反应详情

To a chilled solution of 5-cyano-2-oxo-2,3-dihydro-benzoimidazole-1-carboxylic acid tert-butyl ester (50 mg, 0.19 mmol) in dry DMF (1 mL) NaH (60% dispersion mineral oil, 8 mg, 0.20 mmol) was added under N2 atmosphere. The reaction was stirred at room temperature for 15 min. Then, a solution of tert-butyl-2-bromobutyrate (0.054 mL, 0.29 mmol) in DMF (2 mL) was added at 0° C. The reaction mixture was stirred at room temperature for 3 hours, diluted with ethyl acetate, washed with water, with a saturated NH4Cl aqueous solution, brine, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by flash chromatography in silica gel using 15% ethyl acetate in n-heptane as eluent to afford 3-(1-tert-butoxycarbonylpropyl)-5-cyano-2-oxo-2,3-dihydro-benzoimidazole-1-carboxylic acid tert-butyl ester (55 mg, 72%) as a white solid.

1. stirringThe reaction mixture was stirred at room temperature for 3 hours
2. washwashed with water, with a saturated NH4Cl aqueous solution, brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by flash chromatography in silica gel using 15% ethyl acetate in n-heptane as eluent