反应详情

A 30% hydrogen bromide acetic acid solution (13.1 mL, 65.9 mmol) was added to an acetic acid (4.4 mL) solution of benzyl (1S)-2-[(2-hydroxyethyl)amino]-2-oxo-1-[4-(trifluoromethoxy)benzyl]ethylcarbamate (9.36 g, 22.0 mmol) prepared in Reference Example 6 (6b) under ice-cooling with stirring. The mixture was stirred at room temperature for 4 hours, and then ice water (300 mL) was added thereto. The reaction solution was washed with diethyl ether (50 mL, three times), and subsequently the water layer was neutralized with sodium bicarbonate (about 40 g) and extracted with methylene chloride (300 mL, three times). The organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated. The residue was dried under reduced pressure to give 5.89 g of the title compound (yellow solid, yield: 80%).

1. temperaturecooling
2. stirringThe mixture was stirred at room temperature for 4 hours
3. washThe reaction solution was washed with diethyl ether (50 mL, three times)
4. extractionextracted with methylene chloride (300 mL, three times)
5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
6. customthe solvent was evaporated
7. customThe residue was dried under reduced pressure