Hydrochloric Acid → (6-Methoxypyridin-3-yl)boronic acid

Participants

Reaction Conditions

Reaction Steps

1 g (5.32 mmol) of 5-bromo-2-methoxypyridine is dissolved in 10 ml of absolute tetrahydrofuran and cooled to −78° C. Addition of 0.4 g (6.38 mmol) of a 1.6 M n-butyllithium solution in hexane results in a yellow solution which is stirred at the given temperature for 30 min. Addition of 3 g (15.9 mmol) of triisopropyl borate is followed by stirring for a further hour, during which the solution warms to −20° C. Water is added, and the mixture is stirred overnight. The crude solution is acidified to pH 5 with 1 N hydrochloric acid and extracted twice with ethyl acetate. The organic phase is dried over sodium sulphate, filtered and concentrated, resulting in a pale brown solid which is suspended in diethyl ether and filtered. 0.38 g (47% of theory) of the product is isolated.

Provenance & Evidence