To a mixture of 1-ethyl-1,3-dihydro-benzimidazol-2-one (1 g, 6.2 mmol), (S)-(−)-3-chloro-1-phenyl-1-propanol (1.16 g, 6.8 mmol), and triphenylphosphine (1.78 g, 6.8 mmol) in anhydrous THF (25 mL) was added DIAD (1.38 g, 6.8 mmol) under nitrogen at room temperature. The mixture was stirred under nitrogen at room temperature for 18 hrs and solvent removed in vacuo. The residue was purified by a silica gel column (33% ethyl acetate in hexane) to afford 1-[(1R)-3-chloro-1-phenylpropyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one as an oil (0.5g, 26%). MS (ESI) m/z 315.
