反应详情

A mixture of 20.6 g N-t-butyloxycarbonyl-4-piperidone, 15 g of 4-(2-oxo-1-benzimidazolinyl)piperidine, 300 mL of 1,2-dichloroethane, 4.2 mL of glacial acetic acid and 24 g of sodium triacetoxyborohydride was stirred at room temperature for 48 h. The reaction mixture was poured into 500 mL chloroform and 500 mL saturated aqueous Na2CO3 and the layers separated. The aqueous layer was extracted with 2×250 mL of chloroform and the combined organic layers dried over MgSO4 and concentrated under reduced pressure. Recrystallization of the crude product from 200 mL of ethyl acetate gave in two crops 28.7 g of pure 1,3-dihydro-1-{1-[1-(t-butyloxycarbonyl)piperidin-4-yl]piperidin-4-yl}-2H-benzimidazol-2-one as a white solid.

1. customthe layers separated
2. extractionThe aqueous layer was extracted with 2×250 mL of chloroform
3. dry with materialthe combined organic layers dried over MgSO4
4. concentrationconcentrated under reduced pressure
5. customRecrystallization of the crude product from 200 mL of ethyl acetate