Synthesis
General procedure for the synthesis of 2-(4-fluorophenyl)thiazole-5-carboxaldehyde from 2-bromo-5-formylthiazole and 4-fluorophenylboronic acid: 4-fluorophenylboronic acid (7.29 g, 52.08 mmol) was added to a mixture of 2-bromo-5-thiazole-carboxaldehyde (5.0 g, 26.04 mmol) in a solution of toluene (150 mL) and ethanol (75 mL), protected by argon, 2M aqueous sodium carbonate (73.58 mL) and tetrakis(triphenylphosphine)palladium (1.5 g, 1.3 mmol). The reaction mixture was heated and stirred at 85 °C for 6 hours. Upon completion of the reaction, the reaction mixture was concentrated under reduced pressure and the residue was diluted with water (150 mL) and extracted with ethyl acetate (5 x 500 mL). The organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. The crude product was purified by silica gel column chromatography (eluent: hexane solution of 10% ethyl acetate) to give 2-(4-fluorophenyl)thiazole-5-carboxaldehyde as an off-white solid (200 mg, 88% yield).1H NMR (400 MHz, DMSO-d6) δ: 10.06 (s, 1H), 8.74 (s, 1H), 8.14-8.11 (m 2H), 7.39 (t, 2H); LC-MS m/z calculated value [M+H]+ 208.02, measured value 207.9.
