A production method of tetrabutyl tin by using a single solvent
By using isopropyl ether as a single solvent, combined with temperature, dropping rate and stirring control, low-concentration hydrochloric acid treatment and low-boiling-point distillation, a highly efficient preparation of tetrabutyltin was achieved, solving the problems of solvent loss and high energy consumption in traditional methods, and improving product yield and purity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NINGXIA LINGSHI NEW MATERIAL TECH CO LTD
- Filing Date
- 2026-03-31
- Publication Date
- 2026-06-09
AI Technical Summary
Traditional methods for preparing tetrabutyltin suffer from problems such as high solvent loss, high separation energy consumption, complex dehydration process, and low product yield.
By using isopropyl ether as the sole solvent, and by controlling the temperature, dropping rate, and stirring speed, combined with low-concentration hydrochloric acid treatment and low-boiling-point distillation, efficient solvent recovery and high product yield can be achieved.
It solves the problems of high solvent loss, high separation energy consumption, complex water removal process, and low product yield, improves production efficiency and product purity, and reduces costs and environmental protection pressure.
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Figure CN122167473A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic compound synthesis technology, and to a method for preparing tetrabutyltin using a single solvent. Background Technology
[0002] Tetrabutyltin is an important organotin intermediate, widely used in the synthesis of polyvinyl chloride stabilizers, organotin catalysts, and precursors for functional materials. Currently, the mainstream industrial method for preparing tetrabutyltin is the Grignard reaction, which involves reacting magnesium with chlorobutane to generate butyl magnesium chloride Grignard reagent, which is then alkylated with tin tetrachloride. This reaction has stringent requirements for the solvent system, balancing the stability and reactivity of the Grignard reagent with the ease of subsequent separation. Traditional processes typically use tetrahydrofuran as a single solvent or a mixed solvent system of THF and toluene.
[0003] However, traditional solvent systems have significant technical drawbacks. When using THF as a single solvent, due to the partial miscibility of THF with water, a large amount of THF dissolves in the aqueous phase during the quenching and layering process after the reaction, resulting in severe solvent loss. Furthermore, the wastewater containing THF has a high COD value, leading to high environmental treatment costs. The recovered THF contains moisture and must be dried using molecular sieves before reuse, adding to the process and generating hazardous solid waste. While using a mixture of THF and toluene as a solvent can improve the layering effect by utilizing the immiscibility of toluene with water, toluene has a high boiling point, resulting in high energy consumption for subsequent distillation separation. Additionally, toluene residues are easily found in THF, requiring purification through distillation before reuse, significantly increasing equipment investment and operating costs.
[0004] The aforementioned solvent system leads to problems such as high solvent loss, high separation energy consumption, and complex dehydration processes, directly resulting in high production costs for tetrabutyltin. Furthermore, because toluene has a high boiling point, close to that of the product, a large amount of foredistillate must be removed during distillation to ensure product purity, further reducing the yield per batch. Therefore, developing a simple, efficient solvent recovery, low-energy-consumption, and high-yield method for preparing tetrabutyltin has become a pressing technical challenge for the industry. Summary of the Invention
[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a production method for preparing tetrabutyltin using a single solvent, which solves the four major technical problems that have long existed in the traditional THF and toluene mixed solvent process: large solvent loss, high separation energy consumption, complex dehydration process, and low product yield.
