7-hydroxy-4-(pyridin-3-yl)coumarin → 7-Bromo-4-(pyridin-3-yl)-2H-1-benzopyran-2-one

Participants

Reaction Steps

Commercially available 7-hydroxy-4-(3-pyridyl)coumarin (1.48 g, 6.19 mmol) and triphenylphosphine dibromide (5.22 g, 12.4 mmol) are heated in a sand bath at 320-350° C. for 1.5 h. The cooled solid is taken up with ethanol (200 ml) and silica gel (100 g) and evaporated to dryness. Column chromatography (toluene/acetone; 80:20) affords 7-bromo-4-pyridin-3-yl-2H-chromen-2-one.

Provenance & Evidence