Zirconium tetrachloride (23 mg; 0.10 mmol; 0.1 eq.) was added in one portion to a solution of NBS (160 mg; 0.90 mmol; 0.9 eq.) in DCM (10 mL) at 0° C. A solution of tert-butyl 3-{1-[4-(methoxycarbonyl)phenyl]-1H-1,2,3-triazol-4-yl}-5-methyl-1H-indazole-1-carboxylate (434 mg; 1.00 mmol; 1.0 eq.) in DCM (10 mL) was then added dropwise to the reaction mixture which was subsequently stirred at RT for 16 h. The reaction mixture was then diluted with DCM and washed sequentially with saturated NaHCO3 and brine, dried over magnesium sulfate, filtered and concentrated to give the title compound as a yellow solid (392 mg, 76%) 1H NMR (300 MHz, DMSO) δ 9.70 (s, 1H), 8.62 (d, J=1.0 Hz, 1H), 8.30 (d, J=8.8 Hz, 2H), 8.21 (d, J=8.8 Hz, 2H), 8.16 (d, J=8.8 Hz, 1H), 7.79 (dd, J=8.8 Hz, 1.7, 1H), 4.99 (s, 2H), 3.92 (s, 3H), 1.70 (s, 9H). MS (ESI+): 512.3.
