CN116903436A - Method for synthesizing hexafluorobutadiene by one-step method - Google Patents
Method for synthesizing hexafluorobutadiene by one-step method Download PDFInfo
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- CN116903436A CN116903436A CN202310702745.1A CN202310702745A CN116903436A CN 116903436 A CN116903436 A CN 116903436A CN 202310702745 A CN202310702745 A CN 202310702745A CN 116903436 A CN116903436 A CN 116903436A
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- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
- C07C17/263—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions
- C07C17/269—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions of only halogenated hydrocarbons
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Abstract
本发明涉及一种一步法合成六氟丁二烯的方法，包括以下步骤：向反应器内分别加入新压制的钠丝、经无水无氧处理的甲苯，升温至80～120℃，搅拌至钠丝完全转变为钠砂，通入氨气，活化钠砂1h，将三氟氯乙烯以20～60mL/min的流速通入反应液，钠和三氟氯乙烯物质的量之比为1：1.2～2；通气完成后，保持温度，恒温反应1～4h，收集反应产生的气体得到六氟丁二烯，剩余液体进行后续回收处理。本发明利用钠脱氯偶联的方法，可以一步的实现从廉价易得原料三氟氯乙烯到六氟丁二烯产品的制备，缩短了产品的制备工艺路线。The invention relates to a one-step method for synthesizing hexafluorobutadiene, which includes the following steps: adding newly pressed sodium wire and anhydrous and oxygen-free treated toluene into a reactor, raising the temperature to 80-120°C, and stirring until The sodium wire is completely converted into sodium sand, ammonia gas is introduced, the sodium sand is activated for 1 hour, and chlorotrifluoroethylene is introduced into the reaction solution at a flow rate of 20 to 60 mL/min. The ratio of the amounts of sodium and chlorotrifluoroethylene is 1: 1.2~2; After the ventilation is completed, maintain the temperature and react at a constant temperature for 1~4 hours. Collect the gas generated by the reaction to obtain hexafluorobutadiene, and the remaining liquid will be recycled for subsequent treatment. The present invention utilizes the sodium dechlorination coupling method to achieve the preparation of hexafluorobutadiene products from cheap and easily available raw material chlorotrifluoroethylene in one step, shortening the product preparation process route.
Description
Technical Field
The invention relates to a synthesis method of hexafluorobutadiene, and belongs to the technical field of chemical industry.
Background
Hexafluoro-1, 3-butadiene (hereinafter referred to as hexafluorobutadiene) replaces CF 4 The dry process applied to the KF laser sharp etching plate monomer capacitor graph has obvious etching advantage on the technical level of 0.13 mu m, has good etching selectivity, can quickly form a fluorocarbon polymer protective film with low density and thin thickness on the surface of a material, obtains moderate etching strength, achieves excellent anisotropic etching effect, realizes almost vertical deep groove structure processing, and becomes the electronic circuit etching gas with optimal performance at present. Meanwhile, the GWP value is only 290, the service life is less than 2 days in the atmosphere, the degradation speed is high, and the molecule does not contain chlorine elements. In summary, hexafluorobutadiene is almost the only electron gas that can meet the high precision and high selectivity of etching and has less harm to ozone layer and greenhouse effect.
At present, the synthetic raw materials of hexafluorobutadiene are various, the process is numerous, the steps are complicated, the conditions are harsh, and the summary analysis mainly comprises the ideas in 3: 1. the organic metal reagent coupling process is to produce hexafluorobutadiene with trifluoro vinyl metal halide as material and through coupling reaction in ferric salt and cupric salt condition. The process has relatively short synthetic route and high reaction selectivity, but the reactive reagent has active property and high risk, and the price of partial raw materials such as dibromotetrafluoroethane is high, so that the industrial application of the process is limited. 2. The saturated halogenated hydrocarbon dehalogenation process prepares hexafluorobutadiene with saturated halogenated butane as material and through dehalogenation reaction in zinc powder. The conversion rate of the step is higher, the product is relatively pure, but the synthetic procedures of saturated halogenated butane are more. Although the method is applied to the current industry in a official way, the method has harsh conditions, various impurities and three wastes, so that the cost of the process route is high. 3. The dehalogenation process with format reagent uses 1, 4-dihalogen perfluorobutane as raw material and uses dehalogenation under the action of format reagent to prepare hexafluorobutadiene, and its technological condition is mild, reaction is relatively safe, but a certain quantity of hexafluorobutadiene can be produced in the course of reactionA hexafluorocyclobutene by-product having a boiling point only 0.8 difference from that of hexafluorobutadiene ℃ It is difficult to effectively separate by a general rectification method.
