Diphenyl chlorophosphate → HCID 53907551, compound

Participants

Reaction Conditions

Reaction Steps

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 (602 mg) and 4-(N,N-dimethylamino)pyridine (13.6 ml) in acetonitrile (30 ml) was added a solution of diisopropylethylamine (0.232 ml) in acetonitrile (2.08 ml) at 0° C. To the mixture was further added a solution of diphenyl chlorophosphate (0.242 ml) in acetonitrile (2.18 ml). After stirring at 0° C. for an hour, the mixture was cooled to -15° C. To the mixture was added a solution of diisopropylethylamine (0.775 ml) in acetonitrile (6.97 ml) and N-(4-nitrobenzyloxycarbonyl)cysteamine (299 mg) were added. After standing overnight at -15° C., the mixture was evaporated in vacuo. The residue was dissolved in ethyl acetate (100 ml) and the solution was washed in turn with water and saturated aqueous sodium chloride, dried over magnesium sulfate, and evaporated in vacuo. The residue was chromatographed on silica gel (18 g) eluting with a mixture of benzene and acetone (20:1 to 6:1) to give 4-nitrobenzyl (5R,6R)-6-[1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl]-3-[2-(4-nitrobenzyloxycarbonylamino)ethylthio]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (716 mg) as an amorphous solid.

Provenance & Evidence