| abstract |
FIELD: chemistry. n SUBSTANCE: method of obtaining low-molecular heparin includes obtaining benzethonium salt of non-fractionated heparin in 0.05-0.5 M water solution of sodium chloride at temperature 50-60°C, pH=8.2-8.8 and weight ratio heparin/benzethonium chloride 1/(2,35-2.70), benzylation of heparin benzethonium salt, being carried out for 2-3 hours in medium of bipolar aprotic solvent with benzylchloride in ratio heparin/benzylchloride 1/(0.2-1.0), which is preliminarily subjected to activation in aprotic solvent for 15-20 min, precipitation of heparin benzyl ether by method of Spiro with ethyl alcohol, preliminarily saturated with water-free sodium acetate, with the following removal of protection from sulfo groups, carrying out β-elimination of benzyl ether with degree of heparin etherification 9-13% 1±0.5 N with alkali NaOH at temperature 55±5°C, duration of process is 40-60 min and weight ratio of reagents benzyl ether/alkali 1/(0.5-2). n EFFECT: method improvement. n 4 ex, 3 tbl, 2 dwg |