CN115043694B - Method for preparing methylcyclopentadiene - Google Patents
Method for preparing methylcyclopentadiene Download PDFInfo
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Abstract
The invention provides a method for preparing methylcyclopentadiene by using methyl pentenol Saucy-Marbet reaction byproducts, wherein the byproducts are 3-methyl-1, 3-pentadiene and 2-ethyl-1, 3-butadiene. According to the invention, the metal oxide is used as a catalyst, and the cocatalyst ammonium salt is added at the same time, so that the catalytic dehydrocyclization synthesis of methylcyclopentadiene is performed, the yield is higher than that of the traditional cyclopentadiene synthesis methylcyclopentadiene route, the reaction condition is mild, the use of metallic sodium is avoided, the reaction step is simplified, and the generation of excessive hydrogenation byproducts in the cyclization reaction is inhibited. The recycling of 3-methyl-1, 3-pentadiene and 2-ethyl-1, 3-butadiene reduces the generation of methyl pentenol Saucy-Marbet reaction waste liquid, reduces material loss, and the product methyl cyclopentadiene can be used for manufacturing epoxy resin curing agent, polyolefin catalyst and the like, and has higher economic value.
Description
Technical Field
The invention belongs to the field of organic synthesis, relates to a method for preparing methylcyclopentadiene, and in particular relates to a method for preparing methylcyclopentadiene by using methyl pentenol Saucy-Marbet reaction byproducts.
Background
The Saucy-Marbet reaction (methyl isopropenyl ether method) is to take unsaturated alcohol and methyl isopropenyl ether as raw materials, etherify the raw materials under the action of Bronsted acid catalyst and then isomerize the raw materials to obtain unsaturated ketone products. This method was originally reported by Saucy and Marbet et al (US 3029287, US 6184420). The method is widely used for producing perfume and pharmaceutical intermediates, such as vitamin A, carotene, linalool, nerolidol synthesis, etc. Taking 3-methyl-1-pentene-3-alcohol as an example for synthesizing 6-methyl-5-octene-2-ketone, the reaction catalyst is organic acid, the conversion rate of 3-methyl-1-pentene-3-alcohol can reach more than 99%, the yield of the Saucy-Marbet reaction product 6-methyl-5-octene-2-ketone is about 85%, and the rest is the dehydration byproducts of 3-methyl-1, 3-pentadiene and 2-ethyl-1, 3-butadiene of 3-methyl-1-pentene-3-alcohol in an acid environment. Therefore, about 1/6 of the organic waste liquid is inevitably produced in the unsaturated ketone production process, and the organic waste liquid is used as a byproduct mixture for dehydration of unsaturated alcohols as a raw material, and the saturated alkane is generally obtained by discharging the waste liquid or performing double bond full hydrogenation in industrial production, but the method can cause environmental pollution or have low added value. The problems of high-efficiency treatment and recovery of the organic waste liquid are very important to take the production concepts of environmental protection, economy, green chemical industry and the like into account, and especially, the waste is turned into wealth to produce products with higher added values, so that the economy of a production device is greatly improved, and the production benefit is improved.
Methylcyclopentadiene (MCPD) is a basic chemical raw material, and because of the limited natural sources, the Methylcyclopentadiene (MCPD) cannot obtain the practical output from natural products such as petroleum or coal through one-time processing, and can be used as a high-energy rocket fuel, a high-end fine chemical raw material, and can be used for synthesizing high-grade resin, high-grade dye, high-grade spice, polyolefin catalyst, gasoline additive and the like, and the added value is very high. Cyclopentadiene is easy to obtain a certain yield from petroleum or coal pyrolysis products, and methyl cyclopentadiene has one more methyl group than cyclopentadiene, but has special functions in certain properties and purposes, for example, an addition product (MNA) of methyl cyclopentadiene and maleic acid is in a liquid state at normal temperature, so that the heating process in the process of preparing glass fiber reinforced plastic glue solution can be reduced, and the mechanical property of the cured resin is better than that of anhydride prepared from cyclopentadiene.
