A method for efficiently preparing perfluoro-2-methyl-2,3-epoxy pentane
By using a composite catalyst to prepare perfluoro-2-methyl-2,3-epoxypentane under light irradiation, the problems of poor environmental performance and high safety risks in existing technologies are solved, realizing the efficient and low-cost synthesis of perfluoro-2,3-epoxypentane, which is suitable for green chemical industry and large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN DONGYANG SOLAR SCI RES & DEV CO LTD
- Filing Date
- 2026-03-27
- Publication Date
- 2026-07-10
AI Technical Summary
The existing perfluoro-2-methyl-2,3-epoxypentane synthesis process suffers from problems such as poor environmental performance, high safety risks, low production efficiency, high costs, and difficulty in treating waste, making it difficult to meet the needs of green chemical industry and large-scale safe production.
The reaction was carried out under light irradiation using a composite catalyst. Mesoporous molecular sieves supported on FeWO4 and/or MnWO4 were used as the main catalyst, combined with ionic reagents [BMIM]PF6 or [EMIM]BF4, to prepare perfluoro-2-methyl-2,3-epoxypentane through the reaction of perfluoro-2-methyl-2-pentene with an epoxidizing agent. Organic solvents and ozone were avoided, and the reaction was carried out in a microreactor.
The synthesis of perfluoro-2-methyl-2,3-epoxypentane with high yield and high conversion rate has been achieved, reducing production costs, improving safety and environmental protection, simplifying the post-processing, and making it suitable for industrial production.
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Abstract
Description
Technical Field
[0001] This invention relates to the fields of refrigerants, fire protection, new fluorochemical materials, and chemical synthesis, specifically to a green and efficient method for preparing perfluoro-2-methyl-2,3-epoxypentane. Background Technology
[0002] Perfluoro-2-methyl-2,3-epoxypentane (CAS No.: 788-67-0) is a structurally stable and uniquely reactive perfluoroepoxide with the molecular formula C6F. 12 O, a colorless, transparent, low-viscosity liquid at room temperature, possesses excellent chemical inertness, thermal stability, insulation, and hydrophobic and oleophobic properties, making it an indispensable key intermediate in the field of fluorinated fine chemicals. The most crucial downstream application of this compound is the catalytic ring-opening rearrangement to prepare perfluorohexanone (Novec 1230). Perfluorohexanone, as a new generation of environmentally friendly clean fire extinguishing agent, has an ODP (ozone depletion potential) of 0 and a low GWP (global warming potential), exhibiting high fire extinguishing efficiency, no residue, and environmental friendliness. It has been widely used in fire protection in high-end fields such as data centers, aerospace, electronics, and energy storage power stations. Simultaneously, perfluoro-2-methyl-2,3-epoxypentane can also be used to synthesize special fluorinated ether solvents, fluorinated surfactants, and fluoropolymer functional monomers, showing potential application value in electronic cleaning, precision machining, and pharmaceutical synthesis.
[0003] Currently, the synthesis methods for perfluoro-2-methyl-2,3-epoxypentane suffer from numerous drawbacks, including poor environmental friendliness, insufficient safety, high cost, and difficulty in separation and recovery. Specific shortcomings of existing processes are as follows: Firstly, Chinese patent CN103508983B discloses a process for preparing perfluoro-2-methyl-2,3-epoxypentane by reacting perfluoro-2-methyl-2-pentene with sodium hypochlorite in an aprotic solvent system using an amino compound as an epoxidation catalyst. This process has significant drawbacks: it readily generates high-salt wastewater during the reaction, and the product contains chlorine impurities exceeding 0.5%, making high-salt wastewater treatment difficult and costly. Furthermore, the energy consumption for separating the aprotic solvent from the product is high, and some solvents are difficult to fully recover, increasing overall production costs and potentially leading to solvent residues in the product, affecting its purity. In addition, the high-salt wastewater system is highly corrosive to the reaction equipment, requiring the use of special corrosion-resistant materials, significantly increasing both initial investment and subsequent maintenance costs.
