Water → 4,5-Dimethoxyphthalic acid

Participants

Reaction Steps

To a mixture of 5,6-dimethoxy-3H-isobenzofuran-1-one (4.5 g) and 7% aqueous NaOH (47 ml) was added KMnO4 (4.0 g) diluted in water (125 ml). The mixture was stirred at room temperature for 4 days. Insoluble material was removed by filtration. The filtrate was cooled with ice-water bath and acidified with concentrated HCl. The acidic solution was extracted three times with ethyl acetate (300 ml). The combined organic layers were dried over anhydrous Na2SO4 and evaporated.

Provenance & Evidence