Process for the preparation of cyclic olefin compounds

Abstract

The application relates to the field of olefin compound preparation, and discloses a preparation method of a cyclic olefin compound, which comprises the following steps: heating a multi-component saturated alicyclic secondary alcohol and an acidic catalyst to a molten fluid state in a vacuum and solvent-free environment, fully stirring to carry out a dehydration reaction to generate a cyclic olefin compound and water, and fractionating the cyclic olefin compound during the reaction. Compared with a traditional step-by-step process, the preparation process is simpler, the reaction efficiency is high, the energy consumption and material consumption are low, the side reaction is less, the environmental protection performance is high, and the method is friendly to oxidation-sensitive materials such as unsaturated hydrocarbons, and is particularly suitable for the production and preparation of high-melting-point and high-boiling-point material dehydration reactions.

Description

Technical Field

[0001] This invention relates to the field of olefin compound preparation, and more particularly to a method for preparing cyclic olefin compounds, which is especially suitable for the production and preparation of substances with high melting and boiling points through dehydration reactions. Background Technology

[0002] Epoxy resins are a general term for compounds whose molecular structure contains two or more epoxy groups and which can form a three-dimensional network of cured products in the presence of appropriate chemical agents. They are an important class of thermosetting resins. The epoxy compounds contained in epoxy resin materials, especially cyclic epoxy compounds, exhibit significant differences in the physical properties of the products prepared from them, depending on their structural characteristics and purity.

[0003] Saturated six-membered ring epoxy resin (as shown in chemical formula 3 below) is a multifunctional material that not only has good mechanical strength, insulation and light transmittance, but also has lower viscosity and better processing performance than general-purpose epoxy resin; it also has better UV resistance and weather resistance, which solves the limitations of outdoor product applications and can be used in outdoor, LED and 3D printing and other fields with special requirements for matrix epoxy resin materials.

[0004] [Chemical Formula 3]

[0005]

[0006] In chemical formula 3, A is hydrogen, a single bond, an alkylene group, or a heteroalkylene group; R1~R9 and R11~R19 are each independently hydrogen, an alkylene group, or a heteroalkylene group.

[0007] Currently, one of the technical routes for synthesizing saturated six-membered cyclic epoxy resins is to epoxidize bicyclic alkane compounds with haloalcohols or haloalcohol ethers. For example, in CN104193961A, a bisphenol A epoxy resin is synthesized. This process requires the participation of halogen compounds and is under nitrogen protection throughout. It has disadvantages such as producing a lot of wastewater, having toxic solvents, and having complex impurities, which restricts the industrialization and commercialization of this type of epoxy compound.

[0008] Another route involves epoxidizing cyclic olefin compounds in the presence of a catalyst to obtain epoxy compounds. This involves first preparing a cyclic olefin intermediate, and then using the cyclic olefin as a raw material to synthesize a saturated six-membered cyclic epoxy resin. However, conventional manufacturing processes for cyclic olefins require a high-temperature dehydration reaction in a highly acidic organic solvent using alicyclic alcohols as raw materials. After the reaction, further steps are needed, including cooling, catalyst separation, solution property adjustment, solvent separation, and purification. The separation process is particularly complex and inevitably involves energy waste during high- and low-temperature conversion. For example, in an embodiment published in CN107954948 A, 200g of 4,4'-bicyclohexanol was used as the substrate, and 10% of the substrate mass was treated with the dehydration catalyst NaHSO4. The dehydration reaction was carried out in 800ml of xylene solvent at 145°C. After the reaction, the product underwent cooling, water washing to adjust pH, separation of the organic phase, and two-step distillation purification to obtain 126g of the dehydrated product. The reaction time was 26 hours, with a yield of 75%. In practice, this process has several drawbacks, including a long operating cycle, high energy consumption, relatively complicated product separation, and solvents with a certain degree of toxicity.

