Abstract Tenatoprazole (Ulsacare®) is a recently developed antiulcerative drug used for the treatment of both erosive and nonerosive gastroesophageal reflux disease. During the bulk synthesis of tenatoprazole, we have observed four impurities (tenatoprazole N??oxide, tenatoprazole sulfone N??oxide, N??methyl tenatoprazole, and desmethoxy tenatoprazole) and two metabolites (tenatoprazole sulfide and tenatoprazole sulfone). The present work ...