[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing tetrabutyltin using a single solvent specifically includes the following steps: S1: Weigh 115-130 parts by weight of isopropyl ether as solvent and add 40-45 parts by weight of magnesium shavings. Then raise the temperature of the mixture and stop heating after the reflux in the reaction system is stable. Then add 153-171 parts by weight of chlorobutane and keep warm for 1 hour to obtain a mixture of butyl magnesium chloride and isopropyl ether. S2: Mix equal volumes of tin tetrachloride and isopropyl ether, and add them dropwise to the butyl magnesium chloride obtained in S1 at a rate of 2 drops / s. Stir continuously for 30 minutes, then stir the mixture for 30 minutes and control the temperature of the mixture to room temperature to obtain a mixture of TBT, anhydrous magnesium chloride and isopropyl ether. S3: Transfer the final mixture of TBT, anhydrous magnesium chloride and isopropyl ether obtained in S2 to the reactor and add isopropyl ether. Then heat the system to collect the anhydrous isopropyl ether. S4: Add hydrochloric acid dropwise to the system heated in S3. After the magnesium chloride in the reaction system is completely dissolved, let it stand to separate into layers to obtain a mixture of TBT and isopropyl ether and an aqueous solution of magnesium chloride. S5: The TBT and isopropyl ether mixture obtained in S4 is heated to 50~60℃ to remove solvent and obtain isopropyl ether containing a small amount of water. Finally, the remaining solution is collected by vacuum distillation to obtain the TBT product.
[0007] Preferably, the temperature of the system described in S1 is raised to 50~60°C.
[0008] Preferably, the molar ratio of chlorobutane to magnesium added in S1 is 1~1.2:1.
[0009] Preferably, in S2, tin tetrachloride is added dropwise to butyl magnesium chloride at a stirring speed of 500~1000 rpm.
[0010] Preferably, the molar ratio of tin tetrachloride to butyl magnesium chloride added in S2 is 1.0~1.2:4.
[0011] Preferably, when adding tin tetrachloride and butyl magnesium chloride dropwise to S2, the temperature of the reaction system is controlled to be in the range of 23~27℃.
[0012] Preferably, the anhydrous isopropyl ether collected in S3 is reused as the isopropyl ether solvent used in step S1.
[0013] Preferably, the mass percentage concentration of hydrochloric acid added in S4 is 1~3%.
[0014] Preferably, the isopropyl ether containing a small amount of water obtained in S5 is reused for the isopropyl ether added in S3.
[0015] Preferably, the remaining solution in S5 is distilled under reduced pressure for 30 minutes in a distillation environment with a vacuum degree of -0.08 MPa and a temperature of 80~90℃.
[0016] The technical effects and advantages of the method for preparing tetrabutyltin using a single solvent according to the present invention are as follows: 1. This invention uses isopropyl ether as a single solvent, completely eliminating the traditional mixed solvent system of THF and toluene. It solves the problems of separation difficulties and high energy consumption caused by solvent miscibility. Isopropyl ether has a low boiling point and is almost immiscible with water. It can be efficiently recovered by atmospheric distillation. The recovered solvent can be directly reused without molecular sieve drying, avoiding the loss caused by solvent dissolving in wastewater in the THF process and the high energy consumption caused by the removal of high-boiling-point toluene.
[0017] 2. This invention utilizes the in-situ water-absorbing properties of anhydrous magnesium chloride, a reaction byproduct, to achieve self-drying of the recovered solvent, eliminating the molecular sieve drying step required in traditional processes, and allowing the synthesis reaction to produce... It has strong water absorption properties; after adding the recovered wet solvent, The water content is preferentially combined, and an anhydrous solvent can be obtained through subsequent desolvation for recycling.
[0018] 3. This invention significantly improves the initiation efficiency and main reaction selectivity of the Grignard reaction by increasing the system temperature, achieving a dual breakthrough of high yield and high purity, shortening the initiation time to the minute level, and greatly improving magnesium utilization.
[0019] 4. This invention significantly reduces the removal of foredistillate during the finished product distillation process through the synergistic effect of a single solvent system and low boiling point characteristics, thereby improving single-batch capacity and raw material utilization. Since isopropyl ether has a boiling point much lower than that of the product tetrabutyltin and contains no high-boiling-point toluene residue, distillation separation is extremely easy. Compared to traditional processes that require the removal of approximately 10% of the foredistillate to ensure purity, this invention only requires the removal of 1% of the foredistillate to obtain a qualified product, significantly improving production efficiency.
