Acetic Acid → Pantoprazole

Participants

Reaction Steps

2 g of 5-difluoromethoxy-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]thio]-1H-benzimidazole was suspended in 36 ml of methanol at room temperature, to which 4.1 g of Na2CO3 in 14 ml water was added while stirring. 0.09 g of Na2WO4·2H2O oxidation catalyst was dissolved in 0.74 g H2O2 (50% aqueous solution), and further diluted with 10 ml of water. The oxidant/catalyst solution was added to the reactant/base solution dropwise so that the addition was completed in about 30 minutes while stirring at room temperature. The reaction was continued for additional 10 minutes-while stirring. 10 ml of 10% Na2S2O3 aqueous solution was then added, and the resulting mixture was subjected to a reduced pressure to remove methanol therefrom. Finally, a precipitate was formed after adding a diluted acetic acid aqueous solution to a pH value of about 8, which was filtered, water washed, and dried in vacuo to obtain Pantoprazole with a yield of about 85% (LC purity>95%).

Provenance & Evidence