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Method for refining carbidopa

A refining method and carbidopa technology, applied in the preparation of hydrazine, organic chemistry, etc., can solve the problems of increasing the refining cost of enterprises, reducing production efficiency, and low refining yield, and achieving low production cost, good economic benefits, and impurities. The effect of high removal rate

Active Publication Date: 2012-05-02
ZHEJIANG CHIRAL MEDICINE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Therefore, it is necessary to reach the Pharmacopoeia standard through repeated refining, which will greatly increase the refining cost of the enterprise and reduce production efficiency. Moreover, the yield of pure water refining is not high, and the highest yield is 86%. Technical problems such as low refining yield, high refining cost, and low production efficiency

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  • Method for refining carbidopa

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Effect test

preparation example 1

[0029] 100g of dimethylcarbidopa, add 1000g of hydrobromic acid with a mass percentage of 48%, heat to 120°C, react for 2h, distill off the hydrobromic acid under reduced pressure, add 100g of water, and use 1mol / L sodium hydroxide The pH of the aqueous solution was adjusted to 6.5, and a solid was precipitated, filtered and washed with water and dried in vacuum at 60°C for 4 hours to obtain 80.7 g of crude carbidopa. After detection by high performance liquid chromatography, the purity of carbidopa in the crude carbidopa was 96%. The purity of Quidopa is 2.8%.

Embodiment 1

[0037]1) add 2500g purified water in the reaction flask that stirring, thermometer, reflux device, heating device are housed, the carbidopa crude product that 50g preparation example 1 prepares (the purity of carbidopa is 96%, the purity of methyldopa Purity is 2.8%), under the condition of nitrogen protection, start stirring (300 rev / min), adjust with DL-malic acid (D-type and L-type each account for 50%, analytically pure, Shanghai Boao Biotechnology Co., Ltd.) pH to 3.0, stirred and heated to 98°C±1°C, dissolved to obtain the crude product system;

[0038] 2) Add 2 g of medicinal activated carbon (the specification is that the methylene blue adsorption value is greater than 13 mL) to the crude product system obtained in step 1), and decolorize at 100° C. for 60 minutes under the condition of nitrogen protection;

[0039] 3) After decolorization, filter while hot to obtain the filtrate. Under the condition of nitrogen protection, transfer the filtrate to a nitrogen-protected...

Embodiment 2

[0043] 1) add 2000g purified water in the reaction bottle that stirring, thermometer, reflux device, heating device are housed, the carbidopa crude product that 50g preparation example 1 prepares (the purity of carbidopa is 96%, the purity of methyldopa Purity is 2.8%), start stirring (300 rev / min), adjust pH to 3.0 with DL-malic acid (50% each of D-type and L-type, analytically pure, Shanghai Boao Biotechnology Co., Ltd.), under nitrogen protection Under the condition of stirring and heating to 98°C±1°C, dissolve to obtain the crude product system;

[0044] 2) Add 2 g of medicinal activated carbon (the specification is that the methylene blue adsorption value is greater than 13 mL) to the crude product system obtained in step 1), and decolorize at 100° C. for 60 minutes under the condition of nitrogen protection;

[0045] 3) After decolorization, filter while hot to obtain the filtrate. Under the condition of nitrogen protection, transfer the filtrate to a nitrogen-protected ...

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Abstract

The invention discloses a method for refining carbidopa, which comprises the following steps: diluting a crude carbidopa product with water, regulating the pH value to below 6.5 with acid, and heating to 50-110 DEG C under the nitrogen protection or / and reducer addition condition, thereby obtaining a crude product system; adding a decolorant into the crude product system to decolorize at 50-110 DEG C for 5-60 minutes; after decolorizing, filtering while the crude product system is hot to obtain a filtrate, stirring and cooling the filtrate to 0-30 DEG C, and continuing stirring at 0-30 DEG C for 0.5-5 hours to obtain a refined system; and filtering the refined system, washing the filter cake with water, and carrying out vacuum drying to obtain the finished carbidopa product. The method disclosed by the invention has the advantages of simple preparation method, favorable controllability, strong operability, high methyldopa (impurity) removal rate, high yield and low production cost, can easily implement industrial production, has high economic benefit in the industrial production, can be easily popularized, and has wide application prospects.

Description

technical field [0001] The invention relates to the field of pharmaceutical chemical synthesis, in particular to a method for refining carbidopa. Background technique [0002] Carbidopa (carbidopa), the chemical name is (-)-L-α-hydrazino-3,4-dihydroxy-α-methylphenylpropionic acid monohydrate, is a dopa decarboxylase developed by Merck Company of the United States Inhibitors, because they cannot pass through the blood-brain barrier, only inhibit the conversion of peripheral levodopa into dopamine, increase the amount of levodopa entering the brain, and reduce the adverse reactions caused by peripheral dopamine, so that levodopa in the circulation content increased. Due to the increase of levodopa entering the brain, levodopa enters the center of the brain and converts it into dopamine to play a role. Therefore, increasing the concentration of dopamine in the brain can improve the symptoms of paralysis. The combined use of carbidopa and levodopa has a synergistic effect, and...

Claims

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Application Information

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IPC IPC(8): C07C243/18C07C241/02
Inventor 黄有明胡文钢孙文龙刘田春尤彩定屠佳秋
Owner ZHEJIANG CHIRAL MEDICINE CHEM
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