A novel approach to the synthesis of 6-amino-7-hydroxyflavone

Abstract

A novel approach to the synthesis of 6-amino-7-hydroxyflavone (1) is described. Reaction in acetone of 2′,4′-dihydroxy-5′- nitroacetophenone and benzoyl chloride in the presence of potassium carbonate affords 3-benzoyl-7-hydroxy-6-nitroflavone, which is cleaved in 5% ethanolic potassium hydroxide to give 1-(2,4-dihydroxy-5-nitrophenyl)-3-phenyl-1,3- propanedione. The 1,3-diketone thus formed is then transformed into 7-hydroxy-6-nitroflavone, followed by reduction to afford the title compound.