Sodium Carbonate → (3Ez,5s)-5-{5-[(1s,2r)-1-amino-2-hydroxypropyl]-1,2,4-oxadiazol-3-yl}-1-([1,1'-biphenyl]-4-ylcarbonyl)-3-pyrrolidinone o-methyloxime

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Reaction Steps

4-{[(2S,4EZ)-2-(5-{(1S,2R)-2-tert-butoxy-1-[(tert-butoxycarbonyl)amino]propyl}-1,2,4-oxadiazol-3-yl)-4-(methoxyimino)pyrrolidinyl]carbonyl}-1,1′-biphenyl (100 mg, 1.80 mmol) was treated with a 25% TFA/DCM solution at 0° C. for 1 hour. The reaction was then made basic with a sodium carbonate solution (10%) and extracted with DCM. The organic phases were combined and dried over magnesium sulfate and solvent removal afforded a residue, which was purified by flash-chromatography using dichloromethane/methanol as eluent to give the desired product, (3EZ,5S)-5-{5-[(1S,2R)-1-amino-2-hydroxypropyl]-1,2,4-oxadiazol-3-yl}-1-([1,1′-biphenyl]-4-ylcarbonyl)-3-pyrrolidinone O-methyloxime, as a mixture of E-/Z-isomers in 30% yield (90.3% purity by HPLC).

Provenance & Evidence