反应详情

To a stirred solution of 3-(1-tert-butoxycarbonyl-propyl)-5-cyano-2-oxo-2,3-dihydrobenzoimidazole-1-carboxylic acid tert-butyl ester (55 mg, 0.14 mmol) in CH2Cl2 (5 mL) trifluoroacetic acid (0.10 mL) was added. The reaction mixture was stirred at room temperature for 4 hours, concentrated in vacuo and co-evaporated the solvent with toluene (3×). The residue was purified by flash chromatography in silica gel using 40% ethyl acetate in n-heptane as eluent to afford 2-(6-cyano-2-oxo-2,3-dihydro-benzoimidazol-1-yl)-butyric acid tert-butyl ester (28 mg, 68%) as a white solid.

1. concentrationconcentrated in vacuo
2. customThe residue was purified by flash chromatography in silica gel using 40% ethyl acetate in n-heptane as eluent