Preparation method of 3'-hydroxygenistein

Abstract

This invention relates to a method for preparing 3'-hydroxy pyrrolidone (Orobol). The method uses phloroglucinol as a starting material, which undergoes a condensation reaction with (3,4-dimethoxyphenyl)acetonitrile under the catalysis of hydrogen chloride and zinc chloride. Following this, a cyclization reaction is carried out using a Vilsmeier reagent formed from methanesulfonyl chloride and dimethylformamide. Finally, a demethylation reaction is performed using pyridine hydrochloride to obtain 3'-hydroxy pyrrolidone. This method offers advantages such as fewer reaction steps, high overall yield, good purity, and the use of low-cost catalysts, making it suitable for industrial-scale production.

Claims

1. A method for preparing 3'-hydroxy pyrogallol, comprising the following steps: Step S1: Phloroglucinol and (3,4-dimethoxyphenyl)acetonitrile are subjected to a condensation reaction under the catalysis of hydrogen chloride and zinc chloride to obtain 2-(3,4-dimethoxyphenyl)-1-(2,4,6-trihydroxyphenyl)ethyl ketone; Step S2: The 2-(3,4-dimethoxyphenyl)-1-(2,4,6-trihydroxyphenyl) ethyl ketone is subjected to a cyclization reaction with the Vilsmeier reagent formed by methanesulfonyl chloride and dimethylformamide to obtain an intermediate cyclized product; and Step S3: The intermediate cyclized product is mixed with pyridine hydrochloride to undergo a demethylation reaction to obtain 3'-hydroxy dystomatone, wherein Step S1 is carried out in diethyl ether solvent, and Step S1 is first stirred with hydrogen chloride gas at 0°C for 30 minutes, and then stirred at room temperature for 22 hours to obtain an intermediate product insoluble in diethyl ether. The intermediate product is then added to 1N hydrogen chloride solution and reacted at 100°C for 2 hours to obtain the 2-(3,4-dimethoxyphenyl)-1-(2,4,6-trihydroxyphenyl) ethyl ketone; Step S2 involves reacting at 55°C for 7.5 hours, then cooling to room temperature and adding water to precipitate the intermediate cyclized compound; and step S3 involves reacting at 120°C for 19 hours, then cooling to room temperature and washing with water to obtain the 3'-hydroxy dye xanthophyllone.

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