CN112723978A - Preparation process of tetramethylcyclopentadiene - Google Patents

Preparation process of tetramethylcyclopentadiene Download PDF

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CN112723978A
CN112723978A CN202011582056.4A CN202011582056A CN112723978A CN 112723978 A CN112723978 A CN 112723978A CN 202011582056 A CN202011582056 A CN 202011582056A CN 112723978 A CN112723978 A CN 112723978A
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solution
nabh
reaction
alcohol
mixed solution
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杨倩
刘军
曹堃
郝福兰
栾波
任学斌
刘振学
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Shandong Jingbo Zhongju New Materials Co ltd
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Shandong Jingbo Zhongju New Materials Co ltd
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
    • C07C1/20—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only oxygen atoms as heteroatoms
    • C07C1/24—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only oxygen atoms as heteroatoms by elimination of water
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/132—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group
    • C07C29/136—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH
    • C07C29/143—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of ketones
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2601/00—Systems containing only non-condensed rings
    • C07C2601/06—Systems containing only non-condensed rings with a five-membered ring
    • C07C2601/10—Systems containing only non-condensed rings with a five-membered ring the ring being unsaturated

Abstract

The invention provides a preparation process of tetramethylcyclopentadiene, which comprises the following steps: A) uniformly mixing tetramethylcyclopentenone, alcohol and a catalyst to obtain a mixed solution; B) reacting NaBH4Dropwise adding the solution into the mixed solution, and carrying out reduction reaction to obtain a reaction mixed solution; the NaBH4The solution comprises NaBH4Alcohol, NaOH and water; C) adding water into the reaction mixed solution, and extracting organic matters in the reaction mixed solution by using an extracting agent; D) adding sulfuric acid into the organic matter obtained by extraction in the step C), and dehydrating to obtain the tetramethylcyclopentadiene. According to the reaction system, the conditions such as a catalyst, a solvent, reaction temperature, reaction time and the like are adjusted, so that sodium borohydride reduces tetramethylcyclopentenone into tetramethylcyclopentenol under mild conditions, and tetramethylcyclopentene can be prepared after dehydration.

Description

Preparation process of tetramethylcyclopentadiene
Technical Field
The invention belongs to the technical field of organic matter synthesis, and particularly relates to a preparation process of tetramethylcyclopentadiene.
Background
Tetramethylcyclopentadien is an important chemical intermediate, is an important raw material for organic synthesis, and is commonly used for synthesizing metal organic compounds, medicines and pesticide intermediates. The reduction of ketone and its derivative with hydrogen, borane, metal complex hydride, etc. is an important means for preparing alcohol, and the alcohol can be dehydrated to obtain corresponding olefin compound.
In the commonly used metal complex hydrides, lithium aluminum hydride has strong reducing capability to ketone and derivatives thereof, but when the lithium aluminum hydride is heated or contacts with moisture, water, alcohol and acid, an exothermic reaction occurs and hydrogen is released to burn or explode, the reaction is not easy to operate, the post-treatment is troublesome, the price is high, and the lithium aluminum hydride is not beneficial to large-scale production. The sodium borohydride has mild reaction conditions, easy operation and low price, but the reduction capability of the sodium borohydride is relatively weak, so that the product yield is low.
Disclosure of Invention
The invention aims to provide a preparation process of tetramethylcyclopentadiene, which has the advantages of simple, safe and efficient operation process, no requirement on anhydrous condition and high product yield.
The invention provides a preparation process of tetramethylcyclopentadiene, which comprises the following steps:
A) uniformly mixing tetramethylcyclopentenone, alcohol and a catalyst to obtain a mixed solution;
B) reacting NaBH4Dropwise adding the solution into the mixed solution, and carrying out reduction reaction to obtain a reaction mixed solution;
the NaBH4The solution comprises NaBH4Alcohol, NaOH and water; the NaBH4The pH value of the solution is 7-14;
C) adding water into the reaction mixed solution, and extracting organic matters in the reaction mixed solution by using an extracting agent;
D) adding sulfuric acid into the organic matter obtained by extraction in the step C), and dehydrating to obtain the tetramethylcyclopentadiene.
Preferably, the catalyst is one or more of calcium chloride, zinc chloride, magnesium chloride, manganese chloride and lithium bromide;
the molar ratio of the catalyst to the tetramethylcyclopentenone is (0.5-5): 1.