[0004] Secondly, Chinese patent application CN115490651A discloses a process for preparing the target product by reacting perfluoro-2-methyl-2-pentene and a dispersant under the action of an oxidant. This process still relies on organic solvents such as dimethyl ether, ethanol, or acetonitrile as dispersants, resulting in high costs for subsequent solvent separation, recovery, and purification, as well as large amounts of waste generated that are difficult to treat. Furthermore, the process has a long reaction cycle and low overall reaction efficiency, making it unsuitable for large-scale industrial production.
[0005] Thirdly, Chinese patent CN115785029B discloses a process for preparing perfluoro-2-methyl-2,3-epoxypentane using ozone as an oxidant and one or more of acetonitrile, dimethylformamide, or dimethyl sulfoxide as a solvent. This process poses significant safety hazards and environmental defects. Ozone itself has extremely poor stability and readily decomposes into oxygen upon heating, releasing a large amount of heat and posing a high risk of explosion. When ozone comes into contact with strong reducing agents, metal powders, active metals, or oils, it undergoes a violent exothermic oxidation reaction, potentially leading to spontaneous combustion or explosion. High concentrations of ozone can also cause rapid aging and cracking of rubber and some plastic materials, placing extremely high demands on the safety of production equipment and the production environment. Furthermore, this process still uses organic solvents as the reaction medium, resulting in difficulties in waste treatment and high energy consumption for solvent recovery.
[0006] In addition, the traditional amino catalysts commonly used in existing processes can only be used once and cannot be recycled, which further increases the cost of raw materials and is not conducive to improving the economic efficiency of industrial production.
[0007] In summary, existing processes for synthesizing perfluoro-2-methyl-2,3-epoxypentane generally suffer from poor environmental performance, high safety risks, low production efficiency, high costs, and difficulties in treating waste. These issues make it difficult to meet the current industry demands for green chemistry and large-scale safe production. Therefore, there is an urgent need in this field to develop a green, environmentally friendly, safe, controllable, efficient, stable, and low-cost method for preparing perfluoro-2-methyl-2,3-epoxypentane. Summary of the Invention
[0008] To address the aforementioned technical problems, the present invention provides the following technical solutions.
[0009] In a first aspect, the present invention provides a method for preparing perfluoro-2-methyl-2,3-epoxypentane.
[0010] A method for preparing perfluoro-2-methyl-2,3-epoxypentane, comprising:
[0011] Perfluoro-2-methyl-2-pentene reacts with an epoxidizing agent under light in the presence of a composite catalyst to yield perfluoro-2-methyl-2,3-epoxypentane. The composite catalyst includes a main catalyst and a co-catalyst; The main catalyst comprises a mesoporous molecular sieve supported on FeWO4 and / or MnWO4; The cocatalyst includes an ionic reagent; The ionic reagents include [BMIM]PF6 or [EMIM]BF4.
[0012] In some embodiments, the epoxidizing agent includes hydrogen peroxide.
[0013] In some embodiments, the mesoporous molecular sieve includes SBA-15 mesoporous molecular sieve.
[0014] In some embodiments, the illumination wavelength of the illumination conditions is 200nm to 400nm. In some embodiments, the illumination wavelength of the illumination conditions is 200nm, 250nm, 300nm, 350nm, 360nm, 363nm, 364nm, 365nm, 366nm, 367nm, 370nm, 400nm, or any value within the range of any two of these values. In some preferred embodiments, the illumination wavelength of the illumination conditions is 365nm.
[0015] In some embodiments, the illuminance of the illumination condition is 5 W / cm². 2 ~20 W / cm 2 In some embodiments, the light intensity of the illumination conditions is 5 W / cm². 2 10W / cm 2 15W / cm 2 20 W / cm 2 Or any value within the range of any two values. In some preferred embodiments, the illuminance of the illumination condition is 10 W / cm². 2 .
[0016] In some embodiments, the reaction temperature is 0°C to 5°C. In some embodiments, the reaction temperature is 0°C, 1°C, 2°C, 3°C, 4°C, 5°C, or any value within a range of any two of these values.
