反应详情

5-Bromo-2,4-dimethoxybenzoic acid (10.0 g) and con sulfuric acid (2.4 g) were added to methanol (80 mL). After reaction at 70° C. for 5 hr, completion of the reaction was confirmed by HPLC. The reaction mixture was cooled and adjusted to pH 7 with 2 mol/L aqueous sodium hydroxide solution, and ethyl acetate (50 mL) was added. The organic solvent was evaporated from the mixture under reduced pressure. To the concentrated residue was added ethyl acetate (50 mL), and the mixture was concentrated again under reduced pressure. To the concentrated residue was added ethyl acetate (70 mL), and the mixture was stirred and partitioned. The obtained organic layer was washed successively with water (50 mL), 5% sodium hydrogencarbonate (50 mL) and water (50 mL). After washing, ethyl acetate was evaporated under reduced pressure to give methyl 5-bromo-2,4-dimethoxybenzoate (9.4 g) (90%).

1. customAfter reaction at 70° C. for 5 hr
2. temperatureThe reaction mixture was cooled
3. additionwas added
4. customThe organic solvent was evaporated from the mixture under reduced pressure
5. additionTo the concentrated residue was added ethyl acetate (50 mL)
6. concentrationthe mixture was concentrated again under reduced pressure
7. additionTo the concentrated residue was added ethyl acetate (70 mL)
8. custompartitioned
9. washThe obtained organic layer was washed successively with water (50 mL), 5% sodium hydrogencarbonate (50 mL) and water (50 mL)
10. washAfter washing
11. customethyl acetate was evaporated under reduced pressure