Preparation method of cyclohexyl ethyl vinyl ether
By using nickel/ruthenium carbon-catalyzed hydrogenation reduction and palladium-catalyzed alcohol exchange reaction, the problems of high catalyst cost and difficult separation in the synthesis of cyclohexyl vinyl ether were solved, realizing low-cost and high-efficiency industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 西安国际医学中心有限公司
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-12
AI Technical Summary
Existing methods for synthesizing cyclohexyl vinyl ethers involve high catalyst costs and demanding reaction conditions, making them unsuitable for large-scale industrial production. Furthermore, the separation of intermediates from products is difficult.
Cyclohexylethanol was prepared by hydrogenation reduction of phenylethanol using nickel/ruthenium carbon catalysis, and then by alcohol exchange reaction with alkenyl ether under palladium catalysis to prepare cyclohexylvinyl ether. The catalyst and solvent can be recycled and reused, and the reaction conditions are mild.
It reduces production costs, simplifies the separation process of intermediates and products, is suitable for large-scale batch production, has a high reaction conversion rate, and produces high product purity, making it suitable for large-scale industrial production.
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Figure CN122010696A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical technology, specifically a method for preparing cyclohexylethyl vinyl ether. Background Technology
[0002] Cyclohexyl ethyl vinyl ether compounds are important raw materials for pharmaceuticals, pesticides, and photoresist resins, and are also used as reactive diluents in inks and coatings. Furthermore, cyclohexyl ethyl vinyl ether compounds generally exhibit cationic polymerization properties, making them suitable as raw materials and crosslinking agents for polymers such as optical and transparent resins, as well as for UV curing agents and adhesives. Compared to acrylic and styrene compounds, cyclohexyl ethyl vinyl ether compounds offer advantages such as high stability, low odor, and less skin irritation. However, the variety of cyclohexyl ethyl vinyl ether compounds is currently limited, and their prices are high, while market demand remains substantial but not fully met. Therefore, researching methods suitable for large-scale industrial production of cyclohexyl ethyl vinyl ethers is of great significance.
[0003] Japanese Patent JP2012-020954A discloses a synthetic method using cyclohexylethanol as a raw material, which involves a coupling reaction catalyzed by a transition metal (iridium) to obtain cyclohexylethyl vinyl ether. The drawbacks of this method are the high cost of the catalyst (1,5-cyclooctadiene) iridium dichloride (I), which is as high as 870 yuan / g, requiring a catalyst-to-material ratio of 0.01 eq, resulting in high production costs. Furthermore, the reaction requires a closed system, hindering large-scale industrial production. The patent also discloses another synthetic method using cyclohexylethanol and triacetaldehyde as raw materials, involving a three-step process: acetal formation, acetyl chloride chlorination, and triethylamine elimination to synthesize cyclohexylethyl vinyl ether. The biggest bottleneck of this method is the low conversion rate of acetyl chloride acetalization and chlorination in the second step. Even with a 100% conversion rate, 2 mol of cyclohexylethanol is needed to produce 1 mol of cyclohexylethyl vinyl ether, resulting in low atom economy. Moreover, the cyclohexylethyl vinyl ether product from the third step is difficult to separate from impurities generated during the reaction.
[0004] To address the cost issue, current research often focuses on preparing the product using cyclohexylethanol and other alkenyl ethers as raw materials, catalyzed by Pd(4,7-diphenyl-1,10-phenanthroline)(OOCCF3)2. However, this process uses expensive catalysts, hindering large-scale industrial production. Furthermore, the catalysts have large molecular weights and require significant quantities. Summary of the Invention
[0005] To address the problems in the prior art, this invention provides a method for preparing cyclohexylethyl vinyl ether. This method uses phenethyl alcohol as a raw material, which is catalytically hydrogenated to obtain cyclohexylethanol. The reaction conditions are mild, and the catalyst and solvent can be reused. The obtained cyclohexylethanol is then reacted with an alkenyl ether via alcohol exchange reaction under palladium catalyst catalysis to obtain cyclohexylethyl vinyl ether. The catalyst dosage is low, and the cost is low.
[0006] The technical solution adopted by this invention to solve its technical problem is: a method for preparing cyclohexylethyl vinyl ether, comprising the following steps: S1. Cyclohexylethanol is prepared by hydrogenation reduction reaction using phenylethanol as raw material and low-boiling alcohols as solvents under nickel / ruthenium carbon catalysis at 50-65℃ and 5-6MPa. S2. Under a protective gas atmosphere, the cyclohexylethanol prepared in S1 is added to an alkenyl ether, a base, a palladium catalyst, and a ligand, and cyclohexylethyl vinyl ether is prepared by catalytic alcohol exchange reaction at 100-110℃.