[0017] In some embodiments, the molar ratio of perfluoro-2-methyl-2-pentene to the epoxidizing agent is 1:1 to 1:5. In some embodiments, the molar ratio of perfluoro-2-methyl-2-pentene to the epoxidizing agent is 1:1, 1:2, 1:3, 1:4, 1:5, or any value within the range of any two of these values. In some preferred embodiments, the molar ratio of perfluoro-2-methyl-2-pentene to the epoxidizing agent is 1:3.
[0018] In some embodiments, the mass ratio of the main catalyst to the co-catalyst is 3:1 to 10:1. In some embodiments, the mass ratio of the main catalyst to the co-catalyst is 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or any value within the range of any two of these values. In some preferred embodiments, the mass ratio of the main catalyst to the co-catalyst is 5:1.
[0019] In some embodiments, the perfluoro-2-methyl-2-pentene is pre-treated to remove moisture before feeding. In some embodiments, the method for removing moisture includes: calcining the 3A molecular sieve, cooling it to room temperature, mixing it with the perfluoro-2-methyl-2-pentene, and allowing it to stand for 45h to 60h (e.g., 45h, 50h, 55h, 60h, or any value within the range of any two of these values).
[0020] In some embodiments, the calcination temperature in the method for removing moisture is 300°C to 550°C. In some embodiments, the calcination temperature in the method for removing moisture is 300°C, 350°C, 400°C, 450°C, 550°C, or any value within a range of any two of these values.
[0021] In some embodiments, the calcination time in the method for removing moisture is 2h to 10h. In some embodiments, the calcination time in the method for removing moisture is 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, or any value within the range of any two of these values.
[0022] In some embodiments, the preparation method of the main catalyst includes: impregnating a mesoporous molecular sieve in a solution containing a metal salt, wherein the metal salt includes FeWO4 and / or MnWO4; then drying and calcining to obtain the main catalyst.
[0023] In some embodiments, the method for preparing the composite catalyst includes: mixing and dispersing the obtained main catalyst with a co-catalyst to obtain the composite catalyst.
[0024] In some embodiments, the concentration of the metal salt in the metal salt-containing solution is 10 wt% to 30 wt%. In some embodiments, the concentration of the metal salt in the metal salt-containing solution is 10 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 30 wt%, or any value within the range of any two of these values. In some preferred embodiments, the concentration of the metal salt in the metal salt-containing solution is 20 wt%.
[0025] In some embodiments, the metal salt-containing solution uses water as a solvent.
[0026] In some embodiments, the immersion time includes 12 to 48 hours. In some embodiments, the immersion time includes 12 hours, 15 hours, 20 hours, 24 hours, 25 hours, 30 hours, 35 hours, 36 hours, 40 hours, 45 hours, 48 hours, or any value within a range of any two of these values. In some preferred embodiments, the immersion time is 24 hours.
[0027] In some embodiments, the calcination temperature is 400°C to 700°C. In some embodiments, the calcination temperature is 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, or any value within a range of any two of these values. In some preferred embodiments, the calcination temperature is 550°C.
[0028] In some embodiments, the calcination time is 2 to 8 hours. In some embodiments, the calcination time is 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, or any value within the range of any two of these values. In some preferred embodiments, the calcination time is 4 hours.
[0029] In some embodiments, the drying temperature is selected from 80°C to 150°C. In some embodiments, the drying temperature is selected from 80°C, 90°C, 100°C, 105°C, 110°C, 115°C, 120°C, 130°C, 140°C, 150°C, or any value within a range of any two of these values. In some preferred embodiments, the drying temperature is 110°C.
[0030] In some embodiments, the drying time is 1 to 5 hours. In some embodiments, the drying time is 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, or any value within a range of any two of these values. In some preferred embodiments, the drying time is 2 hours.
[0031] In some embodiments, the reaction is carried out in a microreactor, in which the composite catalyst is packed and then a mixture of perfluoro-2-methyl-2-pentene and an epoxidizing agent is introduced to carry out the reaction.
