To a solution of 2-(4-(hydroxymethyl)-1H-imidazol-1-yl)-5-(2-oxopyridin-1(2H)-yl)benzoic acid prepared above (92 mg, 0.30 mmol) in MeOH (4 mL) and dioxane (2 mL) at room temperature, (trimethylsilyl)diazomethane (2 M in ether, 0.30 mL, 0.60 mmol) was added. After the mixture was stirred at room temperature overnight, more (trimethylsilyl)diazomethane (2 M in ether, 0.40 mL, 0.80 mmol) was added. After stirring for another day, the solution was concentrated in vacuo to give a residue. The residue was dissolved in SOCl2 (4 mL). The solution was stirred at room temperature for 20 min before it was concentrated in vacuo to give a residue, which was then dissolved in DMF (3 mL). To the solution, NaN3 (65 mg, 1.0 mmol) was added. After the mixture was stirred at room temperature for 2 h, water and EtOAc were added, then 5% aq. NaHCO3 was added. The organic layer was separated, dried over Na2SO4, concentrated in vacuo to give methyl 2-(4-(azidomethyl)-1H-imidazol-1-yl)-5-(2-oxopyridin-1(2H)-yl)benzoate (25 mg). MS 351.1 (M+H).