Preferably, the NaBH4The molar ratio of the compound to the tetramethylcyclopentenone is (1.2-3) to 1.
Preferably, the NaBH4In solution, NaBH4The molar ratio of alcohol to NaOH is (0.1-8): (0.25-1): 0.1-1).
Preferably, the temperature of the reduction reaction is 20-80 ℃; the time of the reduction reaction is 1-24 hours.
Preferably, the alcohol in the step A) is aliphatic alcohol and/or aromatic alcohol;
the alcohol in the step B) is aliphatic alcohol and/or aromatic alcohol.
Preferably, the water added in step C) is mixed with NaBH4The molar ratio of (1) to (7-19): 1.
preferably, the mass concentration of the sulfuric acid is 30-50%;
the molar ratio of the tetramethylcyclopentenone to the sulfuric acid is 1 (1.4-2.3).
Preferably, the dehydration temperature is 15-60 ℃; the dehydration time is 20-90 min.
Preferably, after the dehydration reaction, the organic layer in the reaction solution is separated and saturated K is used2CO3Washing the solution, combining the washed water phases, extracting, combining with the organic phase, and removing the solvent by reduced pressure distillation to obtain the tetramethylcyclopentadiene product.
The invention provides a preparation process of tetramethylcyclopentadiene, which comprises the following steps: A) uniformly mixing tetramethylcyclopentenone, alcohol and a catalyst to obtain a mixed solution; B) reacting NaBH4Dropwise adding the solution into the mixed solution, and carrying out reduction reaction to obtain a reaction mixed solution; the NaBH4The solution comprises NaBH4Alcohol, NaOH and water; the NaBH4The pH value of the solution is 7-14; C) adding water into the reaction mixed solution, and extracting the reaction mixed solution by using an extracting agentReacting organic matters in the mixed solution; D) adding sulfuric acid into the organic matter obtained by extraction in the step C), and dehydrating to obtain the tetramethylcyclopentadiene. According to the reaction system, the conditions such as a catalyst, a solvent, reaction temperature, reaction time and the like are adjusted, so that sodium borohydride reduces tetramethylcyclopentenone into tetramethylcyclopentenol under mild conditions, and tetramethylcyclopentene can be prepared after dehydration; meanwhile, the catalytic activity and selectivity can be improved by adding metal salt, and a better 1, 2-reduction product is obtained. The process adopts sodium borohydride to replace lithium aluminum hydride, has simple, safe and efficient operation process, does not require anhydrous condition, and has wide application prospect. Experimental results show that the yield of the tetramethylcyclopentadiene in the preparation process is 43-56%.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a GC-MS total ion flow diagram of tetramethylcyclopentenol in example 1;
FIG. 2 is a GC-MS total ion flow diagram of tetramethylcyclopentylketone in comparative example 1;
FIG. 3 is a GC-MS total ion flow diagram of tetramethylcyclopentediene in example 1.
Detailed Description
The invention provides a preparation process of tetramethylcyclopentadiene, which comprises the following steps:
A) uniformly mixing tetramethylcyclopentenone, alcohol and a catalyst to obtain a mixed solution;
B) reacting NaBH4Dropwise adding the solution into the mixed solution, and carrying out reduction reaction to obtain a reaction mixed solution;
the NaBH4The solution comprises NaBH4Alcohol, NaOH and water; the NaBH4The pH value of the solution is 7-14;
C) adding water into the reaction mixed solution, and extracting organic matters in the reaction mixed solution by using an extracting agent;
D) adding sulfuric acid into the organic matter obtained by extraction in the step C), and dehydrating to obtain the tetramethylcyclopentadiene.
According to the invention, tetramethylcyclopentenone, alcohol and a catalyst are respectively added into a reaction device, and are stirred and dissolved under normal pressure to obtain a mixed solution.
In the invention, the alcohol is preferably aliphatic alcohol and/or aromatic alcohol, and more preferably one or more of methanol, ethanol and isopropanol; the catalyst is preferably one or more of Lewis acid, carboxylic acid, iodine and alkaline earth metal chloride, and more preferably one or more of calcium chloride, zinc chloride, magnesium chloride, manganese chloride and lithium bromide.
