A solution of 4-(4-nitro-2-(trifluoromethyl)phenoxy)piperidine (1.0 g, 1.0 eq, 3.5 mmol) and oxetan-3-one (0.35 g, 1.4 eq, 4.8 mmol) in 1,2-dichloroethane (50 mL) was stirred at room temperature for 30 minutes. Sodium triacetoxyborohydride (1.3 g, 1.8 eq, 6.2 mmol) was added in portions to the above solution and the heterogeneous mixture was stirred at room temperature overnight. The reaction mixture was diluted with CH2Cl2 (50 mL) and pardoned with aqueous saturated NaHCO3 solution (100 mL). The layers were separated and the organic layer was washed with brine solution (2×50 mL). The combined organic layers were dried over Na2SO4. Removal of the solvents and purification of the crude mixture by column chromatography on silica gel (ISCO System) using 20% MeOH in CH2Cl2/CH2Cl2 (gradient system from 0:1 to 1:9) as eluent gave the product in 77% yield.
