Facile Synthesis of 4-Hydroxycoumarins by Sulfur-Assisted Carbonylation of 2′-Hydroxyacetophenones with Carbon Monoxide

Abstract

4-Hydroxycoumarins (4-hydroxy-2-oxo-2H-1-benzopyrans) were synthesized in good to excellent yields by C-carbonylation of 2′-hydroxyacetophenones with carbon monoxide in the presence of sulfur and bases. This is the first example of sulfur-assisted C-Carbonylation with carbon monoxide.