To a solution of methyl 2-bromothiazole-5-carboxylate 1 (222 mg, 1.00 mmol) in acetonitrile (20 mL) were added N-(2-hydroxyethyl)piperazine 14c (156 mg, 1.20 mmol) and potassium carbonate (152 mg, 1.10 mmol) under a N2 atmosphere. The reaction mixture was heated to reflux at 80° C. for 10 h. The reaction mixture was filtered through Celite and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography using silica gel to give the compound 15c (185 mg, 68.2%).
