Process for the preparation of trimethylsiloxyl pentafluorocyclotriphosphazene
By reacting alkoxypentafluorocyclotriphosphazene with trimethylhalosilane in an organic solvent and adding iodide as an auxiliary reagent, the problem of the difficulty in obtaining raw materials was solved, and a high conversion rate of trimethylsiloxypentafluorocyclotriphosphazene was achieved, which is suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHANGJIAGANG GUOTAI HUARONG NEW CHEM MATERIALS CO LTD
- Filing Date
- 2022-05-20
- Publication Date
- 2026-05-26
AI Technical Summary
In the existing technology, raw materials such as potassium trimethylsilanolate, sodium, and lithium are not readily available, which limits the industrial production of trimethylsiloxypentafluorocyclotriphosphazene.
Trimethylsiloxypentafluorocyclotriphosphazene was prepared by reacting alkoxypentafluorocyclotriphosphazene with trimethylhalosilane in an organic solvent, with iodide added as an auxiliary reagent, and by controlling the reaction temperature and time.
This method achieves readily available raw materials, a simple reaction route, mild conditions, and high conversion rate, making it suitable for the industrial production of trimethylsiloxypentafluorocyclotriphosphazene.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of compound synthesis technology, and in particular to a method for synthesizing silicon-containing cyclic phosphazenes. Background Technology
[0002] Cyclic phosphazenes are a novel type of inorganic-organic hybrid compound with a backbone of alternating phosphorus and nitrogen atoms. This unique structure endows cyclic phosphazenes with excellent properties.
[0003] Organosilicon flame retardants are a new type of high-efficiency, low-toxicity, and environmentally friendly halogen-free flame retardant.
[0004] Trimethylsiloxypentafluorocyclotriphosphide is a flame retardant that combines cyclic phosphazene and organosilicon. Its molecule contains four flame retardant elements, P, N, F and Si, which have a synergistic effect and can reduce the amount of flame retardant added in lithium-ion battery electrolyte and improve flame retardant efficiency.
[0005] CN107915759A mentions the synthesis of trimethylsiloxypentafluorocyclotriphosphazene by reacting potassium trimethylsilanolate, sodium trimethylsilanolate, or lithium trimethylsilanolate with hexafluorocyclotriphosphazene, and its use as a flame retardant in lithium-ion battery electrolytes, achieving excellent flame retardant effects.
[0006] However, the raw material potassium trimethylsilanolate (sodium, lithium) is not a widely available material, and its industrial production is limited by the availability of raw materials, making large-scale production impossible. Summary of the Invention
[0007] The purpose of this invention is to provide a method for preparing trimethylsiloxypentafluorocyclotriphosphazene, which uses readily available raw materials, has a simple reaction route, mild reaction conditions, and is conducive to industrial production.
[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows.
[0009] To achieve the above objectives, the technical solution adopted in this invention is: a method for preparing trimethylsiloxypentafluorocyclotriphosphazene, comprising the following steps: reacting alkoxypentafluorocyclotriphosphazene and trimethylhalosilane in an organic solvent to synthesize trimethylsiloxypentafluorocyclotriphosphazene; the structure of the alkoxypentafluorocyclotriphosphazene is as follows: In the formula, R is an alkane group of 1 to 30.
[0010] The reaction equation is shown below:
[0011]
[0012] In the formula, X is a halogen atom, and trimethylhalosilane is preferably trimethylchlorosilane, trimethylbromosilane, or trimethyliodosilane.
[0013] Furthermore, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, when trimethylchlorosilane or trimethylbromosilane is selected as the trimethylhalosilane, an iodide is added.
[0014] Further, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, the iodide is potassium iodide, sodium iodide, or lithium iodide; the molar ratio of the iodide to the alkoxypentafluorocyclotriphosphazene is 1:1. Further, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, the molar ratio of the alkoxypentafluorocyclotriphosphazene to trimethylhalosilane is 1:1 to 1.5.
