反应详情

温度

60 °C

To a suspension of betulinic acid (12 g, 26.3 mmol) and potassium carbonate (7.26 g, 52.6 mmol) in DMF (150 mL) was added benzyl bromide (3.28 mL, 27.6 mmol). The mixture was heated to 60° C. for 3.5 h, and then it was cooled to rt. Solids started to precipitate upon cooling. The mixture was diluted water (200 mL) and the solids that formed were collected by filtration to give the title compound (13.92 g, 25.5 mmol, 97% yield) as a white solid. 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 7.39-7.28 (m, 5H), 5.16-5.06 (m, 2H), 4.71 (d, J=1.83 Hz, 1H), 4.59 (s, 1H), 3.17 (ddd, J=11.44, 5.65, 5.49 Hz, 1H), 3.01 (td, J=10.99, 4.88 Hz, 1H), 2.27 (ddd, J=12.36, 3.20, 3.05 Hz, 1H), 2.21-2.13 (m, 1H), 1.93-1.81 (m, 2H), 1.67 (s, 3H), 0.95 (s, 3H), 0.93 (s, 3H), 1.71-0.82 (m, 20H), 0.79 (s, 3H), 0.75 (s, 3H), 0.74 (s, 3H).

1. temperatureit was cooled to rt
2. customto precipitate
3. temperatureupon cooling
4. customthe solids that formed
5. filtrationwere collected by filtration