C(=O)([O-])[O-].[Cs+].[Cs+].[Br:7][C:8]1[CH:9]=[C:10]([N+:15]([O-:17])=[O:16])[C:11]([OH:14])=[N:12][CH:13]=1.[CH3:18][O:19][CH2:20][CH2:21]Br.O>CN(C)C=O>[Br:7][C:8]1[CH:9]=[C:10]([N+:15]([O-:17])=[O:16])[C:11](=[O:14])[N:12]([CH2:21][CH2:20][O:19][CH3:18])[CH:13]=1Cesium carbonate (14.88 g, 45.66 mmol) was added to a solution of 5-bromo-3-nitropyridin-2-ol (10.0 g, 45.7 mmol) and 2-bromoethyl methyl ether (4.29 mL, 45.66 mmol) in N,N-dimethylformamide (400 mL). After 3 h, additional 2-bromoethyl methyl ether (4.29 mL, 45.7 mmol) was added, and the reaction was heated to 60° C. After 4 h, water was added. The mixture was extracted with ethyl acetate (3×), and the combined organic extracts were washed with saturated brine, dried over sodium sulfate, filtered and concentrated. Purification by silica gel chromatography (100% hexanes→40% ethyl acetate/hexanes) gave the title compound (7.39 g). MS 277 (M).
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