反应详情

Methyl 4-hydroxy-2-methoxybenzoate (10 g, 55 mmol) from step 3 above and 1-fluoro-3,5-dichloropyridinium trifluoromethanesulfonate (21 g, 66 mmol) were refluxed in dichloromethane (250 mL) for 48 h. The solution was washed with 5% aqueous citric acid (250 mL) and the organic phase was dried (MgSO4), filtered, and the solvent was removed under reduced pressure. The residue was purified by pressurized silica gel column chromatography using 99:1 CH2Cl2 :MeOH as eluant. Crystallization from ether gave methyl 5-fluoro-4-hydroxy-2-methoxybenzoate.

1. washThe solution was washed with 5% aqueous citric acid (250 mL)
2. dry with materialthe organic phase was dried (MgSO4)
3. filtrationfiltered
4. customthe solvent was removed under reduced pressure
5. customThe residue was purified by pressurized silica gel column chromatography
6. customCrystallization from ether