Abstract: Two acyl groups were respectively introduced at C-3 and C-28 hydroxyl groups of betulin. 3,28-di-O-succinyl-betulin was synthesized with pyridine as solvent and dimethylaminopyridine (DMAP) as catalyst from betulin and succinyl anhydride. The influences of the ratio of betulin to succinyl anhydride and reaction time on the purity of 3,28-di-O-succinyl-betulin were studied. The qualitative analysis was studied by FT-IR,¹H NMR and MS.The quantitative analysis was examined by HPLC. The results showed that the optimal condition was as follows: molar ratio of betulin to succinyl anhydride 1 to 18, reaction temperature 95℃ and reaction time 10 h. The yield was 70.43% and the purity was 81.854% under these conditions.

Key words: betulin, 28-di-O-succinyl-betulin, esterification