反应详情

To prepare this compound, initially 1.0 mL of 98% concentrated sulfuric acid was added to a solution of 5-bromo-2-hydroxy-3-methoxy-benzoic acid, (compound 6) (1.0 g, 4.0 mmol) in 50 ml of methanol. The reaction mixture was refluxed overnight until thin layer chromatography using 20% ethyl acetate and 80% hexane as the mobile phase indicated that the reaction was complete. After evaporating the methanol, the residue was dissolved in 60 mL of ethyl acetate and washed with a saturated NaHCO3 aqueous solution and then brine. After drying with anhydrous sodium sulfate, the solution was concentrated, and the crude product was purified on a silica gel column to isolate the intermediate, 5-bromo-2-hydroxy-3-methoxy-benzoic acid methyl ester. The yield of this intermediate was 94%. The 1H-NMR spectrum (300 MHz, CDCl3) of the purified product was: 3.88 (s 3H), 3.95 (s, 3H), 7.09 (d, 1H), 7.55 (t, 1H), 10.96 (d, 1H).

1. temperatureThe reaction mixture was refluxed overnight until thin layer chromatography
2. customAfter evaporating the methanol
3. dissolutionthe residue was dissolved in 60 mL of ethyl acetate
4. washwashed with a saturated NaHCO3 aqueous solution
5. dry with materialAfter drying with anhydrous sodium sulfate
6. concentrationthe solution was concentrated
7. customthe crude product was purified on a silica gel column