反应详情

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.

1. temperaturecooling
2. customThe solvent was evaporated under a reduced pressure
3. additionthe resulting residue was mixed with 80% aqueous ethanol (15 ml) and triethylamine (3 ml)
4. temperatureheated
5. temperatureunder reflux for 4 hours
6. temperatureAfter cooling
7. customthe solvent was evaporated under a reduced pressure
8. additionthe thus obtained residue was mixed with chloroform (30 ml)
9. washwashed with water (10 ml) and saturated sodium chloride aqueous solution (10 ml)
10. dry with materialdried over anhydrous sodium sulfate
11. customThe solvent was evaporated under a reduced pressure
12. washeluted with chloroform