[0020] 5. This invention does not use a catalyst in the preparation of tetrabutyltin. It achieves efficient start-up and control of the reaction only through precise parameter control of temperature, dropping rate and stirring speed, thereby avoiding the loss of raw materials and the cost of subsequent separation caused by the introduction of a catalyst. Attached Figure Description
[0021] Figure 1 This is a flowchart of a method for preparing tetrabutyltin using a single solvent, as proposed in this invention. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0024] Example 1 This embodiment provides a method for preparing tetrabutyltin using a single solvent, the specific implementation steps of which include: Experimental materials: Isopropyl ether, magnesium, chlorobutane, tin tetrachloride.
[0025] Experimental objective: Tetrabutyltin was prepared using a single solvent.
[0026] Experimental steps: S1: Weigh 560g of isopropyl ether as solvent and add 41g of magnesium shavings. Then raise the temperature of the mixture to 60℃. After the reflux in the reaction system stabilizes, stop heating. Then add 163g of chlorobutane dropwise and keep warm for 1 hour to obtain a mixture of butyl magnesium chloride and isopropyl ether. S2: Add an equal volume of tin tetrachloride and isopropyl ether mixture to the butyl magnesium chloride obtained in S1 at a dropping rate of 2 drops / s, and stir continuously at 500 rpm for 30 minutes. Then stir the mixture for 30 minutes and control the temperature of the mixture at 25°C room temperature to obtain a mixture of TBT, anhydrous magnesium chloride and isopropyl ether. S3: Transfer the final mixture of TBT, anhydrous magnesium chloride and isopropyl ether obtained in S2 to the reactor and add isopropyl ether. Then heat the system to collect the anhydrous isopropyl ether. S4: Add 1% hydrochloric acid dropwise to the system heated in S3. After the magnesium chloride in the reaction system is completely dissolved, let it stand to separate into layers to obtain a mixture of TBT and isopropyl ether and an aqueous solution of magnesium chloride. S5: The TBT and isopropyl ether mixture obtained in S4 is heated to 60°C to remove solvent and obtain isopropyl ether containing a small amount of water. Finally, the remaining solution is collected by vacuum distillation to obtain the TBT product.
[0027] Experimental results: See Table 1 for details.
[0028] Table 1: Test Results of Example 1
[0029] Example 1 systematically solves the four major technical problems in the traditional THF and toluene mixed solvent process by synergistically combining a series of technical features such as in-situ dehydration, precise droplet control, and low boiling point distillation. Data shows that the method of the present invention achieves excellent performance in terms of yield, purity and solvent recovery rate, and the process is greatly simplified, which has significant industrial application value and green environmental protection advantages.
[0030] Example 2 This embodiment provides a method for preparing tetrabutyltin using a single solvent, the specific implementation steps of which include: Experimental materials: Isopropyl ether, magnesium, chlorobutane, tin tetrachloride.
[0031] Experimental objective: To investigate the effect of lower reaction temperatures on product yield.
[0032] Experimental steps: S1: Weigh 560g of isopropyl ether as solvent and add 41g of magnesium shavings. Then raise the temperature of the mixture to 50℃. After the reflux in the reaction system stabilizes, stop heating. Then add 163g of chlorobutane dropwise and keep warm for 1 hour to obtain a mixture of butyl magnesium chloride and isopropyl ether. S2: Add an equal volume of tin tetrachloride and isopropyl ether mixture to the butyl magnesium chloride obtained in S1 at a dropping rate of 2 drops / s, and stir continuously at 500 rpm for 30 minutes. Then stir the mixture for 30 minutes and control the temperature of the mixture at 25°C room temperature to obtain a mixture of TBT, anhydrous magnesium chloride and isopropyl ether. S3: Transfer the final mixture of TBT, anhydrous magnesium chloride and isopropyl ether obtained in S2 to the reactor and add isopropyl ether. Then heat the system to collect the anhydrous isopropyl ether. S4: Add 1% hydrochloric acid dropwise to the system heated in S3. After the magnesium chloride in the reaction system is completely dissolved, let it stand to separate into layers to obtain a mixture of TBT and isopropyl ether and an aqueous solution of magnesium chloride. S5: The TBT and isopropyl ether mixture obtained in S4 is heated to 60°C to remove solvent and obtain isopropyl ether containing a small amount of water. Finally, the remaining solution is collected by vacuum distillation to obtain the TBT product.
