反应详情

In a mixture of 50 ml of methanol and 5 ml of acetic acid was dissolved 3 g of benzyloxycarbonyl-2-[1-(2,4-dimethoxybenzyl)-2,5-dioxopyrrolidin-3-yl]glycine methyl ester and after addition of 500 mg of palladium black, the mixture was stirred in a stream of hydrogen at room temperature for 2.5 hours. The catalyst was filtered off and the filtrate was concentrated to dryness under reduced pressure. The concentrate was chromatographed on a silica gel column and eluted with toluene-acetone (4:1). The eluate was concentrated under reduced pressure and to the residue was added 100 ml of ethyl ether-petroleum ether (1:5). The mixture was allowed to stand in a refrigerator overnight and the resulting precipitate was collected by filtration and dried. Yield 1.4 g.

1. filtrationThe catalyst was filtered off
2. concentrationthe filtrate was concentrated to dryness under reduced pressure
3. customThe concentrate was chromatographed on a silica gel column
4. washeluted with toluene-acetone (4:1)
5. concentrationThe eluate was concentrated under reduced pressure and to the residue
6. additionwas added 100 ml of ethyl ether-petroleum ether (1:5)
7. customto stand in a refrigerator overnight
8. filtrationthe resulting precipitate was collected by filtration
9. customdried