Boron tribromide → 3-Fluoro-4-hydroxybenzonitrile

Participants

Reaction Steps

BBr3 (23 mL, 0.242 mol) was added to 3-fluoro-4-methoxy-benzonitrile (24.4 g, 0.16 mol; see step (iii) above) in dichloromethane (200 mL) at −78° C. Stirring was continued at room temperature overnight. Another portion of BBr3 (23 mL, 0.242 mol) was added at −78° C. and stirring was continued at RT for a further 2 days under a nitrogen atmosphere. The reaction mixture was quenched with ice water and extracted with dichloromethane. The organic layer was washed with water and brine, and then dried over sodium sulfate. Solvent evaporation under reduced pressure gave 20 g of the sub-title compound as a solid. This was employed directly in the next step without further purification.

Provenance & Evidence