Sodium Carbonate → 5-Chloro-6-phenyl-3-pyridinol

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-bromo-5-chloropyridin-3-ol (Preparation 239, 100 mg, 0.48 mmol), and phenylboronic acid (117 mg, 0.96 mmol) in 1,4-dioxane (5 mL) under nitrogen was added 2M aqueous Na2CO3 solution (1 mL) and palladium tetrakistriphenylphosphine (28 mg, 0.024 mmol). The mixture was stirred at 80° C. for 3.5 hours. The reaction mixture was allowed to cool to room temperature and partitioned between water and EtOAc. The desired product was in the aqueous phase (pH ˜11). The organic phase was washed with 10 wt % aqueous NaOH solution (2×15 mL). The combined aqueous phases were neutralised with 1N aqueous citric acid solution and extracted with EtOAc (4×30 mL). The combined organic phases were washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo to give a crude product. The crude product was purified by silica gel chromatography eluting with 0-30% EtOAc in heptane to give the title compound (67 mg, 68%) as a white solid.

Provenance & Evidence