chinese patent CN116947916A: relates to a method for preparing a metal complex, belonging to the field of chemical synthesis technology. The preparation method comprises the following steps: S1, under a protective atmosphere, n-butyl lithium, an activator and a solvent are mixed evenly to obtain a mixed solution; S2, at -30°C to 0°C, an amine compound is added to the mixed solution of S1 to react to obtain a reaction solution; S3, at -30°C to 0°C, a metal chloride is added dropwise to the reaction solution of S2 to react under heating reflux;

[0008] S4. After the reaction is completed, the solvent is removed by reduced pressure, and then the metal complex is obtained by reduced pressure distillation or sublimation.

[0009] Chinese patent CN113563198B: discloses a method for synthesizing tetrakis(dimethylamino)zirconium, comprising the following steps: (1) mixing zirconium tetrachloride and an alkane solvent under a protective atmosphere to obtain a mixed solution; (2) introducing dimethylamine into the mixed solution at -20°C to -10°C to obtain a reaction solution after reaction; (3) adding a dialkylamine into the reaction solution at -20°C to -10°C to cause a reaction; wherein the dialkylamine is diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine or diisobutylamine; (4) collecting the fraction by reduced pressure distillation to obtain tetrakis(dimethylamino)zirconium.

[0010] The problem to be solved by the present invention is to provide a novel continuous synthesis process of tetrakis(dimethylamino)tin to overcome the shortcomings of the existing traditional synthesis process, such as serious heat release, difficult chemical process control, low safety factor, etc. It is urgent and necessary to synthesize and purify the tin source precursor and find a technology that is efficient, accurately controlled, safe, has a small reaction volume, is easy to scale up, is energy-saving and environmentally friendly, and has continuous production. Summary of the invention

[0011] In order to solve the above problems, the present invention provides a new preparation method of tetrakis(dimethylamino)tin, and its operating steps are:

[0012] S1: Under nitrogen atmosphere, 0.04-0.2 mol / L n-butyl lithium in n-hexane solution and 0.05-0.25 mol / L dimethylamine in n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -30 to -20°C. The reaction is carried out in flow reactor 1 and flow reactor 2.

[0013] Obtaining a lithium dimethylamide mixed solution;

[0014] S2: The lithium dimethylamide mixed solution and 0.01-0.05 mol / L tin tetrachloride n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -30 to -20°C. The mixture is reacted in flow reactor 3 and flow reactor 4 to obtain a crude tetrakis(dimethylamino)tin product;

[0015] S3: The crude tetrakis(dimethylamino)tin product is centrifuged and filtered, impurities are adsorbed by a resin column, and the solvent is removed by distillation under reduced pressure to obtain tetrakis(dimethylamino)tin.

[0016] The flow rate of the raw material S1 is 1-1.5 ml / min.

[0017] The residence time of the reactor 1 is 40-60 min, and the oil bath temperature is 20-25°C.

[0018] The residence time of the reactor 2 is 20-30 min, and the oil bath temperature is 40-50°C.

[0019] The residence time of the reactor 3 is 40-60 min, and the oil bath temperature is 20-25°C.

[0020] The residence time of the reactor 4 is 20-30 min, and the oil bath temperature is 40-50°C.

[0021] The method of using a resin column to adsorb impurities in S3 is as follows:

[0022] T1: Column Packing and Sample Loading

[0023] By volume: Use 100-200 parts of wet column packing, soak the modified macroporous adsorption resin with 2000-3000 parts of DMF, slowly pour it into the chromatography column, and turn on the vacuum pump to remove the air in the column to ensure that the resin is tightly filled and free of bubbles;

[0024] Sample loading method: slowly add 20-40 parts of tetrakis(dimethylamino)tin crude product to the top of the loaded resin column to avoid destroying the resin layer structure;

[0025] T2: Flow rate and time

[0026] Flow rate control: The flow rate of the eluent is controlled by adjusting the pressure of the vacuum pump, preferably within 1-3 column volumes per hour to ensure sufficient adsorption and desorption; the operation time is 10-20 hours, and the reaction is terminated;

[0027] The resin column adsorbs impurities using modified macroporous adsorption resin, and its preparation method is as follows:

[0028] According to weight, 100-150 parts of D190 macroporous styrene mercapto resin, 1000-1200 parts of ethylene dichloride, 2-5 parts of tetramethylguanidine, 1.5-3.2 parts of 5-allylpyrimidine-4,6-diol, and 2.4-4.8 parts of ethylene boric anhydride pyridine complex CAS: 442850-89-7 are stirred and reacted at 83-95° C. for 60-100 minutes, filtered, and dried to obtain a modified macroporous adsorption resin.

