Modified Algar-Flynn-Oyamada reaction for the synthesis of 3-hydroxy-2-styryl-chromen-4-ones under solvent-free conditions

A simple and efficient condition for Algar-Flynn-Oyamada reaction for the synthesis of 3-hydroxy-2-styryl-chromen-4-ones involving grinding of different 1-(2'-hydroxy-phenyl)-5-aryl-penta-2,4-dien-1-ones with UHP (urea-hydrogen peroxide), pulverized potassium hydroxide and few drops of ethanol at room temperature under solvent-free conditions has been described. A faster reaction and higher yields compared to the conventional methods are the advantages of present protocol. The structure of the synthesised compounds was identified from their spectral data (IR, ¹H-NMR).