In the invention, the molar ratio of the catalyst to the tetramethylcyclopentenone is preferably (0.5-5): 1, more preferably (1-4): 1, most preferably (1.5-3.5): 1, and specifically, in the embodiment of the invention, the molar ratio can be 3:1, 2:1 or 1.5: 1; the molar ratio of the first alcohol to tetramethylcyclopentenone is preferably (13-30): 1, and more preferably (15-25): 1.
The invention uses NaBH4Adding alcohol into NaOH aqueous solution to prepare NaBH4Solution, direct addition of solid NaBH4The reaction is violent, a large amount of gas is generated, and the experiment is difficult to control and has high danger; the invention uses NaBH4Dissolving in an alkaline alcoholic solution, NaBH4Does not decompose in an alkaline alcohol solution, has good solubility, and is easier to control the reaction by dripping the solution. The reaction and yield are not greatly affected. The alcohol is preferably aliphatic alcohol and/or aromatic alcohol, and more preferably one or more of methanol, ethanol and isopropanol;
the NaBH4In solution, NaBH4The molar ratio of alcohol to NaOH is preferably (0.1-8): (0.25-1): (0.1-1), more preferably (1-7): (0.5-0.8): 0.2-0.8), most preferably (3-5): 0.6-0.7): (0.5-0.6).
The NaBH4In the solution, the solution is added with a solvent,NaBH4the concentration of (b) is preferably 1 to 20mol/L, more preferably 4 to 15mol/L, most preferably 5 to 10mol/L, and specifically, in the embodiment of the present invention, it may be 6.67mol/L, 0.4mol/L, 5mol/L, 13.3mol/L or 10 mol/L.
The NaBH4The pH value of the solution is preferably 7-14, more preferably 8-13, and most preferably 9-12. The NaBH4The molar ratio of tetramethylcyclopentenone to tetramethylcyclopentenone is preferably (1.2-3): 1, more preferably (1.5-2.5): 1, and specifically, may be 2:1, 1.2:1 or 1.5:1 in the embodiment of the present invention.
In the present invention, the alcohol in the step A) and the alcohol in the step B) may be the same or different.
Preparing to obtain NaBH4After the solution, the present invention is preferably placed in an ice bath environment for use, as is the case with NaBH in the present invention4The preparation of the solution and the preparation of the mixed solution in the step A) are not in sequence.
Then, the invention gradually adds NaBH into the mixed solution4And after the solution is dropwise added, carrying out reduction reaction under the stirring condition to obtain a reaction solution containing the tetramethylcyclopentenol.
In the present invention, the NaBH4The dropping speed of the solution is preferably 1-2 mL/min, the temperature of the reduction reaction is preferably 20-80 ℃, more preferably 25-75 ℃, most preferably 30-70 ℃, most preferably 35-65 ℃, and specifically, in the embodiment of the invention, the temperature can be 60 ℃, 50 ℃ or 70 ℃; the time of the reduction reaction is preferably 1 to 24 hours, more preferably 4 to 20 hours, and most preferably 6 to 18 hours, and specifically, in an embodiment of the present invention, the time may be 4 hours or 6 hours.
After the reduction reaction is finished, a certain amount of deionized water is added into the reaction solution containing the tetramethylcyclopentenol obtained by the reaction, an extracting agent such as normal hexane or diethyl ether is used for extracting the organic tetramethylcyclopentenol in the reaction solution, and the organic tetramethylcyclopentenol is separated from the water phase.
Adding sulfuric acid into the separated organic phase, and performing dehydration reaction at a certain temperature to obtain a dehydration product.
In the invention, the deionized water and NaBH4The molar ratio of (a) to (b) is preferably (7-19): 1, in the present invention, the deionized water serves to decompose unreacted NaBH4In the invention, the added water is completely excessive until no bubbles are generated; the concentration of the sulfuric acid is preferably 30-50%, more preferably 35-45%, and specifically, in the embodiment of the present invention, the concentration may be 40% or 45%; the molar ratio of the tetramethylcyclopentenone to the sulfuric acid is preferably 1 (1.4-2.3), more preferably 1 (1.5-2.2), and most preferably 1: (1.6-2.0).
In the present invention, the temperature of the dehydration reaction is preferably 15 to 60 ℃, more preferably 20 to 55 ℃, and most preferably 25 to 50 ℃, specifically, in the embodiment of the present invention, 50 ℃, 35 ℃, 45 ℃ or 55 ℃.
