Water → 4-Fluoro-2-hydroxybenzonitrile

To a solution of 1 g of 4-fluoro-2-methoxy-benzonitrile in 15 mL of dichloroethane was added 1.1 g of aluminum trichloride. The resulting mixture was refluxed for 1 day then poured slowly into water and extracted with ethyl acetate. The organic extracts were washed twice with 10% aqueous solution of sodium hydroxide. The combined basic layers were washed twice with ethyl acetate, acidified with concentrated aqueous solution of hydrochloric acid and extracted three times with ethyl acetate. The combined organic extracts were washed with water, with brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 0.78 g of 4-fluoro-2-hydroxy-benzonitrile as a white solid.