Preparing method for 1,2-pentadiol

A technology of pentanediol and n-pentene, applied in the preparation of organic compounds, hydrolysis preparation, chemical instruments and methods, etc., can solve the problems of environmental pollution, difficult recovery of by-products, flammable and explosive peracetic acid, etc. The effect of improving economic efficiency and easy recycling

Inactive Publication Date: 2004-12-08
LINHAI LIANSHENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

U.S. Patent No. 4,605,795 discloses a method of epoxidizing pentene and perpropionic acid into 1-pentene oxide in a continuous phase in a benzene solvent, and then directly saponifying 1-pentene oxide to obtain 1,2-pentanediol. preparation process, but the recovery of by-products is difficult and pollutes the environment; in addition
U.S. Patent No. 4,479,021 discloses a conti

Method used

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Examples

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Effect test

Embodiment 1

[0016] Example 1: Put 520kg of hydrogen peroxide (50%) and 700kg of formic acid (94%) into a reactor equipped with a thermometer and a stirrer, that is, the molar ratio of formic acid and hydrogen peroxide is 1:0.53, and keep the temperature at -20℃~- 10°C, then add 400kg of n-pentene dropwise to the reactor, that is, the molar ratio of n-pentene to formic acid is 1:2.54, and the addition is completed in about 1.5 hours. After completion, keep it at 25°C~30°C for 4 hours; Raise the temperature to 60°C, divide the reactants into two tanks (acid-resistant tanks), add sodium hydroxide dropwise to each reaction tank to adjust the pH value. When the pH is 7, transfer the solution in the reaction tank to the neutralization tank ( It is an alkali-resistant kettle), continue to add sodium hydroxide dropwise for hydrolysis, stop the dropwise addition when the pH is 10-11, keep it at 60℃~70℃ for 1 hour; after the temperature is kept, cool to room temperature, add 1100kg methyl isobutyl meth...

Embodiment 2

[0017] Example 2: In the present invention, ethyl acetate can also be used as an organic solvent.

[0018] Feeding: 250kg of n-pentene, 280kg of formic acid, 320kg of hydrogen peroxide, that is, the molar ratio of formic acid: hydrogen peroxide is 1:0.82, and the molar ratio of n-pentene: formic acid is 1:1.62

[0019] Step Repeat the steps in Example 1 and change the organic solvent to ethyl acetate. After the reaction, 163.5 kg of 1,2-pentanediol with a purity greater than 99.0% was obtained by extraction and refinement. The yield was 65.4% (using n-pentene meter).

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PUM

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Abstract

A process for preparing 1,2-pentanediol includes such steps as adding formic acid and H2O2 to reactor at low temp, dripping n-pentylene in it, hydrolyzing reacting at a certain temp for a certain time in alkaline condition to obtain coarse 1,2-pentanediol, extracting in organic solvent, distilling for recovering solvent, and rectifying to obtain high-purity (99%) 1,2-pentanediol and sodium formate as by-product.

Description

Technical field [0001] The invention relates to a method for preparing 1,2-pentanediol as a chemical product, in particular to a method for preparing 1,2-pentanediol using n-pentene, formic acid and hydrogen peroxide as raw materials. Background technique [0002] 1,2-pentanediol is an important chemical raw material, commonly used to produce polyester and surfactants, 1,2-pentanediol is also the main raw material for preparing the fungicide propiconazole, and propiconazole is a substitute Fungicide for organophosphorus pesticides. US Patent No. 4,605,795 discloses an epoxidation of pentene and perpropionic acid into 1-pentene oxide in a continuous phase in a benzene solvent, and then direct saponification of 1-pentene oxide to obtain 1,2-pentanediol However, it is difficult to recover the by-products produced by the preparation process, causing pollution to the environment; in addition. The continuous production process of 1,2-pentanediol disclosed in US Paten...

Claims

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Application Information

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IPC IPC(8): C07C29/00C07C29/09C07C31/20
Inventor 俞小鸥
Owner LINHAI LIANSHENG CHEM
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