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A synthesis method and solution technology, applied in the field of medicinal chemistry, can solve the problems of low reaction yield and achieve high yield, low cost, and improved purity
Active Publication Date: 2011-12-21
JILIN BODA PHARMA
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From the perspective of chemical reaction, ethyl acetoacetate is easier to react with phenylhydrazine than butanone amide, and ethyl acetoacetate is easier to obtain and cheaper, but the reaction yield is low, about 70%
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Embodiment 1
[0026] Embodiment 1: Edaravone is prepared from phenylhydrazine.
[0027] a. Weigh 5.1 g of phenylhydrazine (47 mmol), add it into a round bottom flask filled with 45 mL of water under stirring, take an appropriate amount of concentrated hydrochloric acid, measure and adjust the pH value of the solution to 6.0 with a pH meter.
[0028] b. Slowly add 5.85 g (45 mmol) of ethyl acetoacetate dropwise to the above solution, the reaction is exothermic, and after cooling down to room temperature, add 1.5 g of sodium dithionite (Na 2 S 2 o 4 ), heated to 105° C. and refluxed for 3 hours, then stopped heating, then stirred, cooled, suction filtered, and dried to obtain the crude product of pale yellow granular Edaravone.
[0029] c. Recrystallize with absolute ethanol, filter with suction, and dry to obtain white crystalline powder, which is refined Edaravone, with a yield of 85% and a purity of 99.2%.
Embodiment 2
[0030] Embodiment 2: Edaravone is prepared from phenylhydrazine hydrochloride.
[0031] a. Weigh 6.8 g of phenylhydrazine hydrochloride (47 mmol), add it into a round-bottom flask filled with 45 mL of water under stirring, and adjust the pH value of the solution to 6.0 with ammonia water.
[0032] b. Slowly add 5.85g (45mmol) of ethyl acetoacetate dropwise to the above solution. 2 S 2 o 4 ), heated to 105° C. and refluxed for 3 hours, then stopped heating, then stirred, cooled, suction filtered, and dried to obtain the crude product of pale yellow granular Edaravone.
[0033] c. Recrystallize with absolute ethanol, filter with suction, and dry to obtain white crystalline powder, which is refined Edaravone, with a yield of 84% and a purity of 99.2%.
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Abstract
The invention belongs to the technical field of medical chemistry, and particularly relates to an optimal edaravone synthesis method. The method comprises the following steps in sequence: (1) adding phenyl hydrazine or phenylhydrazine hydrochloride serving as an initial raw material into a container in which water is held under a stirring condition and adjusting the pH value to be 6.0 by taking a proper amount of concentrated hydrochloric acid or ammonia water; (2) slowly dropwise adding ethyl acetoacetate into the solution obtained in the step (1), reacting and discharging heat, adding sodium hyposulfate after the solution is cooled to room temperature, heating the solution, performing reflux reaction for 2-5 hours, stopping heating, stirring, cooling, and performing vacuum filtration to obtain a light yellow granular edaravone rough product; and (3) recrystallizing the edaravone rough product obtained in step (2) by using absolute ethanol, performing vacuum filtration and drying to obtain white crystalline powder solid, namely an edaravone finished product. The method has the advantages of low cost, high yield and high purity; and the problems existing in the conventional edaravone synthesis process are solved.
Description
technical field [0001] The invention belongs to the technical field of medicinal chemistry, and in particular relates to an optimized synthesis method of Edaravone. Background technique [0002] Edaravone, chemical name: 2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-one, molecular formula: C 10 h 10 N 2 O, molecular weight: 174.20, structural formula: [0003] [0004] Edaravone is a new cerebral infarction therapeutic drug that removes harmful factors (free radicals) and protects nerve cells in the acute stage of cerebral infarction. Clinical studies have shown that N-acetylaspartic acid (NAA) is a specific marker of surviving nerve cells, and its content decreases sharply in the early stage of cerebral infarction. When patients in the acute stage of cerebral infarction were given edaravone, the reduction of local cerebral blood flow around the infarction was improved, and the content of NAA in the brain on day 28 after the onset was significantly higher than that of the ...
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