Boron tribromide → 5-Bromo-2-fluoro-4-hydroxybenzaldehyde

Participants

Reaction Steps

To the solution of 2-fluoro-4-methoxybenzaldehyde (3 g, 19.5 mmol, 1 eq., Aldrich, Milwaukee, Wis., USA) in DCM (80 mL) was added dropwise BBr3 (14.5 g, 58.7 mmol, 3 eq.) at 0° C. The mixture was stirred for 15 min, then warmed to room temperature and continued to stir for additional 3 h. The reaction was quenched by careful addition of water (50 mL), the organic layer was separated, and remaining the aqueous layer was extracted with DCM (2×50 mL). The combined organic layers were concentrated in vacuo and purified by silica gel chromatography (DCM:MeOH=25:1 to 10:1) to afford 2.2 g (80.6%) of 2-fluoro-4-hydroxybenzaldehyde (24).

Provenance & Evidence