[CH3:1][C:2]1([CH3:14])[O:6][B:5]([C:7]2[CH:8]=[N:9][NH:10][CH:11]=2)[O:4][C:3]1([CH3:13])[CH3:12].Cl.Cl.Br[CH2:18][C:19]1[CH:24]=[N:23][CH:22]=[CH:21][N:20]=1.C(=O)([O-])[O-].[Cs+].[Cs+]>C(#N)C>[CH3:1][C:2]1([CH3:14])[O:6][B:5]([C:7]2[CH:8]=[N:9][N:10]([CH2:18][C:19]3[CH:24]=[N:23][CH:22]=[CH:21][N:20]=3)[CH:11]=2)[O:4][C:3]1([CH3:13])[CH3:12]A 100-mL round-bottom flask was charged with a solution of 4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (265 mg, 1.37 mmol), acetonitrile (40 mL), 2-(bromomethyl)pyrazine dihydrochloride (500 mg, 2.03 mmol) and cesium carbonate (2.23 g, 6.84 mmol). The resulting mixture stirred overnight at 70° C. After cooling to room temperature, the reaction mixture was filtered and the filtrate was concentrated under reduced pressure. The residue was purified by preparative thin layer chromatography (eluting with 2:1, ethyl acetate/petroleum ether) to afford 2-[[4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]methyl]pyrazine (0.12 g, 31%) as red oil.
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