The general procedure for the synthesis of 6-bromo-5-methyl-pyridine-2-carboxylic acid from 5-methyl-6-bromo-pyridine-2-carbonitrile was as follows: 6-bromo-5-methyl-pyridine-2-carbonitrile (1.0 g, 5.0 mmol) was dissolved in an aqueous solution of sodium hydroxide (0.3 g, 7 mmol, 20 mL), and the reaction was stirred at 120 °C overnight. Upon completion of the reaction, the reaction mixture was adjusted to pH=3 with acid and subsequently extracted with ethyl acetate (3 x 15 mL). The organic phases were combined, washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford the target product 6-bromo-5-methyl-pyridine-2-carboxylic acid (0.7 g, 63.8% yield). Mass spectrometry (EI) analysis showed m/e 216.0 [M+H]+.
