1,2-Dichloroethane → ethyl 5-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octan-2-yl)-1,2,4-oxadiazole-3-carboxylate

Participants

Reaction Steps

EDC (0.916 g, 4.78 mmol) was added to a solution of (2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylic acid (1.2 g, 4.34 mmol) and HOBt (0.732 g, 4.78 mmol) in DMF (12 mL) at rt. The mixture was stirred at rt for 0.5 h, then ethyl 2-(hydroxyamino)-2-iminoacetate (0.689 g, 5.21 mmol) was added and the mixture was stirred for another 0.5 h at rt. The reaction mixture was then heated to 100° C. under microwave for 80 minutes. The solvent was removed under vacuum and the residue was purified by silica gel column chromatography (0 to 5% MeOH/DCM) to afford ethyl 5-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octan-2-yl)-1,2,4-oxadiazole-3-carboxylate (0.85 g, 53%). ESI-MS (EI+, m/z): 373.4.

Provenance & Evidence