To a solution of 5-Formyl-2-methoxyphenylboronic acid (324 mg, 1.8 mmol, 1.5 eq, Frontier Scientific, Inc., Logan, Utah, USA) in dioxane:H2O (2:1; 15 mL) was added 4-bromo-1-fluoro-2-(methylsulfonyl)benzene (300 mg, 1.2 mmol, 1.0 eq., Apollo Scientific Ltd., Stockport, Cheshire, UK), K2CO3 (496 mg, 3.6 mmol, 2 eq.) and Pd(PPh3)4 (30 mg). The mixture was stirred under nitrogen at 140° C. in a microwave for 40 min. Solvent was evaporated and the residue was dissolved in DCM and washed with water. The DCM layer was dried and evaporated. Purification via column chromatography (eluent: PE:EA=3:1) yielded 400 mg (72%) of 3-(4-fluoro-3-(methylsulfonyl)phenyl)-4-methoxybenzaldehyde (27).
