An efficient preparation process of octanohydroxamic acid
By using silver oxide and ceria modified solid acid catalysts in the octanoyl hydroxamic acid synthesis process, the problem of poor reusability of the catalyst is solved, efficient and stable catalytic reactions are achieved and the environmental protection performance of the process is improved.
Patent Information
- Application Number
- CN202510281577.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2045-03-11
AI Technical Summary
In the existing octanoyl hydroxamic acid synthesis process, the reusability of solid acid catalysts is poor, and the catalytic activity is significantly reduced after recycling, resulting in low yield, high energy consumption and high environmental pressure.
A solid acid catalyst prepared by adding two metal oxides silver oxides and ceria simultaneously is used to improve the strength of the catalyst and the total amount of acid catalytic center by adjusting the preparation steps and conditions, and enhance its catalytic stability and reusability.
The purity and yield of ethyl n-octanoate are significantly improved, ensuring that the catalytic activity remains high after 100 cycles of catalysis, shortening the catalytic reaction time, and improving the preparation efficiency and the reuse performance of the catalyst.
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fine chemical synthesis, and particularly relates to an efficient preparation process of octanoyl hydroxamic acid. Background Art
[0002] Octanoyl hydroxamic acid, also known as octanoyloxyoxime acid, has wide applications in the fields of surfactants, cleaning agents, metal working fluids, etc. In the traditional synthesis process of octanoyl hydroxamic acid, usually, ethyl octanoate is first generated by reacting n-octanoic acid with ethanol under the catalysis of sulfuric acid; then, ethyl octanoate and hydroxylamine react under the action of a catalyst to undergo a hydroxylation reaction to obtain n-octanoyl hydroxamic acid.
[0003] Taking sulfuric acid as a catalyst, a large amount of sulfuric acid is consumed in this step, the yield is low, there are many by-products, the energy consumption is high, and a large amount of wastewater will be generated during the reaction, resulting in significant environmental protection pressure. In the existing solutions, attempts have been made to use solid acid catalysts instead of liquid acids for catalysis, which reduces the wastewater discharge to a certain extent. However, due to the relatively small contact area between the solid acid catalyst and the reactants, its activity performance is not high and the conversion rate is low. In related technologies, the solid acid catalyst is prepared into hollow spheres to improve its reaction activity and reaction conversion rate. However, after repeated use, its structure is prone to collapse, and coupled with the reduction of its own catalytic activity, its performance is not good during later repeated use. Summary of the Invention
[0004] In order to improve the reusability of the solid acid catalyst, the present application provides an efficient preparation process of octanoyl hydroxamic acid.
[0005] In a first aspect, the present application provides an efficient preparation process of octanoyl hydroxamic acid, adopting the following technical solution:
[0006] An efficient preparation process of octanoyl hydroxamic acid, which comprises the following preparation steps:
[0007] S1. Preparation of ethyl octanoate:
[0008] Mix 90 - 110 parts by weight of n-octanoic acid and 35 - 40 parts by weight of ethanol, then add a solid acid catalyst, heat and reflux for 2.5 - 3 h, filter to obtain a precipitate and a filtrate, and subject the filtrate to vacuum distillation to obtain ethyl octanoate;
[0009] S2. Preparation of octanoyl hydroxamic acid:
[0010] Add 0.4 - 0.6 parts by weight of sodium acetate and 0.2 - 0.4 parts by weight of sodium carbonate to water, stir until dissolved, add ethanol, stir, then add 24 - 32 parts by weight of hydroxylamine and ethyl octanoate prepared by S1, stir and react for 1.5 - 2.5 h, filter to obtain a filtrate. Distill the filtrate under reduced pressure to remove ethanol, add water, lower the temperature to (-5) - 5 °C, adjust the pH of the solution to 3, and white solid will precipitate simultaneously. Filter to obtain octanohydroxamic acid;
[0011] The preparation steps of the solid acid catalyst are as follows:
[0012] S1: Using water as a solvent, add 0.4 - 0.6 parts by weight of zirconium oxychloride, 0.05 - 0.07 parts by weight of titanium sulfate, 0.003 - 0.007 parts by weight of silver nitrate, and 0.005 - 0.009 parts by weight of ammonium cerium nitrate, stir until dissolved, then while stirring, dropwise add ammonia water until the pH reaches 9 - 11, stop dropping, then age, filter to obtain a solid, and wash and dry the solid;
[0013] S2: Calcinate the dried solid in a muffle furnace, then soak it in sulfuric acid solution, and dry to obtain the solid acid catalyst.