[0032] In some embodiments, the residence time of the mixture in the microreactor is 10 min to 30 min. In some embodiments, the residence time of the mixture in the microreactor is 10 min, 15 min, 20 min, 25 min, 30 min, or any value within the range of any two of these values.
[0033] In some embodiments, the filling volume of the composite catalyst is 40% to 70% of the volume of the microreactor. In some embodiments, the filling volume of the composite catalyst is 40%, 45%, 50%, 55%, 60%, 65%, 70% of the volume of the microreactor, or any value within a range of any two of these values.
[0034] In some embodiments, the inner diameter of the pipe in the microreactor is 0.3 mm to 2 mm. In some embodiments, the inner diameter of the pipe in the microreactor is 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, or any value within a range of any two of these values. In some preferred embodiments, the inner diameter of the pipe in the microreactor is 1 mm.
[0035] In some embodiments, the effective reaction length of the pipeline of the microreactor is 10m to 30m. In some embodiments, the effective reaction length of the pipeline of the microreactor is 10m, 11m, 12m, 13m, 14m, 15m, 16m, 17m, 18m, 19m, 20m, 21m, 22m, 23m, 24m, 25m, 26m, 27m, 28m, 29m, 30m, or any value within the range of any two of these values.
[0036] In some embodiments, the method further includes post-processing after the reaction is completed. The post-processing includes: allowing the mixture to stand and separate, removing the lower layer to obtain crude perfluoro-2-methyl-2,3-epoxypentane, then dehydrating, distilling, and taking the fraction at 50°C-55°C to obtain pure perfluoro-2-methyl-2,3-epoxypentane.
[0037] Secondly, the present invention provides a composite catalyst.
[0038] A composite catalyst comprising the composite catalyst prepared by the method described in the first aspect.
[0039] Thirdly, the present invention provides an application of the composite catalyst described in the second aspect.
[0040] The use of the composite catalyst described in the second aspect in the reaction of catalyzing perfluoro-2-methyl-2-pentene to prepare perfluoro-2-methyl-2,3-epoxypentane.
[0041] Beneficial effects Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects: (1) The composite catalyst provided by this invention can efficiently synthesize perfluoro-2-methyl-2,3-epoxypentane under UV light conditions. The resulting perfluoro-2-methyl-2,3-epoxypentane has a high yield, high substrate conversion rate, and can be recycled many times, showing unexpectedly excellent technical effects. In addition, the method for preparing perfluoro-2-methyl-2,3-epoxypentane provided by this invention does not require organic solvents, does not require the addition of chlorine-containing oxidants such as sodium hypochlorite, and does not require the addition of ozone, making it greener, safer, and more environmentally friendly. The post-processing is simple. The reaction speed is fast and the efficiency is high. In industrial production, production can be expanded by increasing the number and / or size of microreactors. The reaction conditions are mild and do not require high pressure and high temperature conditions.
[0042] (2) Compared with the condition without UV light, the present invention preferably carries out the reaction in the presence of UV light, which is more conducive to improving the yield of perfluoro-2-methyl-2,3-epoxypentane and the substrate conversion rate, and has unexpectedly excellent technical effects.
[0043] (3) Compared with not adding a composite catalyst, the composite catalyst provided by the present invention is more conducive to improving the yield and substrate conversion of the obtained perfluoro-2-methyl-2,3-epoxypentane, and has unexpectedly excellent technical effects.
[0044] (4) The FeWO4@SBA-15 of the present invention and the ionic reagent ([BMIM]PF6 or [EMIM]BF4) work together to achieve unexpected synergistic effects.
[0045] (5) Compared with other ionic reagents (such as [BMIM]BF4), the present invention preferably uses [BMIM]PF6 and / or [EMIM]BF4 as the ionic reagents of the composite catalyst of the present invention, which is more conducive to improving the activity and stability of the obtained composite catalyst, and more conducive to improving the yield of perfluoro-2-methyl-2,3-epoxypentane, substrate conversion and the number of times the obtained composite catalyst can be recycled, with unexpectedly excellent technical effects.
