3-Bromo-N-[(2S)-2-(4-fluorophenyl)-4-oxobutyl]-N-methyl-5-(trifluoromethyl)benzamide (see method 1; 0.16 g, 0.36 mmol) and 1-azetidin-3-yl-4-(azetidin-1-ylcarbonyl)piperidine (see method 2; 0.10 g, 0.47 mmol) were dissolved in methylene chloride (10 mL) together with a small amount of dry methanol (0.2 mL). To the resultant solution were added DIPEA (0.14 g, 1.08 mmol) and sodium triacetoxyborohydride (0.15 g, 0.72 mmol). The mixture was stirred under nitrogen for 4 h at RT. The mixture was diluted with methylene chloride and washed twice with saturated aqueous NaHCO3 and then with brine. The organic phase was filtered through a phase separator and the solvent was removed by evaporation. The product was purified by chromatography on silica gel (methanol-methylene chloride, 10:1). There was obtained 0.14 g (59%) of the title compound as a white foam. 1H NMR (500 MHz, CDCl3): δ 1.4-1.8 (cm, 6H), 2.1 (m, 1H) 2.2 (qn, 2H), 2.3-2.4 (cm, 2H), 2.5-3.5 (cm, 14H), 3.6 (d, 1H), 3.9 (t, 2H), 4.1 (t, 2H), 6.8-7.4 (cm, 6H), 7.7 (s, 1H); LCMS: m/z 654 (M+1)+.