[0033] Experimental results: See Table 2 for details.
[0034] Table 2: Test Results of Example 2
[0035] The lower reaction temperature used in Example 2 resulted in decreased magnesium surface activation, with some magnesium failing to react, leading to a reduced chlorobutane conversion rate. Insufficient butyl magnesium chloride production also resulted in incomplete tin tetrachloride reaction.
[0036] Example 3 This embodiment provides a method for preparing tetrabutyltin using a single solvent, the specific implementation steps of which include: Experimental materials: Isopropyl ether, magnesium, chlorobutane, tin tetrachloride.
[0037] Experimental objective: Investigate the effect of omitting thorough stirring on the reaction.
[0038] Experimental steps: S1: Weigh 560g of isopropyl ether as solvent and add 41g of magnesium shavings. Then raise the temperature of the mixture to 50℃. After the reflux in the reaction system stabilizes, stop heating. Then add 163g of chlorobutane dropwise and keep warm for 1 hour to obtain a mixture of butyl magnesium chloride and isopropyl ether. S2: Add an equal volume of tin tetrachloride and isopropyl ether mixture to the butyl magnesium chloride obtained in S1 at a dropping rate of 2 drops / s. Then stir the mixture for 30 minutes and control the temperature of the mixture at 25°C room temperature to obtain a mixture of TBT, anhydrous magnesium chloride and isopropyl ether. S3: Transfer the final mixture of TBT, anhydrous magnesium chloride and isopropyl ether obtained in S2 to the reactor and add isopropyl ether. Then heat the system to collect the anhydrous isopropyl ether. S4: Add 1% hydrochloric acid dropwise to the system heated in S3. After the magnesium chloride in the reaction system is completely dissolved, let it stand to separate into layers to obtain a mixture of TBT and isopropyl ether and an aqueous solution of magnesium chloride. S5: The TBT and isopropyl ether mixture obtained in S4 is heated to 60°C to remove solvent and obtain isopropyl ether containing a small amount of water. Finally, the remaining solution is collected by vacuum distillation to obtain the TBT product.
[0039] Experimental results: See Table 3 for details.
[0040] Table 3: Test Results of Example 3
[0041] In Example 3, the lack of stirring caused excessively high local temperatures in tin tetrachloride during dropwise addition, resulting in the formation of polysubstituted side reactions. , And some unreacted tin tetrachloride was subsequently treated with hydrochloric acid. The purity was significantly reduced because the byproducts were difficult to separate by distillation.
[0042] Example 4 This embodiment provides a method for preparing tetrabutyltin using a single solvent, the specific implementation steps of which include: Experimental materials: Isopropyl ether, magnesium, chlorobutane, tin tetrachloride.
[0043] Experimental objective: To investigate the effect of excessive residual hydrochloric acid concentration on product hydrolysis.
[0044] Experimental steps: S1: Weigh 560g of isopropyl ether as solvent and add 41g of magnesium shavings. Then raise the temperature of the mixture to 50℃. After the reflux in the reaction system stabilizes, stop heating. Then add 163g of chlorobutane dropwise and keep warm for 1 hour to obtain a mixture of butyl magnesium chloride and isopropyl ether. S2: Add an equal volume of tin tetrachloride and isopropyl ether mixture to the butyl magnesium chloride obtained in S1 at a dropping rate of 2 drops / s, and stir continuously at 500 rpm for 30 minutes. Then stir the mixture for 30 minutes and control the temperature of the mixture at 25°C room temperature to obtain a mixture of TBT, anhydrous magnesium chloride and isopropyl ether. S3: Transfer the final mixture of TBT, anhydrous magnesium chloride and isopropyl ether obtained in S2 to the reactor and add isopropyl ether. Then heat the system to collect the anhydrous isopropyl ether. S4: Add 5% hydrochloric acid dropwise to the system heated in S3. After the magnesium chloride in the reaction system is completely dissolved, let it stand to separate into layers to obtain a mixture of TBT and isopropyl ether and an aqueous solution of magnesium chloride. S5: The TBT and isopropyl ether mixture obtained in S4 is heated to 60°C to remove solvent and obtain isopropyl ether containing a small amount of water. Finally, the remaining solution is collected by vacuum distillation to obtain the TBT product.
