Methyl iodide → 2-Bromo-6-ethylpyridine
反応式
[CH2:1]([Li])CCC.C(NC(C)C)(C)C.C(=O)=O.CC(C)=O.[Br:20][C:21]1[CH:26]=[CH:25][CH:24]=[C:23]([CH3:27])[N:22]=1.CI>O1CCCC1.O>[Br:20][C:21]1[CH:26]=[CH:25][CH:24]=[C:23]([CH2:27][CH3:1])[N:22]=1[CH2:1]([Li])CCC.C(NC(C)C)(C)C.C(=O)=O.CC(C)=O.[Br:20][C:21]1[CH:26]=[CH:25][CH:24]=[C:23]([CH3:27])[N:22]=1.CI>O1CCCC1.O>[Br:20][C:21]1[CH:26]=[CH:25][CH:24]=[C:23]([CH2:27][CH3:1])[N:22]=1Add under nitrogen a solution of 2.5; M n-butyllithium in hexanes (186.74; mL, 0.467; mol) over 41; min to a solution of diisopropylamine (68.7; mL, 0.488; mol) in tetrahydrofuran (745; mL, 9.16; mol) at −78° C. (dry-ice/acetone bath). Stir for 15; min and add 2-bromo-6-methylpyridine (49.3; mL, 0.424; mol) dropwise over 22; min. Stir 15; min, add methyl iodide (52.87; mL, 0.848; mol) dropwise over 1; hour and then warm to room temperature over 1.5; hour. Add water (250; mL) while cooling with a dry-ice/acetone bath and separate the layers. Extract the aqueous phase twice with ethyl acetate (300 mL). Combine the organic phases, concentrate and purify by silica gel chromatography, gradient eluting from 100:0; to 80:20; using hexanes:ethyl acetate, to give the title compound as a yellow oil (59.74; g, 75%). 1H NMR (CDCl3) δ 1.28; (t, 3H), 2.80; (q, 2H), 7.11; (d, 1H), 7.27; (d, 1H), 7.45; (t, 1H).
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