ABSTRACT
OBJECTIVE: To synthesize the impurity A of sitagliptin which is a highly selective DPP-4 inhibitor used for treatment of type 2 diabetes. METHODS: 1-{3-Trifluoromethyl-5,6-dihydro-1,2,4-triazo[4,3-a] piperazin-7 (8H)-y1}-4-(2,4,5-trifluorophenyl)butane-1,3-dione was prepared from 2,4,5-triflurophenylacetic acid, meldrum's acid and 3-trifLuromethyl-5,6,7,8-tetrahydro-1, 2,4-triazolo[4,3-a] pyrazine hydrochloride with one-pot reaction, followed by reduction with sodium borohydride to yield the impurity A of sitagliptin. RESULTS: The structure of the impurity A of sitagliptin was characterized by IR, MS, and 1H-NMR. CONCLUSION: The established synthetic route of the impurity A in this study has not been reported in the literature, and has the advantages of low-cost, easy operation, mild reaction, and high overall yield.