Phosphoric Acid → Sitagliptin Phosphate Monohydrate

Participants

Reaction Conditions

Reaction Steps

The sitagliptin freebase is dissolved in a mixture of isopropyl alcohol (5 mL) and water (0.2 mL), to which 85% phosphoric acid (0.056 g) is added. The contents are heated to about 70° C. for about 30 minutes, then cooled to about 30° C., and stirred for about 15 hours. The separated solid is filtered, washed with isopropyl alcohol (1 mL), and dried at about 50° C. for about 3 hours to afford the title compound. (Yield: 68%; purity by HPLC: 99.87%; SOR: −20.7° C. (c=1% in water))

Provenance & Evidence