HCID 21087446, compound → HCID 21087443, compound

Participants

Reaction Steps

In an atmosphere of nitrogen, 1 M borane-tetrahydrofuran complex solution (5.6 ml) was added dropwise to tetrahydrofuran solution (15 ml) of 4-(R)-[1-(tert-butoxycarbonyl)amino-1-cyclobutyl]methyl-1-[1-(R)-phenylethyl]-2pyrrolidone (isomer B1) (700 mg, 1.88 mmol) under ice-cooling, and the mixture was stirred at room temperature for 13 hours. The solvent was evaporated under a reduced pressure, and the resulting residue was mixed with 80% aqueous ethanol (15 ml) and triethylamine (3 ml) and heated under reflux for 4 hours. After cooling, the solvent was evaporated under a reduced pressure, and the thus obtained residue was mixed with chloroform (30 ml), washed with water (10 ml) and saturated sodium chloride aqueous solution (10 ml) and then dried over anhydrous sodium sulfate. The solvent was evaporated under a reduced pressure, and the thus obtained residue was applied to a silica gel column chromatography and eluted with chloroform:methanol=20:1, thereby obtaining 565 mg (84%) of the title compound as colorless crystals.

Provenance & Evidence