To a mixture of 3-bromo-5-formylbenzoic acid (8.0 g, 34.9 mmol), p-tolylboronic acid (9.5 g, 70 mmol), toluene (300 mL), cesium carbonate (28 g, 87 mmol), and water (25 mL) under nitrogen was added tetrakis(triphenylphosphine)palladium(0) (2.0 g, 1.7 mmol). The mixture was heated under reflux for 5 h. After cooling, the mixture was filtered through Celite and the filter cake was washed with EtOAc. The filtrate was washed with brine, dried, and concentrated. The residue was purified by column chromatography using methylene chloride:methanol gradient (0-5%) to afford the title compound (4.8 g, 51%). LC-MS: 239.0 [M−1]−.
