Preparation method of tris (2-cyanoethoxy) phosphate
By simplifying the preparation process of tris(2-cyanoethoxy) phosphate, using mild reaction conditions and multiple solvent washing, the problems of high production cost and low purity in the existing technology have been solved, and high-purity tris(2-cyanoethoxy) phosphate has been prepared, which is suitable for lithium-ion battery electrolyte additives.
Patent Information
- Application Number
- CN202411173105.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2026-03-03
AI Technical Summary
In the existing technology, the preparation method of tris(2-cyanoethoxy) phosphate is complicated, the production cost is high, and the solvent is difficult to recover, resulting in low product purity, which cannot meet the requirements of lithium-ion battery electrolyte additives.
Using phosphorus oxychloride and hydroxypropionitrile as raw materials, the reaction was carried out at a controlled temperature of 30-50℃. HCl was bubbled out, and then toluene or xylene was added as a solvent to precipitate the crude product. The crude product was then washed and purified using solvents such as dichloromethane or dichloroethane. Finally, the product was washed with water and concentrated to prepare high-purity tris(2-cyanoethoxy) phosphate.
This process achieves simple operation, controllable temperature, recyclable solvent, reduced production costs, and product purity of over 99%, meeting the purity requirements for lithium-ion battery electrolyte additives.
Smart Images
Figure CN121591777A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrolyte additive synthesis technology, specifically to a method for preparing tris(2-cyanoethoxy) phosphate. Background Technology
[0002] Electrolyte systems, a crucial component of lithium-ion batteries, are constantly evolving. Research on electrolyte systems, including lithium salts, novel organic solvents, and electrolyte additives, is ongoing. Additives, in particular, are receiving widespread attention due to their significant impact on battery performance.
[0003] Literature records that esters containing cyano groups can improve the non-flammability of electrolytes, thereby enhancing their safety. Tris(2-cyanoethoxy)phosphate is one such example. Therefore, this invention application aims to provide a method for preparing tris(2-cyanoethoxy)phosphate. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing tris(2-cyanoethoxy) phosphate, which has a simple preparation process, high product purity, and recyclable organic solvents, thereby effectively reducing production costs.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing tris(2-cyanoethoxy) phosphate, comprising the following steps: 1. First, mix phosphorus oxychloride and hydroxypropionitrile, and stir the reaction at a controlled temperature of 30-50℃. During the reaction, HCl is bubbled out. Then, continue to raise the temperature to 75-85℃. 2. After the reaction is complete, add the first solvent to the reaction solution to precipitate the crude product. Collect the crude product and wash it with a mixture of the second and third solvents to obtain the purified product. The first solvent is toluene or xylene; the second solvent is dichloromethane or dichloroethane; and the third solvent is n-hexane, cyclohexane, or petroleum ether. 3. After adding the second solvent used in the second step to the purified product, wash it with water, collect the organic phase, dehydrate it, and concentrate it to obtain the final product.
[0006] The structural formula of tris(2-cyanoethoxy) phosphate is as follows: .
[0007] Furthermore, in the aforementioned method for preparing tris(2-cyanoethoxy) phosphate, the molar ratio of phosphorus oxychloride to hydroxypropionitrile is 1:3 to 3.3.
[0008] Furthermore, in the aforementioned method for preparing a tris(2-cyanoethoxy) phosphate, the step of bubbling during the reaction includes: inserting a nitrogen inlet tube and controlling the nitrogen flow rate to be 0.5–3 L / min.
[0009] Furthermore, in the aforementioned method for preparing a tris(2-cyanoethoxy) phosphate, the amount of the first solvent used is 1 to 1.5 times the mass of the reaction solution after the reaction is completed.
[0010] Furthermore, in the aforementioned method for preparing a tris(2-cyanoethoxy) phosphate, the mass ratio of the second solvent to the third solvent in the mixed solvent is 1:2 to 4, and the amount of mixed solvent used is the same as the mass of the crude product.
[0011] Furthermore, in the aforementioned method for preparing a tris(2-cyanoethoxy) phosphate, the mixture is washed at least twice with a mixed solvent.