[0007] Specifically, in S1, the low-boiling-point alcohol solvent is ethanol or isopropanol; In S1, the mass ratio of phenylethanol to low-boiling-point alcohol solvent is 1:3-6; In S1, the catalyst is nickel containing 10% water or ruthenium carbon containing 10% water, and the mass ratio of phenylethanol to the catalyst is 1:0.03-0.06; In S1, after the reaction is complete, filter to recover the catalyst, and concentrate at atmospheric pressure to recover the solvent; In S1, both the recovered catalyst and the solvent can be recycled and reused.
[0008] Specifically, in S2, the molar ratio of cyclohexylethanol to alkenyl ether is 1:2-20.
[0009] Specifically, in S2, the base is pyridine or triethylamine.
[0010] Specifically, in S2, the molar ratio of cyclohexylethanol to alkali is 1:0.1-0.6.
[0011] Specifically, in S2, the palladium catalyst is palladium chloride, palladium trifluoroacetate, palladium bis(benzylacetone)-acetone, or 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, preferably palladium chloride.
[0012] Specifically, in S2, the molar ratio of cyclohexylethanol to the catalyst is 1:0.001-0.003.
[0013] Specifically, in S2, the ligand is 1,10-phenanthroline.
[0014] Specifically, in S2, the molar ratio of cyclohexylethanol to the ligand is 1:0.002-0.006.
[0015] Specifically, in S2, the alkenyl ether is butyl vinyl ether, pentyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, or other alkyl vinyl ethers, preferably butyl vinyl ether.
[0016] Specifically, in S2, after the reaction is complete, water is added to the reaction solution, the solution is washed with water to adjust the pH to 7, then passed through a column and distilled.
[0017] The beneficial effects of this invention are: (1) This invention uses phenylethanol as raw material and low-boiling-point alcohols as solvents to prepare cyclohexylethanol via hydrogenation reduction reaction under nickel / ruthenium carbon catalysis. Compared with existing methods, this step has milder reaction conditions and lower equipment requirements, which can be met by using a hydrogenation reactor, making it suitable for large-scale industrial production; no phase transfer catalyst or co-catalyst is needed during the reaction, the reaction system is simple and clean, no solid waste is generated, and it is green and environmentally friendly; a single low-boiling-point alcohol is used as the solvent, the solvent can be recycled and reused, and the amount of catalyst used is small and can also be recycled and reused, which greatly reduces the production cost; the reaction conversion rate is good, and the gas chromatography content can reach 93%-96%; at the same time, some low-boiling-point impurities can be concentrated and removed during the concentration process, and the gas chromatography content of the product can reach 97%-99%, with a yield of generally 95%-97%.
[0018] (2) Under a protective gas atmosphere, the cyclohexylethanol obtained above is converted into cyclohexylethyl vinyl ether by palladium-catalyzed alcohol exchange reaction in an alkaline environment. Compared with existing methods, this step is easier to separate and purify the intermediate and the final product, the process is simple, the intermediate cyclohexylethanol does not require additional post-processing and purification, the operation is easy, and it is suitable for large-scale batch production. Attached Figure Description
[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0020] Figure 1 The synthetic route diagram for cyclohexylethyl vinyl ether provided by the present invention. Detailed Implementation
[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.
[0022] like Figure 1 As shown, the preparation method of a cyclohexylethyl vinyl ether according to the present invention includes the following steps: S1. In a hydrogenation reactor, cyclohexylethanol is prepared by catalytic reduction reaction at 50-65℃ using phenylethanol as raw material and low-boiling alcohols as solvent under nickel / ruthenium carbon catalysis. S2. Under a protective gas atmosphere, cyclohexylethanol prepared in S1 is subjected to a palladium-catalyzed alcohol exchange reaction at 100-110℃ in an alkaline environment to prepare cyclohexylethyl vinyl ether. Its synthetic route is shown in the appendix. Figure 1 As shown.
[0023] Preferably, in S1, the low-boiling-point alcohol is ethanol or isopropanol.
[0024] Preferably, in S1, the mass ratio of phenylethanol to a low-boiling-point alcohol solvent is 1:3-6.
[0025] Preferably, in S1, the catalyst is 10% hydrated nickel or 10% ruthenium carbon.
[0026] Preferably, in S1, the mass ratio of phenylethanol to catalyst is 1:0.03-0.06.
[0027] Preferably, in step S1, after the reaction is complete, the catalyst is filtered out and the solvent is concentrated and recovered.
[0028] Preferably, in S2, the base is pyridine or triethylamine, and the molar ratio of cyclohexylethanol to the base is 1:0.1-0.6.
[0029] Preferably, in S2, the palladium catalyst is palladium chloride or palladium trifluoroacetate, and the molar ratio of cyclohexylethanol to the catalyst is 1:0.001-0.003.
