反应详情

A mixture of piperazine-1-carboxylic acid benzyl ester (6.6 g, 29.96 mmol) and 4-oxo-piperidine-1-carboxylic acid tert-butyl ester in dichloroethane (150 mL) containing two drops of acetic acid was stirred at RT for 1 h and then sodium triacetoxyborohydride (19.05 g, 89.89 mmol) was added in portions. The reaction mixture was stirred at RT overnight, water (150 mL) was added, and the reaction mixture was stirred at RT for 2 h. The reaction mixture was extracted with DCM (4×30 mL). Combined organic layers were dried over sodium sulfate, filtered, concentrated under reduced pressure, and purified by silica gel chromatography (20-30% EtOAc/petroleum ether) to provide the title intermediate (9 g, 74% yield) as a colorless oil. (m/z): [M+H]+ calcd for C22H33N3O4 404.25, found 404.3.

1. stirringThe reaction mixture was stirred at RT overnight
2. stirringthe reaction mixture was stirred at RT for 2 h
3. extractionThe reaction mixture was extracted with DCM (4×30 mL)
4. dry with materialCombined organic layers were dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. custompurified by silica gel chromatography (20-30% EtOAc/petroleum ether)