To a solution of 2′-chloro-4-hydroxy-6,5′-dimethyl-[1,4′]bipyridinyl-2-one of part A (6.0 g, 20.1 mmol) in N,N-dimethylformamide (20 mL) was added 4-methoxybenzylchloride (2.73 mL, 20.1 mmol), potassium carbonate (6.93 g, 50.2 mmol) and 18-crown-6 (100 mg). The slurry was heated at 60° C. for 3 h and was stirred at ambient temperature for 18 h. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed with water and brine and dried over magnesium sulfate. The solution was concentrated in vacuo to provide a brown oil. Normal phase chromatography (ethyl acetate/heptane) provided the alkylated product as a light yellow solid (4.6 g): MS (ES) m/e 371 (M+H).
