Trifluoroacetic acid → 4-Chloro-7-(1H-benzoimidazol-2-yl)isoindolinone

Participants

Reaction Steps

4-Chloro-3-hydroxy-7-(1H-benzoimidazol-2-yl)-2-(1-methyl-1-phenylethyl)isoindolinone (39.4 mg, 0.0943 mmol) was dissolved in nitromethane (2.8 mL), and the solution was added with trifluoroacetic acid (0.073 mL, 0.94 mmol) and triethylsilane (0.030 mL, 0.19 mmol), followed by stirring at room temperature for 23.5 hours. Then, the mixture was added with trifluoroacetic acid (0.146 mL, 1.89 mmol) and triethylsilane (0.045 mL, 0.28 mmol) and warmed to 70° C., followed by stirring for 7.5 hours. Further, the mixture was added with trifluoroacetic acid (1.00 mL) and triethylsilane (0.15 mL, 0.94 mmol), followed by stirring for 4 hours. The reaction mixture was added with saturated aqueous sodium hydrogencarbonate solution and extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The residue was purified by slurry using chloroform/methanol (9/1) and by preparative thin-layer chromatography (hexane/ethyl acetate=2/1, 1/1) to obtain Compound 174 (13.7 mg, yield 51%).

Provenance & Evidence