反应详情

温度

60 °C

To a solution of naltrexone (2.5 g, 7.3 mmol) and benzylbromide (1.5 g, 8.8 mmol) in DMF (25 mL) was added potassium carbonate (2.8 g, 20 mmol). The mixture was stirred for 12 hrs at 60° C., then cooled and diluted with water. The resulting oily product was extracted with EtOAc. The extract was washed with water dried over MgSO4 and concentrated. The residue was chromatographed on silica gel (hexane-EtOAc, 3;2) to afford 3-benzylnaltrexone (4) (2.3 g, 74%). 1H NMR (CDCl3) δ 0.15(2H, m, H-20β, H-21β), 0.56(2H, m, H-20α, H-21α), 0.87(1H, m, H-19), 1.58(1H, dd, J=12.3 Hz, 2.4 Hz, H-15), 1.64(1H, dt, J=13.5 Hz, 2.4 Hz, H-8), 1.89(1H, d, J= 13.5 Hz, H-8), 2.13(1H, dt, J=12.3 Hz, 2.4 Hz, H-15), 2.30(1H, dt, J=12.3 Hz, 2.4 Hz, H-16), 2.40(3H, m, H-7, H-18), 2.55(1H, dd, J=18.3 Hz, 6.0 Hz, H-10), 2.69(1H, dd, J=12.3 Hz, 2.4Hz, H-16), 3.03(2H, m, H-7, H-10), 3.18(1H, d, J=6.0 Hz, H-9), 4.70(1H, s, H-5), 5.20(1H, d, J=12.0 Hz, Bz CH), 5.29(1H, d, J=12.0 Hz, Bz CH), 6.56(1H, d, J=7.2 Hz, H-1), 6.71(1H, d, J=7.2 Hz, H-2), 7.25-7.60(5H, m, Bz aromatic H).

1. temperaturecooled
2. extractionThe resulting oily product was extracted with EtOAc
3. washThe extract was washed with water
4. dry with materialdried over MgSO4
5. concentrationconcentrated
6. customThe residue was chromatographed on silica gel (hexane-EtOAc, 3;2)