Combine 2,4,6-trifluoro-N-[6-(piperidin-4-yloxy)pyridin-2-yl]-benzamide (example 84, 250 mg, 0.71 mmol), propionaldehyde (124 mg, 2.14 mmol), acetic acid (85 mg, 1.42 mmol), molecular sieve 4 Å (0.4 g) and THF (6 mL), stir for 15 min. Then add NaBH(tri-acetate) portionwise and stir for 3 hr. Quench the reaction with 0.1N NaOH, extract with methylene dichloride three times. Combine the organic layers, dry over Na2SO4, filter and concentrate to give a residue. Chromatography (silica gel) eluting with 5% 2M NH3-methanol in methylene dichloride provides 192 mg (69%) of the title compound: mass spectrum (ion spray): m/z=394.1 (M+1); 1H NMR (CDCl3, ppm): 8.00 (s, br, 1H), 7.84 (d, br, 1H), 7.64 (t, 1H), 6.78 (m, 2H), 6.52 (d, 1H), 4.94 (m, 1H), 2.75 (m, 2H), 2.32 (m, 4H), 2.04 (m, 2H), 1.85 (m, 2H), 1.55 (m, 2H), 0.92 (t, 3H). Mono-hydrochloride salt: Anal calcd for C20H22F3N3O2.HCl.0.25H2O: C, 55.30; H, 5.45; N, 9.67. Found: C, 55.13; H, 5.36; N, 9.61.
