Hydrochloric Acid → Pantoprazole

Participants

Reaction Conditions

Reaction Steps

A flask is charged with acetonitrile (0.1 L). Under mixing, compound VI (5 g) is added, followed by NaOH pellets (2.18 g, 4.0 eq.). The reactor is cooled to −7° C. A commercial 10.5% NaOCl solution (11.5 ml, 1.4 eq.) is diluted by a factor of 3 by adding water. The diluted NaOCl solution (34.5 ml) is added dropwise over 25 min. The two-phase mixture is stirred at room temperature for 2.5 h. Then, aqueous Na2S2O5 (20 ml) is added. The pH of the aqueous phase is adjusted to 8 with 10% HCl (10 ml). The phases are then separated. The organic layer is washed with water, and the aqueous phase is washed twice with acetonitrile. The combined organic phases are combined, dried over magnesium sulfate (MgSO4), and concentrated to one quarter of the original volume. A precipitate forms in the concentrate, which is separated by filtration to obtain pantoprazole (2.78 g, 53.8%) containing 0.07% compound VI and free of sulfone within the limited of UV detection.

Provenance & Evidence