[0046] (6) Compared with other supports (such as MCM-41 molecular sieve), the present invention preferably uses SBA-15 molecular sieve as support, which is more conducive to improving the activity and stability of the obtained composite catalyst, and more conducive to improving the yield of perfluoro-2-methyl-2,3-epoxypentane, substrate conversion and the number of times the obtained composite catalyst can be recycled, with unexpectedly excellent technical effects.
[0047] Terminology Explanation In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0048] The term “room temperature” refers to ambient temperature, which is between approximately 10°C and approximately 30°C, or approximately 20°C and approximately 30°C, or approximately 25°C.
[0049] "[BMIM]PF6" represents 1-butyl-3-methylimidazolium hexafluorophosphate, CAS number: 174501-64-5.
[0050] “[EMIM]BF4” represents 1-ethyl-3-methylimidazolium tetrafluoroborate, CAS No.: 143314-16-3.
[0051] “[BMIM]BF4” represents 1-butyl-3-methylimidazolium tetrafluoroborate, CAS No.: 174501-65-6.
[0052] "Perfluoro-2-methyl-2-pentene" refers to the compound with CAS number 1584-03-8.
[0053] The “filling volume” mentioned in this invention refers to the apparent volume occupied by the accumulation of solid catalyst (including support) particles, which includes the void volume between particles.
[0054] In this invention, "inner diameter" refers to the internal diameter of the hollow pipe.
[0055] In this invention, "residence time" refers to the average residence time of reactants in the microreactor channel, that is, the average time that reactant micro-elements take from entering the microreactor to flowing out of the reactor.
[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0057] In the following content, all numbers disclosed herein, whether or not they are expressed using words such as "approximately" or "about," are approximate values. The value of each number may vary by 1%, 2%, 5%, 7%, 8%, 10%, 15%, or 20%, etc. Whenever a number with a value of N is disclosed, any number having a value of N+ / -1%, N+ / -2%, N+ / -3%, N+ / -5%, N+ / -7%, N+ / -8%, N+ / -10%, N+ / -15%, or N+ / -20% will be explicitly disclosed, where "+ / -" indicates addition or subtraction. Detailed Implementation
[0058] To enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting embodiments are further disclosed below to provide a more detailed description of the present invention.
[0059] The reagents or consumables used in this invention can be purchased from the market or prepared by the methods described in this invention.
[0060] 3A molecular sieve: Changsha Jingkang New Material Technology Co., Ltd. (40-60 mesh); SBA-15 molecular sieve: Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., Model: XFF01-1; Pore size: 6 nm~13 nm, specific surface area: 700 m² 2 / g~800 m 2 / g; MCM-41 molecular sieve: Chemical Wisdom, model: NFF02.
[0061] Example 1: Preparation of composite catalyst and synthesis of perfluoro-2-methyl-2,3-epoxypentane 1. Preparation of composite catalysts (1) Raw material pretreatment: First, 3A molecular sieve is calcined in a muffle furnace at 300℃ for 8 hours. After cooling to room temperature, it is mixed with perfluoro-2-methyl-2-pentene and placed for 48 hours to remove the moisture from perfluoro-2-methyl-pentene. (2) Catalyst preparation: SBA-15 molecular sieve was impregnated in a 20wt% FeWO4 aqueous solution for 24h, then dried at 110℃ for 2h and calcined at 550℃ for 4h to obtain FeWO4@SBA-15.
[0062] (3) Preparation of composite catalyst: FeWO4@SBA-15 obtained in step (2) and ionic reagent [BMIM]PF6 are mixed in a ratio of FeWO4@SBA-15:[BMIM]PF6=5:1 (mass ratio), and ultrasonically dispersed for 30 min to obtain composite catalyst.