[0045] Experimental results: See Table 4 for details.
[0046] Table 4: Test Results of Example 4
[0047] In Example 4, the excessively high concentration of hydrochloric acid caused tetrabutyltin to hydrolyze under acidic conditions. The equation is as follows: The butyltin oxide generated by further hydrolysis enters the aqueous phase, leading to losses.
[0048] Example 5 This embodiment provides a method for preparing tetrabutyltin using a single solvent, the specific implementation steps of which include: Experimental materials: Isopropyl ether, magnesium, chlorobutane, tin tetrachloride.
[0049] Experimental objective: To investigate the effect of distillation temperature on product purity and yield.
[0050] Experimental steps: S1: Weigh 560g of isopropyl ether as solvent and add 41g of magnesium shavings. Then raise the temperature of the mixture to 50℃. After the reflux in the reaction system stabilizes, stop heating. Then add 163g of chlorobutane dropwise and keep warm for 1 hour to obtain a mixture of butyl magnesium chloride and isopropyl ether. S2: Add an equal volume of tin tetrachloride and isopropyl ether mixture to the butyl magnesium chloride obtained in S1 at a dropping rate of 2 drops / s, and stir continuously at 500 rpm for 30 minutes. Then stir the mixture for 30 minutes and control the temperature of the mixture at 25°C room temperature to obtain a mixture of TBT, anhydrous magnesium chloride and isopropyl ether. S3: Transfer the final mixture of TBT, anhydrous magnesium chloride and isopropyl ether obtained in S2 to the reactor and add isopropyl ether. Then heat the system to collect the anhydrous isopropyl ether. S4: Add 1% hydrochloric acid dropwise to the system heated in S3. After the magnesium chloride in the reaction system is completely dissolved, let it stand to separate into layers to obtain a mixture of TBT and isopropyl ether and an aqueous solution of magnesium chloride. S5: The TBT and isopropyl ether mixture obtained in S4 is heated to 90°C to remove solvent and obtain isopropyl ether containing a small amount of water. Finally, the remaining solution is collected by vacuum distillation to obtain the TBT product.
[0051] Experimental results: See Table 5 for details.
[0052] Table 5: Test Results of Example 5
[0053] In Example 5, since isopropyl ether has a boiling point of 68°C, its distillation temperature in S4 reaches 80°C, and most of the main product is retained. However, overheating can lead to localized thermal decomposition of the product. Due to the excessively high distillation temperature, a small number of side reactions and product isomerization occur.
[0054] Comparative Example 1 This embodiment provides a conventional method for preparing tetrabutyltin, the specific implementation steps of which include: Experimental materials: Magnesium shavings, anhydrous THF, chlorobutane, tin tetrachloride, toluene, 5% dilute hydrochloric acid.
[0055] Experimental objective: Tetrabutyltin was prepared using conventional tetrahydrofuran.
