2-Fluorophenylboronic acid

1072-85-1

1993-03-9

The general procedure for the synthesis of 2-fluorophenylboronic acid from o-bromofluorobenzene was as follows: 10.0 g (57.1 mmol) of 1-bromo-2-fluorobenzene and anhydrous tetrahydrofuran were added to a reaction flask and the mixture was subsequently cooled to -70 °C. At -70 °C, 44.2 ml (68.5 mmol) of 1.55 M n-butyllithium solution was slowly added dropwise to the reaction mixture. The temperature was maintained at -70 °C and stirring of the reaction mixture was continued for 1.5 hours. Subsequently, 21.5 g (114.2 mmol) of triisopropyl borate was added dropwise and the reaction temperature was gradually raised to room temperature and stirring was continued for 4 hours. Upon completion of the reaction, aqueous hydrochloric acid was added to the reaction mixture and extracted with dichloromethane. The organic phases were combined and the solvent was removed by distillation under reduced pressure to give the crude product of 2-fluorophenylboronic acid. The crude product was purified by column chromatography (eluent: hexane/acetone) to give 4.8 g (yield: 61%) of pure 2-fluorophenylboronic acid.