Many synthetic methods of methylcyclopentadiene have limited yields due to their excessive cost and inability to produce continuously. Methyl cyclopentadiene is generally prepared by a heterogeneous catalytic methylation method through methylation reaction of methanol and cyclopentadiene, and favorable conditions are created for synthesizing the methyl cyclopentadiene, wherein the methyl generated by the methanol is combined with cyclopentadienyl generated by the cyclopentadiene in the presence of a catalyst to obtain the methyl cyclopentadiene, and a plurality of byproducts such as ethylene, dimethyl ether, cyclopentane, cyclopentene and the like are also generated, so that the reaction conversion rate and the selectivity are low. In addition, the preparation of methylcyclopentadiene from methylated cyclopentadiene is troublesome in the process of separating products, unreacted cyclopentadiene is required to be dimerized and then separated from other impurities, and then the coarse dimer is subjected to thermal polymerization and rectification to collect methylcyclopentadiene, so that the yield is low and the process energy consumption is high.
There is also research on synthesizing methylcyclopentadiene from cyclopentadiene, sodium metal and chloromethane, which includes two steps of cyclopentadiene preparation, sodium cyclopentadiene preparation and sodium cyclopentadiene methylation. The molar ratio of cyclopentadiene to sodium is 2-5, the molar ratio of solvent diethylene glycol dimethyl ether to sodium is 1-3, the optimal reaction temperature for methylation reaction of cyclopentadiene sodium and chloromethane is 25 ℃, under the condition, the yield of methyl cyclopentadiene is higher than 80%, and the yield of dimethyl cyclopentadiene is higher than 5%. This method uses a large amount of metallic sodium and does not control the degree of methylation, resulting in the formation of part of dimethylcyclopentadiene:
disclosure of Invention
The invention aims to provide a method for preparing methylcyclopentadiene, which can recycle byproducts of methyl pentenol Saucy-Marbet reaction, directly takes pure products or mixtures of the byproducts as raw materials, and generates dehydrocyclization reaction under the catalysis of metal oxide and the action of ammonium salt auxiliary agent to obtain methylcyclopentadiene. The reaction process has high yield, suppresses the generation of byproducts of methylcyclopentene and methylcyclopentane, has simple steps, is easy to recycle and reuse the catalyst, has simple post-treatment, and avoids the generation of mass production of organic waste liquid. The method is a more economic and safe route for producing methyl cyclopentadiene, does not use cyclopentadiene methylation catalyst metal sodium, has low requirements on raw materials, replaces more expensive cyclopentadiene with byproduct waste liquid, and is more suitable for industrial production.
In order to achieve the above purpose, the technical scheme adopted by the invention specifically comprises the following contents:
a method for preparing methylcyclopentadiene by using methyl pentenol Saucy-Marbet reaction byproducts comprises the following steps:
3-methyl-1-pentene-3-alcohol dehydration byproduct 3-methyl-1, 3-pentadiene and/or 2-ethyl-1, 3-butadiene are used as raw materials, and are subjected to dehydrogenation cyclization under the action of a metal oxide catalyst and an ammonium salt cocatalyst to obtain methylcyclopentadiene.
In a specific embodiment, the reacting step comprises: and (3) laying a certain amount of solvent in an autoclave reactor, adding a catalyst and a cocatalyst, placing the reaction system in a nitrogen atmosphere, continuously dripping and adding reaction raw materials, and performing dehydrocyclization reaction under certain conditions to obtain the methylcyclopentadiene.
The dehydrocyclization reaction raw material is 3-methyl-1, 3-pentadiene and/or 2-ethyl-1, 3-butadiene, and the two raw materials can be mixed in any proportion.
