METHOD FOR PRODUCING BETULIN Russian patent published in 2022 - IPC C07J53/00 C07J63/00 B01D11/04 

FIELD: technological processes.

SUBSTANCE: invention relates to a method of producing betulin from birch bark, which is used in pharmaceutical, medical, cosmetic, food and agricultural industries. Method of producing betulin involves grinding birch bark, hydrolysis of birch bark with intense stirring in an aqueous solution of 15–25 % alkali in the presence of C₃ or C₄ alcohol, separation of alcohol solution of betulin from reaction mixture. After separation, betulin solution is concentrated by evaporation. Birch bark is ground in aqueous alkali solution. Hydrolysis is carried out in a straight-flow pulsating column at temperature of 105–110 °C for 60–90 minutes at a ratio of birch bark:alkali:alcohol equal to 1:7:20, respectively. After hydrolysis, the reaction mass is cooled by lowering the pressure to temperature of 90–95 °C and directed into a blow tank for removal of boiling vapors of the reaction mass into a buffer tank. Reaction mass is continuously fed from the blow-out vessel into a separator for separation of the alcohol solution of betulin. Obtained alcohol solution of betulin from the separator is fed into a cube-evaporator for concentration by evaporation at pressure of 110–120 kPa. Precipitated betulin in the evaporator cube is directed to the filter. After washing with water, betulin is dried with hot air, wherein alcohol vapors from the cube-evaporator and the blow tank are condensed and sent to a buffer tank as a solvent for hydrolysis of birch bark.

EFFECT: method enables to obtain betulin with output of up to 35 % of the weight of dry birch bark according to the technology of a continuous process with minimum power consumption.

1 cl, 1 dwg, 2 tbl, 27 ex