Br[C:2]1(Br)[C:10]2[C:5](=[N:6][CH:7]=[CH:8][CH:9]=2)[N:4]([CH2:11][O:12][CH2:13][CH2:14][Si:15]([CH3:18])([CH3:17])[CH3:16])[C:3]1=[O:19]>C1COCC1.[Cl-].[NH4+].[Zn]>[CH3:16][Si:15]([CH3:18])([CH3:17])[CH2:14][CH2:13][O:12][CH2:11][N:4]1[C:5]2=[N:6][CH:7]=[CH:8][CH:9]=[C:10]2[CH2:2][C:3]1=[O:19]Zinc (100 g, 1.54 mol) was added to a solution of 3,3-dibromo-1-{[2-(trimethylsilyl)ethoxy]methyl}-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one from Step B (65 g, 0.154 mol) in THF (880 mL) and saturated aqueous ammonium chloride (220 mL). After 3 h, the reaction was filtered and concentrated in vacuo. The residue was partitioned between EtOAc and H2O which resulted in the formation of a white precipitate. Both layers were filtered through a Celite pad and the layers were separated. The aqueous layer was washed with EtOAc (2×) and the combined organic layers were washed with H2O, dried over MgSO4, filtered, and concentrated. The crude product was filtered through a plug of silica gel eluting with EtOAc:CH2Cl2—1:9 and the eluant was concentrated under reduced pressure to provide the title compound. MS: m/z 265 (M+1).
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