[0030] Preferably, in S2, the ligand is 1,10-phenanthroline, and the molar ratio of cyclohexylethanol to the ligand is 1:0.002-0.006.
[0031] Preferably, in S2, the alkenyl ether is butyl vinyl ether, pentyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, or other alkyl vinyl ethers, preferably butyl vinyl ether, and the molar ratio of cyclohexylethanol to alkenyl ether is 1:2-20.
[0032] Preferably, in S2, after the reaction is complete, water is added to the reaction solution, the solution is washed with water to adjust the pH to 7, and then passed through a column and distilled.
[0033] Example 1
[0034] A method for preparing a cyclohexylethyl vinyl ether includes the following steps: Preparation of S1 and cyclohexylethanol 3000 ml of isopropanol, 500.0 g of phenylethanol, and 15.0 g of 10% ruthenium carbon (dry weight) were added to a 5000 ml hydrogenation reactor. The air in the system was replaced three times with hydrogen. Heating and stirring were started, and the temperature was raised to 50 °C. The reaction was carried out at a pressure of 5-6 MPa for 8 h. After the reaction was completed, the temperature was lowered to room temperature, the catalyst was filtered off, and the filtrate was concentrated under normal pressure to recover isopropanol, yielding 500.0 g of cyclohexylethanol liquid with a GC content of 98.8% and a yield of 95.9%.
[0035] Preparation of S2, cyclohexylethyl vinyl ether Under nitrogen protection, 200.0 g of cyclohexylethanol, 624.9 g of butyl vinyl ether, 49.6 g of triethylamine, 0.350 g of palladium chloride, and 0.618 g of 1,10-phenanthroline were added to a 2000 ml three-necked flask. Stirring was started, and the temperature was raised to 100 °C, where the reaction was carried out for 10 h. After confirming that no cyclohexylethanol remained, 400 ml of water was added for washing. Washing was repeated until the pH reached 7. The mixture was separated, filtered by column chromatography, concentrated, and distilled to obtain a colorless liquid with a cyclohexylethyl vinyl ether content of 97.9% and a yield of 79.4%.
[0036] Example 2
[0037] A method for preparing a cyclohexylethyl vinyl ether includes the following steps: Preparation of S1 and cyclohexylethanol 1200 ml of ethanol, 200.0 g of phenylethanol, and 6.0 g of 10% nickel (dry weight) were added to a 2000 ml hydrogenation reactor. The air was replaced three times with hydrogen, and the temperature was raised to 55 °C. The reaction was carried out at 5-6 MPa for 10 h. After the reaction was completed, the temperature was lowered to room temperature, the catalyst was filtered off, and the filtrate was concentrated at atmospheric pressure to recover ethanol, yielding cyclohexylethanol with a GC content of 97.9% and a yield of 93.1%.
[0038] Preparation of S2, cyclohexylethyl vinyl ether Under nitrogen protection, 200.0 g of cyclohexylethanol, 624.9 g of butyl vinyl ether, 49.6 g of triethylamine, 0.518 g of palladium trifluoroacetate, and 0.618 g of 1,10-phenanthroline were added to a 2000 ml three-necked flask. Stirring was started, and the temperature was raised to 100 °C, where the reaction was carried out for 10 h. After confirming that no cyclohexylethanol remained, 400 ml of water was added for washing. Washing was repeated until the pH reached 7. The mixture was separated, filtered by column chromatography, concentrated, and distilled to obtain a colorless liquid with a cyclohexylethyl vinyl ether content of 97.3% and a yield of 79.7%.
[0039] Example 3
[0040] A method for preparing a cyclohexylethyl vinyl ether includes the following steps: Preparation of S1 and cyclohexylethanol 3000 ml of isopropanol, 500.0 g of phenylethanol, and 15.0 g of 10% ruthenium carbon (dry weight) were added to a 5000 ml hydrogenation reactor. The air in the system was replaced three times with hydrogen. Heating and stirring were started, and the temperature was raised to 50 °C. The reaction was carried out at a pressure of 5-6 MPa for 10 h. After the reaction was completed, the temperature was lowered to room temperature, the catalyst was filtered off, and the filtrate was concentrated under normal pressure to recover isopropanol, yielding cyclohexylethanol liquid with a GC content of 96.7% and a yield of 93.9%.
[0041] Preparation of S2, cyclohexylethyl vinyl ether Under nitrogen protection, 200.0 g of cyclohexylethanol, 624.9 g of butyl vinyl ether, 47.4 g of triethylamine, 0.700 g of palladium chloride, and 1.236 g of 1,10-phenanthroline were added to a 2000 ml three-necked flask. Stirring was started, and the mixture was heated to 100 °C and reacted at this temperature for 10 h. After confirming that no cyclohexylethanol remained, 400 ml of water was added for washing. Washing was repeated until the pH reached 7. The mixture was separated, filtered by column chromatography, concentrated, and distilled to obtain a colorless liquid with a cyclohexylethyl vinyl ether content of 98.5% and a yield of 84.3%.