[0015] Furthermore, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, the organic solvent is selected from one or more combinations of acetonitrile, acetone, dichloromethane, dichloroethane, tetrahydrofuran, benzene, ethylbenzene, diethylbenzene, chloroform, carbon tetrachloride, trichloroethane, tetrachloroethane, 1,4-dioxane, and diethyl ether. The amount of organic solvent used is 2 to 3 times the mass of the alkoxypentafluorocyclotriphosphazene.
[0016] Furthermore, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, the organic solvent is acetonitrile.
[0017] Furthermore, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, R is preferably ethyl.
[0018] Furthermore, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, the reaction temperature is controlled between 0°C and 80°C.
[0019] Furthermore, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, the reaction time is controlled within 1 to 12 hours.
[0020] Furthermore, in the aforementioned method for preparing trimethylsiloxypentafluorocyclotriphosphazene, the feeding step includes: adding trimethylhalosilane and an organic solvent, then adding alkoxypentafluorocyclotriphosphazene dropwise, and finally heating to the reaction temperature. The dropwise addition of alkoxypentafluorocyclotriphosphazene results in a mild reaction without material backflow, and heating to reflux shortens the reaction time.
[0021] The advantages of this invention are: the raw materials used in this method are readily available, the reaction route is simple, the reaction conditions are mild, the conversion rate is high, and it is conducive to industrial production. Detailed Implementation
[0022] The present invention will be further described below through specific embodiments.
[0023] Since commercially available ethoxypentafluorocyclotriphosphazenes are more common than other alkoxypentafluorocyclotriphosphazenes, the following examples all use ethoxypentafluorocyclotriphosphazenes as typical representatives of alkoxypentafluorocyclotriphosphazenes. However, this does not mean that only ethoxypentafluorocyclotriphosphazenes can be used as reactants.
[0024] Example 1: In a 2000mL three-necked flask equipped with a stirrer, condenser, and thermometer, 600g of acetonitrile and 300g of ethoxypentafluorocyclotriphosphazene were added. The mixture was stirred and heated to 30°C. Then, 260g of trimethyliodosilane was added dropwise. After the addition was complete, the mixture was refluxed at 74°C for 4 hours, and the reaction was stopped by cooling. The residual ethoxypentafluorocyclotriphosphazene was less than 1%, and the reaction conversion rate was 99%.
[0025] Example 2: In a 2000mL three-necked flask equipped with a stirrer, condenser, and thermometer, 600g of tetrahydrofuran, 178g of trimethylchlorosilane, and 181g of potassium iodide were added. The mixture was stirred and heated to 30°C. Then, 300g of ethoxypentafluorocyclotriphosphazene was added dropwise. After the addition was complete, the mixture was refluxed at 66°C for 12 hours, and then the reaction was stopped by cooling. The conversion rate of ethoxypentafluorocyclotriphosphazene was 98%.
[0026] Example 3: In a 2000mL three-necked flask equipped with a stirrer, condenser, and thermometer, 600g of dichloroethane, 200g of trimethylbromosilane, and 181g of sodium iodide were added. The mixture was stirred and heated to 30°C. Then, 300g of ethoxypentafluorocyclotriphosphazene was added dropwise. After the addition was complete, the mixture was refluxed at 74°C for 6 hours, and then cooled to stop the reaction. The conversion rate of ethoxypentafluorocyclotriphosphazene was 98%.
[0027] Example 4: In a 2000mL three-necked flask equipped with a stirrer, condenser, and thermometer, 600g of 1,4-dioxane, 166g of trimethylchlorosilane, and 145g of lithium iodide were added. The mixture was stirred and heated to 30°C. Then, 300g of ethoxypentafluorocyclotriphosphazene was added dropwise. After the addition was complete, the mixture was refluxed at 64°C for 3 hours and then cooled to stop the reaction. The conversion rate of ethoxypentafluorocyclotriphosphazene was 96%.
