Acetic Acid → (1-phenyl-1H-pyrazol-5-yl)boronic acid

Participants

Reaction Steps

To a solution of 1-phenyl-1H-pyrazole (20.0 g) in THF (700 mL) was added dropwise n-butyllithium (2.5M hexane solution, 58.3 mL) at −78° C. under a nitrogen atmosphere, and the mixture was stirred at the same temperature for 30 min. To the reaction mixture was added triisopropyl borate (52.2 g) at −78° C., and the mixture was stirred at the same temperature for 1 hr, gradually allowed to be warmed to room temperature, and stirred at room temperature for 20 hr. The pH of the reaction mixture was adjusted to 5 with acetic acid (20 mL), and concentrated to give the title compound (25.0 g).

Provenance & Evidence