Phosphoric Acid → 8-Methoxypsoralen

Participants

Reaction Steps

A solution of 40 mg. (0.13 mmole) of 7-acetoxy-6-[2-acetoxyvinyl]-8-methoxycoumarin in 5 ml. of 85% phosphoric acid was heated at 90° for 30 minutes. The solution was cooled and partitioned between water/methylene chloride. The aqueous phase was further extracted with methylene chloride. The organic phases were combined, dried over sodium sulfate, and evaporated to afford pure 9-methoxy-7H-furo[3,2-g][1]benzopyran-7-one, mp 145°-146°, as a crystalline white solid.

Provenance & Evidence