[0028] Example 5: In a 2000mL three-necked flask equipped with a stirrer, condenser, and thermometer, 600g of acetonitrile, 166g of trimethylchlorosilane, and 181g of potassium iodide were added and stirred. Then, 300g of ethoxypentafluorocyclotriphosphazene was added dropwise starting at 0°C. After the addition was complete, the temperature was raised to 74°C and refluxed for 3 hours. The reaction was then cooled to stop. The conversion rate of ethoxypentafluorocyclotriphosphazene was 96%.
[0029] Example 6: In a 2000mL three-necked flask equipped with a stirrer, condenser, and thermometer, 600g of acetonitrile, 178g of trimethylchlorosilane, and 181g of potassium iodide were added. The mixture was stirred and heated. At 30°C, 300g of ethoxypentafluorocyclotriphosphazene was added dropwise. After the addition was complete, the temperature was raised to 80°C and refluxed for 3 hours. The reaction was then cooled to stop the reaction. The conversion rate of ethoxypentafluorocyclotriphosphazene was 98%.
[0030] Comparative Example 1: In a 2000mL three-necked flask equipped with a stirrer, condenser, and thermometer, 600g of acetonitrile and 178g of trimethylchlorosilane were added. The mixture was stirred and heated. At 30°C, 300g of ethoxypentafluorocyclotriphosphazene was added dropwise. After the addition was complete, the temperature was raised to 80°C and refluxed for 12 hours. The reaction was then cooled to stop the reaction. The conversion rate of ethoxypentafluorocyclotriphosphazene was 35%.
[0031] The comparative examples show that when trimethyliodosilane is used as a raw material, the conversion rate of ethoxypentafluorocyclotriphosphazene after reaction with acetonitrile is as high as 99%; while when trimethylchlorosilane is used as a raw material, potassium iodide (or sodium iodide, lithium iodide) must be added as an auxiliary material to increase the conversion rate to over 96%.
[0032] The above examples show that the method for preparing trimethylsiloxypentafluorocyclotriphosphazene of the present invention uses readily available raw materials, has a simple reaction route, mild reaction conditions, and high conversion rate, which is beneficial for industrial production.
Claims
1. A process for the preparation of trimethylsiloxy pentafluorocyclotriphosphazene comprising the steps of: Trimethylsiloxypentafluorocyclotriphosphazene was synthesized from alkoxypentafluorocyclotriphosphazene and trimethylhalosilane in an organic solvent; the trimethylhalosilane was selected from trimethylchlorosilane, trimethylbromosilane, and trimethyliodosilane; when trimethylchlorosilane or trimethylbromosilane was selected as the trimethylhalosilane, an iodide was added, wherein the iodide was potassium iodide, sodium iodide, or lithium iodide; the structure of the alkoxypentafluorocyclotriphosphazene is as follows: wherein R is an alkyl group of 1 to 30.
2. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 1, characterized in that: The molar ratio of iodide to alkoxypentafluorocyclotriphosphazene is 1:
1.
3. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 1, characterized in that: The molar ratio of alkoxypentafluorocyclotriphosphazene to trimethylhalosilane is 1:1 to 1.
5.
4. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 1, characterized in that: The organic solvent is selected from one or more combinations of acetonitrile, acetone, dichloromethane, dichloroethane, tetrahydrofuran, benzene, ethylbenzene, diethylbenzene, chloroform, carbon tetrachloride, trichloroethane, tetrachloroethane, 1,4-dioxane, and diethyl ether; the amount of organic solvent used is 2 to 3 times the mass of alkoxypentafluorocyclotriphosphazene.
5. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 4, characterized in that: The organic solvent is acetonitrile.
6. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 1, characterized in that: R stands for ethyl.
7. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 1, characterized in that: The reaction temperature is controlled between 0℃ and 80℃.
8. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 1, characterized in that: The reaction time should be controlled between 1 and 12 hours.
9. The method for preparing trimethylsiloxypentafluorocyclotriphosphazene according to claim 1, characterized in that: The feeding steps include: adding trimethylhalosilane and organic solvent, then adding alkoxypentafluorocyclotriphosphazene dropwise, and then heating to the reaction temperature after the addition is complete.