Potassium Carbonate → 3,5-Dibenzyloxybenzaldehyde

Participants

Reaction Steps

To a mixture of DHBD (24.4 g, 177 mmol) and potassium carbonate (12.2 g, 88.5 mmol) heated at reflux under argon in dry acetone (200 ml) was added dropwise over 12 hours a solution of BzBr (43.4 g, 30.2 ml, 248 mmol) in dry acetone (30 ml). Thin layer chromatography showed very little DHBD after the addition was complete. The reaction mixture was evaporated to dryness and the residue partitioned between dichloromethane/water. The aqueous layer was further extracted with dichloromethane (3×100 ml) and the combined dichloromethane layers extracted with aqueous sodium hydroxide (1N, 3×100 ml). Evaporation of the dichloromethane layers gave 18.1 g of essentially pure 3,5-dibenzyloxybenzaldehyde (34.0% based on DHBD). The sodium hydroxide extracts were acidified with glacial acetic acid, extracted with chloroform (3×100 ml), and the combined chloroform extracts dried and evaporated to dryness. The residue was recrystallized from methanol/water to give 14.5 g of compound XVI (36.0% based on DHBD).

Provenance & Evidence