[0009] In the patent with publication number CN101421205B, the dehydration process for producing olefins is simplified, but still requires at least two steps. The specific process is as follows: First, the cycloalcohol is placed in an organic solvent, a dehydration catalyst is added, and the mixture is heated to the reaction temperature. The dehydration reaction occurs simultaneously with the removal of the byproduct water by distillation. Second, after the reaction is complete, the reaction mixture is appropriately depressurized and heated to the separation temperature. The solvent and the desired olefin compound are then separated by multi-stage distillation. In its preferred embodiment 3, 2000g of 4,4'-bicyclohexanol is used as the substrate, along with 220g of sulfuric acid + DBU composite catalyst and 2400g of 1,2,4-trimethylbenzene solvent. The dehydration reaction is carried out simultaneously with distillation of water at atmospheric pressure and a temperature of 165-171°C. The reaction solution is then subjected to solid-liquid separation. The solvent trimethylbenzene is removed using a distillation column, and the product is then distilled at 1.33kPa and 138-141°C to obtain 1491.2g of the dehydrated reaction product, with a yield of 91%. Compared to the previously introduced patent process, this method simplifies the process to some extent, but it still requires appropriate treatment of the reaction mixture, such as filtration, extraction, and adjustment of solution properties, when necessary. Furthermore, the presence of solvent still has unavoidable side effects on the reaction and separation processes, resulting in high energy and material consumption.

[0010] Based on this, the present invention provides a preparation process for cyclic olefin compounds that can be prepared in one step, which has the advantages of simpler preparation process and lower overall energy and material consumption. Summary of the Invention

[0011] The invention aims to solve the technical problems existing in the prior art. To this end, the invention provides a method for preparing cyclic olefin compounds with a simpler preparation process and lower overall energy and material consumption.

[0012] The technical solution adopted by the invention to solve its technical problem is:

[0013] A method for preparing cyclic olefin compounds is provided, wherein a polycyclic saturated alicyclic secondary alcohol and an acidic catalyst are heated to a molten fluid state under vacuum and solvent-free conditions, and a dehydration reaction is carried out with thorough stirring to generate cyclic olefin compounds and water, while the cyclic olefin compounds are fractionally distilled off during the reaction; the method specifically includes the following steps:

[0014] S1. Set up the reaction-distillation coupling device and connect it to the vacuum system. Check that the device is airtight and ensure that the vacuum level inside the device is controllable.

[0015] S2. Using polycyclic alicyclic secondary alcohols as raw materials, adding an acidic catalyst, the two materials are directly fed into the reactor of the device for premixing;

[0016] S3. Maintain the pressure inside the reactor not exceeding 3 kPa (preferably 1 kPa) while heating to heat the mixed raw materials to a molten fluid state, and stir thoroughly to carry out the dehydration reaction;

[0017] S4. Based on the pressure inside the reactor and the boiling point of the product, synchronously adjust the temperature of the upper distillation separation section and the condensation temperature of each stage of the device, and collect cyclic olefin compounds in the corresponding condensation areas.

[0018] S5. Adjust the reaction temperature and control the reaction and separation process by adjusting the liquid level or flow rate in each separation zone, and add materials or terminate the reaction as needed.

[0019] Preferably, the polycyclic alicyclic secondary alcohol is a compound having two or more saturated alicyclic secondary hydroxyl groups. The above preparation method involves intramolecular dehydration of the polycyclic alicyclic secondary alcohol represented by Chemical Formula 1 to prepare a cyclic olefin compound represented by Chemical Formula 2.

[0020] [Chemical Formula 1]

[0021]

[0022] [Chemical Formula 2]

[0023]

[0024] In chemical formulas 1 and 2, A is hydrogen, a single bond, an alkylene group, or a heteroalkylene group; R1~R9 and R11~R19 are each independently hydrogen, an alkylene group, or a heteroalkylene group.

[0025] Preferably, the acidic catalyst is selected from at least one of the following:

[0026] Sulfonic acids, phosphoric acids, sulfuric acid, complete neutralized salts of sulfonic acids and organic bases, complete neutralized salts of phosphoric acid and organic bases, complete neutralized salts of sulfuric acid and organic bases, partially neutralized salts of sulfonic acids and organic bases, partially neutralized salts of phosphoric acid and organic bases, and partially neutralized salts of sulfuric acid and organic bases.

[0027] The mass ratio of the acidic catalyst is 4% to 15% of the polycyclic alicyclic secondary alcohol, preferably 6% to 12%.

[0028] Preferably, the reaction-distillation coupling device has multiple trays and is filled with at least triangular spiral packing or Westergren packing; its reactor is stirred by magnetic stirring or paddle stirring at a stirring rate of 200~1200 r / min; its condensation zone is divided into multi-stage condensation, and different refrigeration equipment and refrigerants are used for multi-stage condensation in different areas according to the different boiling points of the products, wherein the refrigeration equipment includes a high and low temperature integrated machine and a refrigeration unit.

