Acetic Acid → 7-methoxy-3,4-dihydro-2H-1-benzopyran-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To 7-methoxy-4-(trimethylsilyloxy)-3,4-dihydro-2H-chromene-4-carbonitrile (1.62 g, 5.84 mmol) in acetic acid (15 mL) and HCl (15 mL) was added SnCl2 dihydrate (5.27 g, 23.4 mmol). The reaction was heated at 130° C. for 1 day. The reaction was cooled, diluted with dichloromethane (50 mL) and washed with water (50 mL) and brine (50 mL). The combined organic layers were dried over magnesium sulfate and concentrated. The residue was chromatographed over silica gel using a gradient of 0.5% MeOH/CH2Cl2 containing 0.5% acetic acid to 10% MeOH/CH2Cl2 containing 0.5% acetic acid to provide the title compound (0.95 g, 78.1% yield).

Provenance & Evidence