1,2-Dichloroethane → N-({3-[(2S,4EZ)-1-([1,1'-biphenyl]-4-ylcarbonyl)-4-(methoxyimino) pyrrolidinyl]-1,2,4-oxadiazol-5-yl}methyl)-3-(1-piperidinyl)propanamide

Participants

Reaction Conditions

Reaction Steps

4-{[(2S,4EZ)-2-(5-{[(tert-butoxycarbonyl)amino]methyl}-1,2,4-oxadiazol-3-yl)-4-(methoxyimino)pyrrolidinyl]carbonyl}-1,1′-biphenyl (Example 50) was treated with a 25% TFA/DCM solution at 0° C. The reaction was monitored by LC/MS and stopped after completion. The reaction was then made basic with sodium carbonate solution (10%) and extracted with DCM. The combined organic phases were dried over magnesium sulfate. Solvent removal afforded a crude product, which was used without purification in the next step. The residue was dissolved in DCM at room temperature, DMAP (1.1 equivalent) and 3-(1-piperidinyl)propanoic acid (1 equivalent) were added. The reaction mixture was then cooled down to 0° C. and EDC (1.1 equivalent) was added portion-wise. After stirring for 1 hour at 0° C., the reaction mixture was allowed to warm to room temperature. The reaction was monitored by TLC and LC/MS. Usually after 12 hours stirring at RT, the reaction mixture was hydrolyzed, washed with sodium carbonate solution (10%), dried over MgSO4, and evaporated in vacuo to give a crude product. Flash chromatography on silica gel, eluting with 60% EtOAc in hexane, gave the title compound as a mixture of E- and Z-isomers in 50% yield (87.4% purity by HPLC).

Provenance & Evidence