The method comprises the steps of separating out organic phases in reaction liquid obtained after dehydration reaction, washing the organic phases by using a saturated potassium carbonate solution, combining washed water phases, extracting the combined water phases by using n-hexane or diethyl ether, combining extracts with the organic phases, then carrying out reduced pressure distillation to remove a solvent, and then carrying out rectification to obtain the tetramethylcyclopentadiene.
In the invention, the temperature of the reduced pressure distillation is 20-40 ℃, and the pressure is 0.098 MPa; the time of reduced pressure distillation is preferably 50-90 min; the rectification temperature is preferably 70-90 ℃; the rectification pressure is preferably 0.098 MPa; the rectification time is preferably 30-60 min.
The invention provides a preparation process of tetramethylcyclopentadiene, which comprises the following steps: A) uniformly mixing tetramethylcyclopentenone, first alcohol and a catalyst to obtain a mixed solution; B) reacting NaBH4Dropwise adding the solution into the mixed solution, and carrying out reduction reaction to obtain a reaction mixed solution; the NaBH4The solution comprises NaBH4A second alcohol, NaOH and water; the NaBH4The pH value of the solution is 7-14; C) adding water into the reaction mixed solution, and extracting organic matters in the reaction mixed solution by using an extracting agent; D) adding sulfuric acid into the organic matter obtained by extraction in the step C), and dehydrating to obtain tetramethylcyclopentediAn alkene. According to the reaction system, the conditions such as a catalyst, a solvent, reaction temperature, reaction time and the like are adjusted, so that sodium borohydride reduces tetramethylcyclopentenone into tetramethylcyclopentenol under mild conditions, and tetramethylcyclopentene can be prepared after dehydration; meanwhile, the catalytic activity and selectivity can be improved by adding metal salt, and a better 1, 2-reduction product is obtained. The process adopts sodium borohydride to replace lithium aluminum hydride, has simple, safe and efficient operation process, does not require anhydrous condition, and has wide application prospect. Experimental results show that the yield of the tetramethylcyclopentadiene in the preparation process is 43-56%.
In order to further illustrate the present invention, the following examples are provided to describe the preparation process of tetramethylcyclopentadiene in detail, but should not be construed as limiting the scope of the present invention.
Example 1
Adding CaCl2(33.30g/0.3mol), tetramethylcyclopentenone (13.82g/0.1mol) and methanol (100ml) were respectively added to a reaction flask equipped with a reflux condenser, and dissolved by stirring under normal pressure; reacting NaBH4(7.56g/0.2mol) in a solution prepared from 15ml of methanol and an aqueous solution of 2% NaOH15ml, and gradually dropwise adding NaBH into the reaction system under the ice-bath condition4The solution is dropwise added for 30min, after dropwise addition is finished, the solution is continuously stirred and reacts for 4h at the temperature of 60 ℃, sampling is carried out for GC-MS detection (shown in figure 1), tetramethylcyclopentenone basically completely reacts, no other by-products are generated, and the metal chloride has a good double-bond protection effect;
after the reaction is finished, adding 50ml of deionized water into the system for decomposition, extracting an organic phase with 25ml of n-hexane for three times, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, collecting all organic phases to obtain tetramethylcyclopentenol, and sampling for GC-MS detection (see figure 2);
50ml of 45% H were added to the organic phase2SO4Stirring at 50 deg.C for 30min, pouring the mixture into separating funnel, and mixing the organic phase with 20ml saturated K2CO3Washing with the solution for three times, combining the washed water phases and usingExtracting with 25ml n-hexane, and combining all organic phases; vacuum distilling to remove n-hexane, rectifying to obtain tetramethylcyclopentadiene, sampling, and GC-MS detecting (see figure 3), wherein the yield is 55.3%, and the GC content is 98.9%.
Example 2
Adding CaCl2Respectively adding (22.20g/0.2mol), tetramethylcyclopentenone (13.82g/0.1mol) and isopropanol (100ml) into a reaction bottle provided with a reflux condensing device, and stirring under normal pressure to dissolve; reacting NaBH4(4.54g/0.12mol) in a solution prepared by 15ml of isopropanol and an aqueous solution of 1 percent NaOH15ml, and gradually dropwise adding NaBH into the reaction system under the ice-bath condition4The solution is dripped for 30min, and after the dripping is finished, the solution is continuously stirred and reacts for 4h at the temperature of 70 ℃;
after the reaction is finished, adding 40ml of deionized water into the system for decomposition, extracting the organic phase by using 25ml of n-hexane for three times, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, and collecting all organic phases to obtain tetramethyl cyclopentenol;
50ml of 40% H were added to the organic phase2SO4Stirring at 50 deg.C for 30min, pouring the mixture into separating funnel, and saturating the organic phase with 25ml of saturated K2CO3Washing the solution for three times, combining the washed water phases, extracting by using 25ml of n-hexane, and combining all organic phases; vacuum distilling to remove n-hexane, and rectifying to obtain tetramethylcyclopentadiene with yield of 49.5% and GC content of 97.6%.