[0014] By adopting the above technical solutions, the solid acid catalyst prepared by adding two metal oxides, silver oxide and cerium dioxide, simultaneously in this application can improve the purity and yield of ethyl octanoate, and through experiments, it still has very high catalytic activity after 100 cycles of catalysis; while for the solid acid catalyst adding only silver oxide or cerium dioxide, after 100 cycles of catalysis, the reduction amplitude of its catalytic activity is relatively high; it shows that by adding silver oxide and cerium dioxide, the crystallization and sintering of zirconium dioxide and titanium dioxide can be greatly slowed down, thereby improving the strength of the solid acid catalyst and the total amount of acid catalytic centers, and can greatly improve the catalytic stability of the solid acid catalyst, shorten the catalytic reaction time, improve the preparation efficiency and the recycling performance of the solid acid catalyst.
[0015] Preferably: In the preparation of ethyl octanoate, the addition amount of the solid acid catalyst is 0.005 - 0.015 parts by weight.
[0016] By adopting the above technical solutions, at this addition amount, the catalytic reaction can proceed stably and the catalytic efficiency is relatively high.
[0017] Preferably: In the preparation steps of the solid acid catalyst, in S1, first add 0.1 - 0.3 parts by weight of polyvinylpyrrolidone to water, stir until dissolved, and then continue to add the zirconium oxychloride, the titanium sulfate, the silver nitrate, and the ammonium cerium nitrate.
[0018] By adopting the above technical solution, by adding polyvinylpyrrolidone during the preparation of the solid acid catalyst, it can adhere to the particle surface and prevent the particles from further growing, thereby further reducing the particle size of the solid acid catalyst, increasing its specific surface area, and improving its catalytic activity.
[0019] Preferably, the model of the polyvinylpyrrolidone is K30.
[0020] Preferably, in the preparation step of the solid acid catalyst, ammonia water is added dropwise to pH 10 in S1.
[0021] By adopting the above technical solution, when the pH is 10, the aging effect is relatively high, and the metal ions can be completely precipitated.
[0022] Preferably, the calcination temperature is 500 - 600 °C, and the calcination time is 2 - 4 h.
[0023] By adopting the above technical solution, calcination at this temperature can better form acid catalytic centers.
[0024] Preferably, the mass fraction of the ammonia water is 25%.
[0025] By adopting the above technical solution, the concentration of ammonia water should not be too low, as too low is not conducive to the aging effect. If it is too high, the aging speed is likely to be too fast, and the particles of the solid acid catalyst are relatively large.
[0026] Preferably, in the preparation step of the solid acid catalyst, the concentration of the sulfuric acid solution in S2 is 2 mol / L.
[0027] Preferably, after the catalytic reaction of the solid acid catalyst, it is put into use after activation. The activation operation is as follows:
[0028] The precipitate obtained in the preparation step of ethyl octanoate is washed with ethanol, then calcined at 500 - 600 °C for 1.5 - 3 h, and then soaked in the sulfuric acid solution and dried to obtain the activated solid acid catalyst.
[0029] By adopting the above technical solution, through activation, the catalytic activity of the solid acid catalyst can be better restored.
