General procedure for the synthesis of 5-methylpyrimidine-2-carboxylic acid from 5-methylpyrimidine-2-carbonitrile: To a solution of 5-methylpyrimidine-2-carbonitrile (2 g, 16.8 mmol, 1.00 equiv) in water (30 mL) was added sodium hydroxide (1.01 g, 25.2 mmol, 1.50 equiv). The reaction mixture was stirred at 50 °C for 3 hours. Upon completion of the reaction, the pH of the solution was adjusted to 4-5 with 3 M hydrochloric acid. the reaction mixture was concentrated under reduced pressure to remove water. The residue was diluted with methanol (50 mL) and the solid product was collected by filtration. The filtrate was dried with anhydrous sodium sulfate and concentrated under reduced pressure to give 5-methylpyrimidine-2-carboxylic acid (2 g, 86.2% yield) as a white solid.LC-MS: m/z = 139 [M + H]+.
