Hydrochloric Acid → Pantoprazole

Participants

Reaction Conditions

Reaction Steps

A flask equipped with a stirrer is charged with acetonitrile (0.6 L). Under mixing, compound VI (30 g) is added, followed by 18.8% aqueous NaOH (70 ml, 5.0 eq.). The flask is then cooled to −7° C. Aqueous 10.6% active NaOCl (70 ml, d=1.16, 1.4 eq.) is added dropwise over 45 min. The two-phase mixture is stirred at room temperature for 1.5 h. Aqueous Na2S2O5 (120 ml) is added. The pH is then adjusted to 8 with 10% HCl solution (120 ml). The phases are separated. The organic layer is washed with water, and the aqueous phase is washed twice with acetonitrile. The organic phases are combined, dried over MgSO4, and concentrated to one quarter of their original volume. Pantoprazole is precipitated from the concentrate and separated by filtration to yield pantoprazole (20.1 g, 64.8%) containing 0.04% compound VI and free of sulfone within the limit of UV detection.

Provenance & Evidence