

COUMARIN-BASED HOMOISOFLAVONOIDS AS PRECURSORS IN THE SYNTHESIS OF 8-HETEROARYLMETHYLCOUMARINS

Abstract
A series of homoisoflavonoids bearing 3-(het)arylcoumarin moiety were synthesized by cascade reaction of enaminones with 8-dimethylaminomethyl-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-(1H-pyrazol-4-ylmethyl)coumarins, 7-hydroxy-8-(isoxazol-4-ylmethyl)coumarins, and 7-hydroxy-8-(pyrimidin-5-ylmethyl)coumarins.
Keywords
coumarins; homoisoflavonoids; pyrazoles; pyrimidines; inverse electron-demand Diels–Alder reaction.
Latvian Institute of Organic Synthesis - Aizkraukles iela, 21, Riga, LV-1006, Latvia - hgs@osi.lv