[0029] Reaction mechanism

[0030] The macroporous styrene mercapto resin and 5-allyl pyrimidine-4,6-diol undergo a mercapto-olefin addition reaction to obtain grafted pyrimidine; then, the grafted pyrimidine reacts with an ethylene boric anhydride pyridine complex to obtain an adsorption resin of the boric anhydride pyridine complex.

[0031] Technical Effects

[0032] The present invention relates to a novel preparation method of tetrakis(dimethylamino)tin. Compared with the prior art, the present invention has the following significant effects:

[0033] 1. Continuous reaction: The pre-made reaction solution is pumped into the pipeline by a propulsion pump, and the reaction is carried out in stages to obtain the crude product of tetrakis(dimethylamino)tin, which can achieve uninterrupted continuous production 24 hours a day; at the same time, the portability of the reaction operation is further increased.

[0034] 2. Improve the safety factor: Since the reaction process is relatively intense, it is difficult to dissipate heat in traditional kettle reactions. Continuous flow reactions can strictly control the reaction process by adjusting the concentration of the prepared reaction solution, controlling the flow rate in the pipeline, and performing staged reactions, thereby further improving the reaction safety factor.

[0035] 3. Adsorption of impurities: The crude tetra(dimethylamino)tin contains a variety of impurities, such as metal ions, organic matter, etc. The macroporous styrene mercapto resin and 5-allylpyrimidine-4,6-diol undergo a mercapto-olefin addition reaction to obtain grafted pyrimidine, which can improve the resin's adsorption capacity for impurities; at the same time, the active functional groups on the grafted pyrimidine can react chemically with the impurities to further enhance its adsorption capacity.

[0036] 4. Improve purity: By reacting grafted pyrimidine with ethylene boric anhydride pyridine complex, an adsorption resin of boric anhydride pyridine complex is obtained; this resin has a high specific surface area and pore structure, and can effectively adsorb impurities in tetrakis(dimethylamino)tin; at the same time, the boron element in the boric anhydride pyridine complex can form a stable compound with tin, thereby reducing the interaction between tin and other impurities and further improving the purity.

[0037] 5. Selective adsorption: Since the active functional groups on the grafted pyrimidine have a certain selectivity, they will preferentially react with impurities during the adsorption process; this makes the adsorption resin have good selectivity when treating crude tetra(dimethylamino)tin, and can effectively remove impurities without affecting the purity of tin. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a process flow chart.

[0039] Figure 2 The 1H NMR image of the product finally obtained by the above process system.

[0040] Figure 3 The 1H NMR image of the final product synthesized by the traditional method (batch feeding) DETAILED DESCRIPTION

[0041] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0042] The purity of the product was determined by NMR.

[0043] Example 1

[0044] A new preparation method of tetrakis(dimethylamino)tin, the operating steps are:

[0045] S1: Under nitrogen atmosphere, 0.04 mol / L n-butyl lithium n-hexane solution and 0.05 mol / L dimethylamine n-hexane solution are pumped into a pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -30°C. After reaction in flow reactor 1 and flow reactor 2, a lithium dimethylamide mixed solution is obtained;

[0046] S2: The lithium dimethylamide mixed solution and 0.01 mol / L tin tetrachloride n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, the temperature is controlled at -30°C, and reacted in flow reactor 3 and flow reactor 4 to obtain a crude tetrakis(dimethylamino)tin product;

[0047] S3: The crude tetrakis(dimethylamino)tin product is centrifuged and filtered, impurities are adsorbed by a resin column, and the solvent is removed by reduced pressure distillation to obtain tetrakis(dimethylamino)tin.

[0048] The flow rate of the raw material S1 is 1 ml / min.

[0049] The residence time of the reactor 1 is 40 min, and the oil bath temperature is 20°C.

[0050] The residence time of the reactor 2 is 20 min, and the oil bath temperature is 40°C.

[0051] The residence time of the reactor 3 is 40 min, and the oil bath temperature is 20°C.

[0052] The residence time of the reactor 4 is 20 min, and the oil bath temperature is 40°C.