[0030] In summary, the present application includes at least one of the following beneficial technical effects:
[0031] 1. The solid acid catalyst prepared by adding two metal oxides, silver oxide and cerium dioxide, simultaneously in this application can improve the purity and yield of ethyl octanoate. Through experiments, it still has very high catalytic activity after 100 cycles of catalysis. However, for the solid acid catalysts that only add silver oxide or cerium dioxide, after 100 cycles of catalysis, the reduction in their catalytic activity is relatively large. This shows that by adding silver oxide and cerium dioxide, the crystallization and sintering of zirconia and titania can be greatly slowed down, thereby improving the strength of the solid acid catalyst and the total amount of acid catalytic centers, and can greatly improve the catalytic stability of the solid acid catalyst, shorten the catalytic reaction time, improve the preparation efficiency and the reusability of the solid acid catalyst.
[0032] 2. The catalytic activity of the solid acid catalyst prepared in this application is excellent, and the purity and yield of the prepared ethyl octanoate are both relatively high. The purity is all 99.1% and above, and the highest can reach 99.5%. At the same time, its yield is also between 91.8 - 96.7%. Detailed implementation mode
[0033] The following further elaborates on this application in combination with specific content.
[0034] Raw materials
[0035] The raw materials used in the preparation examples and implementation examples of this application are all purchased commercially, and their purity is all analytical pure.
[0036] Preparation example 1
[0037] A solid acid catalyst, and its preparation method is as follows:
[0038] S1. Add 0.5 kg of zirconyl chloride, 0.06 kg of titanium sulfate, 0.005 kg of silver nitrate and 0.007 kg of ammonium cerium nitrate to 15 kg of distilled water, stir until dissolved, and then slowly add ammonia water with a mass fraction of 25% under rapid stirring until the pH reaches 10, stop adding, then age for 24 h, filter to obtain a solid, and wash and dry the solid;
[0039] S2. Calcinate the dried solid in a muffle furnace at a calcination temperature of 550 °C for 3 h, then soak it in a 2 mol / L sulfuric acid solution for 2 h, and dry to obtain the solid acid catalyst.
[0040] Preparation example 2
[0041] A solid acid catalyst, which is different from Preparation example 1 in that in S1, first add 0.2 kg of polyvinylpyrrolidone with the model of K30 to distilled water, stir until dissolved, and then continue with the subsequent steps to obtain the solid acid catalyst.
[0042] Preparation example 3
[0043] A solid acid catalyst, which is different from Preparation Example 2 in that the calcination temperature in S2 is 500 °C, and the remaining steps are the same as those in Preparation Example 2.
[0044] Preparation Example 4
[0045] A solid acid catalyst, which is different from Preparation Example 2 in that the calcination temperature in S2 is 600 °C, and the remaining steps are the same as those in Preparation Example 2.
[0046] Example 1 A high-efficiency preparation process of octanoyl hydroxamic acid, and its preparation steps are as follows:
[0047] S1. Preparation of ethyl octanoate:
[0048] Mix 100.8 g of n-octanoic acid and 36.8 g of ethanol, then add 0.01 g of solid acid catalyst, heat under reflux for 3 h, filter to obtain precipitate and filtrate, and subject the filtrate to vacuum distillation to obtain ethyl octanoate; the solid acid catalyst comes from Preparation Example 1;
[0049] S2. Preparation of octanoyl hydroxamic acid:
[0050] Add 0.5 g of sodium acetate and 0.3 g of sodium carbonate to distilled water, stir until dissolved, then add an equal volume of ethanol, stir for 15 min, then add 28 g of hydroxylamine and the ethyl octanoate prepared in S1, stir and react at 25 °C for 2 h, filter to obtain filtrate, subject the filtrate to vacuum distillation to remove ethanol, then add an equal volume of distilled water, lower the temperature to 0 °C, then dropwise add 2 mol / L sulfuric acid at a dropping rate of 0.4 mL / min until the pH of the solution reaches 3, while a white solid precipitates, then let it stand for 1 h, filter, wash with distilled water 3 times, and then dry at 70 °C to obtain octanoyl hydroxamic acid.