[0012] Furthermore, in the aforementioned method for preparing a tris(2-cyanoethoxy) phosphate, in the third step, the amount of the second solvent used is 2 to 3 times the mass of the purified product.
[0013] Furthermore, in the aforementioned method for preparing a tris(2-cyanoethoxy) phosphate, the third step involves washing with water three times.
[0014] The advantages of this invention are: simple process route, few steps, mild and controllable temperature, low purification difficulty, and all organic solvents used can be recycled and reused, thereby effectively reducing production costs. The product has good yield and high purity, reaching over 99%, which meets the purity requirements for additives in lithium-ion battery electrolytes. Attached Figure Description
[0015] Figure 1 This is the 1H NMR spectrum of the product in Example 1.
[0016] Figure 2 This is the carbon NMR spectrum of the product in Example 1. Detailed Implementation
[0017] The preparation method of a tris(2-cyanoethoxy) phosphate ester according to the present invention will be described in detail below through specific embodiments.
[0018] Example 1: 53g of phosphorus oxychloride and 74g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 0.5L / min. The mixture was stirred for 4 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 7 hours until no obvious HCl was produced. The reaction was then complete.
[0019] 100g of reaction solution was mixed with 100g of toluene, and 88g of the lower crude product and 108g of the upper toluene layer were collected. After routine distillation, 80g of the toluene was recovered and used for subsequent washing of the reaction solution. The crude product was further mixed with 88g of a mixture (dichloromethane:n-hexane = 1:2), washed twice, and 90g of the purified product was collected. The mixture collected after the two washings totaled 166g, which was recovered after routine distillation. The mixture was then used for subsequent washing of the crude product after the proportions were checked.
[0020] After adding 180g of dichloromethane, the product was washed three times with water. The organic phase was dehydrated and concentrated to obtain 75g of the final product. 150g of dichloromethane was collected during concentration for subsequent washing. The final product was verified by NMR spectroscopy to be the target product, with a yield of 84% and a purity of 99.2%. The 1H NMR spectrum of the product is shown below. Figure 1 As shown, the carbon NMR spectrum of the product is as follows: Figure 2 As shown.
[0021] Example 2: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 45°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 3L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 75°C and the reaction was continued for 3 hours until no obvious HCl was produced. The reaction was then complete.
[0022] 90g of the reaction solution was added to 100g of toluene and stirred. 80g of the lower crude product and 105g of the upper toluene layer were collected. After routine distillation, 80g of the toluene was recovered and used for subsequent washing of the reaction solution. The crude product was further added to a mixture of 80g (dichloromethane:n-hexane = 1:4), washed twice, and 80g of the purified product was collected. The mixture collected after the two washings totaled 156g. After routine distillation, 149g of the mixture was recovered and used for subsequent washing of the crude product after the proportions were checked.
[0023] After adding 240g of dichloromethane, the product was washed three times with water. The organic phase was dehydrated and concentrated to obtain 68g of product. During concentration, 220g of dichloromethane was collected for subsequent water washing. The product was verified by NMR to be the target product, with a yield of 76% and a purity of 99.1%.
[0024] Example 3: 53g of phosphorus oxychloride and 77g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 1.5L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 6 hours until no obvious HCl was produced. The reaction was then complete.
[0025] 96g of the reaction solution was added to 96g of toluene and stirred. 90g of the lower crude product and 100g of the upper toluene layer were collected. After routine distillation, 81g of toluene was recovered and used for subsequent washing of the reaction solution. The crude product was further added to a mixture of 90g (dichloromethane:n-hexane = 1:3), washed twice, and 89g of purified product was collected. The mixture collected after the two washings totaled 181g. After routine distillation, 169g of the mixture was recovered and used for subsequent washing of the crude product after the proportions were checked.
[0026] After adding 220g of dichloromethane, the product was washed three times with water. The organic phase was dehydrated and concentrated to obtain 70g of product. During concentration, 203g of dichloromethane was collected for subsequent water washing. The product was verified by NMR to be the target product, with a yield of 78% and a purity of 99.3%.
[0027] Example 4: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 2L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 7 hours until no obvious HCl was produced. The reaction was then complete.
