To a stirred solution of N-(4-chloro-5-formylpyridin-2-yl)acetamide (3 g, 15.11 mmol), (4-chloro-2-fluorophenyl)boronic acid (2.63 g, 15.11 mmol), cesium carbonate (9.84 g, 30.2 mmol) in a mixture of water (8 mL) and THF (25 mL) was added tetrakis(triphenylphosphine)palladium (19.19 mg, 0.017 mmol) and the reaction was heated to 85° C. overnight (14 h). The reaction mixture was diluted with water (25 mL) and extracted with EtOAc (2×25 mL). The combined organic layers were washed with water (25 mL), brine (25 mL), dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (hexane/EtOAc as eluant), yielding N-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide as an off-white solid (2.8 g, 9.01 mmol, 60% yield). LC/MS (ESI) m/e 291.0 [(M)−, calcd for C14H9ClFN2O2 291.0], LC/MS retention time (method A): tR=1.69 min; 1H NMR (400 MHz, DMSO-d6) δ 11.14 (s, 1H), 9.84 (d, J=Hz, 1H), 8.88 (s, 1H), 8.13 (s, 1H), 7.61 (dd, J=2.00, 10.00 Hz, 1H), 7.46-7.48 (m, 2H), 2.11 (s, 3H).
