Phosphoric Acid → 8-Methoxypsoralen

Beteiligte Stoffe

Reaktionsschritte

A solution of 2.76 g. (0.010 mole) of 7-acetoxy-8-methoxycoumarin-6-acetaldehyde in 30 ml. of 85% phosphoric acid was heated at 100° for 20 min, cooled and partitioned between water/methylene chloride. The aqueous phase was further extracted with methylene chloride. The organic extracts were combined, dried over sodium sulfate, and evaporated to yield 9-methoxy-7H-furo[3,2-g][1]benzopyran-7-one. Purification was achieved by filtration through a silica gel column, eluting with benzene/ethyl acetate, 4:1. The filtrate was evaporated to afford pure end product, mp 145°-146°.

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