Acetic Acid → Methyl 2-amino-5-fluoro-3-hydroxybenzoate

Reaction equation

[F:1][C:2]1[CH:3]=[C:4]([OH:15])[C:5]([N+:12]([O-])=O)=[C:6]([CH:11]=1)[C:7]([O:9][CH3:10])=[O:8].C(O)(=O)C>CO.[Pd]>[NH2:12][C:5]1[C:4]([OH:15])=[CH:3][C:2]([F:1])=[CH:11][C:6]=1[C:7]([O:9][CH3:10])=[O:8]

Participants

Procedure

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.