To a solution of 5-bromo-1,3-benzodioxole-4-carbaldehyde (0.458 g, 2.00 mmol) in dry dimethoxy-ethane were added Pd(PPh3)4 (5 mol %, 0.10 mmol), 2.5 ml 2M Na2CO3 and 2-formylphenylboronic acid (0.450 g, 3.00 mmol) under argon. The reaction mixture was heated under reflux until the starting material was consumed (monitored by TLC). Then the mixture was poured onto ice-water (30 ml) and the aqueous phase was extracted with dichloromethane (3×30 ml). The combined organic phases were dried over anhydrous MgSO4. The solvent was evaporated in vacuo and the crude product was purified by column chromatography with a mixture of hexane:ethyl acetate (9:1) as the eluent.
