反应详情

LiHMDS (1M in toluene, 17.7 mL, 17.7 mmol, 3.1 eq) is added dropwise to a cold (−5° C.) solution of 4-bromo-2-fluoro-pyridine [Marsais, F. et al, Journal of Organic Chemistry, (1992), 57, 565-573] (1 g, 5.7 mmol) and cyclobutanecarbonitrile (1.39 g, 17.1 mmol, 3 eq) in toluene (20 mL). The reaction mixture is allowed to warm to rt, stirred for 5 h, quenched by addition of a saturated solution of NaHCO3 and filtered through a pad of celite. The filtrate is extracted with EtOAc. The organic phase is washed with a saturated solution of NaHCO3, dried (Na2SO4), filtered and concentrated. The residue is purified by silica gel column chromatography (Hex/EtOAc, 1:0→95:5) to afford 933 mg of the title compound as a yellow oil: ESI-MS: 237.0/239.0 [M+H]+; tR=4.27 min (System 1); TLC: Rf=0.30 (Hex/EtOAc, 9:1).

1. customquenched by addition of a saturated solution of NaHCO3
2. filtrationfiltered through a pad of celite
3. extractionThe filtrate is extracted with EtOAc
4. washThe organic phase is washed with a saturated solution of NaHCO3
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue is purified by silica gel column chromatography (Hex/EtOAc, 1:0→95:5)