[0051] Example 2
[0052] A high-efficiency preparation process of octanoyl hydroxamic acid, which is different from Example 1 in that its solid acid catalyst comes from Preparation Example 2, and the remaining steps are the same as those in Example 1.
[0053] Example 3
[0054] A high-efficiency preparation process of octanoyl hydroxamic acid, which is different from Example 1 in that its solid acid catalyst comes from Preparation Example 3, and the remaining steps are the same as those in Example 1.
[0055] Example 4
[0056] A high-efficiency preparation process of octanoyl hydroxamic acid, which is different from Example 1 in that its solid acid catalyst comes from Preparation Example 4, and the remaining steps are the same as those in Example 1.
[0057] Example 5
[0058] An efficient preparation process of octanoyl hydroxamic acid, which is different from Example 2 in that the addition amount of the solid acid catalyst is 0.005 g, and the remaining steps are the same as those in Example 2.
[0059] Example 6
[0060] An efficient preparation process of octanoyl hydroxamic acid, which is different from Example 2 in that the addition amount of the solid acid catalyst is 0.015 g, and the remaining steps are the same as those in Example 2.
[0061] Example 7
[0062] An efficient preparation process of octanoyl hydroxamic acid, which is different from Example 2 in that the solid acid catalyst is reused after being recycled and catalyzed 100 times. After the catalytic reaction, the solid acid catalyst is separated from the reaction system by filtration, that is, the precipitate in S1. After this precipitate is activated, it is catalyzed again. The activation operation is as follows:
[0063] The precipitate obtained in S1 is washed with ethanol, then calcined at 550 °C for 2 h, then soaked in a 2 mol / L sulfuric acid solution for 2 h, and dried to obtain the activated solid acid catalyst, which is then recycled to S1 as a catalyst for repeated catalysis.
[0064] Comparative Example 1
[0065] An efficient preparation process of octanoyl hydroxamic acid, which is different from Example 2 in that the preparation method of the solid acid catalyst is as follows:
[0066] S1. Add 0.5 kg of zirconium oxychloride and 0.072 kg of titanium sulfate to 15 kg of distilled water, stir until dissolved, then slowly dropwise add ammonia water with a mass fraction of 25% under rapid stirring until the pH reaches 10, stop dropping, then age for 24 h, filter to obtain a solid, and wash and dry the solid;
[0067] S2. Calcinate the dried solid in a muffle furnace at a calcination temperature of 550 °C for 3 h, then soak it in a 2 mol / L sulfuric acid solution for 2 h, and dry to obtain the solid acid catalyst;
[0068] And in step S1, the catalytic reaction time is 5 h.
[0069] Comparative Example 2
[0070] An efficient preparation process of octanoyl hydroxamic acid, which is different from Comparative Example 1 in that its solid acid catalyst is after being recycled and catalyzed 100 times. After each catalytic reaction, the catalyzed solid acid catalyst is activated according to the activation method in Example 7, and the remaining steps are the same as those in Comparative Example 1.
[0071] Comparative Example 3
[0072] An efficient preparation process of octanoyl hydroxamic acid, which is different from Example 2 in that the preparation method of its solid acid catalyst is as follows:
[0073] S1. Add 0.5 kg of zirconium oxychloride, 0.06 kg of titanium sulfate and 0.012 kg of silver nitrate to 15 kg of distilled water, stir until dissolved, and then slowly dropwise add ammonia water with a mass fraction of 25% under rapid stirring until the pH reaches 10, stop dropping, then age for 24 h, filter to obtain a solid, and wash and dry the solid;
[0074] S2. Calcine the dried solid in a muffle furnace at a calcination temperature of 550 °C for 3 h, then soak it in a 2 mol / L sulfuric acid solution for 2 h, and dry to obtain a solid acid catalyst;
[0075] And in step S1, the catalytic reaction time is 5 h.