[0028] 102g of the reaction solution was added to 153g of toluene and stirred. 88g of the lower crude product and 163g of the upper toluene layer were collected. After routine distillation, 140g of toluene was recovered and used for subsequent washing of the reaction solution. The crude product was further added to a mixture of 88g (dichloromethane:n-hexane = 1:2), washed twice, and 85g of purified product was collected. After two washings, 165g of the mixture was collected, and after routine distillation, 154g of the mixture was recovered. The mixture ratio was checked and used for subsequent washing of the crude product.
[0029] After adding 170g of dichloromethane, the product was washed three times with water. The organic phase was dehydrated and concentrated to obtain 78g of product. During concentration, 148g of dichloromethane was collected for subsequent water washing. The product was verified by NMR to be the target product, with a yield of 87% and a purity of 99.2%.
[0030] Example 5: After mixing and stirring 53g of phosphorus oxychloride and 81g of hydroxypropionitrile, the temperature was controlled at 35°C. A nitrogen gas inlet tube was inserted, and the gas flow rate was 2L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 85°C and the reaction was continued for 7 hours until no obvious HCl was produced. The reaction was then complete.
[0031] 101g of the reaction solution was added to 153g of xylene and stirred. 89g of the lower crude product and 163g of the upper toluene layer were collected. After routine distillation, 145g of toluene was recovered and used for subsequent washing of the reaction solution. The crude product was further added to a mixture of 89g (dichloroethane:n-hexane = 1:3), washed twice, and 83g of purified product was collected. The mixture collected after the two washings totaled 176g. After routine distillation, 154g of the mixture was recovered and used for subsequent washing of the crude product after the ratio was checked.
[0032] After adding 170g of dichloroethane, the product was washed three times with water. The organic phase was dehydrated and concentrated to obtain 79g of product. During concentration, 151g of dichloromethane was collected for subsequent water washing. The product was verified by NMR to be the target product, with a yield of 87% and a purity of 99.2%.
[0033] Example 6: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 50°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 1.5L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 7 hours until no obvious HCl was produced. The reaction was then complete.
[0034] 102g of the reaction solution was added to 102g of toluene and stirred. 90g of the lower crude product and 108g of the upper toluene layer were collected. After routine distillation, 83g of toluene was recovered and used for subsequent washing of the reaction solution. The crude product was further added to a mixture of 90g (dichloroethane:cyclohexane = 1:2), washed twice, and 86g of purified product was collected. The mixture collected after the two washings totaled 174g. After routine distillation, 161g of the mixture was recovered and used for subsequent washing of the crude product after the ratio was checked.
[0035] After adding 258g of dichloroethane, the mixture was washed three times with water. The organic phase was dehydrated and concentrated to obtain 75g of product. During concentration, 240g of dichloromethane was collected for subsequent water washing. The product was verified by NMR spectroscopy to be the target product, with a yield of 84% and a purity of 99.1%. Example 7: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 1.5L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 6 hours until no obvious HCl was produced. The reaction was then complete.
[0036] 96g of the reaction solution was added to 96g of toluene and stirred. 90g of the lower crude product and 99g of the upper toluene layer were collected. After conventional distillation, 80g of the toluene was recovered and used for subsequent washing of the reaction solution. The crude product was further added to a mixture of 90g (dichloromethane: petroleum ether = 1:3), washed twice, and 89g of the purified product was collected. The mixture collected after the two washings totaled 169g. After conventional distillation, 159g of the mixture was recovered and used for subsequent washing of the crude product after the proportions were checked.
[0037] After adding 220g of dichloromethane, the product was washed three times with water. The organic phase was dehydrated and concentrated to obtain 70g of product. During concentration, 200g of dichloromethane was collected for subsequent water washing. The product was verified by NMR to be the target product, with a yield of 78% and a purity of 99.3%.
[0038] Example 8: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 1.5L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 6 hours until no obvious HCl was produced. The reaction was then complete.
[0039] 96g of reaction solution was added to 96g of toluene and stirred. 90g of the lower crude product was collected. 90g of the crude product was further added to a mixture (dichloromethane: petroleum ether = 1:1). The mixture was washed twice. The separation was difficult. 60g of the purified product was collected.
