反应详情

To a solution of tert-butyl 4-(1-ethylpropyl)-3-(2-isopropoxy-2-oxoethyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate (obtained above) in ethyl acetate (20 mL) was added a 4N solution of hydrogen chloride in ethyl acetate (40 mL) at 0° C., and the mixture was stirred at room temperature for 2.5 hr. The reaction mixture was diluted with saturated aqueous sodium hydrogen carbonate (100 ml) and ethyl acetate (40 mL). The organic layer was separated, washed with water (70 mL) and brine (50 mL), dried over anhydrous sodium sulfate and concentrated in vacuo. The residual solid was suspended in n-hexane (40 mL), and the suspension was stirred at 60° C. for 30 min and then at room temperature for 1 hr. The resulting solid was collected by filtration and washed with n-hexane to give the title compound (17.9 g, 58.8 mmol, 77%) as a colorless solid.

1. customThe organic layer was separated
2. washwashed with water (70 mL) and brine (50 mL)
3. dry with materialdried over anhydrous sodium sulfate
4. concentrationconcentrated in vacuo
5. stirringthe suspension was stirred at 60° C. for 30 min
6. waitat room temperature for 1 hr
7. filtrationThe resulting solid was collected by filtration
8. washwashed with n-hexane