(S)-4-(4-((4′-Chlorobiphenyl-2-yl)(hydroxy)methyl)piperidin-1-yl)benzoic acid (INTERMEDIATE 70, 137.4 mg, 0.33 mmol), (R)-4-(4-morpholino-1-(phenylthio)butan-2-ylamino)-3-(trifluoromethylsulfonyl)benzenesulfonamide (INTERMEDIATE 69, 190.3 mg, 0.34 mmol), DMAP (81.0 mg, 0.66 mmol), and EDC (134.5 mg, 0.70 mmol) were placed in a 50 ml flask and flushed with nitrogen. DCM (6.5 ml) was added, and the solution was stirred at room temperature overnight. The reaction mixture was diluted with DCM (40 ml) and washed with 1N aq. sodium bisulfate (35 ml) followed by a saturated aq. sodium bicarbonate (40 ml). The organic layer was dried (Na2SO4), filtered, and evaporated under reduced pressure. The concentrate was purified by column chromatography (ISCO, 12 g silica gel column, eluting with 0→10% MeOH in DCM). Clean fractions were combined, evaporated under vacuum, and dried overnight in a 40° C. vacuum oven to provide the title product as a substantially separated isomer (129.3 mg, yield: 41.5%).
