[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][N:6]=[CH:5]2.[N:11]1[CH:16]=[CH:15][CH:14]=[C:13](B(O)O)[CH:12]=1.N1C=CC=CC=1>ClCCl.C([O-])(=O)C.[Cu+2].C([O-])(=O)C>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[N:7]([C:13]1[CH:12]=[N:11][CH:16]=[CH:15][CH:14]=1)[N:6]=[CH:5]2A mixture of 2.0 g (10.15 mmol) of 5-bromoindazole, 2.49 g (20.30 mmol) of 3-pyridyl boronic acid, 2.77 g (15.25 mmol) of copper acetate, and 2.4 mL of pyridine were dissolved in dry dichloromethane and stirred at room temperature. Oxygen gas was bubbled into the solution for 3 min and the mix was stirred in a screw top reaction vial in open atmosphere. After stirring overnight at room temperature, the reaction was monitored by LCMS which indicated ˜10-15% conversion. The mixture was then warmed to 70° C. After 24 hours, the mixture was cooled to room temperature, diluted with brine and extracted with EtOAc. The organic was washed with brine, dried over sodium sulfate, and concentrated in vacuo onto silica gel. The crude was then purified by Combiflash chromatography using a 0-70% EtOAc/hexanes gradient (product eluted at 35% EtOAc). The product containing fractions were combined and concentrated in vacuo to afford 0.31 g (11%) of 5-bromo-1-pyridin-3-yl-1H-indazole.
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