A sealable vial was charged with (+)-sodium L-ascorbate (0.048 g, 0.241 mmol, Arcos Organics), sodium azide (0.470 g, 7.20 mmol, Aldrich), copper(I) iodide (0.138 g, 0.723 mmol, Aldrich), and N-((4S,6S)-4-(5-bromo-2-fluorophenyl)-4-(fluoromethyl)-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-oxazin-2-yl)benzamide (1.15 g, 2.41 mmol, step 8). The sealed vial was evacuated and backfilled with nitrogen gas. EtOH (5.62 ml) was added followed by water (2.41 ml) and trans-N,N′-dimethylcyclohexane-1,2-diamine (0.069 g, 0.482 mmol). The reaction was stirred in a pre-heated 80° C. oil bath for 16 hours. The reaction mixture was cooled to RT and partitioned between water and EtOAc. The organic layer was washed with brine, dried over magnesium sulfate and concentrated under reduced pressure. The crude residue was taken up in MeOH (20 mL) and sodium borohydride (0.091 g, 2.41 mmol, Aldrich) was added. The reaction was stirred at room temperature for 30 minutes. The reaction was quenched with water and further diluted with water and EtOAc. The organic layer was washed three times with a solution of aqueous saturated ammonium hydroxide and aqueous saturated ammonium chloride solution (1:9), and brine. The organic phase was dried over magnesium sulfate and concentrated under reduced pressure to afford the crude title compound as a grey oil, which was used without further purification assuming theoretical yield. MS m/z=413.9 [M+H]+. Calculated for C19H16F5N3O2: 413.341.
