The synthesis and biological evaluation of A- and B-ring fluorinated flavones and their key intermediates

An efficient three-step method for the synthesis of new polyfluoroflavones has been proposed using substituted benzoyl chlorides and 2-hydroxyacetophenone to form the initial 2-(polyfluoroaroyloxy)acetophenones, which are transformed into 1,3-diaryl-1,3-diketones as a result of the Baker-Venkataraman rearrangement. The ability of these 1,3-diketones to undergo keto-enol and ring-chain tautomerism was found, depending on the nature of the solvent. Under acid- or base-catalyzed conditions the alternative cyclization routes of fluorine-containing 1,3-diaryl-1,3-diketones into A- and B-ring halogenated flavones have been reported. The anti-influenza and fungistatic effects of the synthesized compounds were evaluated, and products with promising antimicrobial properties were found.