A solution of 5.23 g (0.0118 mole) of α,α-bis(4-fluorophenyl)-1-(phenylsulfonyl)-4-piperidinemethanol in 100 ml of acetic acid and 20 ml of 2M sulfuric acid was heated at reflux for 2.5 hours and then poured over ice. The mixture was made basic with 50% sodium hydroxide, and the basic mixture was extracted with methylene chloride. The methylene chloride solution was dried (anhydrous sodium sulfate), and the solvent was removed in vacuo. The residue was recrystallized from ether-hexane to give 3.23 g (64.4%) of white crystalline solid, mp 90°-92.5° C.
