[Br:1][C:2]1[CH:3]=[C:4]([CH3:9])[C:5]([NH2:8])=[N:6][CH:7]=1.[H-].[Na+].I[CH3:13].[Na+].[Cl-]>C1COCC1.CCOC(C)=O>[Br:1][C:2]1[CH:3]=[C:4]([CH3:9])[C:5]([NH:8][CH3:13])=[N:6][CH:7]=1To a solution of 5-bromo-3-methylpyridin-2-amine (B-4-1) (3.7 g, 0.02 mol) in THF (50 mL) was added portionwise NaH (0.8 g, 0.02 mol) at 0° C. After the addition, the mixture was stirred at room temperature for about 0.5 hr, and cooled to 0° C. again. Iodomethane (2.8 g, 0.02 mol) was added slowly. The resulting mixture was allowed to rise to room temperature and stirred for 1 hr. TLC (EtOAc: Petroleum ether=1:4) showed that the reaction was complete. Saturated aqueous NaCl (10 mL) and EtOAc (10 mL) were added. The organic layer was concentrated and the residue was purified via a silica gel column eluted with EtOAc/Petroleum ether (1:8) to give 5-bromo-N,3-dimethylpyridin-2-amine (B-4-2) (2.3 g, 57.8%) as a white solid.
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