[0029] Preferably, the reaction temperature within the reactor of the reaction-distillation coupling device must meet the following conditions:

[0030] Between the melting point and boiling point of the aforementioned polycyclic alicyclic secondary alcohol under reaction pressure;

[0031] Above the boiling point of the cyclic olefin compound under the reaction pressure.

[0032] Compared with existing technologies, the beneficial effects of the invention are:

[0033] 1. High efficiency: The material reacts in a solvent-free environment, resulting in high reaction efficiency. As the reaction time progresses, the main product is separated, causing the reaction equilibrium to tilt towards the formation of water and olefins. At the same time, the catalyst concentration of the remaining material in the reactor is increased, the reaction rate continues to accelerate, and the reaction time is shortened.

[0034] 2. Low cost and fewer impurities: The reaction process requires no solvent, resulting in low material and energy consumption costs. The reaction process does not use traditional organic solvents, leading to fewer side reactions and impurities, and thus better environmental performance.

[0035] 3. Simple process: Through the coupled reaction + distillation reaction, the process flow is upgraded from a two-step method to a one-step method. No solvent is required in the reaction process, and the subsequent product separation process is simplified. While saving time costs, it also reduces labor and energy costs.

[0036] 4. The material is kept in a vacuum environment throughout the process, which effectively isolates it from the interference of external oxidizing substances and reduces the risk of the material being oxidized and denatured. It is especially suitable for the production of oxidation-sensitive substances such as unsaturated hydrocarbons. Detailed Implementation

[0037] To better understand this invention, the technical solutions in the embodiments of the invention will be clearly and completely described below; obviously, the described embodiments are only a part of the embodiments of the invention, and not all of the embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the invention.

[0038] This invention provides a safe and efficient method for preparing cyclic olefin compounds. The method involves heating a polycyclic saturated alicyclic secondary alcohol and an acidic catalyst to a molten fluid state under vacuum and solvent-free conditions, and then stirring thoroughly to carry out a dehydration reaction to generate cyclic olefin compounds and water. The cyclic olefin compounds are fractionated during the reaction (the unreacted materials in the reactor continue to react under the action of the acidic catalyst due to the boiling point difference until they are completely converted into cyclic olefin compounds and water).

[0039] The above reaction is carried out in a reaction-distillation coupled device. The vacuum degree inside the reactor of this device is controllable. Polycyclic saturated alicyclic secondary alcohols and acidic catalysts are added into the reactor for mixing. During the reaction, the pressure inside the reactor is kept not exceeding 3 kPa (preferably 1 kPa) while heating to heat the mixed raw materials to a molten fluid state. The mixture is stirred thoroughly to carry out the dehydration reaction. According to the pressure inside the reactor and the boiling point of the product, the temperature of the upper distillation separation section and the condensation temperature of each stage of the device are adjusted synchronously. Cyclic olefin compounds are collected in the corresponding condensation zones.

[0040] The reaction temperature inside the reactor must meet the following conditions: above the melting point and below the boiling point of the polycyclic alicyclic secondary alcohol under the reaction pressure; and above the boiling point of the cyclic olefin compound under the reaction pressure.

[0041] The reaction temperature is adjusted by regulating the liquid level or flow rate in each separation zone to control the reaction and separation process, and feeding or terminating the reaction is performed as needed.

[0042] The polycyclic alicyclic secondary alcohol raw material mentioned in the above reaction is a compound having two or more saturated alicyclic secondary hydroxyl groups. Specifically, the polycyclic alicyclic secondary alcohol shown in Chemical Formula 1 can be selected:

[0043] [Chemical Formula 1]

[0044]

[0045] In chemical formula 1, A is hydrogen, a single bond, an alkylene group, or a heteroalkylene group; R1~R9 and R11~R19 are each independently hydrogen, an alkylene group, or a heteroalkylene group.