[0056] Experimental steps: S1: Under nitrogen protection, add 41g magnesium shavings, 500mL anhydrous THF and 160g chlorobutane to the flask. Control the dropping rate to keep the system under stable reflux. After the dropping is completed, heat the reflux reaction in a water bath at 60℃ for 3 hours to obtain a gray-black butyl magnesium chloride Grignard reagent solution. S2: Cool the Grignard reagent solution prepared in S1 to room temperature, dissolve 100g of tin tetrachloride in 100mL of toluene under stirring at 500rpm to prepare a mixed solution, then add it dropwise at 1 drop / second, and use an ice-water bath to assist in temperature control so that the reaction temperature is ≤35℃. After the addition is complete, continue stirring at 40℃ for 2 hours to ensure that the reaction is complete, and generate tetrabutyltin and a large amount of white anhydrous magnesium chloride precipitate. S3: After the reaction is complete, cool the system to 10°C, and slowly add 600 mL of 5% dilute hydrochloric acid with stirring until the magnesium salt is completely dissolved. Let the system stand to separate into two phases, and then transfer it to a separatory funnel and let it stand for 30 minutes to separate the phases. S4: Distill the upper organic phase at 66℃ and atmospheric pressure, collect the distillate until the distillation temperature rises to 80℃ to obtain 450mL THF. Then, distill the remaining liquid under reduced pressure at a vacuum of -0.098MPa. First, heat the liquid to 40-50℃ to distill off toluene, and then raise the temperature to 160-170℃ to collect the tetrabutyltin obtained from the distillation.
[0057] Experimental results: See Table 6 for details.
[0058] Table 6: Test Results of Comparative Example 1
[0059] In Comparative Example 1, because THF is partially miscible with water, 8-10% of the THF in the aqueous phase after separation in step S3 cannot be directly recovered, resulting in solvent waste and excessive COD in the wastewater. In step S4, the mixed solvent is separated by two-stage distillation, and the high boiling point of toluene significantly increases energy consumption. Furthermore, the process in Comparative Example 1 is complex, and the recovered THF contains a small amount of water, requiring drying via molecular sieves.
[0060] Example 1 uses a single solvent system of isopropyl ether. The mechanism is that continuous stirring ensures uniform dispersion of tin tetrachloride and avoids side reactions caused by local overconcentration; low-concentration hydrochloric acid gently hydrolyzes magnesium salt to prevent acid decomposition of the product; low-boiling-point isopropyl ether is easy to distill and recover and is not miscible with water, resulting in extremely low solvent loss.
[0061] Example 2 used a lower reaction temperature and relied solely on mechanical stirring to initiate the reaction. The magnesium surface was not sufficiently activated, resulting in some magnesium failing to participate in the reaction. This led to a decrease in the conversion rate of chlorobutane, insufficient production of butyl magnesium chloride, and ultimately incomplete reaction of tin tetrachloride, with the yield dropping to 88.6%. However, under the same conditions, the purity remained at 97.3%.
[0062] In Example 3, no continuous stirring was performed after adding tin tetrachloride dropwise at S2, resulting in an excessively high local concentration of the added tin tetrachloride, which led to the formation of polysubstituted side reactions. , The low-substituted products, along with some tin tetrachloride that was not reacted in time and was subsequently hydrolyzed by hydrochloric acid, resulted in a significant decrease in both yield and purity.
[0063] In Example 4, 5% high-concentration hydrochloric acid was used for quenching, and the standing time for separation was shortened to 10 minutes. The excess acid triggered the acidic hydrolysis of tetrabutyltin, and the generated tributyltin cation was further converted into oxide and entered the aqueous phase.
[0064] Example 5 uses atmospheric distillation with the temperature raised to 80°C, which causes local overheating and leads to thermal decomposition or isomerization of the product; at the same time, the vacuum distillation time is only 15 minutes, and the solvent and low-boiling point impurities are not completely removed.
[0065] Comparative Example 1 uses a traditional THF and toluene mixed solvent process. THF is partially miscible with water, resulting in a large amount of solvent being lost in the aqueous phase, which requires molecular sieve drying before it can be reused; toluene has a high boiling point, and distillation consumes a lot of energy.
