| abstract |
Sitagliptin intermediate compounds of formula (f) and methods of preparation and use thereof are disclosed. Compounds of formula (f) are prepared by the following steps: compounds of formula (a) are subjected to electrophilic reaction with benzyl halides to form compounds of formula (b), which then react with compounds of formula (i) to form novel compounds of formula (e). Gignard agents formed from 2,4,5-trifluoro bromobenzene and magnesium metal react with compounds of formula (e) to afford compounds of formula (f), which are novel intermediates for the preparation of Sitagliptin intermediates of formula (g). Compounds of formula (f) are subjected to reduction by Pd/C, debenzylation, substitution of protecting group to form compounds of formula (g). Compounds of formula (a), (b), (i), (e), (f), and (g) have the following structures, in which R is protecting group of carboxyl and R 2 is (substituted) hydrocarbyl. |