- Improved method for synthesizing febuxostat key intermediate
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The invention relates to an improved cyanation reaction method for synthesizing febuxostat. According to the method, the feeding ratio of a compound II to hydroxylamine hydrochloride to sodium formateis 1:1.3:1.3, the amount of formic acid is 8-15 times by volume, the reaction temperature is 90-130 DEG C, the reaction time is 4-10 hours, after the reaction is finished, the temperature is reducedto 40-80 DEG C, an aftertreatment solvent is dropwise added into reaction liquid, after dropwise adding is finished, the temperature is reduced to 10-35 DEG C, fand iltering and drying are performed,so that an intermediate compound (III) with less than 0.10% of related substances.
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Paragraph 0020-0021; 0024-0025
(2021/01/15)
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- PROCESS FOR THE PREPARATION OF 2-[3-CYANO-4-(2-METHYLPROPOXY)PHENYL]-4-METHYLTHIAZOLE-5-CARBOXYLIC ACID AND ITS PHARMACEUTICALLY ACCEPTABLE SALTS
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The present invention relates to novel and improved processes for the preparation of 2-[3-cyano-4-(2-methylpropoxy) phenyl]-4-methylthiazole-5-carboxylic acid compound of formula-1 and its pharmaceutically acceptable salts thereof. the present invention also provides the novel process for the preparation of crystalline forms of 2-[3-cyano-4-(2-methylpropoxy) phenyl]-4-methylthiazole-5-carboxylic acid compound of formula-1 and its intermediates.
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- PROCESSES FOR PREPARING FEBUXOSTAT
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Febuxostat can be prepared from the compound of the following formula (VI); Formula (VI) has been prepared in a one-pot process by combining a compound of the following formula (II); with an organic solvent, isobutyl halide and an inorganic base, to obtain a compound of the following formula (III); Formula III is optionally filtered before combining it with hydroxylamine base or hydroxylamine HCl. A water scavenger is added to obtain the compound of formula VI. Febuxostat can then be prepared, for example, by combining the compound of formula VI with one organic solvent and an alkali metal hydroxide.
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Page/Page column 18
(2011/04/18)
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