反应详情

To a solution of (2S,4S)-4-acetylthio-1-(4-nitrobenzyloxycarbonyl)-2-[(2-ureidoethyl)oxymethyl]pyrrolidine (1.01 g) in methanol (20 ml) was added sodium methoxide (28% solution in methanol) (0.5 ml) at -15°-10° C. in a nitrogen stream and the mixture was stirred at the same condition for 1.5 hours. To the mixture was added glacial acetic acid (0.17 ml) at -10°-0° C. The mixture was concentrated under reduced pressure to give a residue. The residue was dissolved in ethyl acetate (50 ml). The solution was washed with water (20 ml), dried over magnesium sulfate and concentrated under reduced pressure to give a syrup. The syrup was subjected to a column chromatography on silica gel (20 g) and eluted with a mixture of methanol and chloroform (2:98 V/V) to give (2S,4S)-4-mercapto- 1-(4-nitrobenzyloxycarbonyl)-2-[(2-ureidoethyl)oxymethyl]pyrrolidine (0.74 g).

1. concentrationThe mixture was concentrated under reduced pressure
2. customto give a residue
3. washThe solution was washed with water (20 ml)
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. customto give a syrup
7. washeluted with a mixture of methanol and chloroform (2:98 V/V)