The metal oxide catalyst used in the dehydrocyclization reaction is one or more of silver oxide, chromium oxide, tin oxide, potassium oxide, antimonous oxide, cesium oxide or vanadium pentoxide, preferably one or more of potassium oxide, cesium oxide and vanadium pentoxide;
the catalyst is used in an amount of 0.2 to 5wt%, preferably 0.5 to 2wt%, based on the reaction raw material.
The ammonium salt cocatalyst is selected from one or more of ammonium phosphate, ammonium fluoborate, tetrabutylammonium tetrafluoroborate, tetrapropylammonium chloride and dodecyl trimethyl ammonium bromide;
the amount of the cocatalyst is 0.1 to 3wt%, preferably 0.1 to 1wt%, of the reaction raw material.
The metal oxide catalyst mainly acts on double bond carbon atoms at the tail end of conjugated diallyl carbon chain and sp on alpha, beta-unsaturated double bond 2 The activation of the carbon-hydrogen bond, thereby inducing cyclization, and reducing H under the guidance of various inorganic element atoms of ammonium salt 2 The adsorption capacity of (2) is that hydrogen is quickly dissociated to form a five-membered ring and double bonds are transferred, and C (sp 2) -H activation is the step of cyclization reaction, and the degree of activation is also dependent on substrate electron substituents to a certain extent. In addition, the resolved H 2 The catalyst is coated and modified to different degrees because the added ammonium salt auxiliary agent or solvent contains more P, B, F and other elements, so that the residual inorganic elements on the surface of the metal catalyst modulate the activity of the metal catalytic hydrogenation part but do not obviously damage other catalytic sites, thereby inhibitingThe cyclized dehydrogenation product methylcyclopentadiene is hydrogenated again, so that the selectivity of the cyclized reaction product is improved.
The solvent is at least one selected from ethylene glycol tertiary butyl ether, imidazolyl ionic liquid or fatty acid-based eutectic solvent, wherein the imidazolyl ionic liquid is preferably 1-butyl-3-methylimidazolium hexafluorophosphate and/or 1-butyl-3-methylimidazolium trifluoromethyl sulfonate, and the fatty acid-based eutectic solvent is preferably choline chloride-isobutanol system;
preferably, the mass ratio of the cyclization reaction raw material to the solvent is 1:0.5 to 3.
The dehydrocyclization reaction temperature is 20-120 ℃, preferably 40-80 ℃; the raw material feeding mode is continuous feeding, and the feeding speed is 0.2-2 g/min; the reaction time is 4 to 24 hours, preferably 4 to 8 hours.
The initial pressure of the dehydrocyclization reaction is 1-10 bar, preferably 1-4 bar.
And filtering and distilling the methyl cyclopentadiene reaction liquid obtained by dehydrocyclization to remove a catalyst and a cocatalyst to obtain a methyl cyclopentadiene crude product, and purifying the methyl cyclopentadiene crude product by a rectifying tower to obtain a methyl cyclopentadiene product with the purity of more than 99.0 percent.
The schematic diagram of the present invention is shown in the following reaction equation:
the invention has the positive effects that:
(1) According to the scheme, the methyl cyclopentadiene product with high added value can be prepared by taking the byproduct of the methyl pentenol Saucy-Marbet reaction, namely the 3-methyl-1, 3-pentadiene, the 2-ethyl-1, 3-butadiene and the mixture thereof as raw materials, the reaction steps are simple, the yield is high, and the post-treatment process is simplified.
(2) The method adopts the metal oxide as the catalyst, has high catalytic activity, is environment-friendly and high in recycling rate, avoids the use of sodium catalyst in the methylated cyclopentadiene route, reduces the safety risk of the reaction, and has more economical efficiency.
(3) The invention adopts ammonium salt as auxiliary agent to match with metal oxide catalyst, improves the reaction selectivity and inhibits the generation of byproducts of methylcyclopentene and methylcyclopentane.
Detailed Description
The present invention will be further illustrated by the following specific examples, but the present invention is not limited to the following examples.
