反应详情

温度

0 °C

To a solution of 4-nitrobenzyl (2R,5R,6R)-3,7-dioxo-6-[1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl]-1-azabicyclo[3.2.0]heptane-2-carboxylate (58 mg) and 4-(N,N-dimethylamino)pyridine (1.3 mg) in acetonitrile (3 ml) was added a solution of diisopropylethylamine (22.4 μl) in acetonitrile (0.21 ml) at 0° C. To the mixture was added a solution of diphenyl chlorophosphate (23.3 μl) in acetonitrile (0.21 ml) at 0° C. After stirring at 0° C. for 1.5 hours, the reaction mixture was cooled to -15° C., to which a solution of diisopropylethylamine (74.6 μl) in acetonitrile (0.73 ml) was added. To the mixture was added a solution of N-(2-mercaptoethyl)acetamide (13.4 mg) in acetonitrile (0.12 ml). After standing overnight at -15° C., the mixture was diluted with ethyl acetate (50 ml), washed in turn with water and saturated aqueous sodium chloride, and dried over magnesium sulfate. After evaporation of the solvent, the residue was chromatographed on silica gel (2 g) eluting with a mixture of methylene chloride and acetone (20:1 to 2:1) to give 4-nitrobenzyl (5R,6R)-3-(2-acetamidoethylthio)-6-[1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (56 mg) as an amorphous solid.

1. additionwas added
2. waitAfter standing overnight at -15° C.
3. washwashed in turn with water and saturated aqueous sodium chloride
4. dry with materialdried over magnesium sulfate
5. customAfter evaporation of the solvent
6. customthe residue was chromatographed on silica gel (2 g)
7. washeluting with a mixture of methylene chloride and acetone (20:1 to 2:1)