[0046] The acidic catalyst used in the above reaction is selected from at least one of the following: sulfonic acids, phosphoric acids, sulfuric acid, a completely neutralized salt of sulfonic acids and an organic base, a completely neutralized salt of phosphoric acid and an organic base, a completely neutralized salt of sulfuric acid and an organic base, a partially neutralized salt of sulfonic acids and an organic base, a partially neutralized salt of phosphoric acid and an organic base, and a partially neutralized salt of sulfuric acid and an organic base. The mass ratio of the acidic catalyst is 4% to 15% of the polycyclic alicyclic secondary alcohol, preferably 6% to 12%.

[0047] The cyclic olefin compound mentioned in the above reaction is the cyclic olefin compound represented by the following chemical formula 2:

[0048] [Chemical Formula 2]

[0049]

[0050] In chemical formula 2, A is hydrogen, a single bond, an alkylene group, or a heteroalkylene group; R1~R9 and R11~R19 are each independently hydrogen, an alkylene group, or a heteroalkylene group.

[0051] The reaction-distillation coupling device has multiple trays and is filled with at least triangular spiral packing or Westergren packing. Its reactor is stirred by magnetic stirring or paddle stirring at a stirring rate of 200~1200 r / min. Its condensation zone is divided into multi-stage condensation. Different refrigeration equipment and refrigerants are used for multi-stage condensation in different regions according to the different boiling points of the products. The refrigeration equipment includes a high and low temperature integrated unit and a refrigeration unit.

[0052] Example 1

[0053] 100g of hydrogenated bisphenol A (hereinafter referred to as HBPA, from Hunan Changlian New Material Technology Co., Ltd., industrial grade, purity ≥98.0%), 4% by mass of H2SO4, and 4% by mass of Na2SO4 were added into the reactor. The temperature was raised to 170~210℃ under an absolute pressure of less than 3 kPa, with stirring at 400~1000 r / min. At this point, the material was in a molten state. A dehydration reaction and distillation separation were carried out for 3 hours, ultimately producing a diene product ② (purity ≥96.0%, with raw material impurities ≤2% and by-product impurities ≤2%) and its diene isomer ①. The reaction formula is as follows:

[0054]

[0055] ① ②

[0056] Analysis of the collected product (78.2g) showed that the diene content was 97.52%, and the total yield was 92.00%.

[0057] Example 2

[0058] 500g of HBPA and 10% by mass of NaHSO4 were added to the reactor. Under an absolute pressure of 300Pa, the temperature was raised to 160~200℃. During the process, stirring was started at 400~1000r / min. At this point, the material was in a molten state. Dehydration reaction and distillation separation were carried out for 6 hours, and finally 401.3g of diene product ② was generated. The content of diene product was analyzed to be 98.55%, and the yield reached 94.42%.

[0059] Example 3

[0060] 100g of HBPA and 6% by mass of p-toluenesulfonic acid were added to the reactor. Under an absolute pressure of 1 kPa, the temperature was raised to 120-160℃. During the process, the stirring was turned on at 400-1000 r / min. At this time, the material was in a molten state. The dehydration reaction and distillation separation were carried out for 4 hours, and finally 79.8g of diene product ② was generated. The content of diene product was analyzed to be 97.86%, and the yield reached 93.72%.

[0061] Example 4

[0062] 100g of HBPA and 8% by weight of phosphoric acid were added to the reactor. Under an absolute pressure of 2 kPa, the temperature was raised to 160-200℃. During the process, stirring was started at 400-1000 r / min. At this point, the material was in a molten state. Dehydration reaction and separation were carried out. The reaction was continued for 4 hours, and finally 81.5g of diene product was generated, of which the diene content was 98.64% and the monoene content was 0.45%. The target diene product yield was 95.88%.

[0063] Example 5

[0064] 500g of HBPA and 12% by weight of disodium hydrogen phosphate were added to the reactor. Under an absolute pressure of 2 kPa, the temperature was raised to 160-200℃. During the process, stirring was started at 400-1000 r / min. At this point, the material was in a molten state. Dehydration reaction and separation were carried out. The reaction was continued for 6 hours, and finally 407.1g of olefin product was produced, of which the diene product content was 97.12% and the monoene content was 0.10%. The target total yield of diene product was 95.79%.

