4N HCl in 1,4-dioxane (1 mL) was added to a mixture of 1,1-dimethylethyl 4-[({6-[4-(methylsulfonyl)phenyl]-3-pyridinyl}oxy)methyl]-1-piperidinecarboxylate (462 mg, 1.03 mmol) in 1,4-dioxane (10 mL) at ambient temperature. The mixture was stirred at ambient temperature overnight. The mixture was charged with additional 4N HCl in 1,4-dioxane (1 mL), and stirred at ambient temperature overnight. The mixture was then charged with TFA (2 mL), and stirred at ambient temperature for 4 h. The mixture was concentrated, diluted with water, basified with saturated NaHCO3, and extracted with EtOAc. The organics were dried over MgSO4, filtered, and the filtrate was concentrated. The crude product was purified by reverse-phase preparative HPLC using CH3CN:H2O gradient (5:95 to 75:25) with 0.05% TFA as a modifier to give 107 mg (23%) of 2-[4-(methylsulfonyl)phenyl]-5-[(4-piperidinylmethyl)oxy]pyridine trifluoroacetate as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 8.59-8.50 (m, 1H), 8.44 (d, 1H, J=2.9 Hz), 8.28 (d, 2H, J=8.6 Hz), 8.08 (d, 1H, J=8.8 Hz), 8.00 (d, 2H, J=8.6 Hz), 7.55 (dd, 1H, Ja=8.8 Hz, Jb=3.0 Hz), 4.04 (d, 2H, J=6.2 Hz), 3.40-3.25 (m, 2H), 3.25 (s, 3H), 3.00-2.86 (m, 2H), 2.16-2.06 (m, 1H), 2.05-1.90 (m, 2H), 1.56-1.40 (m, 2H); LRMS (ESI), m/z 347 (M+H).