The medicine is used:
3-methyl-1, 3-pentadiene and 2-ethyl-1, 3-butadiene: self-making;
metal oxide catalyst: komiou;
ammonium salt cocatalyst: chemical formula of Haichuan;
solvent and solvent synthesis raw materials: allatin;
the gas chromatography test conditions of the present invention are as follows:
instrument model: agilent 7890B
Chromatographic column: DB-5 (30 mX0.25 mm X0.25 μm)
Column temperature: the initial temperature is 30 ℃, the temperature is increased to 120 ℃ at 10 ℃/min, the temperature is kept for 5min, then the temperature is increased to 240 ℃ at 20 ℃/min, and the temperature is kept for 10min
Sample inlet temperature: 200 DEG C
FID detector temperature: 240 DEG C
Split sample injection, split ratio 30:1
Sample injection amount: 2.0 μm
N 2 Flow rate: 40ml/min
H 2 Flow rate: 400ml/min.
Example 1
100g of ethylene glycol t-butyl ether was added to a 500mL autoclave for solvent bottoming, 1.2g (1.0 wt% of the reaction raw material) of cesium oxide catalyst and 0.6g of ammonium phosphate (0.5 wt% of the reaction raw material) were added, uniformly mixed, and the air in the reaction system was sufficiently replaced with nitrogen, then stirring at 600rpm was started and the temperature was controlled, the reaction initiation nitrogen pressure in the system was 2bar, and the reaction temperature was 60 ℃. 120g of reaction raw materials are pumped into the reaction system at a feed rate of 1g/min, wherein the molar ratio of 3-methyl-1, 3-pentadiene to 2-ethyl-1, 3-butadiene is 4:1, the pumping is completed for about 2 hours, the heat preservation reaction is continued for 4 hours, and an air inlet valve and an air exhaust valve are controlled in the reaction process to ensure that the same air flow rate of nitrogen inlet and hydrogen exhaust is maintained. After the reaction, the conversion of the raw material was calculated to be 97.1% (wherein the conversion of 3-methyl-1, 3-pentadiene was 99.4%, the conversion of 2-ethyl-1, 3-butadiene was 87.9%) and the selectivity of the product was 98.5%. The obtained methyl cyclopentadiene reaction liquid is filtered and distilled to remove the catalyst and the auxiliary agent to obtain a methyl cyclopentadiene crude product, and the methyl cyclopentadiene crude product is purified by a rectifying tower to obtain 105.8g of methyl cyclopentadiene product with the purity of 99.2 percent.
Product passage 1 H NMR(CDCl 3 ) Confirmation: delta 6.50ppm (bimodal, 1H), delta 6.40ppm (trimodal, 1H), delta 6.18 to 6.40ppm (trimodal, 1H), delta 2.90ppm (trimodal, 2H), delta 2.21ppm (unimodal, 3H) are consistent with methylcyclopentadiene structural formulas.
Example 2
100g of choline chloride-isobutanol eutectic solvent is added into a 500mL high-pressure reaction kettle for solvent bottoming, 0.6g (0.5 wt% of the reaction raw material) of silver oxide catalyst and 0.6g of ammonium fluoborate (0.5 wt% of the reaction raw material) are added into the high-pressure reaction kettle for uniform mixing, the air in the reaction system is fully replaced by nitrogen, then 600rpm stirring and temperature control are started, the reaction initial nitrogen pressure in the system is 4bar, and the reaction temperature is 60 ℃. 120g of reaction raw materials are pumped into the reaction system at a feed rate of 0.5g/min, wherein the molar ratio of 3-methyl-1, 3-pentadiene to 2-ethyl-1, 3-butadiene is 3:2, the pumping is completed for about 4 hours, the heat preservation reaction is continued for 2 hours, and an air inlet valve and an air exhaust valve are controlled in the reaction process to ensure that the same air flow rate of nitrogen inlet and hydrogen exhaust is maintained. After the reaction, the conversion of the raw material was 93.9% (wherein the conversion of 3-methyl-1, 3-pentadiene was 96.1%, the conversion of 2-ethyl-1, 3-butadiene was 90.5%) and the selectivity of the product was 99.1%. Filtering and distilling the obtained methyl cyclopentadiene reaction liquid to remove the catalyst and the auxiliary agent to obtain a methyl cyclopentadiene crude product, and rectifying and purifying the methyl cyclopentadiene crude product to obtain 104.9g of methyl cyclopentadiene product with the purity of 99.0%.
