反应详情

温度

70 °C

To a solution of 2-bromo-4-methylbenzoic acid (10 g) in MeOH (50 ml) was added dropwise concentrated sulfuric acid (10 ml) at 0° C. The mixture was heated at 70° C. for 2 hours. After cooling to ambient temperature, the methanol was removed under reduced pressure. The residue was poured into ice-water (100 ml). The mixture was extracted with EtOAc (×2). The combined organic layers were washed with NaHCO3 (aq. sat. Note: gas evolution), brine, dried over MgSO4, filtered, and concentrated to give the product as a clear oil. Yield: 10.5 g, 99%. 1H NMR (400 MHz, Chloroform-d) δ 7.73 (d, 1H), 7.50 (d, 1H), 7.19-7.11 (m, 1H), 3.92 (s, 3H), 2.36 (s, 3H).

1. temperatureAfter cooling to ambient temperature
2. customthe methanol was removed under reduced pressure
3. additionThe residue was poured into ice-water (100 ml)
4. extractionThe mixture was extracted with EtOAc (×2)
5. washThe combined organic layers were washed with NaHCO3 (aq. sat. Note: gas evolution), brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated