Tert-butyl 4-4-[2-(3-iodophenyl)pyrimidin-5-yl]-1H-pyrazol-1-ylpiperidine-1-carboxylate (intermediate 5, 150 mg; 0.24 mmol; 1.0 eq.), 4-Isoxazoleboronic acid pinacol ester (47 mg; 0.24 mmol; 1.0 eq.), bis(triphenylphosphine)palladium(II)chloride (17 mg; 0.02 mmol; 0.10 eq.) and cesium fluoride (109 mg; 0.72 mmol; 3.0 eq.) were flushed with nitrogen before the addition of dioxane: water (2.25:1.1 mL). The reaction mixture was heated in MW at 120° C. for 30 min. It was then diluted with EtOAc and water. Aqueous phase was extracted with EtOAc and combined organic phases were dried over magnesium sulfate, filtered and concentrated. Purification by flash chromatography (cyclohexane:EtOAc, gradient from 80:20 to 30:70) afforded the title compound as a white beige solid (70 mg; 62%). 1H NMR (300 MHz, DMSO-d6) δ 9.60 (s, 1H), 9.27 (s, 1H), 9.17 (s, 2H), 8.64 (t, J=1.5 Hz, 1H), 8.56 (s, 1H), 8.35 (dt, J=8.0 Hz, 1.5 Hz, 1H), 8.16 (s, 1H), 7.87-7.83 (m, 1H), 7.61 (t, J=8.0 Hz, 1H), 4.47-4.35 (m, 1H), 4.09-4.04 (m, 2H), 2.95 (m, 2H), 2.09-2.06 (m, 2H), 1.87-1.72 (m, 2H), 1.43 (s, 9H). HPLC (Condition A): Rt 4.70 min (purity 97.4%). MS (ESI+): 473.5.