Example 3
100g of 1-butyl-3-methylimidazole hexafluorophosphate was added to a 500mL autoclave for solvent bottoming, and 1.8g (1.5 wt% of the reaction raw material) of potassium oxide catalyst and 0.6g of tetrabutylammonium tetrafluoroborate (0.5 wt% of the reaction raw material) were put into the autoclave, and mixed uniformly, and the air in the reaction system was replaced sufficiently with nitrogen, then stirring at 600rpm and temperature control were started, the reaction initiation nitrogen pressure in the system was 2bar, and the reaction temperature was 70 ℃. 120g of reaction raw materials are pumped into the reaction system at a feed rate of 1g/min, wherein the molar ratio of 3-methyl-1, 3-pentadiene to 2-ethyl-1, 3-butadiene is 4:1, the pumping is completed for about 2 hours, the heat preservation reaction is continued for 4 hours, and an air inlet valve and an air exhaust valve are controlled in the reaction process to ensure that the same air flow rate of nitrogen inlet and hydrogen exhaust is maintained. After the reaction, the conversion of the raw material was 98.2% (wherein the conversion of 3-methyl-1, 3-pentadiene was 99.1%, the conversion of 2-ethyl-1, 3-butadiene was 94.5%) and the selectivity of the product was 99.0%. Filtering and distilling the obtained methyl cyclopentadiene reaction liquid to remove the catalyst and the auxiliary agent to obtain a methyl cyclopentadiene crude product, and rectifying and purifying the methyl cyclopentadiene crude product to obtain 111.0g of methyl cyclopentadiene product with the purity of 99.6%.
Example 4
240g of 1-butyl-3-methylimidazole trifluoromethyl sulfonate was put into a 500mL autoclave for solvent bottoming, 2.4g (2 wt% of the reaction raw material) of tin oxide catalyst and 0.6g of tetrabutylammonium tetrafluoroborate (0.5 wt% of the reaction raw material) were put into the autoclave and mixed uniformly, and the air in the reaction system was replaced sufficiently with nitrogen, then stirring at 600rpm was started and the temperature was controlled, the reaction initiation nitrogen pressure in the system was 2bar, and the reaction temperature was 60 ℃. 120g of reaction raw materials are pumped into the reaction system at a feed rate of 0.5g/min, wherein the molar ratio of 3-methyl-1, 3-pentadiene to 2-ethyl-1, 3-butadiene is 1:4, the pumping is completed for about 4 hours, the heat preservation reaction is continued for 4 hours, and an air inlet valve and an air exhaust valve are controlled in the reaction process to ensure that the same air flow rate of nitrogen inlet and hydrogen exhaust is maintained. After the reaction, the conversion of the raw material was 93.7% (wherein the conversion of 3-methyl-1, 3-pentadiene was 98.4%, the conversion of 2-ethyl-1, 3-butadiene was 92.5%) and the selectivity of the product was 98.4%. Filtering and distilling the obtained methyl cyclopentadiene reaction liquid to remove the catalyst and the auxiliary agent to obtain a methyl cyclopentadiene crude product, and rectifying and purifying the methyl cyclopentadiene crude product to obtain 107.40g of methyl cyclopentadiene product with the purity of 99.3%.