In conclusion, the synthesis of hexafluorobutadiene is limited by the factors of expensive raw materials, active nature, long reaction steps, harsh reaction conditions, various impurities, serious three-waste problem and the like in the prior art, and is difficult to popularize in industrial production.
Disclosure of Invention
The invention aims to solve the technical problem of providing a production process route for efficiently synthesizing hexafluorobutadiene by taking trifluorochloroethylene as a raw material through a one-step method, and the design of the production process route shortens the synthesis step of a target product, simplifies the production process flow, saves equipment investment and is beneficial to improving the productivity.
In order to achieve the aim, the invention adopts the following technical scheme:
a method for synthesizing hexafluorobutadiene by a one-step method, which comprises the following steps: adding newly pressed sodium wires and anhydrous and anaerobic toluene into a reactor respectively, heating to 80-120 ℃, stirring until the sodium wires are completely converted into sodium sand, introducing ammonia gas, activating the sodium sand for 1h, and introducing trifluorochloroethylene into a reaction solution at a flow rate of 20-60 mL/min, wherein the mass ratio of sodium to trifluorochloroethylene is 1:1.2 to 2; after ventilation is completed, maintaining the temperature, carrying out constant-temperature reaction for 1-4 h, collecting gas generated by the reaction to obtain hexafluorobutadiene, and carrying out subsequent recovery treatment on the residual liquid.
Preferably, the reactor is provided with a condensation reflux and temperature-measuring platinum resistor, and the reactor is subjected to vacuum-nitrogen substitution before new pressed sodium wires and anhydrous and anaerobic toluene are added, so that water and oxygen in the reactor are removed.
Preferably, the mass ratio of the freshly pressed sodium wire to the anhydrous oxygen-free treated toluene is 1: 10-20, and the mass of the introduced ammonia gas is 1-5% of the mass of sodium wires.
Preferably, the method for anhydrous oxygen-free treatment of toluene comprises the following steps:
adding a drying agent into analytically pure toluene or recovered toluene, stirring at normal temperature for 1h, distilling, and collecting fractions at 108-112 ℃ to realize pre-drying of toluene; adding sodium wires and diphenyl ketone into pre-dried toluene, wherein the mass ratio of the sodium wires to the diphenyl ketone to the pre-dried toluene is 1:4: reflux is carried out at the temperature of 10-20 ℃ until the solution turns into dark blue, toluene is distilled out, and distillate is transferred into a bottle filled with a 3A molecular sieve activated at the temperature of 500 ℃ for sealing and storage, wherein the volume ratio of the distillate to the molecular sieve is 20:1.
preferably, the drying agent comprises one or more of phosphorus pentoxide, calcium oxide and the like, and the adding amount of the drying agent is based on the condition that powdery solid remains after the drying agent is added and stirred uniformly.
Preferably, the method for carrying out subsequent recovery treatment on the residual liquid comprises the following steps: after the reaction was cooled to room temperature, absolute ethanol was added dropwise to the reaction apparatus to an excess, and the mixture was stirred for 1 hour to remove sodium wires which had not been sufficiently reacted, and toluene solvent was recovered.
Preferably, the method for recovering toluene solvent comprises the following steps: adding water into the reaction system after ethanol quenching until the precipitate is completely dissolved, and separating the solution; and drying and distilling the upper organic phase solution by magnesium sulfate to obtain recovered toluene, wherein the toluene recovery rate is more than 85%. Preferably, the magnesium sulfate is used in an amount sufficient to provide a powder-like solid remaining after the addition and stirring.
Preferably, the gas generated by the reaction is collected to obtain hexafluorobutadiene for rectification and refining.
