To a solution of 4-[2-ethyl-4-(3-methylphenyl)-1,3-thiazol-5-yl]-2-pyridylamine (0.80 g, 2.7 mmol) in tetrahydrofuran (8 mL) was added phenylacetyl chloride (0.47 mL, 3.0 mmol), and triethylamine (0.41 mL, 3.0 mmol) was added to the obtained mixture. The reaction mixture was stirred at room temperature for 2 hrs. Saturated aqueous sodium hydrogen carbonate solution was added and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried and concentrated. The residue was purified by silica gel column chromatography (hexane-ethyl acetate 20:1–4:1) and crystallized from isopropyl ether to give the title compound (0.75 g, yield 67%).
