反应详情

To a solution of (R)-3-(4-Bromo-phenyl)-2-tert-butoxycarbonylamino-propionic acid (1.0 g, 2.91 mmol) in DMF (5 mL) is added Cs2CO3 (1.041 g, 3.2 mmol) and the mixture is stirred at room temperature for 30 minutes. Then iodomethane (1.031 g, 7.26 mmol) is added and the mixture is stirred at room temperature about 72 hours. The pH is adjusted to 5˜6 by adding 1N HCl then the mixture is extracted with EtOAc. The combined organic layers were washed with water and brine, dried over MgSO4, filtered and concentrated to give (R)-3-(4-bromo-phenyl)-2-tert-butoxycarbonylamino-propionic acid methyl ester. HPLC Retention time 1.49 minutes (condition C): MS 358.3 (M−1).

1. stirringthe mixture is stirred at room temperature about 72 hours
2. extractionthe mixture is extracted with EtOAc
3. washThe combined organic layers were washed with water and brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated