Example 1 Synthesis of 5-bromo-3-hydroxy-2-tert-butoxycarbonylaminopyridine (0038): 2-amino-3-hydroxy-5-bromopyridine (10.0 g, 53.0 mmol) and triethylamine (10 mL, 71.8 mmol) were added to dichloromethane (100 mL) followed by di-tert-butyl dicarbonate (12.7 g, 58.4 mmol). The reaction mixture was stirred at room temperature for 18 hours. Water (150 mL) was added and stirring was continued for 30 minutes. The reaction mixture was filtered through diatomaceous earth to separate the organic layer. The aqueous layer was extracted with dichloromethane (150 mL). The combined organic layers were washed with saturated aqueous sodium chloride (2 x 100 mL) and dried over anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure and the residue was ground with hexane (100 mL), filtered and dried in vacuum to give 5-bromo-3-hydroxy-2-tert-butoxycarbonylaminopyridine (15.0 g, 98.0% yield) as a white solid. Product characterization data: 1H NMR (400 MHz, CDCl3) δ 7.98 (d, J = 2.0 Hz, 1H), 7.58 (d, J = 2.0 Hz, 1H), 4.67 (br s, 2H), 1.56 (s, 9H); 13C NMR (100 MHz, CDCl3) δ 150.4, 150.1, 145.3, 133.5, 131.3 133.5, 131.5, 106.5, 85.0, 27.6.