[0042] Example 4
[0043] A method for preparing a cyclohexylethyl vinyl ether includes the following steps: Preparation of S1 and cyclohexylethanol 3000 ml of isopropanol, 500.0 g of phenylethanol, and 15.0 g of 10% ruthenium carbon (dry weight) were added to a 5000 ml hydrogenation reactor. The air in the system was replaced three times with hydrogen. Heating and stirring were started, and the temperature was raised to 50 °C. The reaction was carried out at a pressure of 5-6 MPa for 10 h. After the reaction was completed, the temperature was lowered to room temperature, the catalyst was filtered off, and the filtrate was concentrated at atmospheric pressure to recover isopropanol, yielding cyclohexylethanol liquid with a GC content of 98.8% and a yield of 94.6%.
[0044] Preparation of S2, cyclohexylethyl vinyl ether Under nitrogen protection, 200.0 g of cyclohexylethanol, 624.9 g of butyl vinyl ether, 49.6 g of triethylamine, 1.036 g of palladium trifluoroacetate, and 1.236 g of 1,10-phenanthroline were added to a 2000 ml three-necked flask. Stirring was started, and the temperature was raised to 100 °C, where the reaction was carried out for 10 h. After confirming that no cyclohexylethanol remained, 400 ml of water was added for washing. Washing was repeated until the pH reached 7. The mixture was separated, filtered by column chromatography, concentrated, and distilled to obtain a colorless liquid with a cyclohexylethyl vinyl ether content of 97.9% and a yield of 83.4%.
[0045] To verify the properties of the product prepared by the present invention, the present invention also performed GC-MS qualitative analysis on the product. Since the products prepared in Examples 1-4 are basically the same, only the product of Example 1 is used as an example.
[0046] As demonstrated by the above embodiments, the method of the present invention successfully prepared cyclohexylethyl vinyl ether using palladium catalyst and 1,10-phenanthroline, exhibiting good reaction conversion and selectivity, with a selectivity of 81%-86%. The use of alkenyl ethers such as butyl vinyl ether as both reactant and solvent allows for solvent recycling and low production costs. The small amount of palladium catalyst and ligands further reduces costs. The reaction system is clean, requiring no additional co-catalyst, making it environmentally friendly. The process conditions are mild, equipment requirements are low, and operation is simple; conventional reaction vessels are sufficient, making it suitable for large-scale industrial production. The final product is purified by distillation, making the process easy and suitable for large-scale batch production.
[0047] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing cyclohexylethyl vinyl ether, characterized in that, Includes the following steps: S1. Cyclohexylethanol is prepared by hydrogenation reduction reaction using phenylethanol as raw material and low-boiling alcohols as solvents under nickel / ruthenium carbon catalysis at 50-65℃ and 5-6MPa. S2. Under a protective gas atmosphere, the cyclohexylethanol prepared in S1 is added to an alkenyl ether, a base, a palladium catalyst, and a ligand, and cyclohexylethyl vinyl ether is prepared by catalytic alcohol exchange reaction at 100-110℃.
2. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S1, the low-boiling-point alcohol solvent is ethanol or isopropanol; In S1, the mass ratio of phenylethanol to low-boiling-point alcohol solvent is 1:3-6; In S1, the catalyst is nickel containing 10% water or ruthenium carbon containing 10% water, and the mass ratio of phenylethanol to the catalyst is 1:0.03-0.06; In S1, after the reaction is complete, filter to recover the catalyst, and concentrate at atmospheric pressure to recover the solvent; In S1, both the recovered catalyst and the solvent can be recycled and reused.
3. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, the molar ratio of cyclohexylethanol to alkenyl ether is 1:2-20.
4. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, the base is pyridine or triethylamine.
5. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, the molar ratio of cyclohexylethanol to alkali is 1:0.1-0.
6.
6. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, the palladium catalyst is any one of palladium chloride, palladium trifluoroacetate, palladium dibenzylacetone, and 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride.
7. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, the molar ratio of cyclohexylethanol to catalyst is 1:0.001-0.
003.
8. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, the ligand is 1,10-phenanthroline.
9. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, the molar ratio of cyclohexylethanol to the ligand is 1:0.002-0.
006.
10. The method for preparing a cyclohexylethyl vinyl ether according to claim 1, characterized in that: In S2, after the reaction is complete, add water to the reaction solution, wash with water to adjust the pH to 7, pass through a column, and distill. In S2, the alkenyl ether is any one of butyl vinyl ether, pentyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, or other alkyl vinyl ethers.