A mixture of 10.0 g (0.033 mole) of α,α-bis(4-fluorophenyl)-4-piperidinemethanol, 4.5 g (0.033 mole) of 3-chloro-N,N-dimethylpropanamide, 14.0 g (0.132 mole) of anhydrous sodium carbonate and 0.3 g (0.002 mole) of potassium iodide in 100 ml of N,N-dimethylformamide was heated on a steam bath for 16 h. The mixture was poured into 2 L of water and extracted three times with 500 ml portions of ethyl acetate. The ethyl acetate fractions were combined, washed with water and brine, dried (MgSO4) and concentrated under reduced pressure to give a glass. Upon trituration with petroleum ether (30°-60° C.) the glass solidified to yield 13.2 g (100%) of a yellow solid. A portion of this solid was recrystallized from ethyl ether to give the title compound as a white solid, mp 134°-135° C.
