Hydrochloric Acid → 2-Propoxy-3,5-diisopropyl-phenylboronic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of n-BuLi (1.6 M in hexane, 40 mL, 64.2 mmol) in THF (150 mL) at −78° C. was added 1-bromo-3,5-diisopropyl-2-propoxy-benzene (Intermediate 3,16.0 g, 53.5 mmol) in THF (50 mL and 10 mL rinse) slowly. Thereafter 0.5 h triisopropyl borate (24.7 mL, 107 mmol) in THF (40 mL) was added slowly and the reaction was stirred at −78° C. for 1 h and at room temperature for 2 h. The reaction was then treated with 3M HCl (200 mL) at room temperature for 1.5 h, and extracted with EtOAc (×2). The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The crude product was washed with hexane to give 3.28 g of the title compound as a white solid. The hexane solution was filtered through a pad of SiO2 to give additional 11.0 g of the title compound as a yellow slurry containing minor impurities. This crude material was used in the next step without flirter purification.

Provenance & Evidence