4-amino-N-(1-(3,4-difluorophenyl)propan-2-yl)-2-(trifluoromethyl)nicotinamide (3.61 g, 10.05 mmol) and 3-(benzyloxy)picolinaldehyde (2.57 g, 12.1 mmol) were combined along with a catalytic amount of 4-toluenesulfonic acid (0.03 g, 0.20 mmol) in anhydrous toluene (150 mL). This was heated at reflux overnight in a round bottom flask fitted with a Dean-Stark trap. The resultant dark solution was cooled to room temperature, concentrated in vacuo to a dark brown oil. This oil was purified by silica gel column chromatography using 30% acetone/hexanes as eluant to provide the product diastereomers as an oil (4.61 g, 82% yield). 1H NMR (400 MHz, CDCl3) δ 8.2 (m, 1H), 8.0 (m, 1H), 7.3-7.6 (m, 7H), 5.15 (d, 2H), 3.0 (dd, 1H), 2.8 (m, 1H), 1.25 (d, 3H). MS m/z 555.2 (M+H)+.
