EP2331545A2 - IMPROVED PROCESS FOR PREPARATION OF (2R)-4-OXO-4-[3- (TRIFLUOROMETHYL)-5,6-DIHYDRO [1,2,4]-TRIAZOLO[4,3-A]PYRAZIN- 7(8H)-YL]-L-(2,4,5-TRIFLUOROPHENYL)BUTAN-2-AMINE&NEW IMPURITIES IN PREPARATION THEREOF