Methyl-2,2′-bipyridine (1.7 g, 10 mmol) in a mixed solvent (100 mL) of water and benzene (1:1) was irradiated and refluxed using a halogen lamp (150 W). Bromine (1.6 g, 10 mmol) was added and the mixture was heated to reflux for 30 min. The solution was concentrated under reduced ressure and dissolved in EtOAc. The organic layer was washed with saturated aqueous NaHCO3 solution, dried over MgSO4, and concentrated under reduced pressure to afford the crude brominated product. A mixture of diethyl acetamidomalonate (2.6 g, 12 mmol) and sodium hydride (0.48 g, 12 mmol, 60% in mineral oil) in dry DMF (50 mL) was stirred for 30 min at 0° C. To the solution was added the crude product in dry DMF (20 mL) at 0° C. and the mixture was stirred for 1 h at room temperature. The reaction mixture was diluted with EtOAc (200 mL) and washed with a 10% aqueous sodium thiosulfate solution (2×150 mL). The organic layer was dried over MgSO4 and concentrated under reduced pressure. The crude product was purified by flash column chromatography (0.5% MeOH in CH2Cl2) to give diethyl 2-(2,2′-bipyridin-5-ylmethyl)-2-acetamidomalonate (2.5 g, 65%) as a white solid. 1H-NMR (500 MHz, CDCl3): 1.38 (m, 6H), 2.15 (s, 3H), 3.81 (s, 2H), 4.35 (m, 4H), 6.68 (s, 1H), 7.36 (dd, 1H), 7.55 (dd, 1H), 7.87 (m, 1H), 8.36 (d, 1H), 8.41 (d, 1H), 8.42 (d, 1H), 8.74 (dd, 1H).
