反应详情

温度

45 °C

To an ice-cooled solution of, methyl 3-methyl-2-oxo-7-(trifluoromethyl)-2,3-dihydro-1H-benzimidazole-4-carboxylate (2.80 g, 10.2 mmol) in tetrahydrofuran (30 ml) was added a solution of 3M ethylmagnesium bromide in diethylether (13.6 ml, 40.8 mmol) dropwise and stirred at 45° C. for 16 h. Methanol and water were carefully added to decompose excess reagent. 2N hydrochloric acid was added and extracted with ethyl acetate. The extracts were washed with aqueous saturated sodium bicarbonate and water, dried over magnesium sulfate and concentrated in vacuo. Ethanol (40 ml) and conc. hydrochloric acid (10 ml) were added to the residue and the resulting mixture was heated at 80° C. for 6 h. The reaction mixture was concentrated in vacuo. Aqueous saturated sodium bicarbonate was added to the residue and extracted with ethyl acetate. The extracts were washed with water, dried over magnesium sulfate and concentrated in vacuo. The residue was purified by chromatography on silica gel with a 20% ethyl acetate/n-hexane to give 609 mg (2.14 mmol, 21%, cis/trans=3/1) of the title compound as a white powder.

1. extractionextracted with ethyl acetate
2. washThe extracts were washed with aqueous saturated sodium bicarbonate and water
3. dry with materialdried over magnesium sulfate
4. concentrationconcentrated in vacuo
5. additionEthanol (40 ml) and conc. hydrochloric acid (10 ml) were added to the residue
6. temperaturethe resulting mixture was heated at 80° C. for 6 h
7. concentrationThe reaction mixture was concentrated in vacuo
8. additionAqueous saturated sodium bicarbonate was added to the residue
9. extractionextracted with ethyl acetate
10. washThe extracts were washed with water
11. dry with materialdried over magnesium sulfate
12. concentrationconcentrated in vacuo
13. customThe residue was purified by chromatography on silica gel with a 20% ethyl acetate/n-hexane