[0053] The method of using a resin column to adsorb impurities in S3 is as follows:

[0054] T1: Column Packing and Sample Loading

[0055] Use 100ml wet column packing, soak the modified macroporous adsorption resin with 2000ml DMF, slowly pour it into the chromatography column, and turn on the vacuum pump to remove the air in the column to ensure that the resin is tightly filled and free of bubbles;

[0056] Sample loading method: slowly add 20 ml of crude tetrakis(dimethylamino)tin product to the top of the loaded resin column to avoid destroying the resin layer structure;

[0057] T2: Flow rate and time

[0058] Flow rate control: The flow rate of the eluent is controlled by adjusting the pressure of the vacuum pump, preferably at 1 column volume per hour to ensure sufficient adsorption and desorption; the operation time is 10 hours, and the reaction is terminated;

[0059] The resin column adsorbs impurities using modified macroporous adsorption resin, and its preparation method is as follows:

[0060] 100g D190 macroporous styrene mercapto resin, 1000g ethylene dichloride, 2g tetramethylguanidine, 1.5g 5-allylpyrimidine-4,6-diol, and 2.4g ethylene boric anhydride pyridine complex CAS: 442850-89-7 were stirred and reacted at 83°C for 60 minutes, filtered, and dried to obtain a modified macroporous adsorption resin.

[0061] Example 2

[0062] A new preparation method of tetrakis(dimethylamino)tin, the operating steps are:

[0063] S1: Under nitrogen atmosphere, 0.1 mol / L n-butyl lithium n-hexane solution and 0.1 mol / L dimethylamine n-hexane solution are pumped into a pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -25°C. After reaction in flow reactor 1 and flow reactor 2, a lithium dimethylamide mixed solution is obtained;

[0064] S2: The lithium dimethylamide mixed solution and 0.02 mol / L tin tetrachloride n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, the temperature is controlled at -25°C, and reacted in flow reactor 3 and flow reactor 4 to obtain a crude tetrakis(dimethylamino)tin product;

[0065] S3: The crude tetrakis(dimethylamino)tin product is centrifuged and filtered, impurities are adsorbed by a resin column, and the solvent is removed by distillation under reduced pressure to obtain tetrakis(dimethylamino)tin.

[0066] The flow rate of the raw material S1 is 1.1 ml / min.

[0067] The residence time of the reactor 1 is 44 min, and the oil bath temperature is 22°C.

[0068] The residence time of the reactor 2 is 24 min, and the oil bath temperature is 45°C.

[0069] The residence time of the reactor 3 is 44 min, and the oil bath temperature is 22°C.

[0070] The residence time of the reactor 4 is 24 min, and the oil bath temperature is 45°C.

[0071] The method of using a resin column to adsorb impurities in S3 is as follows:

[0072] T1: Column Packing and Sample Loading

[0073] Use 130ml wet column packing method, soak the modified macroporous adsorption resin with 2400ml DMF, slowly pour it into the chromatography column, and turn on the vacuum pump to remove the air in the column to ensure that the resin is tightly filled and free of bubbles;

[0074] Sample loading method: slowly add 25 ml of crude tetrakis(dimethylamino)tin product to the top of the loaded resin column to avoid destroying the resin layer structure;

[0075] T2: Flow rate and time

[0076] Flow rate control: The flow rate of the eluent is controlled by adjusting the pressure of the vacuum pump, preferably at 2 column volumes per hour to ensure sufficient adsorption and desorption; the operation time is 13 hours, and the reaction is terminated;

[0077] The resin column adsorbs impurities using modified macroporous adsorption resin, and its preparation method is as follows:

[0078] 110 g D190 macroporous styrene mercapto resin, 1050 g ethylene dichloride, 3 g tetramethylguanidine, 2 g 5-allylpyrimidine-4,6-diol, and 3 g ethylene boric anhydride pyridine complex CAS: 442850-89-7 were stirred and reacted at 88° C. for 70 minutes, filtered, and dried to obtain a modified macroporous adsorption resin.

[0079] Example 3

[0080] A new preparation method of tetrakis(dimethylamino)tin, the operating steps are:

[0081] S1: Under nitrogen atmosphere, 0.15 mol / L n-butyl lithium in n-hexane solution and 0.2 mol / L dimethylamine in n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -25°C. After reaction in flow reactor 1 and flow reactor 2, a lithium dimethylamide mixed solution is obtained;

[0082] S2: The lithium dimethylamide mixed solution and 0.04 mol / L tin tetrachloride n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, the temperature is controlled at -25°C, and reacted in flow reactor 3 and flow reactor 4 to obtain a crude tetrakis(dimethylamino)tin product;

[0083] S3: The crude tetrakis(dimethylamino)tin product is centrifuged and filtered, impurities are adsorbed by a resin column, and the solvent is removed by reduced pressure distillation to obtain tetrakis(dimethylamino)tin.

