反应详情

To a solution of methyl 5-fluoro-3-hydroxy-2-nitrobenzoate (1.15 g, 5.34 mmol) in a mixture of CH3OH and glacial acetic acid (3:1, 40 mL) was added 10 wt % palladium on activated charcoal (0.20 g, 17 wt %). The suspension was placed in a Parr hydrogenation apparatus under a H2 atmosphere at 50 psi for 1.5 h. The suspension was filtered through diatomaceous earth eluting with CH2Cl2/CH3OH (9:1, 100 mL). Purification by column chromatography (silica gel, 5 to 100% EtOAc in hexanes) afforded methyl 2-amino-5-fluoro-3-hydroxybenzoate (0.80 g, 83%) as a white solid. 1H NMR and MS consistent.

1. filtrationThe suspension was filtered through diatomaceous earth
2. washeluting with CH2Cl2/CH3OH (9:1, 100 mL)
3. customPurification by column chromatography (silica gel, 5 to 100% EtOAc in hexanes)