50870-44-5

19056-40-7

127-09-3

50870-44-5

General procedure for the synthesis of 1-(4-bromo-3-methoxyphenyl)ethanone from 4-bromo-3-methoxyaniline and sodium acetate: commercially available 4-bromo-3-methoxyaniline (10.2 g, 50.6 mmol) was dissolved in a mixture of concentrated hydrochloric acid and water (11 mL of concentrated hydrochloric acid/25 mL of water) that had been pre-cooled to -5 °C, and sodium nitrite (3.48 g) was added in batches. The reaction mixture was stirred at 0 °C for 1 h, followed by slow transfer to an aqueous solution (20.5 mL) containing acetaldoxime (6.02 g), copper sulfate pentahydrate (2.52 g) and sodium acetate trihydrate (36.64 g) at 0 °C. The resulting mixture was stirred between 0°C and 10°C for 2 hours, then 37% hydrochloric acid (23 mL) was added and the mixture was refluxed for 2 hours. After the reaction mixture was cooled to room temperature, it was extracted with heptane and the organic phase was dried with anhydrous magnesium sulfate. The organic solvent was removed by vacuum evaporation to give a residue which was purified by silica gel column chromatography (eluent was dichloromethane/cyclohexane in a gradual ratio from 50/50 to 90/10). Intermediate 681 (5.9 g) in amorphous solid form was finally obtained.1H NMR (400 MHz; CDCl3): δ 7.55 (d, 1H); 7.50 (d, 1H); 7.40 (dd, 1H); 3.95 (s, 3H); 2.60 (s, 3H).IR (cm-1): 1681.