NOVELTY - Preparation of Ticagrelor comprises: (a) reacting a pyrimidine derivative with a cyclopentanyl derivative in presence of a base to obtain 2-(((3aR,4S,6R,6aS)-6-((5-amino-6-chloro-2-(propylthio)-pyrimidin-4-yl)amino)-2,2-dimethyltetrahydro-3aH-cyclopenta(d)(1,3)dioxol-4-yl)oxy)ethanol; (b) treating the obtained compound in (a) with sodium nitrite in acetic acid and then reacting the mass with a pyrimidine derivative; and (c) deprotecting the obtained compound in (b) in presence of pyridinium p-toluene sulfonate to obtain Ticagrelor.    USE - The method is useful for preparing Ticagrelor (claimed).    ADVANTAGE - The method is highly improved, environment friendly, industrially advantageous, economical and significant for industrial scale preparation of Ticagrelor.    DETAILED DESCRIPTION - Preparation of Ticagrelor comprises: (a) reacting a pyrimidine derivative of Formula (IV) with a cyclopentanyl derivative of Formula (V) in presence of a base to obtain 2-(((3aR,4S,6R,6aS)-6-((5-amino-6-chloro-2-(propylthio)-pyrimidin-4-yl)amino)-2,2-dimethyltetrahydro-3aH-cyclopenta(d)(1,3)dioxol-4-yl)oxy)ethanol of Formula (III), where the reaction is carried out in absence of any solvent; (b) treating the (III) with sodium nitrite in acetic acid and then reacting the mass with trans-(1R,2S)-2-(3,4-difluorophenyl)cyclopropanaminium (2R)-2-hydroxy-2-phenylethanoate to obtain a 2-((3aR,4S,6R,6aS)-(6-(7-(((1R,2S)-2-(3,4-difluorophenyl)-cyclopropyl)amino)-5-(propylthio)-3H-(1,2,3)-triazolo(4,5-d)pyrimidin-3-yl)-2,2-dimethyl-tetrahydro-4H-cyclopenta(d)(1,3)-dioxol-4-yl)oxy)-ethan-1-ol of Formula (II); and (c) deprotecting (II) in presence of pyridinium p-toluene sulfonate to obtain Ticagrelor. INDEPENDENT CLAIMS are included for:    (1) a process for the preparation of 2-(((3aR,4S,6R,6aS)-6-((5-amino-6-chloro-2-(propylthio)-pyrimidin-4-yl)amino)-2,2-dimethyltetrahydro-3aH-cyclopenta(d)(1,3)dioxol-4-yl)oxy)ethanol (III), which involves: reacting a pyrimidine derivative of Formula (IV) with a cyclopentanyl derivative of Formula (V) in presence of a base, where the reaction is carried out in absence of any solvent;    (2) a crystalline form of compound (III) characterized by the X-ray diffraction (XRD) pattern given in the specification;    (3) a process for the purification of compound (III), which involves: (i) dissolving the compound (III) in a mixture of ethyl acetate and cyclohexane; (ii) maintaining the contents of the solution obtained in step (i) till the formation of solid; and (iii) filtering the solid; and    (4) a process for the purification of Ticagrelor, which involves: (i) dissolving Ticagrelor in tetrahydrofuran; (ii) adding diisopropyl ether in the solution obtained in step (i); (iii) maintaining the contents as obtained in step (ii) till the formation of solid; and (iv) filtering the solid.