[0065] Example 6

[0066] 500g of HBPA, 4% by mass of concentrated sulfuric acid (98% by mass), and 6% by mass of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were added to a reactor. Under an absolute pressure of 2 kPa, the temperature was raised to 160-200℃, and stirring was started at 400-1000 r / min. At this point, the material was in a molten state, and dehydration and separation were carried out. The reaction was continued for 6 hours, and 403.2g of olefin product was finally produced, of which the diene product content was 97.89%, the monoene content was 1.78%, and the remaining 0.33% was other impurities. The total yield was 94.87%.

[0067] Example 7

[0068] 100g of 4,4-bicyclohexanol and 8% by mass of NaHSO4 were added to a reactor. The temperature was raised to 150-200℃ under an absolute pressure of 1 kPa, with stirring at 400-1000 r / min. At this point, the material was in a molten state. A dehydration reaction and distillation separation were carried out for 3 hours, ultimately producing a diene product ④ (purity ≥96.0%, with raw material impurities ≤2% and by-product impurities ≤2%) and its diene isomer ③, totaling 76.8g. Analysis showed the diene product content to be 97.51%, with a yield of 93.86%. The reaction formula is as follows:

[0069]

[0070] ③ ④

[0071] Example 8

[0072] 300g of 4,4-bicyclohexanol and 10% by weight of phosphoric acid (purity ≥85%) were added to the reactor. Under an absolute pressure of 1 kPa, the temperature was raised to 150~200℃, and the stirring was turned on at 400~1000 r / min. At this time, the material was in a molten state. The dehydration reaction and distillation separation were carried out for 5 hours, and finally 232.0g of diene product ④ was generated. The content of diene product was analyzed to be 96.86%, and the yield reached 94.52%.

[0073] Example 9:

[0074] 200g of 4,4-bicyclohexanol, 6% by mass of concentrated sulfuric acid (98% by mass), and 6% by mass of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were added to the reactor. Under an absolute pressure of 500Pa, the temperature was raised to 150~200℃, and stirring was started at 400~1000r / min. At this time, the material was in a molten state. Dehydration reaction and distillation separation were carried out for 4 hours, and finally 154.3g of diene product ④ was generated. The content of diene product was analyzed to be 99.11%, and the yield reached 94.29%.

[0075] Example 10:

[0076] 200g of 4,4-bicyclohexanol and 8% by weight of p-toluenesulfonic acid were added to a reactor. Under an absolute pressure of 700Pa, the temperature was raised to 150-200℃, and stirring was started at 400-1000r / min. At this point, the material was in a molten state, and dehydration reaction and water separation were carried out. The reaction was continued for 4 hours, and finally 151.3g of olefin product was produced. The content of diene product ④ was 97.26%, the content of monoene was 2.60%, and the remaining 0.14% was other impurities. The total yield of the target diene product was 92.46%.

[0077] Example 11:

[0078] 200g of 4,4-bicyclohexanol and 10% by mass of NaHSO4 were added to the reactor. Under an absolute pressure of 1 kPa, the temperature was raised to 150-200℃, and stirring was started at 400-1000 r / min. At this point, the material was in a molten state, and dehydration and separation were carried out. The reaction was continued for 3 hours, and 156.1g of olefin product was finally produced. The content of diene product ④ was 96.92%, the content of monoene was 2.92%, and the remaining 0.16% was other impurities. The total yield of the target diene product was 95.39%.

[0079] Comparative Example 1:

[0080] 120g of HBPA, 10% by mass of NaHSO4, and 120g of xylene solvent were placed in a three-necked flask and connected to a laboratory distillation apparatus equipped with a water separator. The mixture was heated to 120-160℃ under normal pressure and stirred continuously for 12 hours to carry out the dehydration reaction and water separation. After 12 hours, 16.7g of water was finally obtained from the water separator, with a calculated conversion rate of 92.78%. The oil phase reaction solution contained 95.35% diene (excluding solvent), 3.31% monoene, and 1.34% other impurities. After purification by distillation, 80.3g of diene product was obtained with a purity of 95.65%, and the overall yield was 78.73%.

[0081] Comparative Example 2:

[0082] 100g of 4,4-bicyclohexanol, 8% by weight of p-toluenesulfonic acid, and 300g of xylene solvent were placed in a three-necked flask and connected to a laboratory distillation apparatus equipped with a water separator. The mixture was heated to 120-160℃ under normal pressure and stirred continuously for 12 hours to carry out the dehydration reaction and water separation. After 12 hours, 17.2g of water was finally obtained from the water separator, with a calculated conversion rate of 94.60%. The oil phase reaction solution contained 97.11% diene (excluding solvent), 1.79% monoene, and 1.10% other impurities. After further purification by distillation, 70.9g of the target diene product was obtained with a purity of 96.87%, and the overall yield was 86.66%.

