反应详情

To a solution of (R)-2-amino-3-(4-bromophenyl)propionic acid (50 g, 0.2 mol) in MeCN (700 mL) was added a solution of NaOH (16.4 g, 0.4 mol) in water (700 mL) at −5° C. After stirring for 10 minutes, a solution of (BOC)2O (44.7 g, 0.2 mol) in MeCN (100 mL) was added. The mixture was warmed to room temperature and stirred overnight. After evaporation of the MeCN, the residue was diluted with DCM (800 mL) and acidified with 1 M HCl to pH 2 at −5° C. The aqueous layer was extracted with DCM (3×200 mL). The combined organic layers were washed with saturated aqueous NaCl (500 mL), dried over anhydrous Na2SO4 and concentrated to yield the title compound as a white solid (64.2 g). LC-MS: [M+Na]:366, [2M+Na]:709.

1. stirringstirred overnight
2. customAfter evaporation of the MeCN
3. additionthe residue was diluted with DCM (800 mL)
4. customacidified with 1 M HCl to pH 2 at −5° C
5. extractionThe aqueous layer was extracted with DCM (3×200 mL)
6. washThe combined organic layers were washed with saturated aqueous NaCl (500 mL)
7. dry with materialdried over anhydrous Na2SO4
8. concentrationconcentrated