反应详情

Lithium diisopropylamide (1.0M in THF, 12.6 mmol) is added to a stirring solution of 2-bromopyridine (2.0 g, 12.6 mmol) in THF (10 ml) at -78° under nitrogen. The resulting mixture is stirred at -78° for two hours followed by addition of dimethylformamide (12.6 mmol) in THF (5 ml) at -78°. The mixture is allowed to warm to 20°-25°, poured into a saturated aqueous solution of ammonium chloride (100 ml), and extracted with ethyl acetate (3×50 ml). The organic phases are combined, dried over sodium sulfate and solvent removed under reduced pressure. The resulting residue is purified via flash chromatography (silica gel; hexane/ethyl acetate (4/1)) to give the title compound, mp 74°-76°; NMR (CDCl3) 7.45, 8.19, 8.59, 10.35δ; MS (EI, m/e) 185 (M+).

1. temperatureto warm to 20°-25°
2. extractionextracted with ethyl acetate (3×50 ml)
3. dry with materialdried over sodium sulfate and solvent
4. customremoved under reduced pressure
5. customThe resulting residue is purified via flash chromatography (silica gel; hexane/ethyl acetate (4/1))