24131-31-5

14615-72-6

To a solution of (3,5-bis(benzyloxy)phenyl)methanol (9.9 g, 31.0 mmol) in dichloromethane (140 mL) was added dimethyl sulfoxide (22 mL, 0.31 mol) and diisopropylethylamine (26.92 mL, 0.154 mol). The reaction mixture was cooled to 0 °C, followed by the addition of sulfur trioxide-pyridine complex (14.76 g, 92.73 mmol). The reaction was stirred continuously at 0 °C for 1 h, after which the reaction was quenched with saturated aqueous sodium thiosulfate solution (310 mL). The reaction mixture was extracted with ethyl acetate (3 x 200 mL) and the organic layers were combined and dried over anhydrous magnesium sulfate. The solvent was removed by evaporation under reduced pressure to afford an oily crude product, which was purified by silica gel column chromatography using dichloromethane as eluent to give 3,5-dibenzyloxybenzaldehyde (9.2 g, 93% yield). The spectral data of the product were in agreement with those reported in the literature.