7-Methoxyflavone

52752-67-7

22395-22-8

1-(2-Hydroxyphenyl)-3-aryl-1,3-propanedione 1a (0.5 g) was mixed with malic acid (1.0 eq.) and placed in an oil bath preheated to 140 °C and reacted for 10 min; or in a microwave reactor for 5 min. The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the reaction mixture was cooled to room temperature and diluted by adding water (10 mL) and ethyl acetate (10 mL). Subsequently, solid NaHCO3 was added to neutralize the reaction mixture. The organic layer was separated and the aqueous layer was further extracted with ethyl acetate (2 x 10 mL). All organic extracts were combined and dried with anhydrous sodium sulfate and subsequently concentrated under vacuum. The crude product was purified by silica gel column chromatography using a mixed solvent system of hexane-ethyl acetate to give the target product 7-methoxy-2-phenyl-4H-benzopyran-4-one in high yield.