The invention has the advantages that:
1) The sodium dechlorination coupling method can realize the preparation of products from cheap and easily available raw materials of chlorotrifluoroethylene to hexafluorobutadiene in one step, and shortens the preparation process route of the products.
2) The method is favorable for reducing the generation of three wastes in a reaction system by recycling the toluene, and reduces the production cost and the environmental protection pressure.
The method has the advantages of simple process route, controllable reaction conditions, high product yield, small three-waste output and good performance for reducing the production cost and environmental protection pressure of the hexafluorobutadiene.
Detailed Description
The following examples are only for further explanation of the present invention and do not limit the scope of protection of the present invention.
Example 1:
(1) Preparation of anhydrous anaerobic toluene
Taking an analytically pure toluene solvent, adding a proper amount of drying agent, stirring for 1h at normal temperature, distilling, and collecting fractions at about 110 ℃ to realize pre-drying of toluene. Sodium silk and diphenyl ketone (mass ratio is about 1:4) are added into pre-dried toluene, after the solution is refluxed to be dark blue, toluene is distilled out, and distillate is transferred into a reagent bottle filled with a 3A molecular sieve activated at 500 ℃ for sealing and storage.
(2) Synthesis of hexafluorobutadiene
Taking a 1L three-port bottle, respectively connecting a condensation reflux, a platinum resistor for measuring temperature and a ventilation pipeline, vacuumizing and replacing 3 times by nitrogen to remove water and oxygen in the device, respectively adding 13.8g of newly pressed sodium wires and 300mL of anhydrous and anaerobic treated toluene, heating to 80 ℃, stirring for 2 hours, completely converting the sodium wires into sodium sand, introducing 0.69g of ammonia (5%) to activate the sodium sand, introducing the trifluorochloroethylene into the reaction solution at a flow rate of 20mL/min, wherein the ventilation quality is 139.2g, and the mass ratio of sodium to trifluorochloroethylene is 1:2. after the aeration was completed, the reaction was carried out at a constant temperature of 80℃for 1 hour, 37.1g of the gas produced by the reaction was collected, and the purity of hexafluorobutadiene was 95.3% and the yield was 72.7%. After the product is rectified by a general rectification mode, the purity of the product can reach 99.91 percent, after the reaction is cooled to room temperature, ethanol is added dropwise into a reaction device until the ethanol is excessive, the mixture is stirred for 1h, and toluene solvent is recovered after sodium wires which are not fully reacted are removed.
(3) Toluene solvent recovery
Adding water into the reaction system after ethanol quenching until the precipitate is completely dissolved, and separating the solution. The upper organic phase solution is dried over magnesium sulfate and filtered before being recovered.
Example 2:
(1) Preparation of anhydrous anaerobic toluene
Taking an analytically pure toluene solvent, adding a proper amount of drying agent, stirring for 1h at normal temperature, distilling, and collecting fractions at about 110 ℃ to realize pre-drying of toluene. Sodium silk and diphenyl ketone (mass ratio is about 1:4) are added into pre-dried toluene, after the solution is refluxed to be dark blue, toluene is distilled out, and distillate is transferred into a reagent bottle filled with a 3A molecular sieve activated at 500 ℃ for sealing and storage.
(2) Synthesis of hexafluorobutadiene
Taking 10L of a reaction kettle connected with a condensation reflux, a platinum resistor for measuring temperature and a ventilation pipeline, vacuumizing, replacing water and oxygen in a 3-time removal device with nitrogen, respectively adding 138.0g of newly pressed sodium wires and 3L of anhydrous and anaerobic toluene, heating to 120 ℃, stirring for 0.5h, completely converting the sodium wires into sodium sand, introducing 1.38g of ammonia (1%) to activate the sodium sand, introducing chlorotrifluoroethylene into a reaction solution at a flow rate of 60mL/min, wherein the ventilation quality is 835.2g, and the mass ratio of sodium to chlorotrifluoroethylene is 1:1.2. after aeration was completed, the reaction was carried out at a constant temperature of 120℃for 2 hours, 413.3g of gas generated by the reaction was collected, and the purity of hexafluorobutadiene was 94.1% and the yield was 80.0%. After the rectification by a general rectification mode, the purity of the product can reach 99.90 percent.
