A sealable vial was charged with (4S,6S)-4-(5-bromo-2-fluoropyridin-3-yl)-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-oxazin-2-amine (5l, 0.093 g, 0.261 mmol), 5-chloropicolinamide (intermediate 18, 0.082 g, 0.522 mmol), copper(I) iodide (10 mg, 0.052 mmol) and potassium carbonate (0.108 mg, 0.783 mmol). The vial was purged with Nitrogen, followed by the addition of 1,4-dioxane (2.0 mL) and (1R,2R)-N,N′-dimethyl-cyclohexane-1,2-diamine (0.033 mL, 0.209 mmol). The vial was sealed and heated to 125° C. for 17 h. The reaction mixture was allowed to cool to room temperature and partitioned between EtOAc and water. The aqueous layer was backextracted with EtOAc. The combined organic layers were washed with brine and dried over sodium sulfate. The filtrate was concentrated and the residue was purified by reversed-phase preparative HPLC using a Phenomenex Gemini column, 10 micron, C18, 110 Å, 100×50 mm, 0.1% TFA in CH3CN/H2O, gradient 10% to 80% over 20 min. The product containing fractions were combined and neutralized with aqueous saturated sodium bicarbonate solution. The free-based product was extracted with DCM. The organic phase was dried over MgSO4 and the solvent was removed under reduced pressure to afford the title compound (0.060 g, 0.139 mmol, 53.2% yield) as white solid (free base). MS m/z=432.0 [M+H]+. Calculated for C17H14ClF4N5O2: 431.8
