NOVELTY - Preparing ticagrelor (I), comprises e.g. carrying out cyclization reaction of 1-((3aR,4S,6R,6aS)-4-(ethoxycarbonylmethoxy)-2,2-dimethyltetrahydro-3aH-cyclopenta(d)(1,3)dioxol-6-yl)-5-amino-4-carbamoyl-1H-1,2,3-triazole (II) with thiourea to obtain ethyl 2-(((3aR,4S,6R,6aS)-6-(7-hydroxy-5-mercapto-3H-(1,2,3)triazolo(4,5-d)pyrimidin-3-yl)-2,2-dimethyl-tetrahydro-3aH-cyclopenta(D)(1,3)-dioxol-4-yl)oxy)-acetate (III), substituting (III) with bromopropane, carrying out condensation with trans-(1R,2S)-2-(3,4-difluorophenyl)cyclopropanamine, reducing obtained compound, and removing protecting group.    USE - The method is useful for preparing ticagrelor.    ADVANTAGE - The method: is simple, economic and environment-friendly; produces product with high chemical and chiral purity; and is suitable for industrial production.    DETAILED DESCRIPTION - Preparing ticagrelor of formula (I), comprises carrying out cyclization reaction of 1-((3aR,4S,6R,6aS)-4-(ethoxycarbonylmethoxy)-2,2-dimethyltetrahydro-3aH-cyclopenta(d)(1,3)dioxol-6-yl)-5-amino-4-carbamoyl-1H-1,2,3-triazole (II) with thiourea to obtain ethyl 2-(((3aR,4S,6R,6aS)-6-(7-hydroxy-5-mercapto-3H-(1,2,3)triazolo(4,5-d)pyrimidin-3-yl)-2,2-dimethyl-tetrahydro-3aH-cyclopenta(D)(1,3)-dioxol-4-yl)oxy)-acetate (III), carrying out substitution reaction of (III) with bromopropane to obtain ethyl 2-(((3aR,4S,6R,6aS)-6-(7-hydroxy-5-(propylmercapto)-3H-(1,2,3)triazolo(4,5-d)pyrimidin-3-yl)-2,2-dimethyl-tetrahydro-3aH-cyclopenta(d)(1,3)-dioxol-4-yl)oxy)-acetate (IV), carrying out condensation reaction of (IV) with trans-(1R,2S)-2-(3,4-difluorophenyl)cyclopropanamine to obtain ethyl 2-(((3aR,4S,6R,6aS)-6-(7-(((1R,2S)-2-(3,4-difluorophenyl)cyclopropyl)amino)-5-(propylmercapto)-3H-(1,2,3)triazolo(4,5-d)pyrimidin-3-yl)-2,2-dimethyl-tetrahydro-3aH-cyclopenta(d)(1,3)-dioxol-4yl)oxy)-acetate (V), carrying out reduction reaction of (V) to obtain 2-(((3aR, 4S, 6R, 6aS) 6-(7-(((1R,2S)-2-(3,4-difluorophenyl)propyl)amino)-5-(propylmercapto)-3H-(1,2,3)triazolo(4,5-d)pyrimidin-3-yl)-2,2-dimethyl-tetrahydro-3aH-cyclopenta(d)(1,3)-dioxol-4-yl)oxy)-1-ethanol (VI), and removing acetone protecting group of (VI) to obtain final product.