Synthesis
B) Synthesis of 5-methoxypyridine-2-carboxylic acid: a solution of lithium hydroxide monohydrate (5.0 g) in water (10 mL) was added to a solution of methyl 5-methoxypyridine-2-carboxylate (4.0 g) in methanol (50 mL) at room temperature. The reaction mixture was stirred at room temperature for 12 hours. Subsequently, the pH of the reaction mixture was adjusted to 4-5 with 2M hydrochloric acid and the precipitate was collected by filtration. The resulting solid was washed with water and dried to afford the target compound 5-methoxypyridine-2-carboxylic acid (2.4 g). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ 3.93 (3H, s), 7.49-7.51 (1H, m), 8.03 (1H, d, J = 7.2 Hz), 8.36 (1H, d, J = 2.8 Hz), 12.85 (1H, s).
