General procedure for the synthesis of 2-fluoro-6-hydroxyacetophenone from 2-fluoro-6-methoxyacetophenone: aluminum chloride (14.3 g, 0.107 mol) was added to an ice-cold solution of intermediate 3 (9.0 g, 53.5 mmol) in dichloromethane (70 mL), followed by slow warming of the reaction mixture to room temperature. After the reaction was carried out for 12 h, the reaction was quenched with aqueous 2N hydrochloric acid and extracted with ethyl acetate. The organic layer was washed sequentially with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give 2-fluoro-6-hydroxyacetophenone as a brown liquid (5.48 g, 66% yield). The product was confirmed by nuclear magnetic resonance hydrogen spectroscopy (1H NMR, CDCl3, 400 MHz): δ 12.72 (s, 1H, OH), 7.40 (m, 1H, Ar-H), 6.78 (d, J = 8.5 Hz, 1H, Ar-H), 6.62 (dd, J = 11.3, 8.3 Hz, 1H, Ar-H), 2.69 (d, J = 7.2 Hz, 3H, CH3).
