A mixture of 2-(6-chloro-2-oxobenzo[d]oxazol-3(2H)-yl)acetic acid (22.7 mg, 0.1 mmol, 1 equiv), 4-(4-chloro-3-methoxy-phenyl)-piperidin-4-ol hydrochloride (69) (27.7 mg, 1 equiv), BOP (58 mg, 1.3 equiv), triethylamine (56 μL, 4 equiv) in 1 ml of DMF was stirred at room temperature for overnight. The solution was then diluted with EtOAc (50 mL) and washed with water. The organic layer was dried over sodium sulfate and concentrated in vacuo. The crude residue was purified by flash chromatography to provide 6-chloro-3-{2-[4-(4-chloro-3-methoxy-phenyl)-4-hydroxy-piperidin-1-yl]-2-oxo-ethyl}-3H-benzooxazol-2-one (70): MS (ES) [M+H]+ expected 451.1, found 451.1.
