METHOD OF OBTAINING METHYL ESTER OF 3-OXO-3'-(NITROMETHYL)-4'-(CHLORMETHYL)-SPIRO[LUPANE-2,1'-CYCLOPENTANE]-28-OIC ACID Russian patent published in 2012 - IPC C07J53/00 C07J63/00 C07J41/00 

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention relates to field of bioorganic and medical chemistry, in particular, to method of obtaining novel potentially biologically active derivative of betulonic acid - methyl ester of 3-oxo-3'-(nitromethyl)-4'-(chlormethyl)-spiro[lupane-2,1'-cyclopenbtane]-28-oic acid. Compound represents methyl alcohol of betulonic acid, containing at carbon atom C-2 spirocyclopentane fragment with vicinal (cis-, trans-configuration) CH₂NO₂- and CH₂Cl-substituents. Method of its obtaining lies in obtaining at first stage methyl ester of 2,2-diallyl-3-oxolupane-28-oic acid (DBK) by interaction of methyldihydrobetulonate (BK) with great molar excess of potassium tret-butilate (Bu^tOK) and allyl bromide with molar reagent ratio - BK: Bu^tOK:allylbromide=1:3-4 (mainly 4):2, in dimethoxyetane at room temperature with further isolation and purification of obtained product by method of column chronomatography on SiO₂, which is later subjected to radical cycloisomerisation under impact of Fe(NO₃)₃·9H₂O, FeCl₃, with molar ratio 2,2-diallyl-derivative and iron salts - DBK: Fe(NO₃)₃·9H₂O:FeCl₃=1:1.2:1.5 with boiling of reagents in tetrahydrofurane for 3-7 hours, mainly 3 hours, with further purification of obtained methyl ester of 3-oxo-3'-(nitromethyl)-4'-(chlormethyl)-spiro[lupane-2,1'-cyclopenbtane]-28-oic acid by method of column chromatography on SiO₂ chromatography on SiO₂. Output of compound in terms of methyldihydrobetulonate constituted 40%.

EFFECT: method is characterised by selectivity, simplicity of carrying out experiment and application of cheap, environmentally friendly and non-toxic reagents Fe(NO₃)₃-9H₂O, FeCl₃ which do not lead to formation of harmful and by- products.

1 cl, 4 ex