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CN-122010684-A - Method for synthesizing methyl butenol through heterogeneous hydrogenation reaction

CN122010684ACN 122010684 ACN122010684 ACN 122010684ACN-122010684-A

Abstract

The invention provides a method for synthesizing methylbutylenol by heterogeneous hydrogenation reaction, which comprises the step of preparing methylbutylenol by catalyzing the hydrogenation of methylbutylenol by using a heterogeneous catalyst prepared by a dinitrogen ligand and a cobalt metal precursor. The method solves the problem of low catalyst activity caused by byproducts of the hydrogenation reaction of the methyl butynol, realizes the cyclic application time of the catalyst to be more than 100 times, has the advantages of relatively mild reaction conditions, simple operation, low cost of the cheap cobalt catalyst and high selectivity.

Inventors

  • DU HONGQUAN
  • SUN QIKUI

Assignees

  • 万华化学集团股份有限公司

Dates

Publication Date
20260512
Application Date
20260120

Claims (10)

  1. 1. A method for synthesizing methylbutinol by heterogeneous hydrogenation reaction is characterized in that a heterogeneous catalyst prepared from a dinitrogen ligand and a cobalt metal precursor is used for catalyzing the hydrogenation reaction of methylbutinol to prepare methylbutinol.
  2. 2. The method of claim 1, wherein the dinitrogen ligand has a structure represented by formula L: wherein the R group is cycloalkyl or substituted cycloalkyl with 4-12 carbon atoms, and the R1 group is methyl or ethyl.
  3. 3. The method according to claim 1, wherein the cobalt metal precursor is a cobalt salt selected from any one of CoCl2, co (acac) 2 and CoBr2, preferably CoCl2.
  4. 4. A process according to any one of claims 1 to 3, wherein the heterogeneous catalyst is prepared by adding the cobalt metal precursor to a tetrahydrofuran solution containing the dinitrogen ligand under nitrogen protection, stirring and mixing, adding a molecular sieve, stirring and reacting, removing the solvent under reduced pressure after the reaction is finished, and vacuum drying.
  5. 5. A process according to claim 4, wherein the molar ratio of the dinitrogen ligand to the cobalt metal precursor is 1-2, preferably 1.1-1.3, and/or The temperature of stirring and mixing is 60-150 ℃, preferably 90-120 ℃, and the stirring time is 6-24 hours, preferably 18-24 hours; Preferably, the molecular sieve is selected from at least one of MSN-48, MSN-50, MSN-41 and ZSM-5, preferably molecular sieve MSN-48 added with 6-10 times of ligand mass, and/or Stirring at 60-120deg.C for 2-12 hr, preferably at 80-100deg.C for 6-8 hr, and/or The vacuum drying temperature is 60-120 ℃, the time is 12-36 hours, and the preferable condition is that the vacuum drying is carried out for 20-30 hours at 90-100 ℃.
  6. 6. The process according to claim 1, characterized in that the heterogeneous catalyst is used in an amount of 0.001-0.08wt%, preferably 0.01-0.05wt% of methylbutinol.
  7. 7. The process according to claim 1 or 6, characterized in that the hydrogenation reaction is carried out in a solvent, preferably selected from one or more of dichloromethane, 1, 2-dichloroethane, dioxane, tetrahydrofuran, diethyl ether, ethylene glycol dimethyl ether, methyl tert-butyl ether, toluene, xylene, n-hexane, ethanol.
  8. 8. The process according to claim 7, wherein the hydrogenation reaction is carried out at a reaction temperature of 40-80 ℃, preferably 50-60 ℃, and a reaction time of 1-12 hours, preferably 4-6 hours.
  9. 9. The process according to claim 8, wherein the hydrogen pressure of the hydrogenation reaction is 0.8-10MPa, preferably 4-6MPa.
  10. 10. The process of any one of claims 1 to 9, wherein the hydrogenation catalyst is applicable more than 100 times with a reaction conversion of >99% and a selectivity of >99%.

