Methyl 3-Oxo-4-(2,4,5-trifluorophenyl)butanoate is a useful synthetic intermediate in the synthesis of Sitagliptin (S491000); a trizolopyrazine dipeptidyl peptidase (DPP) IV inhibitor for the treatment of type II diabetes.
The preparation of methyl 3-Oxo-4-(2,4,5-trifluorophenyl)butanoate is as follows:Stage 1: (2,4,5-trifluorophenyl)acetic acid With 1,1'-carbonyldiimidazole In acetonitrile for 3.5h;Stage 2: monomethyl monopotassium malonate With triethylamine; magnesium chloride In acetonitrile at 50℃; for 8h;Stage 3: In acetonitrile at 30℃; for 26h.