[0076] Comparative Example 4
[0077] An efficient preparation process of octanoyl hydroxamic acid, which is different from Comparative Example 3 in that its solid acid catalyst is after being recycled and catalyzed 100 times. After each catalytic reaction, the catalyzed solid acid catalyst is activated according to the activation method in Example 7, and the remaining steps are the same as those in Comparative Example 3.
[0078] Comparative Example 5
[0079] An efficient preparation process of octanoyl hydroxamic acid, which is different from Example 2 in that the preparation method of its solid acid catalyst is as follows:
[0080] S1. Add 0.5 kg of zirconium oxychloride, 0.06 kg of titanium sulfate and 0.012 kg of ammonium cerium nitrate to 15 kg of distilled water, stir until dissolved, and then slowly dropwise add ammonia water with a mass fraction of 25% under rapid stirring until the pH reaches 10, stop dropping, then age for 24 h, filter to obtain a solid, and wash and dry the solid;
[0081] S2. Calcine the dried solid in a muffle furnace at a calcination temperature of 550 °C for 3 h, then soak it in a 2 mol / L sulfuric acid solution for 2 h, and dry to obtain a solid acid catalyst;
[0082] And in step S1, the catalytic reaction time is 5 h.
[0083] Comparative Example 6
[0084] A high-efficiency preparation process of octanoyl hydroxamic acid, which is different from Comparative Example 5 in that its solid acid catalyst is after being recycled and catalyzed 100 times. After each catalytic reaction, the catalyzed solid acid catalyst is activated according to the activation method in Example 7, and the remaining steps are the same as those in Comparative Example 5.
[0085] Performance detection test
[0086] Detection method / Test method
[0087] Ethyl octanoate was prepared according to the preparation methods of Examples 1-7 and Comparative Examples 1-6, that is, the content in S1. Then, the prepared ethyl octanoate was detected according to the following method, and the detection results are shown in Table 1.
[0088] Purity: Detected by GC (gas chromatography);
[0089] Yield = (output / feed amount) × 100%, where the feed amount is calculated based on the amount of the less reactant input.
[0090] Table 1 Detection results of Examples 1-7 and Comparative Examples 1-6
[0091]
[0092] It can be seen from Examples 1-7, Comparative Examples 1-6, and the detection data in Table 1 that the catalytic activity of the solid acid catalyst prepared in this application is excellent, and the purity and yield of the prepared ethyl octanoate are both relatively high. The purity is all 99.1% and above, and the highest can reach 99.5%. At the same time, its yield is also between 91.8% and 96.7%.
[0093] By introducing two metal oxides, silver oxide and cerium dioxide, into the solid acid catalyst, the catalytic stability of the solid acid catalyst can be improved, its specific surface area can be increased, and the content of acidity and acid sites can be increased, thereby improving its catalytic activity. From the detection data of Example 2, Example 7 and Comparative Examples 1-6, it can be seen that the solid acid catalyst prepared by adding silver oxide and cerium dioxide simultaneously in this application can improve the purity and yield of ethyl octanoate, and by comparison, it still has very high catalytic activity after 100 cycles of catalysis; while the solid acid catalyst with only silver oxide or cerium dioxide added has a relatively high reduction in catalytic activity after 100 cycles of catalysis; it shows that by adding silver oxide and cerium dioxide, the crystallization and sintering of zirconia and titania can be greatly slowed down, thereby improving the strength of the solid acid catalyst and the total amount of acid catalytic centers, and can greatly improve the catalytic stability of the solid acid catalyst, shorten the catalytic reaction time, and improve the preparation efficiency.
[0094] From the detection data of Example 1 and Example 2, it can be seen that by adding polyvinylpyrrolidone during the preparation of the solid acid catalyst, it can adhere to the particle surface and prevent the particles from further growing, so that the particle size of the solid acid catalyst can be further reduced, its specific surface area can be increased, and its catalytic activity can be improved. Combining Examples 3-4, the calcination temperature is preferably 550 °C. It is speculated that due to too high temperature, the ductility of silver and cerium is too high, which is not conducive to the formation of acid catalytic centers or is easy to cover them. On this basis, combining Examples 5-6, the optimal addition amount of the solid acid catalyst is 0.01 g.