Description

Method for synthesizing methyl butenol through heterogeneous hydrogenation reaction Technical Field The invention relates to the field of organic synthesis, in particular to a method for preparing methylbutylenol by catalyzing the hydrogenation of methylbutylenol by using a heterogeneous catalyst prepared from a dinitrogen ligand and a cobalt metal precursor. Background The methyl butenol is mainly used for producing isophytol (VE main intermediate), DV chrysanthemic acid (chrysanthemate intermediate), synthetic vitamin A, vitamin K1, carotenoid intermediate, synthetic rubber monomer and perfume, and can also be used for organically synthesizing important building blocks. In addition, methylbutylenol is also the main component of pheromone for controlling forest pests (beetles). At present, methylbutinol products are produced by an acetylene acetone process, are prepared by the hydrogenation reaction of methylbutinol, and other processes are still in the research and development stage. Because the production scale of foreign methyl butenol is larger and continuous process is adopted for hydrogenation, compared with domestic small-scale production, the method has certain advantages in the aspects of production cost and product quality. Noble metal palladium (patent CN 113121315B) is commonly used as a methylbutynol hydrogenation catalyst, and at present, the problem of poor selectivity (excessive hydrogenation by-product) mainly exists. In order to improve the selectivity of the reaction, the noble metal catalyst needs to be matched with a poisoning agent for use in the use process, and the industrialized operation flow is complex. In addition, the loss of palladium metal catalyst during the catalyst application process leads to an increase in product cost. Therefore, in order to realize the development and popularization of low-cost methylbutinol, the development of the low-cost efficient recyclable methylbutinol hydrogenation catalyst is significant. Disclosure of Invention In order to develop a novel methylbutynol hydrogenation catalytic system, the invention provides a method for synthesizing methylbutynol by catalyzing the hydrogenation of methylbutynol by using a low-cost heterogeneous cobalt catalyst, and the catalyst has high activity and can be recycled, and simultaneously has very high chemical selectivity, so that the production cost of the methylbutylenol can be greatly reduced. In order to achieve the above purpose, the technical scheme provided by the invention is as follows: A method for synthesizing methyl butenol by heterogeneous hydrogenation reaction uses a heterogeneous catalyst prepared from a dinitrogen ligand and a cobalt metal precursor to catalyze the hydrogenation reaction of methyl butynol to prepare the methyl butenol. In some embodiments, the dinitrogen ligand has a structure represented by formula L: wherein the R group is cycloalkyl or substituted cycloalkyl with 4-12 carbon atoms, and the R1 group is methyl or ethyl. In some specific embodiments, the cobalt metal precursor is a cobalt salt selected from any one of CoCl2, co (acac) 2, and CoBr2, preferably CoCl2. In some specific embodiments, the heterogeneous catalyst is prepared by adding the cobalt metal precursor into a tetrahydrofuran solution containing the dinitrogen ligand under the protection of nitrogen, stirring and mixing, adding a molecular sieve, stirring and reacting, decompressing and removing the solvent after the reaction is finished, and vacuum drying. In some specific embodiments, the molar ratio of the dinitrogen ligand to the cobalt metal precursor is from 1 to 2, preferably from 1.1 to 1.3; in some embodiments the temperature of the agitation is 60-150 ℃, preferably 90-120 ℃, and the agitation time is 6-24 hours, preferably 18-24 hours; In some specific embodiments, the molecular sieve is selected from at least one of MSN-48, MSN-50, MSN-41, and ZSM-5, preferably molecular sieve MSN-48 having a ligand mass of 6-10 times that of the molecular sieve; In some embodiments, the temperature of the agitation reaction is 60-120 ℃, the agitation reaction time is 2-12 hours, preferably the reaction conditions are 80-100 ℃ and the agitation reaction time is 6-8 hours; In some embodiments, the vacuum drying is at a temperature of 60-120 ℃ for a time of 12-36 hours, preferably at 90-100 ℃ for 20-30 hours. In some specific embodiments, the heterogeneous catalyst is used in an amount of 0.001 to 0.08wt%, preferably 0.01 to 0.05wt% of methylbutinol. In some specific embodiments, the hydrogenation reaction is carried out in a solvent, preferably the solvent is selected from one or more of dichloromethane, 1, 2-dichloroethane, dioxane, tetrahydrofuran, diethyl ether, ethylene glycol dimethyl ether, methyl t-butyl ether, toluene, xylene, n-hexane, ethanol. In some embodiments, the hydrogenation reaction is carried out at a reaction temperature of 40-80 ℃, preferably 50-60 ℃ and a reaction time of 1-12 hours, preferably 4-6