Methyl 3-amino-2-(4-(benzyloxy)phenyl)-6-bromoisonicotinate (3.28 g, 7.94 mmol) was dissolved in TFA (40 mL) and the yellow solution was cooled in an ice bath. Solid sodium nitrite (1.1 g, 15.9 mmol) was added with stirring to give a red mixture with gas evolution. After 20 min, solid sodium azide (5.16 g, 79 mmol) was added over 5 min followed immediately by Et2O (40 mL). After 20 minutes water was added and the mixture was extracted with EtOAc. The combined organic phases were washed with water (3×), and saturated Na2CO3 solution (until the aqueous phase was basic) and brine. After drying the solvent with sodium sulfate, the solvent was removed. Flash chromatography (step gradient elution with hexane containing 10 to 40% DCM) afforded methyl 3-azido-2-(4-(benzyloxy)phenyl)-6-bromoisonicotinate (2.23 g, 5.08 mmol, 64% yield). 1H NMR (500 MHz, chloroform-d) δ ppm 7.68-7.79 (3H, m), 7.29-7.49 (5H, m), 7.06 (2H, d, J=8.55 Hz), 4.00 (3H, s).
