General procedure for the synthesis of 2-methoxy-4-pyridinol from 4-(benzyloxy)-2-methoxypyridine: In Example (16a), prepared 4-(benzyloxy)-2-methoxypyridine (4.65 g, 21.6 mmol) and 10% palladium carbon (2.30 g, 2.16 mmol) were dissolved in ethanol (100 mL). The mixture was stirred at room temperature for 30 minutes under hydrogen atmosphere. Upon completion of the reaction, the insoluble material was removed by filtration and the filtrate was subsequently concentrated to afford 2-methoxy-4-pyridinol (2.70 g, 99%) as a colorless oily product. Its 1H-NMR (400 MHz, CDCl3) data were as follows: δppm: 3.90 (3H, s), 6.13 (1H, s), 6.42 (1H, d, J = 5.9 Hz), 7.80 (1H, brs).
