反应详情

温度

50 °C

A mixture of benzoylbutyric acid (9.0 g, 46.8 mmol), 1,8-dibromooctane (31.5 g, 117.0 mmol), potassium carbonate (16.4 g, 117.0 mmol), dry DMF (70 mL), and a catalytic amount of tetra-n-butylammonium iodide (1.0 mol %) was stirred and heated at 50° C. overnight. The solvent was evaporated. The residue was washed with dilute HCl and then extracted into ether, washed with brine, and dried with MgSO4. The solvent and excess 1,8-dibromooctane were removed under reduced pressure. The crude product was chromatographed on silica using 0-20% ethyl acetate in hexane. Isolated yield=13.5 g (75%) as a colorless liquid. 1H NMR (CDCl3, 200 MHz): δ ppm 7.95 (dd, J=8.24, 1.49 Hz, 2H), 7.47 (m, 3H), 4.05 (t, J=6.64 Hz, 2H), 3.37 (t, J=6.81, 2H), 3.04 (t, J=7.13 Hz, 2H), 2.42 (t, J=7.20 Hz, 2H), 2.01 (m, 2H), 1.82-1.73 (m, 2H), 1.69-1.51 (m, 2H), 1.47-1.21 (m, 8H). 13C NMR (CDCl3, 50.28 MHz): δ 199.29, 173.25, 136.75, 133.00, 128.52, 127.94, 64.41, 37.40, 33.90, 33.34, 32.67, 28.96, 28.50, 27.97, 25.76, 19.34. HRMS (EI) m/z: 405 ((M+Na)+•). Elemental analysis: Calculated for C19H27BrO3: C, 59.53; H, 7.10; Br, 20.85; O, 12.52. Found: C, 59.77; H, 7.52.

1. customThe solvent was evaporated
2. washThe residue was washed with dilute HCl
3. extractionextracted into ether
4. washwashed with brine
5. dry with materialdried with MgSO4
6. customThe solvent and excess 1,8-dibromooctane were removed under reduced pressure
7. customThe crude product was chromatographed on silica using 0-20% ethyl acetate in hexane
8. customIsolated yield=13.5 g (75%) as a colorless liquid