To a solution of (4-[4-(3-pyrrolidin-1-ylpropoxy)phenyl]tetrahydropyran-4-yl}methylamine (254 mg, 0.798 mmol) in dichloroethane (5 mL) under nitrogen atmosphere were added acetic acid (37 mg, 1.6 mmol), triethylamine (97 mg, 1.6 mmol) and cyclopentanone (10 mg, 1.19 mmol). The mixture was stirred for 30 min at ambient temperature and NaHB(OAc)3 (204 mg, 1.6 mmol) was added at 0° C. After stirring overnight, the reaction mixture was filtered over celite, concentrated in vacuo and purified by column chromatography on silica gel eluting with DCM:MeOH:NH3 (89:10:1) to give the title compound (226 mg, 58%). 1H NMR (400 MHz, CDCl3) δ 7.20 (d, 2H), 6.88H), 4.03 (t, 2H), 3.78-3.73 (m, 2H), 3.59-3.53 (m, 2H), 2.84 (q, 1H), 2.73 (t, 2H), 2.65-2.68 (m, 6H), 2.03-2.12 (m, 4H), 1.84-1.94 (m, 6H), 1.65-1.72 (m, 2H), 1.51-1.58 (m, 2H), 1.41-1.46 (m, 2H), 1.07-1.16 (m, 2H).