Example 5
200g of 1-butyl-3-methylimidazole hexafluorophosphate was added to a 500mL autoclave for solvent bottoming, and 1.8g (1.5 wt% of the reaction raw material) of potassium oxide catalyst and 0.3g of tetrabutylammonium tetrafluoroborate (0.25 wt% of the reaction raw material) were added to mix uniformly, and the air in the reaction system was replaced sufficiently with nitrogen, then stirring at 600rpm was started and the temperature was controlled, the reaction initiation nitrogen pressure in the system was 2bar, and the reaction temperature was 50 ℃. 120g of reaction raw materials are pumped into the reaction system at a feed rate of 0.5g/min, wherein the molar ratio of 3-methyl-1, 3-pentadiene to 2-ethyl-1, 3-butadiene is 1:4, the pumping is completed for about 4 hours, the heat preservation reaction is continued for 4 hours, and an air inlet valve and an air exhaust valve are controlled in the reaction process to ensure that the same air flow rate of nitrogen inlet and hydrogen exhaust is maintained. After the reaction, the conversion of the raw material was calculated to be 95.1% (wherein the conversion of 3-methyl-1, 3-pentadiene was 97.6%, the conversion of 2-ethyl-1, 3-butadiene was 94.5%) and the selectivity of the product was 99.4%. Filtering and distilling the obtained methyl cyclopentadiene reaction liquid to remove the catalyst and the auxiliary agent to obtain a methyl cyclopentadiene crude product, and then obtaining 108.9g of methyl cyclopentadiene product with the purity of 99.5% through a rectifying and purifying tower.
Example 6
200g of 1-butyl-3-methylimidazole trifluoromethyl sulfonate was put into a 500mL autoclave for solvent bottoming, 1.8g (1.5 wt% of the reaction raw material) of chromium oxide catalyst and 0.12g of ammonium fluoroborate (0.1 wt% of the reaction raw material) were put into the autoclave and mixed uniformly, and the air in the reaction system was replaced sufficiently with nitrogen, then stirring at 600rpm was started and the temperature was controlled, the reaction initiation nitrogen pressure in the system was 3bar, and the reaction temperature was 50 ℃. 120g of reaction raw materials are pumped into the reaction system at a feed rate of 0.5g/min, wherein the molar ratio of 3-methyl-1, 3-pentadiene to 2-ethyl-1, 3-butadiene is 3:2, the pumping is completed for about 4 hours, the heat preservation reaction is continued for 4 hours, and an air inlet valve and an air exhaust valve are controlled in the reaction process to ensure that the same air flow rate of nitrogen inlet and hydrogen exhaust is maintained. After the reaction, the conversion of the raw material was calculated to be 97.4% (wherein the conversion of 3-methyl-1, 3-pentadiene was 98.8%, the conversion of 2-ethyl-1, 3-butadiene was 95.3%) and the selectivity of the product was 97.1%. Filtering and distilling the obtained methyl cyclopentadiene reaction liquid to remove the catalyst and the auxiliary agent to obtain a methyl cyclopentadiene crude product, and then obtaining 106.4g of methyl cyclopentadiene product with the purity of 99.6% through a rectifying and purifying tower.
Comparative example 1
100g of 1-butyl-3-methylimidazole hexafluorophosphate is added into a 500mL high-pressure reaction kettle for solvent bottoming, 1.8g (1.5 wt% of the reaction raw material) of potassium oxide catalyst is added for uniform mixing, the air in the reaction system is fully replaced by nitrogen, then 600rpm stirring and temperature control are started, the initial nitrogen pressure in the system is 2bar, and the reaction temperature is 70 ℃. 120g of reaction raw materials are pumped into the reaction system at a feed rate of 1g/min, wherein the molar ratio of 3-methyl-1, 3-pentadiene to 2-ethyl-1, 3-butadiene is 4:1, the pumping is completed for about 2 hours, the heat preservation reaction is continued for 4 hours, and an air inlet valve and an air exhaust valve are controlled in the reaction process to ensure that the same air flow rate of nitrogen inlet and hydrogen exhaust is maintained. After the reaction, the conversion of the raw material was 73.0% (wherein the conversion of 3-methyl-1, 3-pentadiene was 75.1%, the conversion of 2-ethyl-1, 3-butadiene was 64.5%) and the selectivity of the product was 93.5%.
