2-Aminothiophenol → 4-nitrobenzyl (5R,6R)-3-(2-aminophenylthio)-6-[1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of N,N-diisopropyl-N-ethylamine (0.247 ml) in acetonitrile (2.2 ml) was added 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 (640 mg) and 4-(N,N-dimethylamino)pyridine (14.4 mg) in acetonitrile (32 ml) at 0° C. A solution of diphenyl chlorophosphate (0.257 ml) in acetonitrile (2.3 ml) was then added thereto at 0° C. After the mixture was stirred at 0° C. for 30 minutes, N,N-diisopropyl-N-ethylamine (0.824 ml) and a solution of 2-aminobenzenethiol (155 mg) in acetonitrile (1.4 ml) were added at 0° C. After stirring at 0° C. for an hour, the mixture was evaporated in vacuo and the residue was dissolved in ethyl acetate (50 ml). This solution was washed twice with water (X2) and an aqueous sodium chloride, dried over magnesium sulfate, and then evaporated in vacuo. The residue was chromatographed on silica gel (20 g) eluting with a mixture of benzene and acetone (50:1 to 10:1) to give 4-nitrobenzyl (5R,6R)-3-(2-aminophenylthio)-6-[1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (603 mg) as an oil.

Provenance & Evidence