Production process of dicyclohexane-18-crown-6

Abstract

The invention discloses a production process of dicyclohexane-18-crown-6, which belongs to the technical field of chemical synthesis, and is characterized in that dibenzene-18-crown-6 is used as a starting raw material, and is subjected to catalytic hydrogenation in the presence of an organic solvent under the action of a Ru-Ni / ZrO2 catalyst at the temperature of 20-50 DEG C and the pressure of 2.0-4.0 MPa to obtain the dicyclohexane-18-crown-6; according to the invention, by controlling the preparation and dosage of the catalyst and other reaction conditions, the purposes of high yield, high purity and low production cost are achieved; the production process disclosed by the invention can be carried out in a high-pressure reaction kettle, can also be used for production by adopting a continuous flow production device, and has the advantage of good selectivity.

Description

Technical Field

[0001] This invention relates to a production process for dicyclohexane-18-crown-6, belonging to the field of chemical synthesis technology. Background Technology

[0002] 90 Sr has a half-life of nearly 29 years and is a highly toxic, long-lived beta radionuclide. It is one of the radioactive wastes generated during the operation and decommissioning of reactors and other nuclear power plants (In International Symposium NUCEF 2001, 31, 2002-2004). 90 Separating Sr from radioactive waste can reduce the storage time and depth of solidified waste, thereby significantly reducing the difficulty and cost of waste treatment. Dicyclohexano-18-crown-6 has attracted widespread attention in the industry as an effective extractant (Nuclear Chemistry and Radiochemistry, 2013, 35, 235-240), but its high cost limits its application.

[0003] Existing methods for synthesizing dicyclohexano-18-crown-6 mainly include: synthesizing dicyclohexano-18-crown-6 from chlorocyclohexane and diethylene glycol. This method is costly and has a yield of only 10%, resulting in low profits and low output. Many other studies have indicated the use of dibenzo-18-crown-6 as a starting material for ring-opening to synthesize dicyclohexano-18-crown-6. Although the yield is significantly higher than that synthesized from chlorocyclohexane, the cost is several times higher, with substantial increases in both raw material and catalyst costs. Some literature reports the direct catalytic hydrogenation of dibenzo-18-crown-6 to dicyclohexano-18-crown-6 using catalysts, but the conditions are demanding and the catalysts are expensive. For example, (Catalysis Journal, 1994, 147, 214-222) has a rhodium catalyst for this reaction, and there are also cases of ruthenium catalysts supported on alumina, but the loading is above 5 wt%, which is expensive. Although the loading of rhodium catalysts can be slightly reduced, the cost of the original precursor is higher than that of ruthenium. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a production process for dicyclohexano-18-crown-6 with high yield, high purity and low production cost.

[0005] The technical solution adopted in this invention is as follows:

[0006] A process for producing dicyclohexano-18-crown-6, characterized in that: dibenzo-18-crown-6 is used as a starting material, and in the presence of an organic solvent and under the action of a Ru-Ni / ZrO2 catalyst, dicyclohexano-18-crown-6 is obtained by catalytic hydrogenation at 20-50℃ and 2.0-4.0 MPa.

[0007] Further settings include:

[0008] The organic solvent is selected from any one or a combination of two of methanol, ethanol, isopropanol, trifluoroethanol, tert-butanol, and hexafluoroisopropanol.

[0009] The catalytic hydrogenation reaction was carried out at 30°C and 3.0 MPa for 3 hours.

[0010] The Ru-Ni / ZrO2 catalyst was prepared by the following method: Ruthenium acetylacetonate, nickel acetylacetonate, and hollow ZrO2 spheres were dissolved in ethanol, then urea was added, and the mixture was ultrasonically dispersed for 30 minutes. After standing for 4 hours, the impregnated sample was dried at 85°C for 12 hours to remove the solvent. The sample was then calcined at 600°C for 2 hours in an inert atmosphere and cooled to room temperature to obtain the Ru-Ni / ZrO2 catalyst.

[0011] The amount of the Ru-Ni / ZrO2 catalyst used is 1% to 15% of the mass of the raw material dibenzo-18-crown-6. Preferably, it is 10% of the mass of the raw material dibenzo-18-crown-6.