Claims (13)
1. A method for preparing methylcyclopentadiene is characterized in that 3-methyl-1, 3-pentadiene and/or 2-ethyl-1, 3-butadiene are used as raw materials, and dehydrocyclization is catalyzed under the action of a metal oxide catalyst and an ammonium salt cocatalyst to obtain methylcyclopentadiene; wherein the metal oxide catalyst is one or more of silver oxide, chromium oxide, tin oxide, potassium oxide, antimonous oxide, cesium oxide or vanadium pentoxide, and the cocatalyst is one or more of ammonium phosphate, ammonium fluoroborate, tetrabutylammonium tetrafluoroborate, tetrapropylammonium chloride and dodecyl trimethyl ammonium bromide.
2. The method according to claim 1, wherein the catalyst is used in an amount of 0.2 to 5wt% of the raw material.
3. The method according to claim 2, wherein the catalyst is used in an amount of 0.5-2 wt% of the raw material.
4. The method according to claim 1, wherein the cocatalyst is used in an amount of 0.1 to 3wt% of the raw material.
5. The method according to claim 4, wherein the cocatalyst is used in an amount of 0.1 to 1wt% of the raw material.
6. The method according to any one of claims 1 to 5, wherein a solvent is further used, and the solvent is at least one selected from ethylene glycol tertiary butyl ether, an imidazolyl ionic liquid, and a fatty acid based eutectic solvent.
7. The method according to claim 6, wherein the imidazolyl ionic liquid is selected from 1-butyl-3-methylimidazolium phosphate and/or 1-butyl-3-methylimidazolium triflate, and the fatty acid based eutectic solvent is a choline chloride-isobutanol system.
8. The method according to claim 6, wherein the mass ratio of the cyclization reaction raw material to the solvent is 1:0.5 to 3.
9. The method according to any one of claims 1 to 5, wherein the dehydrocyclization reaction temperature is 20 to 120 ℃ and the reaction time is 4 to 24 hours.
10. The method according to claim 9, wherein the dehydrocyclization reaction temperature is 40-80 ℃ and the reaction time is 4-8 hours.
11. The method according to any one of claims 1 to 5, wherein the reaction is carried out in a nitrogen atmosphere at an initial pressure of 1 to 10bar.
12. The method according to claim 11, wherein the reaction is carried out in a nitrogen atmosphere at an initial pressure of 1 to 4bar.
13. The method according to any one of claims 1 to 5, wherein the methylcyclopentadiene reaction liquid obtained by dehydrocyclization is filtered and distilled to remove a catalyst and a cocatalyst to obtain a methylcyclopentadiene crude product, and then the methylcyclopentadiene crude product is rectified and purified to obtain a methylcyclopentadiene product with a purity of more than 99.0%.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US3004081A (en) * | 1959-05-29 | 1961-10-10 | Cities Service Res & Dev Co | Cycloolefin production |
| US5543480A (en) * | 1994-06-28 | 1996-08-06 | The Dow Chemical Company | Polymerization process using diene containing catalysts |
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| EP1910431B1 (en) * | 2005-07-19 | 2013-11-27 | ExxonMobil Chemical Patents Inc. | Polyalpha-olefin compositions and processes to produce the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3004081A (en) * | 1959-05-29 | 1961-10-10 | Cities Service Res & Dev Co | Cycloolefin production |
| US5543480A (en) * | 1994-06-28 | 1996-08-06 | The Dow Chemical Company | Polymerization process using diene containing catalysts |
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