Benzyl Bromide → Benzyl betulinate

関与物質

反応条件

反応手順

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).

情報源と証拠