A solution of N-(2,4-dimethoxybenzyl)-3-methyl-1H-pyrazolo[4,3-d]pyridin-4-amine (110 mg, 0.37 mmol) in N,N-dimethylformamide (2 mL) was treated with sodium hydride (30 mg, 0.75 mmol) and stirred at 20° C. for 30 minutes. The reaction mixture was treated with a solution of 5-[3-chloro-5-(1-chloroethyl)-6-methoxy-2-methylphenyl]N,N-dimethylpyridine-2-carboxamide (130 mg, 0.34 mmol) in N,N-dimethylformamide (1 mL) and heated at 50° C. overnight. The reaction mixture was diluted with water and extracted with ethyl acetate (2×). The combined organic extracts were washed with water and brine, dried with magnesium sulfate, filtered, and concentrated to a crude residue. Purification via preparative LCMS (XBridge C18 column, eluting with a gradient of acetonitrile/water containing 0.1% ammonium hydroxide, at flow rate of 60 mL/min) gave the desired product (110 mg, 49%). LCMS for C34H38ClN6O4 (M+H)+: m/z=629.3; Found: 629.1.
