Acetic Anhydride → 5-Acetoxy-3,4-dihydrobenzofuran-6-carboxaldehyde

Participants

Reaction Steps

A solution of 5-hydroxy-2,3-dihydrobenzofuran-6-carboxaldehyde (5.0 g, 0.030 mol) in pyridine (10 ml) was cooled to an internal temperature of -5° C. Acetic anhydride (3.2 g, 0.03 mol) was added dropwise. The cooling bath was removed and the mixture was allowed to stir under nitrogen for 18 hours. The reaction was quenched into water (50 ml) at which time the product crystallized and was collected by filtration. The product was dissolved in methylene chloride (100 ml) and was washed with water (25 ml), saturated sodium bicarbonate (25 ml) saturated sodium chloride (25 ml), dried (MgSO4) and concentrated to a dark oil which solidified on standing. The product was ground, washed with ethyl ether and dried to afford 5-acetoxy-3,4-dihydrobenzofuran-6-carboxaldehyde (4.6 g, 74%). m.p. 68°-70° C.

Provenance & Evidence