To a solution of methyl 2-chloro-3-(isopropyl(methyl)amino)quinoxaline-6-carboxylate (Scheme I, 200.0 mg, 0.68 mmol) in 1,4-dioxane (1 mL) was added 1H-indazol-6-ylboronic acid (386.0 mg, 2.38 mmol), K3PO4 (434.0 mg, 2.05 mmol), Pd(PPh3)4 (39.0 mg, 0.03 mmol) under nitrogen atmosphere. After stirring 20 min at 90° C., the reaction mixture was dissolved in dichloromethane (30 mL), washed with water (3×20 mL), dried over anhydrous magnesium sulfate and concentrated under reduced pressure to afford a residue, which was purified by a silica gel column with 1%-10% ethyl acetate in petroleum ether to afford methyl 2-(1H-indazol-6-yl)-3-(isopropyl(methyl)amino)quinoxaline-6-carboxylate as a light yellow solid (200 mg, 78%).
