反应详情

Triethylamine (17.0 mL, 122 mmol), acetic anhydride (7.6 mL, 80.4 mmol) and 4-dimethylaminopyridine (20 mg, 0.16 mmol) were added to a solution of (2R)-2-amino-2-methyl-4-(1-ethylpyrrol-2-yl)butan-1-ol ½ D-(−)-tartrate (2.70 g, 7.80 mmol) obtained in Reference example 3 (3e) in methylene chloride (30 mL) and the mixture was stirred at room temperature for 3 hours and 30 minutes. Water and methylene chloride were added to the reaction mixture to separate it. The thus obtained organic phase was separated, washed with water and a saturated aqueous NaCl solution and dried over anhydrous sodium sulfate. After filtration, it was concentrated to dryness under reduced pressure and the residue was purified by silica gel chromatography (ethyl acetate) to obtain the title compound (2.2 g, yield: 96%).

1. customto separate it
2. customThe thus obtained organic phase was separated
3. washwashed with water
4. dry with materiala saturated aqueous NaCl solution and dried over anhydrous sodium sulfate
5. filtrationAfter filtration, it
6. concentrationwas concentrated to dryness under reduced pressure
7. customthe residue was purified by silica gel chromatography (ethyl acetate)