Sulfation of Betulin with Chlorosulfonic Acid in Pyridine

Abstract

It was found that when betulin is sulfated with chlorosulfonic acid in pyridine medium, 3,28-disulfate of betulin is formed in a stable salt form. Under optimal synthesis conditions: temperature 70 °C, duration 2 hours, molar ratio betulin / chlorosulfonic acid 4.0, betulin is completely converted into betulin 3.28-disulfate. The structure and composition of betulin 3,28-disulfate were confirmed by elemental analysis, IR, Raman and 13C NMR spectroscopy. Betulin 3,28-disulfate was isolated both in the form of an unstable H + -form and in a stable forms of sodium and pyridinium salts. Sodium salt of 3,28-disulfate is a needle-like crystals collected in cobweb-like aggregates. The sodium salt of 3,28-disulfate has mycellar properties, the critical concentration of mycellar formation is 0.23 mmol / L.