Isopropanol → 5-Bromo-3-methyl-2-[(propan-2-yl)oxy]pyridine
反応式
Br[C:2]1[C:7]([CH3:8])=[CH:6][C:5]([Br:9])=[CH:4][N:3]=1.[CH:10]([OH:13])([CH3:12])[CH3:11]>C([O-])(O)=O.[Na+]>[Br:9][C:5]1[CH:6]=[C:7]([CH3:8])[C:2]([O:13][CH:10]([CH3:12])[CH3:11])=[N:3][CH:4]=1参加物
4
実験手順
To a solution of potassium tert. butylate (1.26 g, 11.3 mmol) in isopropanol (30 mL), 2,5-dibromo-3-picoline (2.89 g, 11.3 mmol) is added. The mixture is stirred at 80° C. for 15 h before another portion of potassium tert.-butylate (2.53 g, 27.5 mmol) is added. Stirring is continued at 80° C. for 24 h before the mixture is diluted with sat. aq. NaHCO3-solution. The mixture is extracted with ether, the org. extract is dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 9:1 to give 5-bromo-2-isopropoxy-3-methyl-pyridine (1.24 g) as a colourless oil; LC-MS: tR=1.06 min; [M+1]+=230.00; 1H NMR (CDCl3): δ1.35 (d, J=6.3 Hz, 6H), 2.16 (s, 3H), 5.27 (hept, J=6.3 Hz, 1H), 7.48 (d, J=1.5 Hz, 1H), 8.02 (d, J=2.0 Hz, 1H).