After the reaction was cooled to room temperature, ethanol was added dropwise to the reaction apparatus to an excessive amount, and the mixture was stirred for 1 hour to remove sodium wires which had not been sufficiently reacted, and then toluene solvent was recovered.
(3) Toluene solvent recovery
Adding water into the reaction system after ethanol quenching until the precipitate is completely dissolved, and separating the solution. The upper organic phase solution is dried over magnesium sulfate and filtered before being recovered.
Example 3:
(1) Preparation of anhydrous anaerobic toluene
Taking an analytically pure toluene solvent, adding a proper amount of drying agent, stirring for 1h at normal temperature, distilling, and collecting fractions at about 110 ℃ to realize pre-drying of toluene. Sodium silk and diphenyl ketone (mass ratio is about 1:4) are added into pre-dried toluene, after the solution is refluxed to be dark blue, toluene is distilled out, and distillate is transferred into a reagent bottle filled with a 3A molecular sieve activated at 500 ℃ for sealing and storage.
(2) Synthesis of hexafluorobutadiene
Taking 5L of a reaction kettle connected with a condensation reflux, a platinum resistor for measuring temperature and a ventilation pipeline, vacuumizing and replacing 3 times by nitrogen to remove water and oxygen in the device, respectively adding 92.0g of newly pressed sodium wires and 2L of anhydrous and anaerobic toluene, heating to 100 ℃, stirring for 1h, completely converting the sodium wires into sodium sand, introducing 2.76g of ammonia (3%) to activate the sodium sand, introducing the chlorotrifluoroethylene into the reaction liquid at a flow rate of 40mL/min, wherein the ventilation mass is 696.0g, and the mass ratio of sodium to chlorotrifluoroethylene is 1:1.5. after aeration was completed, the reaction was carried out at a constant temperature of 100℃for 4 hours, 298.5g of the gas produced by the reaction was collected, and the purity of hexafluorobutadiene was 96.2%, with a yield of 88.6%. After the product is rectified by a general rectification mode, the purity of the product can reach 99.92 percent, after the reaction is cooled to room temperature, ethanol is added dropwise into a reaction device until the ethanol is excessive, the mixture is stirred for 1h, and toluene solvent is recovered after sodium wires which are not fully reacted are removed.
(3) Toluene solvent recovery
Adding water into the reaction system after ethanol quenching until the precipitate is completely dissolved, and separating the solution. The upper organic phase solution is dried over magnesium sulfate and filtered before being recovered.
The technical features of the present invention are not limited to the above embodiments, and any technical problems that are basically the same with the present invention are solved, basically the same technical effects are implemented, and simple changes, substitutions or modifications made, etc. are all covered in the technical protection scope of the present invention.
Claims (9)
1. A method for synthesizing hexafluorobutadiene by a one-step method, which is characterized by comprising the following steps: adding newly pressed sodium wires and anhydrous and anaerobic toluene into a reactor respectively, heating to 80-120 ℃, stirring until the sodium wires are completely converted into sodium sand, introducing ammonia gas, activating the sodium sand for 1h, and introducing trifluorochloroethylene into a reaction solution at a flow rate of 20-60 mL/min, wherein the mass ratio of sodium to trifluorochloroethylene is 1:1.2 to 2; after ventilation is completed, maintaining the temperature, carrying out constant-temperature reaction for 1-4 h, collecting gas generated by the reaction to obtain hexafluorobutadiene, and carrying out subsequent recovery treatment on the residual liquid.
2. The one-step synthesis of hexafluorobutadiene according to claim 1, wherein the reactor is provided with a condensing reflux and temperature measuring platinum resistor, and the reactor is subjected to vacuum-nitrogen substitution to remove water and oxygen in the reactor before adding newly pressed sodium wire and anhydrous oxygen-free toluene.
3. The one-step method for synthesizing hexafluorobutadiene as claimed in claim 1, wherein the mass ratio of freshly pressed sodium wire to anhydrous oxygen-free treated toluene is 1: 10-20, and the mass of the introduced ammonia gas is 1-5% of the mass of sodium wires.
