Hexane → 5-(tert-Butyl)-2-methoxybenzeneboronic acid

Participants

Reaction Conditions

Reaction Steps

n-Butyllithium in hexane (2.5 M, 18.1 mL, 45.24 mmol) was added dropwise to a solution of 2-bromo-4-(tert-butyl)-1-methoxybenzene (10.0 g, 41.13 mmol) and triisopropyl borate (11.39 mL, 49.35 mmol) in tetrahydrofuran (90 mL) at −78° C. under nitrogen. The reaction mixture was stirred at −78° C. for 3 hours then allowed to warm slowly to 0° C. over 90 minutes. The reaction was then quenched by the addition of water (90 mL) and the tetrahydrofuran removed under reduced pressure. The resulting aqueous suspension was partitioned between diethyl ether (80 mL) and 1.0 M aqueous sodium hydroxide solution (100 mL). The aqueous phase was separated, cooled to 0° C. then acidified to pH 1 by the addition of concentrated hydrochloric acid. The resulting white suspension was stood at 0° C. for 15 minutes then filtered washing the solid product with water and cold hexane to give (5-(tert-butyl)-2-methoxyphenyl)boronic acid (6.349 g, 74% yield) as a white crystalline solid.

Provenance & Evidence