Hydrochloric Acid → Methyl 3-amino-5-fluoropicolinate

Participants

Reaction Conditions

Reaction Steps

Tin dichloride (45 g, 230 mmol) was added to a solution of 5-fluoro-3-nitropyridine-2-carbonitrile (Ark Pharm, 7.2 g, 43 mmol) in EtOH (80 mL). The mixture was stirred at 90° C. for 2 h, and then concentrated under reduced pressure. Aq. HCl (10 M; 40 mL, 400 mmol) was then added and the mixture was heated under reflux for 6 h. The reaction mixture was then concentrated under reduced pressure and the resulting residue was dissolved in MeOH (120 mL). Thionyl chloride (7.2 mL, 99 mmol) was added. The solution was then stirred at 90° C. for 24 h. The reaction mixture was concentrated under reduced pressure, diluted with EtOAc (300 mL), washed with a saturated aq. NaHCO3 (300 mL) and brine (200 mL), dried over Na2SO4 and concentrated again under reduced pressure. The resulting residue was purified by chromatography on silica gel (0-100% EtOAc in hexanes) to afford the sub-title compound (4.6 g, 63%). LCMS calc. for C7H8FN2O2 (M+H)+: m/z=171.0. found 171.1.

Provenance & Evidence