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

Participants

Reaction Steps

Butyllithium (2.5 M in hexanes, 88 ml, 0.219 mol) was added dropwise to a stirred, cooled (−78° C.) solution of difluorobenzene (25.0 g, 0.219 mol) in dry THF (400 ml) under a stream of dry nitrogen. The reaction mixture was maintained under these conditions for 2.5 h and then trimethylborate (45.5 g, 0.438 mol) was added dropwise to the reaction mixture and left overnight to reach room temperature. The reaction mixture was stirred for 1 h with 10% HCl (100 ml) at room temperature. The product was extracted into ether (2×200 ml) and the combined ethereal extracts were washed with water and dried (MgSO4), the solvent was removed under reduced pressure to give white crystals.

Provenance & Evidence