N-Methyl morpholine (340 uL, 3.09 mmol) was added to a suspension of (2R)-4-[5-fluoro-2-oxo-4-(4-{[trans-4-(tetrahydro-2H-pyran-2-yloxy)cyclohexyl]methoxy}-phenyl)pyridin-1(2H)-yl]-2-methyl-2-(methylsulfonyl)butanoic acid (1.28 g, 2.21 mmol), 2-chloro-4,6-dimethoxy-1,3,5-triazine (510 mg, 2.87 mmol) in 2-methyltetrahydrofuran (30 mL) and the reaction was stirred for 1 h at rt. O-(Tetrahydro-2H-pyran-2-yl)hydroxylamine (61 mg, 0.52 mmol) was added, and the reaction was stirred overnight at rt. Water (50 mL) was added, and the mixture was extracted with EtOAc (3×150 mL). The combined organic phases were dried (Na2SO4), filtered, and concentrated under reduced pressure. The crude material was purified via flash chromatography using an eluent of EtOAc in n-heptane (75-100%) to afford the title compound as a light brown residue (700 mg, 46%). MS (LCMS) m/z 677.4 (M+1).
