2,5-Dihydroxybenzoic acid → Sitagliptin

Participants

Reaction Steps

The gentisic acid salt of (2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine was formed by mixing gentisic acid (0.113 g), (2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (0.300 g) in a mixture of isopropylalcohol (0.6 mL) and chloroform (1.5 mL), followed by stirring at reflux temperature for 2 h. The solvent was distilled out at reduced pressure to obtain solid gentisate salt of (2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine as an amorphous solid. [Wt.: 0.410 g, % purity: 98.9%, XRD=amorphous FIG. (2)].

Provenance & Evidence