Preparation method of 3-methyl-5-phenyl-pentanol

Preparation method of 3-methyl-5-phenyl-pentanol

  • CN 105,924,332 B
  • Filed: 05/06/2016
  • Issued: 06/09/2020
  • Est. Priority Date: 05/06/2016
  • Status: Active Grant
First Claim
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1. A preparation method of 3-methyl-5-phenyl-pentanol is characterized by comprising the following steps:

  • the method comprises the following steps;

    preparing phenyl-dihydropyran and hydrogenation reaction;

    the hydrogenation reaction comprises the following steps;

    (1) charging ofSequentially adding phenyl-dihydropyran, a cocatalyst and a catalyst into an autoclave, sealing the autoclave, replacing with nitrogen and then hydrogen;

    the catalyst is 3% Pd/silica;

    the cocatalyst is 0.34% oxalic acid aqueous solution;

    the adding amount of the phenyl-dihydropyran is 200g, the adding amount of the cocatalyst is 50g, and the adding amount of the catalyst is 2.5 g;

    (2) hydrogenation ofHeating the high-pressure kettle to 95-100 ℃

    , and starting hydrogenation when the pressure of the hydrogen charging gas reaches 1.2 MPa;

    (3) cooling, pressure reduction and nitrogen purgingWhen the residual content of the raw materials is below 0.5 percent in gas phase detection, cooling the hydrogenated materials to room temperature, discharging hydrogen to 0.04-0.06 Mpa, introducing nitrogen to the kettle until the pressure is not less than 0.3Mpa, discharging to 0.04-0.06 Mpa, repeating the operation for 3 times, reacting for 6.5 hours, then filtering, washing, and carrying out reduced pressure rectification on the crude product to obtain the catalyst;

    the oil phase is distilled to obtain 3-methyl-5-phenyl-pentanol with purity of more than 98.5%, selectivity of 98.3% and yield of 97.5%;

    the Pd/silica catalyst is mechanically used;

    filtering to obtain Pd/silicon dioxide, wherein the hydrogenation reaction selectivity is more than 98.0 percent and the average yield is 97.5 percent after ten times of reuse;

    the cocatalyst is used mechanically;

    filtering the reaction liquid, standing and layering to obtain a water phase, wherein the hydrogenation selectivity is more than 98.0% and the average yield is 96.8% after the reaction liquid is reused for ten times;

    158.6g of benzaldehyde, 100.0g of xylene and 0.15g of SO are charged into a tower reactor provided with 5 tower plates to prepare the phenyl-dihydropyran42-

    MoO3/ZrO2(ii) a Vacuumizing the reaction system to-0.09 MPa, heating the material to reflux, adding 86.0g of 3-methyl 3-butenol, removing byproduct water, and reacting at the reflux temperature of 65 ℃

    for 8.0 h;

    stopping the reaction when the reaction residue of the 3-methyl-3-butenol is less than 0.5 percent, cooling to 30-50 ℃

    , filtering, and then washing with water;

    standing, separating to remove water layer, and distilling organic layer;

    the xylene and the phenyl-dihydropyran with a purity of more than 96.5% are recovered by distillation, with a yield of 91.8%.

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