THE REACTION OF 4-AMINOCOUMARIN WITH β-CARBONYL-SUBSTITUTED 4Н-CHROMENES: SYNTHESIS OF 5H-CHROMENO[4,3-b]PYRIDIN-5-ONE DERIVATIVES

Abstract

Reactions of 4Н-chromene-3-carbaldehydes and 1Н-benzo[f]chromene-3-carbaldehydes with 4-aminocoumarin were used to obtain a series of pyridocoumarin derivatives containing a 2-hydroxybenzyl or 2-hydroxy-1-naphthyl substituent at the β-position relative to the nitrogen atom. The reaction mechanism includes a Michael reaction, chromane ring opening, and cyclodehydration.