METHOD OF PRODUCING DIHYDROQUERCETIN Russian patent published in 2011 - IPC C07D311/40 C07D311/32 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing dihydroquercetin, involving extraction of dried and ground larchwood with aqueous solution of ethyl alcohol while heating, distillation of ethyl alcohol, cooling the aqueous part of the extract in order to separate oil and resin, characterised by that extraction of the ground larchwood is carried in ratio of raw material to extraction agent equal to 1:(6-7), the aqueous part of the dihydroquercetin extract is cooled to 38-42°C, fed into a chromatographic column filled with a polyvinyl benzene-based hydrophobic sorbent, elution of the end product is carried out with 32-40% ethyl alcohol, the eluate is collected in single portion or divided into 2-3 fractions, each fraction is evaporated until dry, the residue is crystallised from water, and the column is cleaned by washing with 96% ethyl alcohol and then filled with water to deposit a new portion of the aqueous extract.

EFFECT: method enables to obtain the end product with output of 1,5-2,5% of the mass of absolutely dry wood with 95,5-99,5% degree of purity, and also simplifies the process of producing dihydroquercetin, improves its environmental friendliness and cuts duration.

3 cl, 2 ex