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
CONDITIONS
反应条件
- 温度
- 50 °C
PROCEDURE
实验过程
A solution of N-(4-bromo-2-fluoro-benzyl)-4-chloro-2-hydroxy-benzamide (3.25 g, 9.06 mmol) in acetone (45 mL, 0.2 M) was treated with aq K2CO3 (2 M, 6.8 mL, 14 mmol) and ethyl bromoacetate (1.2 mL, 11 mmol). After being heated to 50° C. for 8 h, the solution was cooled to room temperature and concentrated under reduced pressure until most of the acetone was removed. The solution was acidified to pH 1–2 with 2 N HCl, diluted with ethyl acetate and washed with saturated aq NaCl. The organic layer was dried over Na2SO4, filtered and concentrated. Purification by MPLC (10–60% ethyl acetate in heptane, 23 mL/min, 70 min) gave [2-(4-bromo-2-fluoro-benzylcarbamoyl)-5-chloro-phenoxy]-acetic acid ethyl ester as a white crystalline solid (3.78 g, 94%): mp 126–127° C.; Rf 0.61 (50% ethyl acetate in heptane); 1H NMR (DMSO-d6, 300 MHz) δ 8.90 (t, J=6 Hz, 1 H), 7.82 (d, J=8.4 Hz, 1 H), 7.52–7.47 (m, 1 H), 7.39–7.31 (m, 2 H), 7.28 (d, J=1.8 Hz, 1 H), 7.14 (dd, J1=8.4 Hz, J2=1.8 Hz, 1 H), 5.00, (s, 2 H), 4.49 (d, J=6 Hz, 2 H), 4.16 (q, J=7.2 Hz, 2 H), 1.18 (t, J=6.6 Hz, 3 H). ESI-LC/MS m/z calcd for C18 H11BrClFNO4: 444.7; found 446.0 (M+1)+. Anal. calcd for C16H16BrClFNO4: C, 48.62; H, 3.63; N, 3.15; Cl, 15.95. Found C, 48.57; H, 3.63; N, 3.11; Cl, 16.00.
WORKUP
后处理
- temperaturethe solution was cooled to room temperature
- concentrationconcentrated under reduced pressure until most of the acetone
- customwas removed
- additiondiluted with ethyl acetate
- washwashed with saturated aq NaCl
- dry with materialThe organic layer was dried over Na2SO4
- filtrationfiltered
- concentrationconcentrated
- customPurification by MPLC (10–60% ethyl acetate in heptane, 23 mL/min, 70 min)