反应详情

To a solution of 1-(3-methylbutyl)1,2-dihydro-2H-benzimidazol-2-one (Step 1, 140 mg, 0.69 mmol) in dichloromethane (2.5 mL) were added triethylamine (0.32 mL, 2.3 mmol) and 4-nitrophenyl chloroformate (150 mg, 0.76 mmol) at 0° C. and the mixture was stirred for 4 h at rt. Then to this mixture was added a solution of L-tert-leucinamide (steps 1 and 2 in example 4, 99 mg, 0.76 mmol) in dichloromethane (2 mL) at 0° C. and stirred rt. After 22 h, the reaction was quenched by addition of water (20 mL) and extracted with ethyl acetate (30 mL×2). The combined organic layers were washed with water (20 mL×3), brine (20 mL) and dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (3/1-1/1) to afford 240 mg (96%) of the titled compound. The obtained product was further purified by recrystallization from hexane/ethyl acetate to give 220 mg of the title compound.

1. stirringstirred rt
2. waitAfter 22 h
3. customthe reaction was quenched by addition of water (20 mL)
4. extractionextracted with ethyl acetate (30 mL×2)
5. washThe combined organic layers were washed with water (20 mL×3), brine (20 mL)
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (3/1-1/1)