反应详情

To a solution of 3-bromo-4-methoxyaniline IV (2.0 g, 9.90 mmol) in AcOH (25.0 mL) was added ammonium thiocyanate (3.80 g, 49.50 mmol) and the reaction mixture was stirred at room temperature for 1 h. The reaction mixture was then cooled to 0° C. followed by addition of a solution of Br2 (0.60 mL, 11.0 mmol) in AcOH (10.0 mL). The reaction mixture was then allowed to stir at room temperature for 2 h. After the completion of the reaction (TLC monitoring), AcOH was distilled off, and the residue was cooled to 0° C. followed by basification with aqueous NH3 till pH 12 and extraction with EtOAc (2×250 mL). The combined organics was washed with brine, dried (Na2SO4), filtered and concentrated under reduced pressure to obtain the desired product (2.0 g, 78%). 1H NMR (400 MHz, DMSO-d6): δ 3.80 (s, 3H), 7.41 (br s, 2H), 7.49 (s, 1H) and 7.50 (s, 1H).

1. temperatureThe reaction mixture was then cooled to 0° C.
2. stirringto stir at room temperature for 2 h
3. distillationwas distilled off
4. temperaturethe residue was cooled to 0° C.
5. extractionfollowed by basification with aqueous NH3 till pH 12 and extraction with EtOAc (2×250 mL)
6. washThe combined organics was washed with brine
7. dry with materialdried (Na2SO4)
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure