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Novel synthesis method for rhein

A synthetic method and technology of rhein, applied in the field of compounds, can solve the problems of low yield, environmental pollution, and great harm to human body, and achieve the effects of high yield, high purity, and reduced environmental pollution

Active Publication Date: 2013-01-16
台州达辰药业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The method has miscellaneous raw materials, many side reactions, low yield, difficult post-processing and easy to cause iron ion residues in the product and iron ion pollution to the environment
In CN1789229A, chrysophanol is used as a starting material, and rhein is obtained by oxidation with alkaline potassium permanganate. This method will use a large amount of potassium permanganate, and there is a serious problem of environmental pollution
1085, 1909), the heavy metal chromium used in it is very harmful to the human body

Method used

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  • Novel synthesis method for rhein
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preparation example Construction

[0022] The more specific synthetic method of rhein of the present invention comprises the following process:

[0023] Add 50.0 grams of 30% hydrogen peroxide into a clean 250mL four-necked bottle, cool to -5.0~5.0°C, then slowly add 12.0 grams of 98% concentrated sulfuric acid dropwise at a controlled temperature of -5.0~5.0°C, and stir for 2.0 ~2.5 hours, then slowly add 7.0 grams of aloe-emodin under control of the temperature at 15.0-20.0°C, and keep the temperature at 15.0-20.0°C for 2.0-4.0 hours after the addition.

[0024] Add 300.0 g of 5% DMF aqueous solution into another 500 ml four-necked bottle, and cool to 15.0-20.0°C.

[0025] After the heat preservation is completed, slowly add the reaction feed liquid at a controlled temperature of 20.0-35.0°C to the DMF aqueous solution in a 500ml four-necked bottle, and keep stirring at 20.0-35.0°C for 2.0-2.5 hours after the addition.

[0026] After the heat preservation is completed, filter, wash with 100.0 g of drinking w...

Embodiment 1

[0029] Add 50.0 grams of 30% hydrogen peroxide into a 250ml four-necked bottle, cool to -5.0°C, then slowly add 15.0 grams of 98% concentrated sulfuric acid dropwise at temperature control -5.0°C--3.0°C, and stir for 2.5 hours after the dropwise addition. Slowly add 7.0 grams of aloe-emodin at a temperature of 15.5-17.5°C, and keep the temperature at 15.5-17.5°C for 2.5 hours to react. At the end of the heat preservation, slowly add the reaction solution into a 500ml four-necked bottle containing 300.0 grams of 5.0% DMF aqueous solution, control the temperature of the addition process at 25.0-30.0°C, and keep stirring for 2.5 hours after the addition. Suction filtration, washing with 100.0 grams of drinking water, drying to obtain 6.72 grams of rhein, HPLC content 98.6%, yield 91.3%

Embodiment 2

[0031] Add 50.0 grams of 30% hydrogen peroxide into a 250ml four-neck bottle, cool to 0.0°C, then slowly add 7.0 grams of 98% concentrated sulfuric acid dropwise at a temperature of 0.0-3.0°C, stir for 2.5 hours after the addition, and control the temperature at 16.5-18.5 Slowly add 7.0 grams of aloe-emodin at ℃, and keep the temperature at 16.5-18.5 to react for 3.0 hours after the addition. At the end of the heat preservation, slowly add the reaction solution into a 500ml four-necked bottle containing 300.0 grams of 5.0% DMF aqueous solution, control the temperature of the addition process at 35.0° C., and stir for 2.0 hours after the addition is complete. Suction filtration, washing with water, drying to obtain 6.42 grams of rhein, HPLC content 98.8%, yield 87.2%

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Abstract

The invention discloses a novel synthesis method for rhein, which comprises the following steps: (1) slowly dripping concentrated sulfuric acid in hydrogen peroxide of -5.0 to 5.0 DEG C while stirring; (2) controlling the temperature of the mixed solution in step (1) to 0 to 30 DEG C, slowly adding aloe-emodin and stirring the mixture, and then preserving the heat for 2.0 to 4.0 hours while stirring; and (3) controlling the temperature of the reaction liquid in step (2) at 10 to 50 DEG C, slowly adding the reaction liquid to the aqueous solution of N,N-dimethyl formamide, stirring the mixed solution, preserving the heat for 2.0 to 2.5 hours, and filtering and washing the mixed solution to obtain a wet rhein product. According to the novel synthesis method, the concentrated sulfuric acid-hydrogen peroxide is taken as an oxidizing agent, so as to avoid the pollution from heavy metallic salt, replace the potassium permanganate, ferric oxide, chromium reagent and hypochlorite in the conventional method, and greatly reduce environmental pollution and the residual of harmful metallic ion in the product; and furthermore, the product prepared by the method is high in yield and purity.

Description

technical field [0001] The invention relates to the technical field of compounds, in particular to a new synthetic method of rhein. Background technique [0002] Rhein, CAS: 478-43-3, chemical name is 1.8-Dihydroxy-3-carboxy-anthraquinone (1.8-Dihydroxy-3-carboxy-anthraquinone), yellow needle-like crystal, insoluble in water, can Soluble in pyridine, sodium bicarbonate aqueous solution, slightly soluble in ethanol, chloroform, ether, petroleum ether and benzene. Rhein has antibacterial, antitumor, immunosuppressive, diuretic, laxative, anti-inflammatory, and treatment of diabetic nephropathy effects. It has high medicinal value and is widely used in various medicines. [0003] The structural formula of rhein is shown in the following formula II: [0004] [0005] The preparation of rhein includes two ways: extraction from plants, and chemical synthesis; rhein is mainly distributed in Polygonaceae rhubarb, and can be extracted from rhubarb to obtain rhein, which has been...

Claims

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Application Information

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IPC IPC(8): C07C66/02C07C51/285C07C51/43
Inventor 孔叶青姜礼进冯玲琴马良秀
Owner 台州达辰药业有限公司
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