Trimethyl borate → (6-Fluoropyridin-3-yl)boronic acid

Participants

Reaction Steps

To a mixture of 5-bromo-2-fluoro-pyridine (1.71 g, 6.20 mmol) in dry ether (100 mL) was added n-BuLi (1.6 M in hexane, 41.4 mL, 0.0663 mol) at −78° C. After 30 minutes, trimethyl borate (8.2 mL, 0.0722 mol) was added to the above mixture and the reaction was warmed to room temperature and stirred overnight. The reaction was quenched with water and brine and acidified with 10% HCl until pH=8. The mixture was extracted with EtOAc, washed with 50% brine, dried over MgSO4, filtered, concentrated to give 5.1 g (60%) of the desired product. The crude product was used in the next step without further purification.

Provenance & Evidence