反应详情

To a solution of 7-methyl-1-[2-(methylthio)ethyl]-1,3-dihydro-2H-benzimidazol-2-one (0.21 g, 0.93 mmol) in 1,2-dichloroethane (5 mL) were added triethylamine (0.43 mL, 3.1 mmol) and 4-nitrophenyl chloroformate (0.23 g, 1.1 mmol) at 0° C. and the mixture was stirred at rt for 4 h. Then to this mixture was added a solution of N,N-dimethyl-tert-leucinamide (ca. 1.4 mmol, prepared according to the procedure described in steps 1 and 2 of example 3 from dimethylamine hydrochloride) in 1,2-dichloroethane (3 mL) at 0° C. and stirred rt. After 14 h, the reaction was quenched by addition of water (50 mL) and extracted with dichloromethane (50 mL×2). The combined organic layers were washed with water (30 mL×4), brine (30 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by preparative TLC eluting with dichloromethane/methanol (10/1) to afford 0.31 g (83%) of the title compound.

1. customprepared
2. customat 0° C.
3. stirringstirred rt
4. waitAfter 14 h
5. customthe reaction was quenched by addition of water (50 mL)
6. extractionextracted with dichloromethane (50 mL×2)
7. washThe combined organic layers were washed with water (30 mL×4), brine (30 mL)
8. dry with materialdried over sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe residue was purified by preparative TLC
12. washeluting with dichloromethane/methanol (10/1)