67-56-1

499-81-0

4591-55-3

The general procedure for the synthesis of methyl 3,5-pyridinedicarboxylate from methanol and 3,5-pyridinedicarboxylic acid is as follows: 3,5-pyridinedicarboxylic acid (5.00 g, 29.92 mmol) was dissolved in methanol (100 ml), concentrated sulfuric acid (2 ml) was added slowly as a catalyst, and the reaction mixture was stirred for 18 hrs under reflux conditions. After completion of the reaction, the solvent methanol was removed by distillation under reduced pressure. Subsequently, the reaction mixture was neutralized with aqueous sodium bicarbonate and separated by extraction with dichloromethane. The dichloromethane layer was collected and washed with saturated aqueous sodium chloride solution to remove residual water-soluble impurities. Eventually, the dichloromethane layer was concentrated by decompression to give the white solid product methyl 3,5-pyridinedicarboxylate (5.5 g, 94% yield).