To a mixture of 9-bromo-1-butoxybenzo[c]-1,6-naphthyridin-6-ol (251 mg, 0.723 mmol), 1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (256 mg, 1.229 mmol), lithium chloride (184 mg, 4.34 mmol), and tetrakis(triphenylphosphine)palladium (251 mg, 0.217 mmol) in DMF (7229 μl) in a sealed tube, sodium carbonate (3615 μl, 7.23 mmol, 2 M) was added, and the reaction mixture was heated to 135° C. After 2 h, the reaction mixture was allowed to cool to room temperature and poured into water. This mixture was then filtered through a frit. The filter cake was washed with dichloromethane. The filter cake was then collected and dried under high vacuum to afford 1-butoxy-9-(1-methyl-1H-pyrazol-4-yl)benzo[c]-1,6-naphthyridin-6-ol as a white solid. LRMS (APCI) calc'd for (C20H21N4O2) [M+H]+, 349.2; found 349.1.