[0066] Comparing the examples and comparative examples, Example 1 achieves the optimal balance in reaction efficiency, product purity, solvent recovery, and process simplicity. Through in-situ dehydration, precise droplet control, and the selection of low-boiling-point solvents, it improves the atom economy and greening of the Grignard reaction, making it suitable for large-scale industrial production scenarios with stringent requirements for cost, environmental protection, and product quality. Example 2, while lowering the reaction temperature, sacrificed yield; Example 3 omitted the stirring step, simplifying the process but leading to serious side reactions; Example 4 used high-concentration hydrochloric acid, which accelerated magnesium salt dissolution but triggered product hydrolysis; Example 5 increased the distillation temperature to shorten processing time, but caused thermal decomposition and decreased purity. Comparative Example 1 highlights the limitations of traditional mixed solvent processes in terms of solvent miscibility, high energy consumption, and complex procedures. Therefore, this invention, through innovation in the solvent system and synergistic optimization of key process parameters, achieves significant progress in the preparation technology of tetrabutyltin.
[0067] refer to Figure 1 The process flow diagram, as shown in the figure, uses isopropyl ether as the sole solvent throughout the process. It achieves the efficient synthesis of tetrabutyltin through four core steps: S1 rapidly generates butyl magnesium chloride Grignard reagent; S2 ensures uniform reaction of tin tetrachloride to generate tetrabutyltin and anhydrous magnesium chloride through precise drop control and continuous stirring; S3 uses low-concentration hydrochloric acid for gentle quenching and allows the mixture to stand and separate into layers to obtain the organic phase; S4 recovers isopropyl ether by atmospheric distillation and then obtains high-purity product by vacuum distillation. This process achieves high purity through the synergistic effect of in-situ dehydration and low-boiling-point distillation.
[0068] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.
[0069] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing tetrabutyltin using a single solvent, characterized in that, Specifically, the following steps are included: S1: Weigh 115-130 parts by weight of isopropyl ether as solvent and add 40-45 parts by weight of magnesium shavings. Then raise the temperature of the mixture and stop heating after the reflux in the reaction system is stable. Then add 153-171 parts by weight of chlorobutane and keep warm for 1 hour to obtain a mixture of butyl magnesium chloride and isopropyl ether. S2: Mix equal volumes of tin tetrachloride and isopropyl ether, and add them dropwise to the butyl magnesium chloride obtained in S1 at a rate of 2 drops / s. Stir continuously for 30 minutes, then stir the mixture for 30 minutes and control the temperature of the mixture to room temperature to obtain a mixture of TBT, anhydrous magnesium chloride and isopropyl ether. S3: Transfer the final mixture of TBT, anhydrous magnesium chloride and isopropyl ether obtained in S2 to the reactor and add isopropyl ether. Then heat the system to collect the anhydrous isopropyl ether. S4: Add hydrochloric acid dropwise to the system heated in S3. After the magnesium chloride in the reaction system is completely dissolved, let it stand to separate into layers to obtain a mixture of TBT and isopropyl ether and an aqueous solution of magnesium chloride. S5: The TBT and isopropyl ether mixture obtained in S4 is heated to 50~60℃ to remove solvent and obtain isopropyl ether containing a small amount of water. Finally, the remaining solution is collected by vacuum distillation to obtain the TBT product.
2. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, The temperature of the system mentioned in S1 is specifically raised to 50~60℃.
3. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, The molar ratio of chlorobutane to magnesium added in S1 is 1~1.2:
1.
4. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, In S2, tin tetrachloride is added dropwise to butyl magnesium chloride while stirring at a speed of 500-1000 rpm.
5. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, The molar ratio of tin tetrachloride to butyl magnesium chloride added in S2 is 1.0~1.2:
4.
6. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, When adding tin tetrachloride and butyl magnesium chloride dropwise to S2, the temperature of the reaction system should be controlled within the range of 23~27℃.
7. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, The anhydrous isopropyl ether collected in step S3 is reused as the isopropyl ether solvent used in step S1.
8. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, The mass percentage concentration of hydrochloric acid added in S4 is 1~3%.
9. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, The isopropyl ether containing a small amount of moisture obtained in S5 is reused for the isopropyl ether added in S3.
10. The method for preparing tetrabutyltin using a single solvent as described in claim 1, characterized in that, The remaining solution in S5 is distilled under reduced pressure for 30 minutes in a distillation environment with a vacuum degree of -0.08 MPa and a temperature of 80~90℃.