[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([F:8])[C:3]=1[C:9]1[CH:10]=[C:11]2[C:15](=[CH:16][CH:17]=1)[NH:14][N:13]=[CH:12]2.[OH-].[K+].C1C(=O)N([Br:27])C(=O)C1.O>CN(C=O)C>[Br:27][C:12]1[C:11]2[C:15](=[CH:16][CH:17]=[C:9]([C:3]3[C:4]([F:8])=[CH:5][CH:6]=[CH:7][C:2]=3[F:1])[CH:10]=2)[NH:14][N:13]=1To a solution of 5-(2,6-difluoro-phenyl)-1H-indazole (1 g, 4.35 mmol) in DMF (13 ml) were added KOH (488 mg, 8.7 mmol) and NBS (1.15 g, 6.48 mmol) at RT. The reaction mixture was stirred for 2 h at RT. Water was added to the reaction mixture and extracted with EtOAc (2×20 ml). Combined organic layers were washed with brine and dried over Na2SO4. The organic layer was concentrated and purified by column using silica (100-200 mesh) and 0-15 EtOAc-hexane to provide 3-bromo-5-(2,6-difluoro-phenyl)-1H-indazole (600 mg, 45% yield). MS (ESI, pos. ion) m/z: 306.9 (M−1).
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