[0012] After the catalytic hydrogenation reaction is completed, the catalyst is removed by centrifugation. The catalyst is then washed sequentially with deionized water and ethanol, dried in an oven, activated, and then reintroduced into the catalytic hydrogenation reaction.

[0013] The catalytic hydrogenation reaction is carried out in a high-temperature reactor or a continuous flow production unit.

[0014] The catalytic hydrogenation reaction is carried out in a continuous flow production unit, which includes a slurry mixer, a hydrogen tank, a feed valve, a temperature controller, a fixed-bed reactor, a gas-liquid separator, a control valve, and a gas-liquid mixer. The fixed-bed reactor consists of two sets of tubular reactors connected in parallel. While one set of reactors is cleaning or activating the catalyst, the other set of reactors performs the catalytic hydrogenation reaction. Each set of tubular reactors consists of three reaction columns connected in series, with an inner diameter of 10 mm and a total length of 12 m. The reaction columns are filled with Ru-Ni / ZrO2 catalyst at a packing density of 0.5 g / cm³. 3 .

[0015] The catalytic hydrogenation reaction was carried out in a high-pressure reactor. 0.4 g of dibenzo-18-crown-6 benzene, 0.04 g of catalyst A, and 10 mL of hexafluoroisopropanol were added sequentially. After purging with argon and hydrogen, catalytic hydrogenation was performed at 30 °C and 3 MPa. The reaction was stopped after 3 hours, and the catalyst was removed by centrifugation to obtain a dicyclohexan-18-crown-6 solution. After rotary evaporation, the solution was dried in a vacuum drying oven at 50 °C for 8 hours to obtain the product dicyclohexan-18-crown-6. The final product conversion rate was 99.6%, and the product selectivity was 95.3%.

[0016] The beneficial effects of this invention are as follows:

[0017] (1) This invention provides a production process for dicyclohexane-18-crown-6, which achieves high yield, high purity and low production cost by controlling the preparation and dosage of catalyst and other reaction conditions.

[0018] (2) The present invention provides a production process for dicyclohexano-18-crown-6, which can be carried out in a high-pressure reactor or in a continuous flow production device. It has the advantage of good selectivity. By adopting a specific continuous flow production process, costs can be further reduced, efficiency can be improved, and production safety can be enhanced.

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0020] Figure 1 The XRD pattern of the Ru-Ni / ZrO2 catalyst prepared in the embodiments of the present invention.

[0021] Figure 2 XPS image of the Ru-Ni / ZrO2 catalyst prepared in the embodiments of the present invention.

[0022] Figure 3 The 1H NMR spectrum of dicyclohexane-18-crown-6 prepared in an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of the continuous flow production apparatus of the present invention.

[0024] Figure 4 In the middle section: 1 is the pulping mixer; 2 is the hydrogen tank; 3 is the feed valve; 4 is the temperature controller; 5 is the fixed bed reactor; 6 is the gas-liquid separator; 7 is the control valve; and 8 is the gas-liquid mixer. Detailed Implementation

[0025] Unless otherwise specified, the reagents and equipment used in the embodiments of the present invention are existing technologies or commercially available products.

[0026] In this embodiment of the invention, the Ru-Ni / ZrO2 catalyst is prepared using the following method:

[0027] 0.1218 g of ruthenium acetylacetonate, 0.01218 g of nickel acetylacetonate, and 1.0 g of hollow ZrO2 spheres were dissolved in 10 mL of ethanol. A small amount of urea was then added, and the mixture was ultrasonically dispersed for 30 minutes and allowed to stand for 4 hours. The impregnated sample was then dried at 85 °C for 12 hours to remove the solvent. It was then calcined at 600 °C for 2 hours under an inert atmosphere (nitrogen). After cooling to room temperature, the Ru-Ni / ZrO2 catalyst was obtained and labeled as catalyst A.

[0028] Example 1

[0029] In a high-pressure reactor, 0.4 g of dibenzo-18-crown-6 benzene, 0.04 g of catalyst A, and 10 mL of trifluoroethanol were added sequentially. The air in the reactor was first replaced with argon, and then the argon was replaced with hydrogen. Catalytic hydrogenation was carried out at a temperature of 30 °C and a pressure of 3 MPa. After 3 h, the reaction was stopped, and the catalyst was removed by centrifugation to obtain a solution of dicyclohexan-18-crown-6. After rotary evaporation, the solution was dried in a vacuum drying oven at 50 °C for 8 h to obtain the product dicyclohexan-18-crown-6. The final product conversion rate was 99.6%, and the product selectivity was 95.3%.