[0063] 2. Synthesis of perfluoro-2-methyl-2,3-epoxypentane
[0064] The composite catalyst obtained in step 1 was packed into a microreactor (1 mm inner diameter, 20 m length) at a loading volume of 50% of the reactor volume; then, perfluoro-2-methyl-2-pentene (100 g) and 30% H2O2 aqueous solution (113.33 g) were pumped in, and the reaction was carried out at 0 °C (reaction temperature) under 365 nm UV light (10 W / cm²). 2 The reaction was carried out in a microreactor under irradiation conditions for 20 min. After the reaction, the reaction solution was collected, allowed to stand and separated, the lower layer was removed, dehydrated by a ZIF-8 membrane, and then distilled under reduced pressure (60℃, 0.1 kPa). The fraction from 50℃ to 54℃ was collected to obtain perfluoro-2-methyl-2,3-epoxypentane. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were determined and the results are shown in Table 1.
[0065] The composite catalyst obtained in Example 1 was repeatedly recycled using the above-described method for synthesizing perfluoro-2-methyl-2,3-epoxypentane. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were tested in the 10th and 20th uses. The results are shown in Table 1.
[0066] Example 2: Preparation of composite catalyst and synthesis of perfluoro-2-methyl-2,3-epoxypentane The only difference from Example 1 is that the reaction temperature of “2. Synthesis of perfluoro-2-methyl-2,3-epoxypentane” was adjusted to 5°C. The rest of the operation was the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were tested, and the results are shown in Table 1.
[0067] Example 3: Preparation of composite catalyst and synthesis of perfluoro-2-methyl-2,3-epoxypentane The only difference from Example 1 is that FeWO4 in “(2) Catalyst Preparation” is changed to MnWO4. The rest of the operation is the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion of perfluoro-2-methyl-2-pentene were tested, and the results are shown in Table 1.
[0068] Example 4: Preparation of composite catalyst and synthesis of perfluoro-2-methyl-2,3-epoxypentane The only difference from Example 1 is that the ionic reagent [BMIM]PF6 in “(3) Preparation of composite catalyst” is replaced with [EMIM]BF4. The rest of the operation is the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion of perfluoro-2-methyl-2-pentene were tested, and the results are shown in Table 1.
[0069] Example 5: Preparation of composite catalyst and synthesis of perfluoro-2-methyl-2,3-epoxypentane The only difference from Example 1 is that the residence time in "2. Synthesis of perfluoro-2-methyl-2,3-epoxypentane" was adjusted to 10 min. The rest of the operation was the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were detected, and the results are shown in Table 1.
[0070] Example 6: Preparation of composite catalyst and synthesis of perfluoro-2-methyl-2,3-epoxypentane The only difference from Example 1 is that the residence time for “2. Synthesis of perfluoro-2-methyl-2,3-epoxypentane” was adjusted to 30 min. The rest of the operation was the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were tested, and the results are shown in Table 1.
[0071] Example 7: Preparation of composite catalyst and synthesis of perfluoro-2-methyl-2,3-epoxypentane The only difference from Example 1 is that the mass of the 30% H2O2 aqueous solution used in the "2. Synthesis of perfluoro-2-methyl-2,3-epoxypentane" was adjusted to 56.67 g. The rest of the operation was the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were tested, and the results are shown in Table 1.
[0072] Comparative Example 1: Traditional Synthesis Process First, a three-necked flask equipped with a constant-pressure dropping funnel and a thermometer was placed in a low-temperature constant-temperature reaction bath for cooling. 276.1 g of acetonitrile and 1600 g of sodium hypochlorite aqueous solution (10 wt% sodium hypochlorite) were added to the flask. Then, 326.4 g of perfluoro-2-methyl-2-pentene was added dropwise to the flask through the constant-pressure dropping funnel, maintaining the temperature no higher than -5°C. After reacting for 2 hours, the mixture was poured into a separating funnel, allowed to stand for separation, and the lower layer was collected. The upper layer contained 1905.8 g of chlorine-containing waste liquid. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were determined, and the results are shown in Table 1.
[0073] Comparative Example 2: Investigation without UV light The only difference from Example 1 was the absence of UV light irradiation; all other conditions were the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion rate of perfluoro-2-methyl-2-pentene were measured, and the results are shown in Table 1.
