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Rectification method of allopurinol

A purification method and technology of allopurinol, applied in the field of chemical reaction purification, can solve the problems of low yield, large steam consumption, large amount of cooling water, etc., and achieve high product yield and purity, cheap and easy-to-obtain raw materials, and high yield. rate increase effect

Inactive Publication Date: 2011-08-17
无锡紫杉药业股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The highest solubility is only 1% during refined production, and the yield is lower than 80% under the condition of 90-100°C
The steam consumption is large, and a large amount of cooling water is required for cooling

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Alkaline dissolution: first add 10ml of purified water to a 100mL three-necked bottle, then add 5g (0.036mol) of crude allopurinol, start stirring, slowly add 65mL of 0.5mol / L NaOH solution, and control the pH to 6~7 until dissolved , a pale yellow liquid was obtained.

[0022] (2) Decolorization: add 0.5 g of activated carbon for needles, stir at 60° C. for 1 hour, and filter while hot.

[0023] (3) Acidification of the filtrate: prepare 66 mL (0.033 mol) of 0.5 mol / L HCl solution, put the filtrate in a 250 mL three-neck flask, add slowly while stirring, white objects will precipitate out, and keep the pH between 6 and 7. After the addition, continue to stir for 20 minutes and filter. The filter cake is washed 3 times with cold water and dried at 100° C. to obtain 4.1 g of off-white solid with a yield of 82%. Quality indicators: identification (color, UV, IR) in compliance with regulations; heavy metals ≤ 20ppm; residue on ignition ≤ 0.01%; HPLC product content 99...

Embodiment 2

[0025] (1) Alkaline dissolution: first add 15ml of purified water to a 250ml three-necked flask, then add 10g (0.0734mol) of crude allopurinol, in a 60°C water bath, start stirring, slowly add 73mL of 1.0mol / L NaOH solution, and control pH 6-7 until dissolved to obtain a light yellow liquid.

[0026] (2) Decolorization: add 0.8 g of activated carbon for needles, stir at 60° C. for 1 hour, and filter while hot.

[0027] (3) Filtration: prepare 74mL (0.074mol) of 1mol / L HCl solution, put the filtrate in a 250mL three-neck flask, add it under stirring, white objects will precipitate out, and keep the pH between 6 and 7. After the addition, continue to stir for 30 minutes and filter. The filter cake is washed twice with cold water and dried at 90° C. to obtain 8.0 g of off-white color. Yield 80%. Quality indicators: identification (color, UV, IR) in compliance with regulations; heavy metals ≤ 20ppm; residue on ignition ≤ 0.04%; HPLC product content 99.2%; related substances: sin...

Embodiment 3

[0029] (1) Alkaline dissolution: first add 20ml of purified water to a 250ml three-necked bottle, then add 10g (0.0734mol) of crude allopurinol, put it in a water bath at 60°C, start stirring, and slowly drop in 41mL of 1.5mol / L NaOH solution, Control the pH to 6-7 until dissolved to obtain a light yellow liquid.

[0030] (2) Decolorization: Add 0.5 g of activated carbon for needles, stir at 60° C. for 1 h, and filter.

[0031] (3) Filtration: Put the filtrate in a 250ml three-neck flask, start stirring, add 40mL (0.06mol) of 1.5mol / L HCl solution, white objects will precipitate out, and keep the pH between 6 and 7. After the addition, continue to stir for 40 minutes to filter, wash the filter cake 3 times with water, and dry at 80°C to obtain 8.1 g of off-white (a little light yellow) substance. Yield 81%. Quality indicators: identification (color, UV, IR) in compliance with regulations; heavy metals: ≤20ppm; residue on ignition: ≤0.04%; content HPLC: 98.2%; related substan...

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Abstract

The invention provides a rectification method of allopurinol, in particular relates to a rectification method in which the allopurinol is converted into an allopurinol sodium salt so as to enlarge solubility, decolorizing rectification is carried out on the allopurinol sodium salt, then the allopurinol sodium salt is acidized to form the allopurinol, belonging to the technical field of chemical reaction rectification. The rectification method comprises the following steps: adding crude allopurinol in water, stirring with a dilute alkaline liquid to be clear, and controlling the pH to be neutral; adding activated carbon, and filtering under the hot condition after stirring and decoloring; slowly adding a dilute acid solution in filtrate obtained after decloring and filtering, separating out a white solid, maintaining the pH of the solution to be neutral, and continuously stirring and filtering; and washing the obtained filter cake and drying so as obtain the rectified product allopurinol. In the rectification method, the used raw material is available, reaction and treatment conditions are mild and the yield and purity of the product are high; the yield of rectification can be greatly increased by a proper improvement under the condition of the original equipment conditions, and industrialization is conveniently achieved. By using the method, the dissolving amount can be improved by 5-10 times, and simultaneously, the yield can be improved.

Description

technical field [0001] A method for refining allopurinol, specifically referring to converting allopurinol into sodium salt of allopurinol, increasing solubility at a relatively low temperature, decolorizing and refining, and then acidifying into allopurinol, which belongs to chemical reaction refining technology field. Background technique [0002] Allopurinol anti-gout drug is suitable for various diseases with primary or secondary serum uric acid increase, such as gout, acute or chronic leukemia. [0003] General preparation method: put ethyl cyanoacetate, triethyl orthoformate, and acetic anhydride in a reaction tank for reflux reaction for 4 hours, and condense to obtain ethyl α-ethoxymethine cyanoacetate; then dissolve it in ethanol, add Hydrazine hydrate, heated and refluxed for 6 hours to obtain 3-amino-4-ethoxycarbonylpyrazole; finally heated and refluxed with formamide for 8 hours to obtain allopurinol. Dissolve in distilled water and decolorize with activated ca...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D487/04
Inventor 李隆
Owner 无锡紫杉药业股份有限公司
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