[0030] The reaction equations involved are:

[0031]

[0032] Product confirmation: The 1H NMR spectrum of the prepared product, dicyclohexano-18-crown-6, is shown below. Figure 3 As shown, the 1H NMR spectrum shows that the peak positions and the number of hydrogens are consistent with those of the dicyclohexane-18-crown-6 standard, and there is no phenomenon of excess or deficiency of hydrogens, proving that no ring-opening product is formed or the ring-opening product is very small and can be ignored, which proves that it is the product we want.

[0033] The structural formula of the by-product (ring-opening product) is as follows:

[0034]

[0035] analyze:

[0036] This invention utilizes a Ru-Ni / ZrO2 catalyst to catalyze the synthesis of dicyclohexane-18-crown-6, exhibiting significant effects. The mechanism of action is as follows:

[0037] like Figure 1As shown, the Ru-Ni / ZrO2 catalyst exhibits distinct diffraction peaks around 30°, 35°, 50°, 60°, 63°, and 74°, corresponding to the (111), (200), (220), (311), (222), and (400) planes of zirconium oxide, confirming the presence of the zirconium oxide support. The absence of ruthenium and nickel peaks indicates a relatively uniform and dispersed distribution. The XPS pattern of the catalyst is shown below. Figure 2 As shown, most of the oxygen is lattice oxygen, exhibiting high selectivity and preventing excessive hydrogenation of the benzene ring, which would lead to ring opening. The loss of lattice oxygen creates oxygen vacancies, which can be replenished by gaseous oxygen, thus forming a redox cycle. The lattice oxygen stabilizes the highly dispersed metal site bonds through the Zr-O bond. Zr is entirely composed of Zr... 4+ Its existence is primarily responsible for serving as a carrier for ZrO2. Ru, on the other hand, has Ru... 0 Ru 3+ Ru 4+ Three valence states exist, Ru 0 It is primarily responsible for adsorbing H2 and has high reducing properties, thus promoting the hydrogenation reaction. Ru 0 Its d-electron enrichment properties enable it to weaken the conjugated system of the benzene ring through π-complexation, thus promoting stepwise hydrogenation. 3+ It may exist in Ru 0 On the particle surface, the benzene ring is activated through hydrogen overflow or Lewis acid sites, thereby promoting benzene ring hydrogenation. 4+ It exists in RuO2, and its surface oxygen vacancies can heterolytically cleave H2 to generate H. + and H - It indirectly participates in hydrogenation, and all parts participate synergistically in the reduction reaction. Ni also exists in three valence states: Ni 0 Ni 2+ Ni 3+ Ni 0 Its main function is hydrogen desorption and activation. However, in benzene ring hydrogenation experiments, its content is relatively low; Ru is the primary agent, while Ni's greatest role is that of Ni. 3+ The adsorption of benzene rings allows Ru 0 It can better contact the benzene ring, thereby promoting the hydrogenation of the benzene ring, while Ni 2+ This can limit excessive hydrogenation and prevent ring opening.

[0038] Example 2

[0039] To further explore the influence of catalyst synthesis process on catalytic performance, the synthesis process of catalyst A was adjusted, and the prepared catalysts were labeled as catalysts BL:

[0040] Catalyst B: The preparation process is the same as that of catalyst A, except that the inert atmosphere temperature of 600℃ is changed to 500℃.

[0041] Catalyst C: The preparation process is the same as that of catalyst A, except that the inert atmosphere temperature of 600℃ is changed to 700℃.

[0042] Catalyst D: The preparation process is the same as that of catalyst A, except that the amount of ruthenium acetylacetonate and nickel acetylacetonate is adjusted to 0.2436g of ruthenium acetylacetonate and 0.02436g of nickel acetylacetonate.

[0043] Catalyst E: The preparation process is the same as that of catalyst A, except that the amount of ruthenium acetylacetonate and nickel acetylacetonate is adjusted to 0.3248g of ruthenium acetylacetonate and 0.03248g of nickel acetylacetonate.

[0044] Catalyst F: The preparation process is the same as that of catalyst A, except that only ruthenium acetylacetone is added, and nickel acetylacetone is not added.