[0084] The flow rate of the raw material S1 is 1.4 ml / min.

[0085] The residence time of the reactor 1 is 55 min, and the oil bath temperature is 24°C.

[0086] The residence time of the reactor 2 is 25 min, and the oil bath temperature is 45°C.

[0087] The residence time of the reactor 3 is 55 min, and the oil bath temperature is 24°C.

[0088] The residence time of the reactor 4 is 25 min, and the oil bath temperature is 45°C.

[0089] The method of using a resin column to adsorb impurities in S3 is as follows:

[0090] T1: Column Packing and Sample Loading

[0091] Use 180ml wet column packing method, soak the modified macroporous adsorption resin with 2800ml DMF, slowly pour it into the chromatography column, and turn on the vacuum pump to remove the air in the column to ensure that the resin is tightly filled and free of bubbles;

[0092] Sample loading method: slowly add 35 ml of crude tetrakis(dimethylamino)tin product to the top of the loaded resin column to avoid destroying the resin layer structure;

[0093] T2: Flow rate and time

[0094] Flow rate control: The flow rate of the eluent is controlled by adjusting the pressure of the vacuum pump, preferably at 2 column volumes per hour to ensure sufficient adsorption and desorption; the operation time is 18 hours, and the reaction is terminated;

[0095] The resin column adsorbs impurities using modified macroporous adsorption resin, and its preparation method is as follows:

[0096] 140g D190 macroporous styrene mercapto resin, 1150g ethylene dichloride, 4g tetramethylguanidine, 3g 5-allylpyrimidine-4,6-diol, and 4g ethylene boric anhydride pyridine complex CAS: 442850-89-7 were stirred and reacted at 93°C for 90 minutes, filtered, and dried to obtain a modified macroporous adsorption resin.

[0097] Example 4

[0098] A new preparation method of tetrakis(dimethylamino)tin, the operating steps are:

[0099] S1: Under nitrogen atmosphere, 0.2 mol / L n-butyl lithium n-hexane solution and 0.25 mol / L dimethylamine n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -20°C. After reaction in flow reactor 1 and flow reactor 2, a lithium dimethylamide mixed solution is obtained;

[0100] S2: The lithium dimethylamide mixed solution and 0.05 mol / L tin tetrachloride n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, the temperature is controlled at -20°C, and reacted in flow reactor 3 and flow reactor 4 to obtain a crude tetrakis(dimethylamino)tin product;

[0101] S3: The crude tetrakis(dimethylamino)tin product is centrifuged and filtered, impurities are adsorbed by a resin column, and the solvent is removed by reduced pressure distillation to obtain tetrakis(dimethylamino)tin.

[0102] The flow rate of the raw material S1 is 1.5 ml / min.

[0103] The residence time of the reactor 1 is 60 min, and the oil bath temperature is 25°C.

[0104] The residence time of the reactor 2 is 30 min, and the oil bath temperature is 50°C.

[0105] The residence time of the reactor 3 is 60 min, and the oil bath temperature is 25°C.

[0106] The residence time of the reactor 4 is 30 min, and the oil bath temperature is 50°C.

[0107] The method of using a resin column to adsorb impurities in S3 is as follows:

[0108] T1: Column Packing and Sample Loading

[0109] Use 200ml wet column packing method, soak the modified macroporous adsorption resin with 3000ml DMF, slowly pour it into the chromatography column, and turn on the vacuum pump to remove the air in the column to ensure that the resin is tightly filled and free of bubbles;

[0110] Sample loading method: Slowly add 40 ml of crude tetrakis(dimethylamino)tin product to the top of the loaded resin column to avoid destroying the resin layer structure;

[0111] T2: Flow rate and time

[0112] Flow rate control: The flow rate of the eluent is controlled by adjusting the pressure of the vacuum pump, preferably at 3 times the column volume per hour to ensure sufficient adsorption and desorption; the operation time is 20 hours, and the reaction is terminated;

[0113] The resin column adsorbs impurities using modified macroporous adsorption resin, and its preparation method is as follows:

[0114] 150g D190 macroporous styrene mercapto resin, 1200g ethylene dichloride, 5g tetramethylguanidine, 3.2g 5-allylpyrimidine-4,6-diol, and 4.8g ethylene boric anhydride pyridine complex CAS: 442850-89-7 were stirred and reacted at 5°C for 100 minutes, filtered, and dried to obtain a modified macroporous adsorption resin.

