Hydrochloric Acid → (3-Ethoxy-4-methoxyphenyl)boronic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-Bromo-2-ethoxy-1-methoxybenzene (4.00 g, 17.3 mmol) in THF (75 mL) was cooled to −78° C.; during cooling, a precicipitate formed. t-BuLi (22.4 mL, 1.7 M in pentane, 38.1 mmol) was added dropwise, while maintaining the temperature at −78° C. The mixture was stirred at −78° C. for 1 hour following completion of the addition. B(Oi-Pr)3 (9.76 g, 51.9 mmol) was added. The mixture was allowed to gradually warm to room temperature, and then stirred under nitrogen for 16 hours. 3N HCl (20 mL) was added, and the mixture stirred for 10 minutes. The mixture was poured into water (100 mL) and extracted with diethyl ether (3×75 mL), and the combined ethereal layers were washed with water (3×75 mL), dried (MgSO4) and evaporated, providing 3.15 g of the product in 93% yield: 1H NMR (DMSO-d6) δ 1.32 (t, J=7.0 Hz, 3H), 3.75 (s, 3H), 3.99 (q, J=7.0 Hz, 2H), 6.90 (d, J=8.3 Hz, 1H), 7.35-7.37 (m, 2H).

Provenance & Evidence