Synthesis method of rhein and diacerein

A technology of diacerein and rhein, applied in chemical instruments and methods, carboxylate preparation, carboxylate preparation and other directions, can solve the problems of human harm, human and environmental pollution, high price of hydroiodic acid, etc. full response effect

Inactive Publication Date: 2006-06-21
NAN JING RHINE PHARM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

There are isomers during cyclization by this method, and it is difficult to separate and purify
[0013] (3) Halogenated quinone method, ①Gerard.Lang et al. (U.S.Patent 3773801, 1973) use 2-bromo-5-chloro-8-hydroxyquinone and 1,1-diethoxy-3-methylbutadiene to carry out Diels-Alder reaction, the ethoxy compound produced by the reaction is deethylated by hydroiodi...

Method used

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  • Synthesis method of rhein and diacerein
  • Synthesis method of rhein and diacerein

Examples

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Embodiment 1

[0027] Embodiment 1, the preparation of 2-(2-hydroxyl-4-methylbenzoyl)-3-nitrobenzoic acid

[0028] Weigh 96.6g (0.5mol) of 3-nitrophthalic anhydride and 400g (3.7mol) of m-cresol, and put them into a 2L three-necked flask equipped with a sealed stirrer, anhydrous calcium chloride drying tube and reflux condenser In the process, the flask was cooled in an ice-water bath, and 200g (1.5mol) of powdered anhydrous aluminum trichloride was added at one time, started to stir, heated up, heated to 100-110°C, and stirred vigorously for 3 hours until the release of hydrogen chloride stopped. A thick reddish-brown substance was produced. Ice was added while stirring until the excess chromium trichloride passed through the addition of 150ml of concentrated hydrochloric acid, the product coagulated and the solution was clarified. After filtration, the filter cake was treated with 50 g of sodium carbonate, filtered, and dried to obtain 107.8 g of white crystal 2-(2-hydroxy-4-methylbenzoyl...

Embodiment 2

[0029] Embodiment two, the preparation of 2-(2-hydroxyl-4-methylbenzoyl)-3-aminobenzoic acid

[0030] 301 g (1 mol) of 2-(2-hydroxy-4-methylbenzoyl)-3-nitrobenzoic acid, 300 ml of absolute ethanol and 5 g of Raney nickel were put into a 1 L autoclave. Close the autoclave, feed hydrogen, raise the temperature to 25°C to make the pressure 20-40Mpa, stir at a medium speed, rapidly raise the temperature to 90°C, stop heating, and maintain the reaction at 90-100°C for 8 hours. Cool, depressurize, and filter the catalyst. Ethanol was distilled off, and the residue was recrystallized to obtain 255 g of the amino compound, with a yield of 94.1%, mp: 225-226° C., and content (HPLC) ≥ 96.5%.

Embodiment 3

[0031] Embodiment three, the preparation of 2-(2-hydroxyl-4-methylbenzoyl)-3-hydroxybenzoic acid

[0032] Put 27.1g (0.1mol) of 2-(2-hydroxy-4-methylbenzoyl)-3-aminobenzoic acid into a 500ml three-necked flask, add 50ml of water, then slowly add 15ml of concentrated sulfuric acid, and the reaction solution will spontaneously After heating up, cool to 0-5°C. Slowly add 35g of 20% sodium nitrite solution dropwise to the flask, keep the temperature not exceeding 5°C, after the addition, stir and react for 0.5 hours, then add 3g of urea, heat to boiling, cool slightly, add 1g of activated carbon, decolorize and filter, cool to After recrystallization at 0°C, 23.6g of dry product was obtained, yield 76.2%, mp: 240-241°C, content (HPLC) ≥ 97.0%.

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Abstract

The invention relates to a method for synthesizing the emodic acid which is the essential component of the traditional Chinese medicine rhubarb horsetails and duroruiyin which is antipyretic analgesic and osteoarthritis treating medicine, employing 3-nitro-ortho-phthalic anhydride as start raw material, reacting with m-cresol fuke, through reaction of reduction, diazonium salt, ring-combining to prepare intermediate compound chrysophanol, oxygenating to emodic acid, preparing duroruiyin through acetylation, the total productivity of the six reaction is 31.1%, the process is optimize through pilot-scale experiment a nd suitable for industrial production.

Description

field of invention [0001] The present invention relates to the field of organic and pharmaceutical chemistry, specifically, the present invention relates to the synthesis method of rhein, the main component of rhubarb, an antipyretic and analgesic drug, diacerein, an osteoarthritis treatment drug, and the intermediate chrysophanol. Background technique [0002] Chrysophanol and rhein are the main components extracted from the rhizome of Rheum palmatum, a plant of the Polygonaceae family. They have antibacterial, anticancer activities, and catharsis and diuretic effects. The acetyl derivative of rhein, diacerein, is used in the treatment of rheumatism and osteoarthritis. [0003] Chrysophanol, also known as rhubarb root acid, English name: Chrysophanol, CAS: [481-74-3], molecular formula: C 15 h 10 o 4 , molecular weight: 254.23 [0004] Rhein, also known as 1,8-dihydroxyanthraquinone-3-carboxylic acid, English name: Rhein, CAS: [478-43-3], molecular formula: C 15 h 8 o...

Claims

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Application Information

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IPC IPC(8): C07C66/02C07C51/00C07C51/23C07C67/08C07C67/14C07C69/035
Inventor 陈新梅以成
Owner NAN JING RHINE PHARM TECH
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