36914-77-9

140675-42-9

General procedure for the synthesis of 1-(3,5-difluoro-2-hydroxyphenyl)ethanone from 2,4-difluorophenyl acetate: a mixture of intermediate 362 (2 g, 11.6 mmol) and aluminum trichloride (2.8 g) was heated under argon protection at 150 °C for 30 min. After completion of the reaction, it was cooled to room temperature and ice water was added cautiously followed by dropwise addition of 1N aqueous hydrochloric acid solution. The mixture was decanted in the presence of toluene and the organic phase was separated and washed sequentially with water and saturated aqueous sodium chloride. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the solid product intermediate 363 (1.5 g). The product was characterized as follows: 1H NMR (300 MHz, CDCl3): δ 12.00 (m, 1H), 7.25 (m, 1H), 7.10 (m, 1H), 2.65 (s, 3H). ir (cm-1): 1651.