4-tert-Butoxycarbonylaminobicyclo[2.2.2]octane-1-carboxylic acid (101 mg) was dissolved in dichloromethane (2 mL). To this solution, trichloroacetonitrile (74.0 μL) and triphenylphosphine (196 mg) in dichloromethane (1.5 mL) were sequentially added and the mixture was stirred at room temperature for 2 hours. This was followed by addition of triethylamine (0.18 mL) and 4-chloro-N-methylaniline (98.6 μL) and stirring at room temperature for additional 5.5 hours. The reaction mixture was then poured into aqueous citric acid (5 mL) and was extracted with ethyl acetate (3×10 mL). The ethyl acetate extracts were combined, washed with saturated aqueous sodium bicarbonate solution, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by a silica gel column (eluant:hexane:ethyl acetate=2:1) to give 4-tert-butoxycarbonylamino-N-(4-chlorophenyl)-N-methylbicyclo[2.2.2]octane-1-carboxamide (91.4 mg) as a white powder.
