反应详情

温度

70 °C

To a solution of ethyl [7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]acetate (3.91 g, 13.5 mmol) and 2,2′-azobisisobutyronitrile (222 mg, 1.35 mmol) in chlorobenzene (40 mL) was added portionwise N-chlorosuccinimide (1.80 g, 13.5 mmol) at 65° C., and the mixture was stirred at 70° C. for 2 days. After cooling, the reaction mixture was washed with saturated aqueous sodium hydrogen carbonate. The aqueous layer was separated and extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 15-50% ethyl acetate/n-hexane gradient mixture, and the fractions containing the title compound were concentrated in vacuo. The mixture was suspended in diisopropyl ether, and the suspension was stirred at 60° C. for 2 hr. After cooling, the resulting solid was collected by filtration and washed with n-hexane to give the title compound (2.77 g, 8.53 mmol, 63%) as a colorless solid.

1. temperatureAfter cooling
2. washthe reaction mixture was washed with saturated aqueous sodium hydrogen carbonate
3. customThe aqueous layer was separated
4. extractionextracted with ethyl acetate
5. washThe organic layer was washed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated in vacuo
8. customThe residue was purified by silica gel column chromatography
9. washeluting with a 15-50% ethyl acetate/n-hexane gradient mixture
10. additionthe fractions containing the title compound
11. concentrationwere concentrated in vacuo
12. stirringthe suspension was stirred at 60° C. for 2 hr
13. temperatureAfter cooling
14. filtrationthe resulting solid was collected by filtration
15. washwashed with n-hexane