[0074] Comparative Example 3: No ionic reagents added The only difference from Example 1 is that the ionic reagent [BMIM]PF6 was not added during the preparation of the composite catalyst; all other conditions were the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion of perfluoro-2-methyl-2-pentene were measured, and the results are shown in Table 1.
[0075] Comparative Example 4: No composite catalyst added The only difference from Example 1 is that in the "synthesis of perfluoro-2-methyl-2,3-epoxypentane", a composite catalyst was not loaded; other conditions were the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion of perfluoro-2-methyl-2-pentene were measured, and the results are shown in Table 1.
[0076] Comparative Example 5: No FeWO4 added @SBA-15 The only difference from Example 1 is that FeWO4@SBA-15 was not added during the preparation of the composite catalyst; all other conditions were the same as in Example 1. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion of perfluoro-2-methyl-2-pentene were measured, and the results are shown in Table 1.
[0077] Comparative Example 6: Investigation of Ionic Reagents The only difference from Example 1 is that the ionic reagent [BMIM]PF6 was replaced with [BMIM]BF4 in the preparation of the composite catalyst; all other conditions were the same as in Example 1. The composite catalyst obtained in Comparative Example 5 was repeatedly recycled, and the yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion of perfluoro-2-methyl-2-pentene were measured in the 1st, 10th, and 20th cycles. The results are shown in Table 1.
[0078] Comparative Example 7: Examination of the Carrier The only difference from Example 1 is that the SBA-15 molecular sieve was replaced with MCM-41 molecular sieve in the preparation of the composite catalyst; all other conditions were the same as in Example 1. The composite catalyst obtained in Comparative Example 6 was repeatedly recycled, and the conversion and yield were measured for the 1st, 10th, and 20th uses. The yield of perfluoro-2-methyl-2,3-epoxypentane and the conversion of perfluoro-2-methyl-2-pentene were also measured. The results are shown in Table 1.
[0079] Table 1: Conversion and Yield Results
[0080] Results analysis: (1) The composite catalyst provided by this invention can efficiently synthesize perfluoro-2-methyl-2,3-epoxypentane under UV light conditions. The resulting perfluoro-2-methyl-2,3-epoxypentane has a high yield, high substrate conversion rate, and can be recycled many times, showing unexpectedly excellent technical effects. In addition, the method for preparing perfluoro-2-methyl-2,3-epoxypentane provided by this invention does not require organic solvents, does not require the addition of chlorine-containing oxidants such as sodium hypochlorite, and does not require the addition of ozone, making it greener, safer, and more environmentally friendly. The post-processing is simple. The reaction speed is fast and the efficiency is high. In industrial production, production can be expanded by increasing the number and / or size of microreactors. The reaction conditions are mild and do not require high pressure and high temperature conditions.
[0081] (2) Compared with the condition without UV light, the present invention preferably carries out the reaction in the presence of UV light, which is more conducive to improving the yield of perfluoro-2-methyl-2,3-epoxypentane and the substrate conversion rate, and has unexpectedly excellent technical effects.
[0082] (3) Compared with not adding a composite catalyst, the composite catalyst provided by the present invention is more conducive to improving the yield and substrate conversion of the obtained perfluoro-2-methyl-2,3-epoxypentane, and has unexpectedly excellent technical effects.
[0083] (4) The FeWO4@SBA-15 of the present invention and the ionic reagent ([BMIM]PF6 or [EMIM]BF4) work together to achieve unexpected synergistic effects.
[0084] (5) Compared with other ionic reagents (such as [BMIM]BF4), the present invention preferably uses [BMIM]PF6 and / or [EMIM]BF4 as the ionic reagents of the composite catalyst of the present invention, which is more conducive to improving the activity and stability of the obtained composite catalyst, and more conducive to improving the yield of perfluoro-2-methyl-2,3-epoxypentane, substrate conversion and the number of times the obtained composite catalyst can be recycled, with unexpectedly excellent technical effects.
[0085] (6) Compared with other supports (such as MCM-41 molecular sieve), the present invention preferably uses SBA-15 molecular sieve as support, which is more conducive to improving the activity and stability of the obtained composite catalyst, and more conducive to improving the yield of perfluoro-2-methyl-2,3-epoxypentane, substrate conversion and the number of times the obtained composite catalyst can be recycled, with unexpectedly excellent technical effects.
