p-Toluenesulfonic acid → (3EZ,5S)-1-([1,1'-biphenyl]-4-ylcarbonyl)-5-(1,2,4-oxadiazol-3-yl)-3-pyrrolidinone O-methyloxime

Participants

Reaction Steps

To a suspension of (2S,4EZ)-1-([1,1′-biphenyl]-4-ylcarbonyl)-N′-hydroxy-4-(methoxyimino)-2-pyrrolidinecarboximidamide (Intermediate 8, 170 mg, 0.48 mmol) in TMOF (20 ml), a catalytic amount of p-toluenesulfonic acid was added and the reaction mixture was heated to reflux for 16 h. TMOF was then evaporated in vacuo and the residue dissolved in DCM (15 mls). This was washed with NaHCO3(aq) (2×15 ml), dried over MgSO4 and evaporated in vacuo. Silica gel chromatography eluting with 15% EtOAc in hexanes gave the desired product, (3EZ,5S)-1-([1,1′-biphenyl]-4-ylcarbonyl)-5-(1,2,4-oxadiazol-3-yl)-3-pyrrolidinone O-methyloxime (59 mg).

Provenance & Evidence