4. The method for synthesizing hexafluorobutadiene according to claim 1, wherein the method for anhydrous oxygen-free treated toluene comprises the steps of:
adding a drying agent into analytically pure toluene or recovered toluene, stirring at normal temperature for 1h, distilling, and collecting fractions at 108-112 ℃ to realize pre-drying of toluene; adding sodium wires and diphenyl ketone into pre-dried toluene, wherein the mass ratio of the sodium wires to the diphenyl ketone to the pre-dried toluene is 1:4: reflux is carried out at the temperature of 10-20 ℃ until the solution turns into dark blue, toluene is distilled out, and distillate is transferred into a bottle filled with a 3A molecular sieve activated at the temperature of 500 ℃ for sealing and storage, wherein the volume ratio of the distillate to the molecular sieve is 20:1.
5. the method for synthesizing hexafluorobutadiene according to claim 4, wherein the drying agent comprises one or more of phosphorus pentoxide and calcium oxide, and the drying agent is added in an amount such that powdery solid remains after the drying agent is added and stirred uniformly.
6. The method for synthesizing hexafluorobutadiene by one-step method according to claim 1, wherein the method for subjecting the remaining liquid to subsequent recovery treatment comprises the steps of: after the reaction was cooled to room temperature, absolute ethanol was added dropwise to the reaction apparatus to an excess, and the mixture was stirred for 1 hour to remove sodium wires which had not been sufficiently reacted, and toluene solvent was recovered.
7. The method for synthesizing hexafluorobutadiene by one-step method according to claim 6, wherein the method for recovering toluene solvent is as follows: adding water into the reaction system after ethanol quenching until the precipitate is completely dissolved, and separating the solution; and drying and distilling the upper organic phase solution by magnesium sulfate to obtain recovered toluene, wherein the toluene recovery rate is more than 85%.
8. The one-step synthesis method of hexafluorobutadiene according to claim 7, wherein the magnesium sulfate is added in an amount sufficient to leave a powdery solid after being stirred uniformly.
9. The method for synthesizing hexafluorobutadiene by one-step process according to claim 1, wherein the gas produced by the reaction is collected to obtain hexafluorobutadiene, which is refined by rectification.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5068472A (en) * | 1989-12-19 | 1991-11-26 | E. I. Du Pont De Nemours And Company | Multistep synthesis of hexafluoropropylene |
| CN106336342A (en) * | 2016-07-19 | 2017-01-18 | 浙江博瑞电子科技有限公司 | Method for preparing hexafluorobutadiene from iodine and chlorine |
| CN110753680A (en) * | 2017-06-20 | 2020-02-04 | 大金工业株式会社 | Method for producing butadiene compound |
| CN114206817A (en) * | 2019-08-13 | 2022-03-18 | 大金工业株式会社 | Process for producing 1,1, 2-trifluoroethylene, hexafluoro-1, 3-butadiene or 1, 2-dichlorohexafluorocyclobutane |
| CN116082116A (en) * | 2023-02-06 | 2023-05-09 | 浙江科技学院 | Continuous production method of perfluorobutene and modified catalyst |
-
2023
- 2023-06-14 CN CN202310702745.1A patent/CN116903436A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5068472A (en) * | 1989-12-19 | 1991-11-26 | E. I. Du Pont De Nemours And Company | Multistep synthesis of hexafluoropropylene |
| CN106336342A (en) * | 2016-07-19 | 2017-01-18 | 浙江博瑞电子科技有限公司 | Method for preparing hexafluorobutadiene from iodine and chlorine |
| CN110753680A (en) * | 2017-06-20 | 2020-02-04 | 大金工业株式会社 | Method for producing butadiene compound |
| CN114206817A (en) * | 2019-08-13 | 2022-03-18 | 大金工业株式会社 | Process for producing 1,1, 2-trifluoroethylene, hexafluoro-1, 3-butadiene or 1, 2-dichlorohexafluorocyclobutane |
| CN116082116A (en) * | 2023-02-06 | 2023-05-09 | 浙江科技学院 | Continuous production method of perfluorobutene and modified catalyst |
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