39775-31-0

67-56-1

4479-74-7

39775-31-0

2,2'-Bipyridine-3,3'-dicarboxylic acid (3 g, 12.3 mmol) was dissolved in methanol (300 mL) at 0 °C, followed by addition of N,N'-dicyclohexylcarbodiimide (DCC, 12 g, 58.2 mmol). The reaction mixture was stirred at 0 °C for 3 h. The solid by-products were removed by filtration. The filtrate was concentrated and the resulting residue was washed several times with pentane to remove impurities. Finally, the product was purified by gel chromatography (eluent: dichloromethane mixed with methanol in a ratio of 99:1) to afford the target compound dimethyl [2,2'-bipyridyl]-3,3'-dicarboxylate (2.87 g, 85% yield).