[0095] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.
Claims
1. An efficient preparation process of octanoylhydroxamic acid, characterized in that: It comprises the following preparation steps: S1. Preparation of ethyl octanoate: Mix 90-110 parts by weight of n-octanoic acid and 35-40 parts by weight of ethanol, then add a solid acid catalyst, heat and reflux for reaction for 2.5-3 hours, filter to obtain a precipitate and a filtrate, and distill the filtrate under reduced pressure to obtain ethyl n-octanoate; S2. Preparation of octanoylhydroxamic acid: 0.4-0.6 parts by weight of sodium acetate and 0.2-0.4 parts by weight of sodium carbonate are added to water, stirred until dissolved, ethanol is added, and after stirring, 24-32 parts by weight of hydroxylamine and ethyl octanoate prepared from S1 are added, and the mixture is stirred to react for 1.5-2.5 hours, filtered to obtain a filtrate, and the filtrate is distilled under reduced pressure to remove ethanol, water is added, the temperature is lowered to -5~5°C, the pH of the solution is adjusted to 3, and a white solid is precipitated at the same time, which is filtered to obtain octanoylhydroxamic acid; The preparation steps of the solid acid catalyst are as follows: S1. Using water as solvent, add 0.4-0.6 parts by weight of zirconium oxychloride, 0.05-0.07 parts by weight of titanium sulfate, 0.003-0.007 parts by weight of silver nitrate and 0.005-0.009 parts by weight of cerium ammonium nitrate, stir until dissolved, then add ammonia water dropwise under stirring until the pH reaches 9-11, stop adding dropwise, then age, filter, obtain a solid, wash the solid, and dry; S2. The dried solid is calcined in a muffle furnace, then immersed in a sulfuric acid solution and dried to obtain a solid acid catalyst.
2. The efficient preparation process of octanoylhydroxamic acid according to claim 1, characterized in that: In the preparation of ethyl n-octanoate, the addition amount of the solid acid catalyst is 0.005-0.015 parts by weight.
3. The efficient preparation process of octanoylhydroxamic acid according to claim 1, characterized in that: In the preparation step of the solid acid catalyst, in S1, firstly, 0.1-0.3 parts by weight of polyvinyl pyrrolidone is added to water, stirred until dissolved, and then the zirconium oxychloride, the titanium sulfate, the silver nitrate and the cerium ammonium nitrate are added.
4. The efficient preparation process of octanoylhydroxamic acid according to claim 3, characterized in that: The model of the polyvinyl pyrrolidone is K30.
5. The efficient preparation process of octanoylhydroxamic acid according to claim 1, characterized in that: In the step of preparing the solid acid catalyst, aqueous ammonia is added dropwise to S1 until the pH value reaches 10.
6. The efficient preparation process of octanoylhydroxamic acid according to claim 1, characterized in that: The calcination temperature is 500-600° C., and the calcination time is 2-4 hours.
7. The efficient preparation process of octanoylhydroxamic acid according to claim 1, characterized in that: The mass fraction of the ammonia water is 25%.
8. The efficient preparation process of octanoylhydroxamic acid according to claim 1, characterized in that: In the step of preparing the solid acid catalyst, the concentration of the sulfuric acid solution in S2 is 2 mol / L.
9. The efficient preparation process of octanoylhydroxamic acid according to claim 1, characterized in that: After the catalytic reaction, the solid acid catalyst is activated and then put into use. The activation operation is as follows: The precipitate obtained in the preparation step of ethyl n-octanoate is washed with ethanol, then roasted at 500-600° C. for 1.5-3 hours, immersed in a sulfuric acid solution, and dried to obtain an activated solid acid catalyst.
Citation Information
Patent Citations
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