2-Bromo-5-formylthiazole (525 mg, 2.73 mmol) and 4-trifluoromethylphenylboronic acid (519 mg, 2.73 mmol), catalyzed by tetrakis(triphenylphosphine)palladium(0) (95 mg, 0.082 mmol), were mixed with an aqueous solution of 2 M Na2CO3 (5.5 mL, 10.94 mmol) in dioxane (8 mL) The reaction was carried out at reflux for 20 hours. After completion of the reaction, it was cooled to room temperature and extracted with EtOAc and water by partitioning. After separation of the organic phase, it was washed with water and brine sequentially. The organic phase was dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified by column chromatography with EtOAc/hexane as eluent to afford the target compound 2-(4-trifluoromethylphenyl)thiazole-5-carbaldehyde as a yellow solid (145 mg, 21% yield).