[0115] Comparative Example 1

[0116] No resin column is used to adsorb impurities, and the rest is the same as in Example 1.

[0117] Comparative Example 2

[0118] The other steps were the same as in Example 1 except that 5-allylpyrimidine-4,6-diol was not added.

[0119] Comparative Example 3

[0120] The ethylene boric anhydride pyridine complex was not added, and the other steps were the same as in Example 1.

[0121] The test results are shown in Table 1.

[0122] Table 1

[0123]

[0124]

[0125] Through the data analysis of the above examples and comparative examples, the tetrakis(dimethylamino)tin prepared by the present invention has higher purity and yield.

[0126] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A new preparation method of tetrakis(dimethylamino)tin, the operating steps of which are: S1: Under a nitrogen atmosphere, a 0.04-0.2 mol / L n-butyl lithium n-hexane solution and a 0.05-0.25 mol / L dimethylamine n-hexane solution are pumped into a pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -30 to -20°C. The mixture is reacted in flow reactor 1 and flow reactor 2 to obtain a lithium dimethylamide mixed solution; S2: The lithium dimethylamide mixed solution and 0.01-0.05 mol / L tin tetrachloride n-hexane solution are pumped into the pipeline through a propeller, mixed by a T-joint, and the temperature is controlled at -30 to -20°C. The mixture is reacted in flow reactor 3 and flow reactor 4 to obtain a crude tetrakis(dimethylamino)tin product; S3: The crude tetrakis(dimethylamino)tin product is centrifuged and filtered, impurities are adsorbed by a resin column, and the solvent is removed by reduced pressure distillation to obtain tetrakis(dimethylamino)tin.

2. A novel method for preparing tetrakis(dimethylamino)tin according to claim 1, characterized in that: The flow rate of the raw material S1 is 1-1.5 ml / min.

3. A novel method for preparing tetrakis(dimethylamino)tin according to claim 1, characterized in that: The residence time of the reactor 1 is 40-60 min, and the oil bath temperature is 20-25°C.

4. A novel method for preparing tetrakis(dimethylamino)tin according to claim 1, characterized in that: The residence time of the reactor 2 is 20-30 min, and the oil bath temperature is 40-50°C.

5. A novel method for preparing tetrakis(dimethylamino)tin according to claim 1, characterized in that: The residence time of the reactor 3 is 40-60 min, and the oil bath temperature is 20-25°C.

6. A novel method for preparing tetrakis(dimethylamino)tin according to claim 1, characterized in that: The residence time of the reactor 4 is 20-30 min, and the oil bath temperature is 40-50°C.

7. A novel method for preparing tetrakis(dimethylamino)tin according to claim 1, characterized in that: The method of using a resin column to adsorb impurities in S3 is as follows: T1: Column Packing and Sample Loading By volume: Use 100-200 parts of wet column packing, soak the modified macroporous adsorption resin with 2000-3000 parts of DMF, slowly pour it into the chromatography column, and turn on the vacuum pump to remove the air in the column to ensure that the resin is tightly filled and free of bubbles; Sample loading method: slowly add 20-40 parts of tetrakis(dimethylamino)tin crude product to the top of the loaded resin column to avoid destroying the resin layer structure; T2: Flow rate and time Flow rate control: The flow rate of the eluent is controlled by adjusting the pressure of the vacuum pump, preferably at 1-3 column volumes per hour to ensure sufficient adsorption and desorption; the operation time is 10-20 hours, and the reaction is terminated.

8. A novel method for preparing tetrakis(dimethylamino)tin according to claim 1, characterized in that: The resin column adsorbs impurities using modified macroporous adsorption resin, and its preparation method is as follows: According to weight, 100-150 parts of D190 macroporous styrene mercapto resin, 1000-1200 parts of ethylene dichloride, 2-5 parts of tetramethylguanidine, 1.5-3.2 parts of 5-allylpyrimidine-4,6-diol, and 2.4-4.8 parts of ethylene boric anhydride pyridine complex CAS: 442850-89-7 are stirred and reacted at 83-95° C. for 60-100 minutes, filtered, and dried to obtain a modified macroporous adsorption resin.

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