Example 3
Reacting ZnCl2Respectively adding (20.44g/0.15mol), tetramethylcyclopentenone (13.85g/0.1mol) and ethanol (100ml) into a reaction flask equipped with a reflux condensing device, and stirring under normal pressure to dissolve; reacting NaBH4(5.67g/0.15mol) is dissolved in a solution prepared by 15ml of ethanol and 15ml of aqueous solution of 1 percent NaOH, and NaBH is gradually dripped into the reaction system under the ice bath condition4The solution is dripped for 30min, and after the dripping is finished, the solution is continuously stirred and reacts for 6h at the temperature of 50 ℃;
adding 50ml of deionized water into the system for decomposition after the reaction is finished, extracting an organic phase by using 25ml of normal hexane for three times, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, and collecting all organic phases to obtain tetramethylcyclopentenol;
50ml of 40% H were added to the organic phase2SO4Stirring at 45 deg.C for 30min, pouring the mixture into separating funnel, and saturating the organic phase with 25ml of saturated K2CO3Washing the solution for three times, combining the washed water phases, extracting by using 25ml of n-hexane, and combining all organic phases; vacuum distilling to remove n-hexane, and rectifying to obtain tetramethylcyclopentadiene with yield of 50.8% and GC content of 98.3%.
Example 4
Mixing MgCl2Respectively adding (38.08g/0.4mol), tetramethylcyclopentenone (27.64g/0.2mol) and ethanol (150ml) into a reaction bottle provided with a reflux condensing device, and stirring under normal pressure to dissolve; reacting NaBH4(15.13g/0.4mol) is dissolved in a solution prepared by 25ml of ethanol and 25ml of 2 percent NaOH aqueous solution, and NaBH is gradually dripped into the reaction system under the ice bath condition4Dropwise adding the solution for 50min, and continuously stirring and reacting at 60 ℃ for 4h after dropwise adding;
adding 50ml of deionized water into the system for decomposition after the reaction is finished, extracting the organic phase for three times by using 40ml of normal hexane, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, and collecting all the organic phases to obtain tetramethylcyclopentenol;
60ml of 45% H were added to the organic phase2SO4Stirring at 55 deg.C for 30min, pouring the mixture into separating funnel, and saturating the organic phase with 30ml of saturated K2CO3Washing the solution for three times, combining the washed water phases, extracting by using 30ml of n-hexane, and combining all organic phases; vacuum distilling to remove n-hexane, and rectifying to obtain tetramethylcyclopentadiene with yield of 43.0% and GC content of 98.9%.
Example 5
Mixing MnCl2Respectively adding (32.37g/0.2mol), tetramethylcyclopentenone (13.82g/0.1mol) and methanol (100ml) into a reaction bottle provided with a reflux condensing device, and stirring at normal pressure to dissolve; reacting NaBH4(11.34g/0.3mol) was dissolved in 20ml of methanol and 2% NaOIn a solution prepared by H20 ml of aqueous solution, gradually dripping NaBH into a reaction system under the ice bath condition4The solution is added for 40min, and after the solution is added, the solution is continuously stirred and reacts for 5h at the temperature of 60 ℃;
adding 50ml of deionized water into the system for decomposition after the reaction is finished, extracting the organic phase for three times by using 30ml of normal hexane, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, and collecting all the organic phases to obtain tetramethylcyclopentenol;
50ml of 45% H were added to the organic phase2SO4Stirring at 50 deg.C for 30min, pouring the mixture into separating funnel, and mixing the organic phase with 20ml saturated K2CO3Washing the solution for three times, combining the washed water phases, extracting by using 25ml of n-hexane, and combining all organic phases; vacuum distilling to remove n-hexane, and rectifying to obtain tetramethylcyclopentadiene with yield of 48.0% and GC content of 97.5%.
