Iodine → tert-butyl(1-(5-((5R)-6-(benzyloxy)-7-oxo-1,6-diaza-bicyclo[3.2.1]octan-2-yl)-1,3,4-oxadiazol-2-yl)cyclopropyl)methylcarbamate

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Reaction Steps

Et3N (8.3 g, 0.082 mol) was added to a 0° C. solution of I2 (10.43 g, 0.041 mol), PPh3 (10.76 g, 0.041 mol) in CH2Cl2 (250 mL). The mixture was allowed to warm to rt. After stirring at rt for 0.5 hr, tert-butyl(1-(2-((5R)-6-(benzyloxy)-7-oxo-1,6-diaza-bicyclo[3.2.1]octane-2-carbonyl)hydrazinecarbonyl)cyclopropyl)methylcarbamate (10 g, 0.0205 mol) was added. The mixture was stirred at rt for another 1 hr. The mixture was concentrated, EtOAc (250 mL) was added, and the mixture was filtered to remove Ph3PO. The filtrate was concentrated and the residue was purified by silica gel column chromatography (gradient elution 33˜50% EtOAc/petroleum ether) to afford tert-butyl (1-(5-((5R)-6-(benzyloxy)-7-oxo-1,6-diaza-bicyclo[3.2.1]octan-2-yl)-1,3,4-oxadiazol-2-yl)cyclopropyl)methylcarbamate (8 g, 83%) as a white solid. ESI-MS (EI+, m/z): 470.3 [M+H]+.

Provenance & Evidence