2-Benzyloxy-3-methoxybenzaldehyde (benzyl-o-vanillin) can be prepared from the reaction of o-vanillin with benzyl bromide in acetone (solvent) and K2CO3 (base) in the presence of tetra-n-butylammonium iodide (catalyst). The dihedral angle between the two benzene rings in 2-benzyloxy-3-methoxybenzaldehyde crystal is 23.33 (6)°. Crystal structure suggests that all O atoms are involved in intra and intermolecular C-HO interactions. It has been reported as key reagent for the synthesis of new anticancer drugs. It is an important pharmacophore in drug discovery. It exhibits anti-proliferative activity in HL60 leukemia cancer cells.