(1S,2S,3S,5R)-3-(2-Hydroxyethoxy)-5-[7-methoxy-5-(propylthio)-3H-1,2,3-triazolo[4,5-d]pyrimidin-3-yl]-1,2-cyclopentanediol is an intermediate in the synthesis of (1S,2S,3R,5S)-3-[7-Chloro-5-(propylthio)-3H-1,2,3-triazolo[4,5-d]pyrimidin-3-yl]-5-(2-hydroxyethoxy)-1,2-cyclopentanediol which is used in preparation of metaboltes of Ticagrelor (T437700) which is the first reversible oral P2Y12 receptor antagonist, provides faster, greater, and more consistent ADP-receptor inhibition than Clopidogrel.