Triethylamine → 4-nitrobenzyl 2-diazo-4-[(2R,3S)-3-{1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl}-4-oxoazetidin-2-yl]-3-oxobutanoate

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-nitrobenzyl 4-[(2R,3S)-3-{1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl}-4-oxoazetidin-2-yl]-3-oxobutanoate (58.3 mg) in acetonitrile (1.17 ml) was added a solution of p-toluenesulfonyl azide (25.3 mg) in acetonitrile (0.228 ml) at 0° C. After stirring for 5 minutes at 0° C., a solution of triethylamine (53.7 μl) in acetonitrile (0.483 ml) was added dropwise. The stirring mixture was allowed to warm to ambient temperature during 15 minutes and kept at the same temperature for 20 minutes. The solvent was distilled off and the residue (85.9 mg) was flash-chromatographed on silica gel (1 g) eluting with a mixture of methylene chloride and ethyl acetate (50:1 to 3:1) to give 4-nitrobenzyl 2-diazo-4-[(2R,3S)-3-{1-methyl-1-(4-nitrobenzyloxycarbonyloxy)ethyl}-4-oxoazetidin-2-yl]-3-oxobutanoate (58.4 mg) as an amorphous solid.

Provenance & Evidence