Boron tribromide → 2-Hydroxy-6-methyl-4-phenoxy-benzaldehyde

Participants

Reaction Steps

A light yellow solution of 2-methoxy-6-methyl-4-phenoxy-benzaldehyde (6.33 g, 26.13 mmol) in DCM (250 mL) was treated with boron tribromide (1.0 M solution in DCM, 76 mL, 76 mmol) dropwise at −78° C. (dry ice/acetone bath). The red/brown mixture was stirred at −78° C. for 30 minutes, 0° C. (ice-water bath) for 30 minutes, then rt for 3 h. The mixture was quenched with ice water, then extracted with EtOAc. The extracts were washed with brine, dried (Na2SO4), filtered, and concentrated to a brown residue. The residue was purified by column chromatography (SiO2, EtOAc/hexanes; 1:9) to afford 2-hydroxy-6-methyl-4-phenoxy-benzaldehyde (5.06 g, 85%), as a white solid. 1H NMR (400 MHz, CDCl3) δ 12.32 (s, 1H), 10.14 (s, 1H), 7.42 (t, J=7.42 Hz, 2H), 7.30-7.21 (m, 1H), 7.08 (d, J=7.42 Hz, 2H), 6.35 (s, 1H), 6.21 (s, 1H), 2.54 (s, 3H).

Provenance & Evidence