METHOD FOR PREPARING 2,3,5,7,8-PENTAHYDROXY-6-ETHYL-1,4-NAPHTHOQUINONE Russian patent published in 2006 - IPC C07C50/32 C07C46/10 

FIELD: organic chemistry, pharmaceutical technology.

SUBSTANCE: invention relates to pharmaceutical agents and a method for preparing 2,3,5,7,8-tetrahydroxy-6-ethyl-1,4-naphthoquinone (echinochrome). Method involves extraction of the end product from urchins. Raw is washed in reactor with water to remove sea salts, mechanical and other impurities. Washed out raw is treated with a water-mixing organic solvent, for example, ethyl alcohol or acetone for removal of water residue and part of organic substances. Then method involves extraction with organic solvent not mixing with water, for example, hexane or chloroform to remove lipid substances. Treated raw is subjected for 2-fold, not less, acid extraction with inorganic acid aqueous solution in organic solvent. The prepared echinochrome-containing extract is purified from impurities by successive liquid extraction with chloroform and crystallization from organic solvent. The final purification of echinochrome is carried out by vacuum-sublimation of crystal solvate at temperature about 220°C. Invention provides preparing echinochrome with purity above 98.0%.

EFFECT: improved preparing method.

2 cl, 2 dwg, 3 ex