[0045] Catalyst G: The preparation process is the same as that of catalyst A, except that nickel acetylacetone is replaced with strontium acetylacetone.

[0046] Catalyst H: The preparation process is the same as that of catalyst A, except that nickel acetylacetone is replaced with magnesium nitrate and the input mass is changed to 0.0189g.

[0047] Catalyst I: The preparation process is the same as that of catalyst A, except that zirconium dioxide is replaced with magnesium aluminum hydrotalcite.

[0048] Catalyst J: The preparation process is the same as that of catalyst A, except that zirconium dioxide is replaced with titanium dioxide.

[0049] Catalyst K: The preparation process is the same as that of catalyst A, except that zirconium dioxide is replaced with alumina.

[0050] Catalyst L: The preparation process is the same as that of catalyst A, except that only ruthenium acetylacetone is added, nickel acetylacetone is not added, and zirconium dioxide is replaced with activated carbon.

[0051] The catalyst BL prepared above, as well as commercial catalysts Ru / C, Pd / C, Pt / C, and Rh / C, were applied to the synthesis of dicyclohexane-18-crown-6 in Example 1, and their catalytic effects were tested, as shown in Table 1.

[0052] Table 1. Comparison of catalytic performance of different types of catalysts

[0053] catalyst Substrate conversion rate / % Product selectivity / % A 99.6 95.3 B 95.3 92.3 C 93.5 88.9 D 99.3 92.3 E 99.4 89.3 F 99.3 85.2 G 99.5 88.9 H 99.3 82.3 I 85.3 65.3 J 95.6 63.8 K 94.3 65.6 L 5.3 / Ru / C 56.3 / Pd / C 44.2 Pt / C 88.3 40.3 Rh / C 89.3 45.3 .

[0054] analyze:

[0055] As shown in Table 1, the amount of metal loaded on the catalyst, the type of metal loaded, and the different supports have a significant impact on the performance of the catalyst: (1) When the calcination temperature is simply changed, the conversion rate and selectivity do not change much, with 600℃ being the best. (2) When ruthenium is used as the precursor alone, the ring-opening yield is relatively high. (3) In the screening of the best supports for this reaction, zirconium dioxide as a tetragonal phase was found to be very suitable. Although there are other supports with high conversion rates, zirconium dioxide is the most effective in inhibiting the ring-opening product. (4) On this basis, nickel metal was added as a ring-opening inhibitor for this reaction, and the effect was exceptionally significant, increasing the product selectivity from 85.2% to 95.3% while maintaining a high conversion rate.

[0056] Comparing the catalyst of this invention with commercially available catalysts such as Ru / C, Pd / C, Pt / C, and Rh / C, it can be seen that while some commercial catalysts exhibit good conversion effects, their product selectivity is far lower than that of the catalyst prepared in this invention. Furthermore, the use of expensive metals not only increases the preparation cost but also leads to catalytic instability, easily causing ring-opening of the product and making catalytic activity difficult to control. In contrast, the Ru-Ni / ZrO2 catalyst of this invention, with the synergistic effect of ruthenium and nickel, restricts ring-opening of the product. In subsequent continuous flow production processes, the proportion of ring-opening products can even be controlled below 1%. Therefore, the catalyst of this invention not only has low production costs but also excellent catalytic performance.

[0057] In summary, ruthenium-supported catalysts prepared under different process conditions can all effectively catalyze the synthesis of dicyclohexane-18-crown-6, with catalyst A showing the best catalytic performance.

[0058] Example 3

[0059] This embodiment mainly focuses on the selection of catalyst A to explore the effect of catalyst dosage on catalytic performance. The method is the same as in Example 1, except that the amount of catalyst A added is adjusted. The test results are shown in Table 2.

[0060] Table 2: Effect of catalyst A dosage on the reaction

[0061] Serial Number Catalyst A dosage / g Substrate conversion rate / % Product selectivity / % Example 1 0.04 99.6 95.3 Example 3-1 0.01 95.3 85.5 Example 3-2 0.02 96.4 90.2 Example 3-3 0.03 98.3 93.5 .

[0062] As can be seen from Table 2, under the same experimental conditions, the reaction yield was the highest when the amount of catalyst A was 0.04 g. Reducing the amount of catalyst decreased the yield, but it could still reduce dibenzo-18-crown-6 well.

