反应详情

温度

-78 °C

To a cold (−78 °C.) solution of 1,4-dibromobenzene (33 g, 139.8 mmol) in tetrahydrofuran (200 mL) was added n-butyllithium (59.0 mL, 146.8 mmol, 2.49 M in hexane) dropwise. The viscous solution was stirred at −78° C. for 45 min, and cyclopentanone (13.6 mL, 153.8 mmol) was then added dropwise over 30 min. The resulting solution was stirred at −78° C. for 1 h and was then quenched by the addition of 0.5M HCl (200 mL) and ethyl acetate (200 mL). The layers; were separated, and the organics were washed with water (1×100 mL), brine (1×100 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by chromatography on SiO2 gel, eluting with 5% ethyl acetate in hexane to give the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 1.71-1.76 (m, 2 H), 1.78-1.88 (m, 6 H), 4.85 (s, 1 H), 7.39-7.43 (m, 2 H), 7.44-7.49 (m, 2 H).

1. stirringThe resulting solution was stirred at −78° C. for 1 h
2. customwas then quenched by the addition of 0.5M HCl (200 mL) and ethyl acetate (200 mL)
3. customwere separated
4. washthe organics were washed with water (1×100 mL), brine (1×100 mL)
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by chromatography on SiO2 gel
9. washeluting with 5% ethyl acetate in hexane