[0083] Comparative Example 3:

[0084] 150g of cyclohexanol, 8% by mass of phosphoric acid (purity ≥85%), and a small amount of zeolite were placed in a three-necked flask. The flask was then connected to a laboratory distillation apparatus. The temperature was raised and the 70-90℃ fraction was observed for recovery. The distillation was carried out under normal pressure. After 2 hours, when only a small amount of residue remained in the flask and intermittent white fumes appeared, the distillation was stopped. 140.8g of cyclohexene azeotrope obtained from the collection flask was washed in batches with 15g of saturated salt and 5% sodium carbonate (to neutralize trace amounts of acid). The liquid was poured into a small separatory funnel, shaken, and allowed to stand for separation. The lower aqueous solution was discharged from the stopcock at the bottom of the funnel, and the upper crude product was poured from the top of the funnel into a dry conical flask. An appropriate amount of anhydrous calcium chloride was added for drying. The dried product was filtered into a distillation flask, and boiling chips were added again. The product was then heated in a water bath for distillation. The fraction at 80-85℃ was collected. After 2 hours, 78.4 g of cyclohexene was finally obtained. Its chromatographic purity was 98.12%, and the total yield was calculated to be 63.74%.

[0085] The experimental data for each embodiment and comparative example are shown in Table 1 and Table 2 below:

[0086] Table 1. Experimental Statistics of Examples

[0087] Example Reaction substrate / weight (g) Catalyst (wt%) Reaction time / h Conversion rate / % Target olefin selectivity / % Target olefin total yield / % 1 HBPA (100) <![CDATA[4%Na2SO4+4%H2SO4]]> 3 100 97.52 92.00 2 HBPA (500) <![CDATA[NaHSO4(10%)]]> 6 100 98.55 94.42 3 HBPA (100) p-Toluenesulfonic acid (6%) 4 99.96 97.86 93.72 4 HBPA (100) Phosphoric acid (8%) 4 98.67 98.64 95.88 5 HBPA (500) Disodium hydrogen phosphate (12%) 6 99.47 97.12 95.79 6 HBPA (500) <![CDATA[4%H2SO4+6%DBU]]> 6 98.93 97.89 94.87 7 4,4-Bicyclohexanol (100) <![CDATA[NaHSO4(8%)]]> 3 99.92 97.51 93.86 8 4,4-Bicyclohexanol (300) Phosphoric acid (10%) 5 99.98 96.86 94.52 9 4,4-Bicyclohexanol (200) <![CDATA[6%H2SO4+6%DBU]]> 4 100 99.11 94.29 10 4,4-Bicyclohexanol (200) p-Toluenesulfonic acid (8%) 4 98.72 97.26 92.46 11 4,4-Bicyclohexanol (200) <![CDATA[NaHSO4(10%)]]> 3 98.45 96.92 95.39

[0088] Table 2. Comparative Experiment Statistics

[0089] Comparative Example Reaction substrate / weight (g) Catalyst (wt%) Reaction conditions Reaction time / h Conversion rate / % Target olefin selectivity / % Target olefin total yield / % 1 HBPA (120) <![CDATA[NaHSO4(10%)]]> Xylene solvent * 100% 12 92.78 95.35 78.73 2 4,4-Bicyclohexanol (100) p-Toluenesulfonic acid (8%) Xylene solvent * 300% 12 94.60 97.11 86.66 3 Cyclohexanol (150) Phosphoric acid (8%) Solvent-free 4 78.37 98.12 63.74

[0090] The experimental data above show that the preparation method of the solvent-free reaction system described in this invention (Examples 1 to 11) can significantly shorten the reaction time, effectively improve the conversion rate and target olefin selectivity, and also significantly improve the total yield of target olefins compared with the traditional preparation method of the reaction system with solvent participation (Comparative Example 1 and Comparative Example 2).

[0091] While Comparative Example 3 uses a solvent-free system, which can shorten the reaction time, its preparation method has a low conversion rate, complicated procedures, and the total yield of the target olefin is significantly lower than that of the reaction system in this application.