[0063] Example 4

[0064] This embodiment mainly explores the impact of catalyst recycling on the reaction, as detailed below:

[0065] The catalyst A separated by centrifugation in Example 1 (washed several times with deionized water and ethanol, and dried in an oven for 1 hour) was used for the next step of the reaction: In a high-pressure reactor, 0.4 g of dibenzo-18-crown-6 benzene, about 0.04 g of catalyst A recovered in Example 1, and 10 mL of trifluoroethanol were added sequentially. After purging with argon and hydrogen, catalytic hydrogenation was carried out at a temperature of 30 °C and a pressure of 3 MPa. The reaction was stopped after 3 hours. The catalyst was recovered by centrifugation to obtain a dicyclohexan-18-crown-6 solution. After rotary evaporation, the solution was dried in a vacuum drying oven at 50 °C for 8 hours to obtain the product dicyclohexan-18-crown-6.

[0066] The recovered catalyst A was washed several times with deionized water and ethanol, dried in an oven, activated for 1 hour (heated and reduced in a tube furnace), and then put back into the reaction to investigate the reusability of the catalyst. The results are shown in Table 3.

[0067] Table 3: Reuse performance of catalyst A

[0068]

[0069]

[0070] As can be seen from Table 3, the catalyst still exhibits high activity after being reused 5 times, indicating that the catalyst has good repeatability.

[0071] Example 4

[0072] This example mainly investigates the effect of the reaction solvent on the synthesis of dicyclohexane-18-crown-6. The method is the same as in Example 1, except that the reaction solvent is adjusted. The results are shown in Table 4.

[0073] Table 4: Effect of different solvents on the reaction

[0074]

[0075] As can be seen from Table 4, under the same process conditions, the yield is lower than that of trifluoroethanol when tert-butanol and hexafluoroisopropanol are used as solvents alone.

[0076] Example 5

[0077] The preparation method is the same as in Example 1, except that the reactor in Example 1 is replaced with a continuous flow production device, and the continuous flow process is used to produce dicyclohexane-18-crown-6.

[0078] Figure 4A preferred continuous flow production apparatus is shown, comprising a pulping mixer 1, a hydrogen tank 2, a feed valve 3, a temperature controller 4, a fixed-bed reactor 5, a gas-liquid separator 6, a control valve 7, and a gas-liquid mixer 8. The fixed-bed reactor 5 consists of two sets of tubular reactors connected in parallel, controlled by the control valve 7. Each set of tubular reactors comprises three reaction columns connected in series, with an inner diameter of 10 mm and a total length of 12 m. The reaction columns are filled with a Ru-Ni / ZrO2 catalyst (catalyst A) at a packing density of 0.5 g / cm³. 3 .

[0079] The continuous flow production process is as follows: First, trifluoroethanol and dibenzo-18-crown-6 are pulped and mixed in a pulping mixer 1, and then conveyed to a gas-liquid mixer 8 through a feed valve 3 to mix with hydrogen from a hydrogen tank 2. The mixed material is then conveyed to a fixed-bed reactor 5 through a control valve 7. The fixed-bed reactor 5 is equipped with two sets of tubular reactors. When one set of reactors is cleaning or activating the catalyst, the other set of reactors can continue to work without being affected. The two sets of reactors are controlled to work alternately through the control valve 7 to achieve a true continuous flow reaction, thereby effectively improving the working efficiency. After the reaction is completed, the reaction mixture is conveyed to a gas-liquid separator 6 to separate the product, which is then analyzed by liquid phase analysis.

[0080] In this embodiment, the benzene ring of dibenzo-18-crown-6 is reduced by a continuous flow production device to obtain dicyclohexan-18-crown-6. This method can reduce the amount of reducing gas used and has high safety. In addition, the product yield and purity obtained by this method are high, making the post-processing steps simple. Moreover, the catalyst can be used continuously in the continuous flow reactor, which saves costs and is more conducive to industrial production.

