Cesium carbonate → HCID 86596905, compound

Participants

Reaction Steps

A solution of benzyl (S)-1-((1S,2R)-4-isopropoxy-2-(isopropylsulfonyl methyl)cyclohexylamino)-4-(methylthio)-1-oxobutan-2-ylcarbamate (2.8 g, 5.16 mMol) was stirred at rt. After 24 h the solution was evaporated. The residue was redissolved in CH2Cl2 and evaporated. This process was repeated four more times. The residue was dried in vacuo to get a yellow foamy solid. This solid was dissolved in DMSO and treated with Cs2CO3 (3.36 g, 10.32 mMol). The reaction was set to stir at rt. After 4 h, the reaction was quenched with saturated aq. NH4Cl. Extracted the reaction mixture with EtOAc three times. The combined organic layer was washed with brine twice. It was dried (MgSO4), filtered, concentrated and chromatographed to get benzyl (S)-1-((1S,2R,4R)-4-isopropoxy-2-(isopropylsulfonylmethyl)cyclohexyl)-2-oxopyrrolidin-3-ylcarbamate A (faster isomer, 0.41 g, oil) and benzyl (S)-1-((1S,2R,4R)-4-isopropoxy-2-(isopropylsulfonylmethyl)cyclohexyl)-2-oxopyrrolidin-3-ylcarbamate B (slower isomer, 0.62 g, white solid).

Provenance & Evidence