反应详情
EQUATION
反应方程式
REACTANTS
反应物
PRODUCTS
生成物
AUXILIARIES
试剂、催化剂与溶剂
PROCEDURE
实验过程
50 g of (2R,4S)-5-biphenyl-4-yl-4-tert-butoxycarbonylamino-2-methylpentanoic acid (3-a, R1=BOC, R2=R3=H) is added to dimethylformamide (80 ml). Cesium carbonate (69 g) is then added. Ethyl iodide (13.6 g) is then added and the mixture is stirred overnight at room temperature. Water (200 ml) is added to the mixture and the mixture is then extracted with isopropyl acetate (2×200 ml). The combined organic phases are washed with brine, dried (MgSO4) and concentrated in vacuo to give (2R,4S)-5-biphenyl-4-yl-4-tert-butoxycarbonylamino-2-methylpentanoic acid ethyl ester (3-a, R1=BOC, R2=H, R3=Et) (56 g). 1H NMR (DMSO): 1.12 (3H), 1.19 (3H), 1.36 (9H), 1.53 (1H), 1.84 (1H), 2.55 (1H), 2.75 (2H), 3.74 (1H), 4.05 (2H), 6.04 (1H), 7.23 (2H), 7.30 (1H), 7.41 (2H), 7.50 (2H), 7.57 (2H). m/z (ES+): 412 ([MH]+, 100%), 356 (63), 312 (73).
WORKUP
后处理
- extractionthe mixture is then extracted with isopropyl acetate (2×200 ml)
- washThe combined organic phases are washed with brine
- dry with materialdried (MgSO4)
- concentrationconcentrated in vacuo