To a flask charged with 5-chloro-7-(1-methyl-1H-pyrazol-4-yl)imidazo[1,2-c]pyrimidine (Preparation J; 0.650 g, 2.78 mmol), 3-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (0.868 g, 4.17 mmol), and 2 M K3PO4 (4.17 mL, 8.35 mmol) was added 20 mL of DME and argon was bubbled through for 15 minutes before tetrakis(triphenylphosphine)palladium (0) (0.321 g, 0.278 mmol) was added. The flask was sealed and the reaction was heated to 100° C. for 4 hours, then allowed to cool to ambient temperature and stirred overnight. The reaction mixture was diluted with EtOAc (300 mL) and washed with aqueous saturated sodium bicarbonate (50 mL). The organic layer was washed with brine (50 mL), dried over MgSO4, filtered, and concentrated under reduced pressure. The crude material was taken up in DCM in preparation for chromatography when a precipitate began to form and continued to thicken over time. The addition of minimal MeOH (0.5 mL) did not dissolve the precipitate. The solid was collected by vacuum filtration and retained. The rinse was purified by means of silica gel chromatography eluting with a gradient of 5-10% MeOH in EtOAc containing 1% NH4OH. This was successful at generating material that was combined with the solid above to afford 7-(1-methyl-1H-pyrazol-4-yl)-5-(3-methyl-1H-pyrazol-4-yl)imidazo[1,2-c]pyrimidine (0.215 g, 0.770 mmol, 27.7% yield). MS (apci) m/z=280.1 (M+H).
