Pyridine → (3Ez,5s)-1-(biphenyl-4-ylcarbonyl)-5-{[3-(2-hydroxyethyl)-1,2,4-oxadiazol-5-yl]methyl}pyrrolidin-3-one o-methyloxime

Participants

Reaction Steps

To a solution of [(2S,4EZ)-1-(biphenyl-4-ylcarbonyl)-4-(methoxyimino)pyrrolidin-2-yl]acetic acid (Intermediate 7, 50 mg, 0.14 mmol) in tetrahydrofuran (2 ml) was added CDI (37 mg, 0.23 mmol). The reaction mixture was stirred 1 h30. A solution of N′,3-dihydroxypropanimidamide (16 mg, 0.16 mmol), pyridine (34 ml, 0.14 mmol) in tetrahydrofuran was then added and the reaction mixture was stirred at reflux overnight The solvent was removed and ethyl acetate was added. The organic phase was washed with citric acid 5%, NH4Cl, NaHCO3 then brine. The organic phase was dried (MgSO4), concentrated and purified on silica gel column chromatography (Ethyl acetate) to afford (3EZ,5S)-1-(biphenyl-4-ylcarbonyl)-5-{[3-(2-hydroxyethyl)-1,2,4-oxadiazol-5-yl]methyl}pyrrolidin-3-one O-methyloxime (19 mg). Yield: 27%. HPLC purity: 94%

Provenance & Evidence