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Step B Synthesis of 5-bromo-3-methylpyridine-2-carboxylic acid: 5-bromo-3-methylpyridine-2-carbonitrile (3.9 g, 20 mmol) was dissolved in ethanol (30 mL), followed by the addition of 6.0 M aqueous sodium hydroxide solution (15 mL). The reaction mixture was stirred at 80 °C for 1.5 hours. Upon completion of the reaction, the reaction mixture was concentrated, diluted with water and extracted by partitioning with ethyl acetate (EtOAc). The aqueous phase was acidified to pH 2-3 with hydrochloric acid and the product was subsequently extracted with EtOAc. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated to give the yellow solid product 5-bromo-3-methylpyridine-2-carboxylic acid (4.2 g, 98% yield).