[0092] In the above embodiments and comparative examples, the reaction yield was calculated using the mass comparison method, and the product composition was analyzed using chromatography.

[0093] The above description is merely an embodiment of the invention and does not limit the patent scope of the invention. Any equivalent structural or procedural changes made using the content of the invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the invention.

Claims

1. A method for preparing a cyclic olefin compound, characterized in that: A polycyclic alicyclic alcohol and an acidic catalyst are heated to a molten fluid state under vacuum and solvent-free conditions, and a dehydration reaction is carried out with thorough stirring to generate cyclic olefin compounds and water. The cyclic olefin compounds are fractionated off during the reaction. This method includes the following steps: S1. Set up the reaction-distillation coupling device and connect it to the vacuum system. Check that the device is airtight and ensure that the vacuum level inside the device is controllable. S2. Using polycyclic alicyclic secondary alcohols as raw materials, adding an acidic catalyst, the two materials are directly fed into the reactor of the device for premixing; S3. Maintain the pressure inside the reactor not exceeding 3 kPa while heating to heat the mixed raw materials to a molten fluid state, and stir thoroughly to carry out the dehydration reaction; S4. Based on the pressure inside the reactor and the boiling point of the product, synchronously adjust the temperature of the upper distillation separation section and the condensation temperature of each stage of the device, and collect cyclic olefin compounds in the corresponding condensation areas. S5. Adjust the reaction temperature and control the reaction and separation process by adjusting the liquid level or flow rate in each separation zone, and add materials or terminate the reaction as needed.

2. The method for preparing the cyclic olefin compound according to claim 1, characterized in that: The polycyclic alicyclic secondary alcohol is a compound having two or more saturated alicyclic secondary hydroxyl groups.

3. The method for preparing the cyclic olefin compound according to claim 2, characterized in that: The preparation method involves intramolecular dehydration of the polycyclic alicyclic secondary alcohol represented by the following chemical formula 1 to prepare the cyclic olefin compound represented by the following chemical formula 2. [Chemical Formula 1] [Chemical Formula 2] In chemical formulas 1 and 2, A is hydrogen, a single bond, an alkylene group, or a heteroalkylene group; R1~R9 and R11~R19 are each independently hydrogen, an alkylene group, or a heteroalkylene group.

4. The method for preparing the cyclic olefin compound according to claim 1, characterized in that: The acidic catalyst is selected from at least one of the following: Sulfonic acids, phosphoric acids, sulfuric acid, complete neutralized salts of sulfonic acids and organic bases, complete neutralized salts of phosphoric acid and organic bases, complete neutralized salts of sulfuric acid and organic bases, partially neutralized salts of sulfonic acids and organic bases, partially neutralized salts of phosphoric acid and organic bases, and partially neutralized salts of sulfuric acid and organic bases.

5. The method for preparing the cyclic olefin compound according to claim 4, characterized in that: The mass ratio of the acidic catalyst is 4% to 15% of the polycyclic alicyclic secondary alcohol.

6. The method for preparing the cyclic olefin compound according to claim 5, characterized in that: The mass ratio of the acidic catalyst is 6% to 12% of the polycyclic alicyclic secondary alcohol.

7. The method for preparing the cyclic olefin compound according to claim 1, characterized in that: The reaction-distillation coupling device has multiple trays and is filled with at least triangular spiral packing or West Tower ring packing.

8. The method for preparing the cyclic olefin compound according to claim 1, characterized in that: The reactor of the reaction-distillation coupling device is stirred by magnetic stirring or by a stirring paddle at a speed of 200~1200 r / min.

9. The method for preparing the cyclic olefin compound according to claim 1, characterized in that: The condensation zone of the reaction-distillation coupling device is divided into multi-stage condensation. Different refrigeration equipment and refrigerants are used for multi-stage condensation in different areas according to the different boiling points of the products. The refrigeration equipment includes a high and low temperature integrated machine and a refrigeration unit.

10. The method for preparing the cyclic olefin compound according to claim 1, characterized in that: The reaction temperature within the reactor of the reaction-distillation coupling device must meet the following conditions: Between the melting point and boiling point of the aforementioned polycyclic alicyclic secondary alcohol under reaction pressure; Above the boiling point of the cyclic olefin compound under the reaction pressure.

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