反应详情

A mixture of 3-isopropyl-2-oxo-N-(piperidin-4-ylmethyl)-2,3-dihydro-1H-benzimidazole-1-carboxamide (0.50 g, 1.58 mmol, Step 2), tert-butyl acrylate (0.340 mL, 2.37 mmol) and iPrNEt (0.275 mL, 2.37 mmol) in THF (20 mL) was refluxed for 18 h. After cooling, the reaction mixture was diluted with sat. NaHCO3 aq. (100 mL), extracted with CH2Cl2 (100 mL) for three times. The combined extracts were dried over Na2SO4, filtered and concentrated. The residue was chromatographed on a column of silica gel eluted with MeOH/CH2Cl2 (1:20→1:10) and then NH-silica gel eluted with EtOAc/hexane (1:5→1:2) to give 0.111 g (16%) of title compound as colorless syrup.

1. temperaturewas refluxed for 18 h
2. temperatureAfter cooling
3. extractionextracted with CH2Cl2 (100 mL) for three times
4. dry with materialThe combined extracts were dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue was chromatographed on a column of silica gel
8. washeluted with MeOH/CH2Cl2 (1:20→1:10)
9. washNH-silica gel eluted with EtOAc/hexane (1:5→1:2)