FIELD : chemistry.SUBSTANCE : invention relates to a synthesis method of 8-oxo-2' -deoxyguanosine (8-oxo-dG), which can be used in pharmaceutical and chemical industry. Method is carried out by acylation of 8-bromo-2' -nucleoside-deoxyguanosine (8-Br-dG) mixture of acetic anhydride and sodium acetate in a polar aprotic organic solvent in the presence of a N-methylimidazole catalyst followed by hydrolysis of an acyl group, wherein the solvent used is N-dimethylformamide, to which pyridine is added to a final concentration of 1.8 mM to prevent apurination, reaction is carried out at 120–155 °C for 12–28 hours, obtaining desired product (8-oxo-dG) is carried out by removing acyl groups using alkaline hydrolysis in 0.1–1.5 M aqueous NaOH solution.EFFECT : novel efficient method of producing a valuable product.1 cl, 2 dwg, 6 ex