Coumarin-based homoisoflavonoids as precursors in the synthesis of 8-heteroarylmethylcoumarins

series of homoisoflavonoids bearing 3-(het)arylcoumarin moiety were synthesized by cascade reaction of enaminones with 8-dimethyl- aminomethyl-7-hydroxy-3-(het)arylcoumarins. The further reaction of synthesized coumarin-isoflavone hybrids with bidentate nucleophiles led to the formation of substituted 7-hydroxy-8-(1 H -pyrazol-4-ylmethyl)coumarins, 7-hydroxy-8-(isoxazol-4-ylmethyl)- coumarins, and 7-hydroxy-8-(pyrimidin-5-ylmethyl)coumarins.