[O:1]=[C:2]1[N:6]([CH2:7][C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[C:5]2[CH:15]=[CH:16][CH:17]=[CH:18][C:4]=2[NH:3]1.Br[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][N:21]=1.CC([O-])=O.[K+]>N1C=CC=CC=1.[Cu].Cl[Cu]>[O:1]=[C:2]1[N:6]([CH2:7][C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[C:5]2[CH:15]=[CH:16][CH:17]=[CH:18][C:4]=2[N:3]1[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][N:21]=1A mixture of tert-butyl (2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)acetate from Step A (1.75 g, 7.05 mmol), 2-bromopyridine (3.36 mL, 35.2 mmol), copper powder (1.57 g, 24.7 mmol), CuCl (140 mg, 1.41 mmol), and KOAc (2.08 g, 21.1 mmol) in pyridine (30 mL) was heated at 100° C. for 3 h. The cooled mixture was partitioned between EtOAc (150 mL) and 10% aqueous citric acid (100 mL) and the organic layer was dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel chromatography, eluting with a gradient of hexane:EtOAc—100:0 to 0:100, to give the title compound. MS: m/z=326 (M+1).
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