To a sealed tube was added (S)-1-(3-bromopyrazolo[1,5-a]pyrimidin-5-yl)-5-isopropylimidazolidin-2-one (1.50 g, 4.63 mmol), 3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazole (2.51 g, 6.25 mmol), dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine (XPHOS) (0.221 g, 0.463 mmol) and Pd2 dba3 (0.212 g, 0.231 mmol), dioxane (39 mL) and sodium carbonate (2.0 M solution in water) (6.9 mL, 14 mmol) were added. The reaction mixture was heated to 80° C. overnight under nitrogen. After cooling, the reaction mixture was partitioned between EtOAc and water, and the aqueous layer was extracted once with EtOAc. The combined organic layers were washed with saturated aqueous sodium bicarbonate, brine, dried and concentrated in vacuo. The residue was purified by chromatography using EtOAc as eluent to give (S)-5-isopropyl-1-(3-(4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol-3-yl)phenyl)pyrazolo[1,5-a]pyrimidin-5-yl)imidazolidin-2-one (1.35 g, 56%) as a yellow solid.