[0040] After adding 120g of dichloromethane, the mixture was washed three times with water. The organic phase was dehydrated and concentrated to obtain 50g of product. The product was verified by NMR to be the target product, with a yield of 56% and a purity of 99.3%. Example 9: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 1.5L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 6 hours until no obvious HCl was produced. The reaction was then complete.
[0041] 96g of the reaction solution was added to 96g of toluene and stirred. 90g of the lower crude product was collected. 90g of the crude product was further added to a mixture (dichloromethane: petroleum ether = 1:5), washed twice, and 120g of the purified product was collected.
[0042] After adding 240g of dichloromethane, the product was washed three times with water. The organic phase was dehydrated and concentrated to obtain 80g of product. The product was verified by NMR to be mainly the target product with a purity of 96.3%. This purity obviously does not meet the requirements for use as an additive in lithium battery electrolytes.
[0043] Example 10: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 0.6L / min. The mixture was stirred for 4 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 7 hours until no obvious HCl was produced. The reaction was then complete.
[0044] The reaction solution containing 96g of ethyl acetate failed to separate into layers, indicating an experimental failure.
[0045] Example 11: 53g of phosphorus oxychloride and 81g of hydroxypropionitrile were mixed and stirred. The temperature was controlled at 30°C. A nitrogen gas inlet tube was inserted and the gas flow rate was 1.5L / min. The mixture was stirred for 3 hours. The reaction solution gradually became viscous. The temperature was raised to 80°C and the reaction was continued for 6 hours until no obvious HCl was produced. The reaction was then complete.
[0046] After adding 96g of toluene to 96g of the reaction solution and stirring, 90g of the lower crude product was collected. The crude product was further washed with 90g of a mixture (ethyl acetate: petroleum ether = 1:2), but the mixture could not be separated into layers, and the experiment failed.
[0047] The advantages of this invention, as shown in the above embodiments, are: simple process route, few steps, mild and controllable temperature, low purification difficulty, and all organic solvents used can be recycled, thereby effectively reducing production costs. The product yield is good, with high purity, reaching over 99%, meeting the purity requirements for additives in lithium-ion battery electrolytes.
Claims
1. A method for preparing tris(2-cyanoethoxy) phosphate, comprising the following steps:
1. First, mix phosphorus oxychloride and hydroxypropionitrile, and stir the reaction at 30-50℃. During the reaction, HCl is bubbled out. Then, continue to raise the temperature to 75-85℃.
2. After the reaction is complete, add the first solvent to the reaction solution to precipitate the crude product. Collect the crude product and wash it with a mixture of the second and third solvents to obtain the purified product. The first solvent is toluene or xylene; the second solvent is dichloromethane or dichloroethane; and the third solvent is n-hexane, cyclohexane, or petroleum ether.
3. After adding the second solvent used in the second step to the purified product, wash it with water, collect the organic phase, dehydrate it, and concentrate it to obtain the final product.
2. The method for preparing tris(2-cyanoethoxy) phosphate according to claim 1, characterized in that: The molar ratio of phosphorus oxychloride to hydroxypropionitrile is 1:3 to 3.
3.
3. The method for preparing tris(2-cyanoethoxy) phosphate according to claim 1, characterized in that: The bubbling process during the reaction includes inserting a nitrogen inlet tube and controlling the nitrogen flow rate to be 0.5–3 L / min.
4. The method for preparing tris(2-cyanoethoxy) phosphate according to claim 1, characterized in that: The amount of the first solvent used is 1 to 1.5 times the mass of the reaction solution after the reaction is completed.
5. The method for preparing tris(2-cyanoethoxy) phosphate according to claim 1, characterized in that: The mass ratio of the second solvent to the third solvent in the mixed solvent is 1:2 to 4, and the amount of mixed solvent used is the same as the mass of the crude product.
6. The method for preparing tris(2-cyanoethoxy) phosphate according to claim 1, characterized in that: Wash with the mixed solvent at least twice.
7. The method for preparing tris(2-cyanoethoxy) phosphate according to claim 1, characterized in that: In the third step, the amount of the second solvent used is 2 to 3 times the mass of the purified product.
8. The method for preparing tris(2-cyanoethoxy) phosphate according to claim 6, characterized in that: The third step involves washing the water three times.