Example 6
Respectively adding LiBr (17.37g/0.2mol), tetramethylcyclopentenone (13.82g/0.1mol) and ethanol (100ml) into a reaction bottle provided with a reflux condensing device, and stirring at normal pressure to dissolve the LiBr; reacting NaBH4(7.56g/0.2mol) is dissolved in a solution prepared by 15ml of ethanol and 15ml of 2 percent NaOH aqueous solution, and NaBH is gradually dripped into the reaction system under the ice bath condition4The solution is dripped for 30min, and after the dripping is finished, the solution is continuously stirred and reacts for 4h at the temperature of 60 ℃;
adding 50ml of deionized water into the system for decomposition after the reaction is finished, extracting an organic phase by using 25ml of normal hexane for three times, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, and collecting all organic phases to obtain tetramethylcyclopentenol;
50ml of 45% H were added to the organic phase2SO4Stirring at 50 deg.C for 40min, pouring the mixture into separating funnel, and saturating the organic phase with 25ml of K2CO3Washing the solution for three times, combining the washed water phases, extracting by using 30ml of n-hexane, and combining all organic phases; vacuum distilling to remove n-hexane, and rectifying to obtain tetramethylcyclopentadiene with yield of 38.5% and GC content of 96.3%。
Comparative example 1
Adding tetramethylcyclopentenone (6.92g/0.05mol) and methanol (30ml) into a reaction bottle provided with a reflux condensing device respectively, and stirring fully to mix the materials uniformly; reacting NaBH4(1.88g/0.05mol) in a solution prepared from 5ml methanol and 1% NaOH5ml, gradually adding NaBH dropwise into the reaction system under ice bath condition4The solution is added for 10min, after the addition is finished, the solution is continuously stirred and reacts for 24h at the temperature of 30 ℃, the sample is taken for GC-MS detection (shown in figure 2), and the tetramethylcyclopentenone does not completely react, which indicates that NaBH is not completely reacted4The addition amount is insufficient, and tetramethylcyclopentanol is generated, which indicates that NaBH is not enough4Simultaneously reducing the double bond of the ketene;
after the reaction is finished, adding 10ml of deionized water into the system for decomposition, extracting the organic phase with 20ml of ether for three times, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, and collecting all the organic phases to obtain tetramethyl cyclopentenol;
30ml of 33% H were added to the organic phase2SO4Stirring at 25 deg.C for 20min, pouring the mixture into separating funnel, and saturating the organic phase with 20ml of K2CO3The solution is washed for three times, the washed water phases are combined and extracted by 20ml of ether, and all the organic phases are combined; after ether is removed by vacuum distillation, the tetramethylcyclopentadiene is obtained by rectification, the yield is 20.5 percent, and the GC content is 96.3 percent.
Comparative example 2
Adding CaCl2Respectively adding (5.55g/0.05mol), tetramethylcyclopentenone (13.83g/0.1mol) and methanol (60ml) into a reaction bottle provided with a reflux condensing device, stirring at normal pressure to dissolve and uniformly mix; reacting NaBH4(3.78g/0.1mol) in a solution prepared from 10ml of methanol and 2 percent of NaOH10ml aqueous solution, and gradually dropwise adding NaBH into the reaction system under the ice-bath condition4The solution is added for 20min, and after the addition is finished, the solution is continuously stirred and reacts for 24h at the temperature of 30 ℃;
after the reaction is finished, adding 30ml of deionized water into the system for decomposition, extracting the organic phase by using 25ml of n-hexane for three times, pouring the mixed solution into a separating funnel, oscillating, standing for layering, separating, and collecting all organic phases to obtain tetramethylcyclopentenol;
50ml of 45% H were added to the organic phase2SO4Stirring at 35 deg.C for 30min, pouring the mixture into separating funnel, and mixing the organic phase with 20ml saturated K2CO3Washing the solution for three times, combining the washed water phases, extracting by using 20ml of n-hexane, and combining all organic phases; vacuum distilling to remove n-hexane, and rectifying to obtain tetramethylcyclopentadiene with yield of 32.7% and GC content of 97.8%.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (10)

1. A preparation process of tetramethylcyclopentadiene comprises the following steps:
A) uniformly mixing tetramethylcyclopentenone, alcohol and a catalyst to obtain a mixed solution;
B) reacting NaBH4Dropwise adding the solution into the mixed solution, and carrying out reduction reaction to obtain a reaction mixed solution;
the NaBH4The solution comprises NaBH4Alcohol, NaOH and water; the NaBH4The pH value of the solution is 7-14;
C) adding water into the reaction mixed solution, and extracting organic matters in the reaction mixed solution by using an extracting agent;
D) adding sulfuric acid into the organic matter obtained by extraction in the step C), and dehydrating to obtain the tetramethylcyclopentadiene.
