Hydrochloric Acid → (2,3-Difluorophenyl)boronic acid

Participants

Reaction Steps

n-Butyllitium (30 cm3, 10M in hexanes, 0.3 mol) was added dropwise to a stirred, cooled (-78° C.) solution of 1,2-difluorobenzene (34.5 g, 0.3 mol) in dry THF (350 cm3) under a atmosphere of dry nitrogen. The reaction mixture was stirred (2.5 h) then a previously cooled (-78° C.) solution of triisopropyl borate (113 g, 0.6 mol) in dry THF (200 cm3) added dropwise at -78° C. The reaction mixture was allowed to warm to room temperature overnight then stirred (1 h) with hydrochloric acid (10%, 300 cm3). The product was extracted into diethyl ether (2×300 cm3), and the combined extracts washed with water and dried (MgSO4). The solvent was removed in vacuo to yield colourless crystals.

Provenance & Evidence