General procedure for the synthesis of pyrimidine-4,6-dicarboxylic acid from dimethyl pyrimidine-4,6-dicarboxylate: To a solution of dimethyl pyrimidine-4,6-dicarboxylate (170 mg, 0.87 mmol) in methanol (5 mL) was added 1 N sodium hydroxide solution (5 mL, 5.00 mmol). The reaction mixture was stirred at room temperature for 2 hours. Upon completion of the reaction, the solvent was removed by evaporation and the resulting concentrated solution was acidified to pH 2-3 with 5 N hydrochloric acid.The resulting white precipitate was collected by filtration and washed with distilled water (2 mL) to give the final pyrimidine-4,6-dicarboxylic acid (125 mg, 86% yield).