[0086] The method of this invention has been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and applications described herein within the scope, spirit, and context of this invention to implement and apply the technology of this invention. Those skilled in the art can refer to the content herein to appropriately improve process parameters. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of this invention.
Claims
1. A method for preparing perfluoro-2-methyl-2,3-epoxypentane, characterized in that, include: Perfluoro-2-methyl-2-pentene reacts with an epoxidizing agent under light in the presence of a composite catalyst to yield perfluoro-2-methyl-2,3-epoxypentane. The composite catalyst includes a main catalyst and a co-catalyst; The main catalyst comprises a mesoporous molecular sieve supported on FeWO4 and / or MnWO4; The cocatalyst includes an ionic reagent; The ionic reagents include [BMIM]PF6 or [EMIM]BF4.
2. The method according to claim 1, characterized in that, The epoxidizing agent includes hydrogen peroxide; and / or The mesoporous molecular sieve includes SBA-15 mesoporous molecular sieve.
3. The method according to any one of claims 1 to 2, characterized in that, The illumination wavelength of the illumination conditions is 200nm to 400nm, preferably 365nm; and / or The light intensity under the specified illumination conditions is 5 W / cm². 2 ~20 W / cm 2 The preferred value is 10W / cm. 2 ; and / or The reaction temperature is 0℃~5℃.
4. The method according to any one of claims 1 to 3, characterized in that, The molar ratio of perfluoro-2-methyl-2-pentene to the epoxidizing agent is 1:1 to 1:5, preferably 1:3; and / or The mass ratio of the main catalyst to the co-catalyst is 3:1 to 10:1, preferably 5:
1.
5. The method according to any one of claims 1 to 4, wherein the preparation method of the main catalyst comprises: Mesoporous molecular sieves are impregnated in a solution containing metal salts, including FeWO4 and / or MnWO4; then dried and calcined to obtain the main catalyst. and / or The preparation method of the composite catalyst includes: mixing and dispersing the obtained main catalyst and co-catalyst to obtain the composite catalyst.
6. The method according to claim 5, wherein the concentration of the metal salt in the solution containing the metal salt is 10 wt% to 30 wt%, preferably 20 wt%; The metal salt-containing solution uses water as a solvent; and / or The immersion time includes 12 hours to 48 hours, preferably 24 hours; and / or The calcination temperature is 400℃~700℃, preferably 550℃; and / or the calcination time is 2 hours~8 hours, preferably 4 hours; and / or The drying temperature is selected from 80℃ to 150℃, preferably 110℃; and / or The drying time is 1 hour to 5 hours, preferably 2 hours.
7. The method according to any one of claims 1 to 6, wherein the reaction is carried out in a microreactor, the composite catalyst is packed in the microreactor, and then a mixture of perfluoro-2-methyl-2-pentene and an epoxidizing agent is introduced to carry out the reaction; and / or The residence time of the mixture in the microreactor is 10 min-30 min; and / or The composite catalyst is packed in a volume of 40% to 70% of the microreactor volume; and / or The inner diameter of the pipe in the microreactor is 0.3 mm to 2 mm, preferably 1 mm; and / or The effective reaction length of the pipeline in the microreactor is 10m to 30m.
8. The method according to any one of claims 1 to 7, further comprising post-processing after the reaction is completed, the post-processing comprising: After standing and separating the liquids, the lower layer was taken to obtain crude perfluoro-2-methyl-2,3-epoxypentane. The crude product was then dehydrated and distilled. The fraction distilled at 50-55℃ was taken to obtain pure perfluoro-2-methyl-2,3-epoxypentane.
9. A composite catalyst, characterized in that, The composite catalyst prepared by the method of any one of claims 5 to 6.
10. The use of the composite catalyst according to claim 9 in the reaction of catalyzing perfluoro-2-methyl-2-pentene to prepare perfluoro-2-methyl-2,3-epoxypentane.