Hydrochloric Acid → [5-(Trifluoromethyl)pyridin-3-yl]boronic acid

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Reaction Steps

A cooled (−78° C.) solution of 3-bromo-5-(trifluoromethyl)pyridine (5 g, 22.1 mmol) in dry THF (50 ml), under an inert atmosphere of argon, is treated with triethyl borate (3.39 g, 23.21 mmol) followed by drop wise addition of 1.46M n-BuLi in hexanes (15.2 ml, 24.34 mmol). The reaction mixture is allowed to warm to room temperature overnight and treated with 5M HCl (100 ml). After stirring for 30 minutes, the THF is removed in vacuo and the aqueous layer is extracted with EtOAc (4×100 ml). The aqueous portion is concentrated in vacuo and dried under vacuum overnight to afford the title compound as the hydrochloride salt. [M+H]+ 168.

Provenance & Evidence