Diphosgene → (2S,5R)-tert-butyl 2-(5-(1-(((9H-fluoren-9-yl)methoxy)carbonyl)piperidin-4-yl)-1,2,4-oxadiazol-3-yl)-5-(benzyloxy(chlorocarbonyl)amino)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Diphosgene (144 mg, 0.727 mmol) was added to a solution of (2S,5R)-tert-butyl 2-(5-(1-(((9H-fluoren-9-yl)methoxy) carbonyl)piperidin-4-yl)-1,2,4-oxadiazol-3-yl)-5-(benzyloxyamino)piperidine-1-carboxylate (380 mg, 0.559 mmol) and TEA (113 mg, 1.118 mmol) in DCM (5.0 mL). The mixture was stirred at 0° C. for 1 h, then, DCM (20 mL) was added and the mixture was washed with saturated sodium chloride (2×), dried over Na2SO4, and concentrated to give (2S,5R)-tert-butyl 2-(5-(1-(((9H-fluoren-9-yl)methoxy)carbonyl)piperidin-4-yl)-1,2,4-oxadiazol-3-yl)-5-(benzyloxy(chlorocarbonyl)amino)piperidine-1-carboxylate (400 mg), which was directly used in the next step. ESI-MS (EI+, m/z): 742 [M+H]+.

Provenance & Evidence