反应详情

Under a nitrogen atmosphere, 1 mol/l borane-tetrahydrofuran complex solution (5.6 ml) was added dropwise to a tetrahydrofuran solution (15 ml) of 4-(R)-[1-(tert-butoxycarbonyl)amino-1-cyclobutyl]methyl-1-[1-(R)-phenylethyl]-2-pyrrolidone (isomer B1) (700 mg, 1.88 mmol) under ice cooling, followed by stirring at room temperature for 13 hours. After removal of the solvent under reduced pressure, 80% water-containing ethanol (15 ml) and triethylamine (3 ml) were added to the residue and the mixture was heated under reflux for 4 hours. After cooling on standing, the solvent was removed under reduced pressure and chloroform (30 ml) was added to the resulting residue. The solution was washed with water (10 ml) and saturated saline (10 ml) and then, dried over anhydrous sodium sulfate. After removal of the solvent under reduced pressure, the resulting residue was subjected to silica gel column chromatography to obtain the title compound (565 mg, 84%) as colorless crystals from the fraction eluted with chloroform/methanol=20/1.

1. customAfter removal of the solvent under reduced pressure, 80% water-
2. additioncontaining ethanol (15 ml) and triethylamine (3 ml)
3. additionwere added to the residue
4. temperaturethe mixture was heated
5. temperatureunder reflux for 4 hours
6. temperatureAfter cooling
7. customthe solvent was removed under reduced pressure and chloroform (30 ml)
8. additionwas added to the resulting residue
9. washThe solution was washed with water (10 ml) and saturated saline (10 ml)
10. dry with materialdried over anhydrous sodium sulfate
11. customAfter removal of the solvent under reduced pressure