To a solution of 60 mL of 1,4-dioxane and 10 mL of water was added 4-formylphenylboronic acid (3.0 g, 0.02 mol), followed by 1-bromo-2-methoxy-3-nitro-benzene 1c (4.64 g, 0.02 mol), tetrakis(triphenylphosphine)palladium (1.15 g, 1 mmol) and sodium carbonate (4.24 g, 0.04 mol). Upon completion of the addition, the mixture was heated to reflux for 5 hours. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was filtered and the filter cake was washed with ethyl acetate. The filtrate was concentrated under reduced pressure and the residue was purified by silica gel column chromatography to obtain the title compound 3′-nitro-2′-methoxy-biphenyl-4-carbaldehyde 32a (4.1 g, 80.4%) as a yellow solid.
