Method of preparing diacetyl parietic acid from rhubarb extract

A technology for diacetyl rhein and rhubarb extract, which is applied in the field of preparing diacetyl rhein, can solve the problems of difficult control of aloe-emodin, high cost industrialized production, long routes, etc., so as to improve the total product yield and reduce production costs. , the effect of low price

Inactive Publication Date: 2005-08-10
夏士朋
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Some European and American countries use aloe vera from South Africa as the starting material to produce this product. After extracting aloin from aloe vera, they obtain diacetylrhein through oxidative hydrolysis. The main problem of this process route is the residual aloe-emodin in the finished product. Difficult to control, easy to exceed the standard
In addition, there are also people who try to carry out artificial chemical synthesis, but fail to realize industrialized production due to the long route and high cost.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Add 2.1 grams of a mixture containing rhein, chrysophanol and aloe-emodin (4:5:1) into 38 milliliters of acetic anhydride, stir and place for 10 minutes;

[0022] (2) Add 2.1 g of anhydrous sodium acetate to the reaction solution, heat up to 95° C., stir and react for 90 minutes, filter while hot, cool to crystallize, filter and wash with water to obtain the diacetyl compound;

[0023] (3) The obtained diacetyl compound was added to 120 milliliters of glacial acetic acid-acetic anhydride (10:1) mixed solution, the temperature was raised to 50° C., and 64 milliliters of chromium trioxide solution (2.2 grams of chromium trioxide dissolved in 4 milliliter of deionized water, and then add 60 milliliters of glacial acetic acid), after the dropwise addition, keep it warm at 60-65°C for 3 hours, then pour the oxidized solution into ice water, a pale yellow precipitate precipitates, filters, washes with water, and dries to obtain Diacetylrhein crude product;

[0024] (4) A...

Embodiment 2

[0028] (1) Add 2.1 grams of a mixture containing rhein, chrysophanol and aloe-emodin (4:6:1) into 38 milliliters of acetic anhydride, stir and place for 10 minutes;

[0029] (2) Add 0.8 g of anhydrous potassium acetate to the reaction solution, heat up to 95° C., stir and react for 90 minutes, filter while hot, cool to crystallize, filter and wash with water to obtain the diacetyl compound;

[0030] (3) The obtained diacetyl compound was added to 120 milliliters of glacial acetic acid-acetic anhydride (10:1) mixed solution, the temperature was raised to 50° C., and 64 milliliters of chromium trioxide solution (2.2 grams of chromium trioxide dissolved in 4 milliliter of deionized water, and then add 60 milliliters of glacial acetic acid), after the dropwise addition, keep it warm at 60-65°C for 3 hours, then pour the oxidized solution into ice water, a pale yellow precipitate precipitates, filters, washes with water, and dries to obtain Diacetylrhein crude product;

[0031] (4...

Embodiment 3

[0034] (1) Add 2.8 grams of chrysophanol and aloe-emodin mixture (5:1) into 60 ml of acetic anhydride and pyridine mixture (10:1), react at 50°C for 2 hours, and pour the reactants into Put 150 ml of cold water in a stoppered cone, place the cone in an ice-water mixture to cool, crystallize, and separate out yellow crystals by suction filtration to obtain the diacetyl compound;

[0035] (2) Dissolve the diacetyl compound obtained in 120ml of glacial acetic acid-acetic anhydride mixture (10:1), and add dropwise 70ml of chromium trioxide solution (3.3g of chromium trioxide dissolved in 5ml of deionized water, then add glacial acetic acid (65 milliliters), add in about 30 minutes. After the addition, the temperature was raised to 60-65° C. to continue stirring for 4 hours, and then the dark green reaction solution was added to 800 ml of ice-cold deionized water containing disodium edetate for crystallization. After the product is completely precipitated, filter with suction, was...

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PUM

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Abstract

A process for preparing diacetylchrysophanic acid from the extract of rhubab (chrysophanic acid, chrysophanol, or aloe-emodin) includes such steps as acetylating, oxidizing, removing Cr, ammonizing, conversing, acidifying, recrystallizing and drying. Said product can be used for treating osteoarthritis.

Description

technical field [0001] The invention relates to a method for preparing diacetylrhein from rhubarb extract. Background technique [0002] Diacerein was listed by Laboratoires.Negma of France in 1994, and its trade name was "artodar", and then Italy's San Martinos Comaroo Sintek Co., Ltd. , Cologne Madaus Co., Ltd. in Germany, and Cinkate in the United States have successively put into production and listed. However, there is no domestic manufacturer producing this product so far, and the "Ambidine" used is all imported products. [0003] Due to the different resources of different countries, the starting materials for the synthesis of diacetylrhein are also different. The international production of this product is initially based on senna as the starting material, such as the German patents CN1088907A and CN1088571A of the United Nations, which are obtained by extracting sennosides, then hydrolyzing, oxidizing, and acetylating. Some European and American countries use alo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/487C07C66/02
Inventor 夏士朋
Owner 夏士朋
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