反应详情

To a solution of 3-amino-5-hydroxy-4-iodo-benzoic acid (0.20 g, 0.72 mmol, 1.0 equiv) in methanol (5 mL) was added conc. sulfuric acid (0.20 mL, 0.035 g, 0.36 mmol, 0.5 equiv) and the reaction mixture heated to reflux. After 2 h, the reaction mixture was poured on ice, the pH adjusted to 9 by addition of a sat. solution of sodium hydrogencarbonate and extracted with ethyl acetate (2×50 mL). The combined organic phases were dried over MgSO4, concentrated by evaporation under reduced pressure and the crude material purified with column chromatography on silica eluting with hexane/ethyl acetate (1:1) providing 0.07 g (33%) of the title compound. 1H NMR (250 MHz, DMSO): δ 3.78 (s, 3H), 5.45 (br s, 2H), 6.68 (s, 1H), 6.85 (s, 1H), 10.32 (br s, 1H). MS (EI): 293.0 [M]+.

1. temperaturethe reaction mixture heated to reflux
2. additionthe reaction mixture was poured on ice
3. extractionextracted with ethyl acetate (2×50 mL)
4. dry with materialThe combined organic phases were dried over MgSO4
5. concentrationconcentrated by evaporation under reduced pressure
6. customthe crude material purified with column chromatography on silica eluting with hexane/ethyl acetate (1:1)