[0081] Table 5. Comparison of the effects of continuous flow process and conventional reactor process

[0082]

[0083] As shown in Table 5, the continuous flow production process significantly reduces production costs, the amount of hydrogen required, and the amount of catalyst needed. The catalyst only needs to be loaded onto the reaction column to continuously catalyze the reduction of the feedstock. Unlike conventional processes, which require large amounts of hydrogen to be introduced into the reactor, resulting in waste, the continuous flow process only requires adjusting the hydrogen flow rate and ensuring the feedstock solution enters the reactor in the correct quantity. Conventional processes not only require pressurization and reactor shutdown but also suffer from leaks and insufficient hydrogen, making operation more cumbersome and potentially dangerous. Furthermore, catalyst recovery involves losses and deactivation. Moreover, experiments have shown that the conversion rate in the continuous flow process is close to 100%, and the ring-opening yield is significantly reduced, almost negligible. In conclusion, the continuous flow process is more suitable for this reaction.

[0084] This invention provides a novel production process for dicyclohexane-18-crown-6, which reduces production costs and solves the problems of low product yield in existing processes. It ensures complete hydrogenation of the reaction substrate and safety of the reaction conditions, and the post-processing is simple. The catalyst used is easy to prepare, reusable, and inexpensive.

Claims

1. A process for producing dicyclohexano-18-crown-6, characterized in that: Starting from dibenzo-18-crown-6, dicyclohexan-18-crown-6 was catalytically hydrogenated in the presence of an organic solvent and with the aid of a Ru-Ni / ZrO2 catalyst at 20-50 °C and 2.0-4.0 MPa to obtain dicyclohexan-18-crown-6.

2. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: The organic solvent is selected from any one or a combination of two of methanol, ethanol, isopropanol, trifluoroethanol, tert-butanol, and hexafluoroisopropanol.

3. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: The catalytic hydrogenation reaction was carried out at 30°C and 3.0 MPa for 3 hours.

4. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: The Ru-Ni / ZrO2 catalyst was prepared by the following method: Ruthenium acetylacetonate, nickel acetylacetonate, and hollow ZrO2 spheres were dissolved in ethanol, then urea was added, and the mixture was ultrasonically dispersed for 30 minutes. After standing for 4 hours, the impregnated sample was dried at 85°C for 12 hours to remove the solvent. The sample was then calcined at 600°C for 2 hours in an inert atmosphere and cooled to room temperature to obtain the Ru-Ni / ZrO2 catalyst.

5. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: The amount of the Ru-Ni / ZrO2 catalyst used is 1% to 15% of the mass of the raw material dibenzo-18-crown-6.

6. The production process of dicyclohexano-18-crown-6 according to claim 5, characterized in that: The amount of the Ru-Ni / ZrO2 catalyst used is 10% of the mass of the raw material dibenzo-18-crown-6.

7. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: After the catalytic hydrogenation reaction is completed, the catalyst is removed by centrifugation. The catalyst is then washed sequentially with deionized water and ethanol, dried in an oven, activated, and then reintroduced into the catalytic hydrogenation reaction.

8. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: The catalytic hydrogenation reaction is carried out in a high-temperature reactor or a continuous flow production unit.

9. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: The catalytic hydrogenation reaction is carried out in a continuous flow production unit, which includes a slurry mixer, a hydrogen tank, a feed valve, a temperature controller, a fixed-bed reactor, a gas-liquid separator, a control valve, and a gas-liquid mixer. The fixed-bed reactor consists of two sets of tubular reactors connected in parallel. While one set of reactors is cleaning or activating the catalyst, the other set of reactors performs the catalytic hydrogenation reaction. Each set of tubular reactors consists of three reaction columns connected in series, with an inner diameter of 10 mm and a total length of 12 m. The reaction columns are filled with Ru-Ni / ZrO2 catalyst at a packing density of 0.5 g / cm³. 3 .

10. The production process of dicyclohexano-18-crown-6 according to claim 1, characterized in that: The catalytic hydrogenation reaction was carried out in a high-pressure reactor. 0.4 g of dibenzo-18-crown-6 benzene, 0.04 g of catalyst A and 10 ml of trifluoroethanol were added sequentially. After purging with argon and hydrogen, catalytic hydrogenation was carried out at a temperature of 30 °C and a pressure of 3 MPa. The reaction was stopped after 3 h, and the catalyst was removed by centrifugation to obtain a dicyclohexane-18-crown-6 solution. After rotary evaporation, the product was dried in a vacuum drying oven at 50°C for 8 hours to obtain dicyclohexan-18-crown-6. The final product conversion rate was 99.6%, and the product selectivity was 95.3%.

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