Method for synthesizing 2,3,5-trimethylhydroquinone diester

A technology of trimethylhydroquinone diester and synthetic method, which is applied in two fields, can solve the problems of high price of nitroxide free radical peroxide and unfavorable industrial production, and achieve low production cost, easy operation and high reaction yield Effect

Active Publication Date: 2011-09-14
ZHEJIANG NHU PHARMA +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But the fly in the ointment is that the price of nitroxide free radical p

Method used

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  • Method for synthesizing 2,3,5-trimethylhydroquinone diester
  • Method for synthesizing 2,3,5-trimethylhydroquinone diester
  • Method for synthesizing 2,3,5-trimethylhydroquinone diester

Examples

Experimental program
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Example Embodiment

[0037] Example 1

[0038] 1) Mix 1mol α-isophorone (138g) and 1.5mol (153g) acetic anhydride, add H 3 PMo 12 O 40 0.0043mol (7.85g), react at 100℃ for 8h, recover the dry solvent, add 0.006mol (0.672g) of potassium tert-butoxide, 200ml of DMSO, heat the oil bath to 115℃ and let in air, react for 100h, sample and check the content of raw materials ≤1 %, stop passing air, spin the reaction solution to dry the solvent to obtain the crude oil of the monoesterification product of ketoisophorone.

[0039] 2) Add 0.051mol (6.89g) HBr (60%) and 2mol (204g) acetic anhydride, cool to 0℃, add dropwise 0.004mol (0.9g) ZnBr dissolved in 100ml acetic acid 2 , Control the dripping time for 5h, after dripping at 10℃, keep the reaction for 20h, check that the intermediate content is ≤0.5%, recover the excess acetic anhydride and the acetic acid produced by the reaction to obtain the crude oil crystallized with acetic acid / water mixed solvent, which is off-white or light 165 grams of yellow crystals...

Example Embodiment

[0040] Example 2

[0041] 1) Mix 1mol α-isophorone (138g) and 1.5mol (153g) acetic anhydride, add H 3 PMo 12 O 40 0.0043mol (7.85g), react at 100℃ for 8h, recover the dry solvent, add 0.006mol (0.672g) of potassium tert-butoxide, 200ml of DMSO, heat the oil bath to 150℃ and let in air, react for 60h, sample and check the content of raw materials ≤1 %, stop passing air, spin the reaction solution to dry the solvent to obtain the crude oil of the monoesterified product of ketoisophorone.

[0042] 2) Add 0.051mol (6.89g) HBr (60%) and 2mol (204g) acetic anhydride, cool to 0℃, add dropwise 0.004mol (0.9g) ZnBr dissolved in 100ml acetic acid 2 , Control the dripping time for 5h, after dripping at 10℃, keep the reaction for 20h, check that the intermediate content is ≤0.5%, recover the excess acetic anhydride and the acetic acid produced by the reaction to obtain the crude oil crystallized with acetic acid / water mixed solvent, which is off-white or light 152g yellow crystals, 94.7% inter...

Example Embodiment

[0043] Example 3

[0044] 1) Mix 1mol α-isophorone (138g) and 1.5mol (153g) acetic anhydride, add H 3 PMo 12 O 40 0.0043mol (7.85g), react at 100℃ for 8h, recover the dry solvent, add 0.006mol (0.672g) of potassium tert-butoxide, DMSO 200ml, increase the temperature of the oil bath to 115℃ and introduce air, react for 24h, stop the air supply, The reaction liquid is spin-dried to dry the solvent to obtain the crude oil of the monoesterified product of ketoisophorone.

[0045] 2) Add 0.051mol (6.89g) HBr (60%) and 2mol (204g) acetic anhydride, cool to 0℃, add dropwise 0.004mol (0.9g) ZnBr dissolved in 100ml acetic acid 2 , Control the dripping time for 5h, after dripping at 10℃, keep the reaction for 20h, check that the intermediate content is ≤0.5%, recover the excess acetic anhydride and the acetic acid produced by the reaction to obtain the crude oil crystallized with acetic acid / water mixed solvent, which is off-white or light 105g yellow crystals, internal standard 94.3%, mp: 1...

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Abstract

The invention discloses a method for synthesizing a medicine intermediate 2,3,5-trimethylhydroquinone diester. The conventional methods are not environment-friendly, or difficultly realize industrial production due to high production cost. The method is characterized by comprising the following steps of: 1) reacting carboxylic acid anhydride serving as an acylating agent with alpha-isophorone in the presence of a catalyst to obtain the enol isomer esterification product of isophorone; 2) adding a solvent dimethyl sulfoxide (DMSO), a heteropolyacid catalyst and alkali into the enol isomer esterification product, blowing air, and reacting to obtain the monoesterification product of ketoisophorone; and 3) recycling the solvent in the monoesterification product, and reacting in the presence of the carboxylic acid anhydride and the catalyst to obtain the 2,3,5-trimethylhydroquinone diester. By changing the molecular structure of the alpha-isophorone, reaction activity is improved, reaction yield is high, the method is easy and convenient to operate, environment-friendly and low in production cost, and the industrial production is easy to realize.

Description

technical field [0001] The invention relates to a drug intermediate, in particular to a method for synthesizing 2,3,5-trimethylhydroquinone diester. Background technique [0002] 2,3,5-trimethylhydroquinone diester and its hydrolysis product 2,3,5-trimethylhydroquinone are beneficial drug intermediates. More specifically, they are one of the main raw materials of vitamin E. [0003] 2,3,5-Trimethylhydroquinone diester can be prepared by reacting ketoisophorone with acylating agent in the presence of catalyst. Some scholars have proposed some catalysts for this reaction in the past, for example: the concentrated sulfuric acid of inorganic acid, p-toluenesulfonic acid of organic acid, strongly acidic ion exchange resin, and Lewis acid etc., see DE2149159, EP-0916642A and EP -1028103A. Other methods basically have the same process as the above operation, that is, the trimethylhydroquinone diester is obtained by the reaction of ketoisophorone and acid anhydride in the presenc...

Claims

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Application Information

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IPC IPC(8): C07C69/16C07C67/46
Inventor 曾庆宇宋文杰张琴潘洪高均勇倪程勇
Owner ZHEJIANG NHU PHARMA
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