2. The preparation process according to claim 1, wherein the catalyst is one or more of calcium chloride, zinc chloride, magnesium chloride, manganese chloride and lithium bromide;
the molar ratio of the catalyst to the tetramethylcyclopentenone is (0.5-5): 1.
3. The process of claim 1, wherein the NaBH is prepared by4The molar ratio of the compound to the tetramethylcyclopentenone is (1.2-3) to 1.
4. The process of claim 1, wherein the NaBH is prepared by4In solution, NaBH4The molar ratio of alcohol to NaOH is (0.1-8): (0.25-1): 0.1-1).
5. The preparation process according to claim 1, wherein the temperature of the reduction reaction is 20 to 80 ℃; the time of the reduction reaction is 1-24 hours.
6. The process according to claim 1, wherein the alcohol in step a) is an aliphatic alcohol and/or an aromatic alcohol;
the alcohol in the step B) is aliphatic alcohol and/or aromatic alcohol.
7. The process of claim 1, wherein the water added in step C) is mixed with NaBH4The molar ratio of (1) to (7-19): 1.
8. the preparation process according to claim 1, wherein the mass concentration of the sulfuric acid is 30-50%;
the molar ratio of the tetramethylcyclopentenone to the sulfuric acid is 1 (1.4-2.3).
9. The preparation process according to claim 1, wherein the dehydration temperature is 15-60 ℃; the dehydration time is 20-90 min.
10. The production process according to any one of claims 1 to 9, wherein after the dehydration reaction, an organic layer in the reaction solution is separated and saturated K is used2CO3Washing with the solution, combining the washed aqueous phases, extracting, and combining with the organic phaseAnd distilling under reduced pressure to remove the solvent to obtain the tetramethylcyclopentadiene product.
CN202011582056.4A 2020-12-28 2020-12-28 Preparation process of tetramethylcyclopentadiene Pending CN112723978A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000041987A1 (en) * 1999-01-12 2000-07-20 Basell Polypropylen Gmbh Method for producing substituted cyclopentadienes
CN1597647A (en) * 2003-09-19 2005-03-23 中国石油天然气股份有限公司 Preparation technology of cyclopentadiene or substituted cyclo pentadiene
CN1673205A (en) * 2004-03-24 2005-09-28 中国石油天然气股份有限公司 Synthesis of cyclopentadiene or substituted cyclopentadiene
KR20100121332A (en) * 2009-05-08 2010-11-17 주식회사 엘지화학 Method for production of cyclopentadiene derivatives and composition for preparing cyclopentadiene derivatives

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000041987A1 (en) * 1999-01-12 2000-07-20 Basell Polypropylen Gmbh Method for producing substituted cyclopentadienes
CN1597647A (en) * 2003-09-19 2005-03-23 中国石油天然气股份有限公司 Preparation technology of cyclopentadiene or substituted cyclo pentadiene
CN1673205A (en) * 2004-03-24 2005-09-28 中国石油天然气股份有限公司 Synthesis of cyclopentadiene or substituted cyclopentadiene
KR20100121332A (en) * 2009-05-08 2010-11-17 주식회사 엘지화학 Method for production of cyclopentadiene derivatives and composition for preparing cyclopentadiene derivatives

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
CAROL M. FENDRICK ET AL.: "Manipulation of Organoactinide Coordinativo Unsaturation. Synthesis, Structures, and Reactivity of Thorium Hydrocarbyls and Hydrides with Chelating Bis(tetramethylcyclopentadienyl) Ancillary Ligands", 《ORGANOMETALLICS》 *
DIPAK KALITA ET AL.: "Synthesis and electrochemical properties of slipped-cofacial porphyrin dimers of ferrocene-functionalized Zn-imidazolyl-porphyrins as potential terminal electron donors in photosynthetic models", 《NEW JOURNAL OF CHEMISTRY》 *
罗代暄: "《化学试剂与精细化学品合成基础》", 31 May 1991, 高等教育出版社 *

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