Transformation routes of tetrafluoroflavones in the reactions with aliphatic amines

Routes of modification of 5,6,7,8-tetrafluoro-3-methoxycarbonyl-2-(4-methoxyphenyl)-4H-chromen-4-one and its decarboxylated analogs in the reactions with aliphatic amines were studied and the biological activity of both the starting compounds and the products was tested. It was found that 5,6,7,8-tetrafluoro-3-methoxycarbonyl-2-(4-methoxyphenyl)-4H-chromen-4-one under the action of primary amines underwent the flavone-coumarin rearrangement through the addition of the amine at the C(2) atom. 7-Amino-substituted flavones were formed as by-products in the reactions with methyl- and benzylamines and as major products in the reactions with pyrrolidine. The process of nucleophilic aromatic substitution at the C(7) atom becomes a key one in the reactions of decarboxylated tetrafluoroflavones with primary amines and pyrrolidine. Mechanisms for the studied transformations were proposed. The starting tetrafluoroflavones were found to exhibit high antifungal activity, while antigonorrheal agents were revealed among the products of their transformations.