Example 102A. Synthesis of 3-amino-5-methylpyridin-2-ol: 5-methyl-3-nitropyridin-2-ol (50 mg, 0.32 mmol) was dissolved in methanol (5 mL) and ammonium chloride (174 mg, 3.24 mmol) and zinc powder (106 mg, 1.62 mmol) were added sequentially. The reaction mixture was stirred at room temperature for 1 h, during which a color change was observed. After completion of the reaction, the suspension was removed by filtration and the filter cake was washed with methanol. The filtrates were combined and concentrated under reduced pressure to remove the solvent. The crude product was purified by grinding with a solvent mixture of methanol and ethyl acetate (1:1, v/v). After filtration, the solvent was removed under reduced pressure to afford the target compound 3-amino-5-methylpyridin-2-ol (16 mg, 0.13 mmol, 40% yield). The product was characterized by NMR hydrogen spectroscopy (400 MHz, MeOD): δ 2.03 (s, 3H), 6.56 (s, 1H), 6.63 (s, 1H).
