Sitagliptin Tartrate Hemihydrate Standard

(R)-3-Amino-1-(3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (2R,3R)-2,3-dihydroxysuccinate Hemihydrate;