SYNTHESIS METHOD OF LINOLEUM AND LINOLENIC ACIDS, MARKED BY CARBON COMPOUNDS 13C AND 14C

摘要

FIELD: chemistry.;SUBSTANCE: synthesis method by ¹³C-linoleic, ¹³C-linolenic, ¹⁴C-linoleic and ¹⁴C-linolenic acids includes the carbon dioxide condensation, marked by ¹⁴C or ¹³C, with the Grignard reagent, produced from 1-bromo-8.11-heptadecandiene (in case of linoleic acid) or from 1-bromo-8.11.14-heptadecanthriene (in the case of linolenic acid), carried out in the following sequence of steps: a - production of the Grignard reagent by the reaction of metallic magnesium with 1-bromo-8.11-heptadecandiene (in case of linoleic acid) or with 1-bromo-8.11.14-heptadecantriene (in case of linolenic acid) in the presence of metallic iodine; b - carboxylation of the Grignard reagent, produced at point a, for 5-15 min at temperature -20°C at constant stirring, carbon dioxide, marked by ¹⁴C or ¹³C, produced by the sulfuric acid of barium carbonate decomposition, marked by ¹⁴C and ¹³C, at the CO₂ pressure of not more than 500 mm Hg. (maintaining by the drop metering of sulfuric acid); after stopping the pressure change in the system, the reaction flask is cooled with the liquid nitrogen in order to provide the quantitative transfer of the remaining in the system ¹⁴CO₂ or ¹³CO₂ in it, close the tap connecting the device to the CO₂ source, and the reaction mixture is stirred for 15 minutes at the temperature -20°C with the purpose to fully incorporate the isotopically marked carbon dioxide into the product of the synthesis: linoleic or linolenic acid.;EFFECT: target products manufacture process acceleration, reduction of carbon dioxide losses, increase of its total chemical and radiation yield in comparison with the prototype, and elimination of the isotope-marked atoms distribution along the entire length of the acyl chain, the simplification and cheapening of the target products the linoleic and linolenic acids manufacture process, is ensured by the decrease in the duration, the increase of the radiation and chemical yield of the product along the source of the isotope in comparison with the prototype, the radioactive wastes release into the external environment is almost completely excluded, as its inclusion into the target product is approaching to the quantitative.;10 tbl, 2 ex, 4 dwg