反应详情

温度

0 °C

To a solution of 4-nitrobenzyl(2R,5R,6S)-3,7-dioxo-6-[1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl]-1-azabicyclo[3.2.0]heptane-2-carboxylate (145.1 mg) and 4-(N,N-dimethylamino)pyridine (3.27 mg) in acetonitrile (7.3 ml) was added dropwise a solution of N,N-diisopropyl-N-ethylamine (56.0 μl) in acetonitrile (0.504 μl), followed by a solution of diphenyl-chlorophosphate (58.3 μl) in acetonitrile (0.525 ml) at 0° C. After stirring for an hour at 0° C., thereto was added a solution of N,N-diisopropyl-N-ethylamine (186.4 μl) in acetonitrile (1.68 ml), followed by 4-mercaptopyridine (31.3 mg) at -15° C. The mixture was allowed to stand overnight at -15° C. The resultant solution was diluted with ethyl acetate (15 ml) and then washed in turn with water and saturated aqueous sodium chloride. After drying over magnesium sulfate, the solution was filtered and evaporated in vacuo. The residue was chromatographed on silica gel (4 g) eluting with a mixture of benzene and acetone (30:1 to 6:1) to give 4-nitrobenzyl(5R,6S)-3-(4-pyridylthio)-6-[1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (139.1 mg).

1. washwashed in turn with water and saturated aqueous sodium chloride
2. dry with materialAfter drying over magnesium sulfate
3. filtrationthe solution was filtered
4. customevaporated in vacuo
5. customThe residue was chromatographed on silica gel (4 g)
6. washeluting with a mixture of benzene and acetone (30:1 to 6:1)