Syntheses Of Organic Impurities Of Anti-peptic Ulcer Prazole Compounds

Omeprazole and rabeprazole are commonly used in the treatment of peptic ulcer disease, belonging to proton pump inhibitors (PPI). The last step of gastric acid secretion is the exchange of proton pump drive H+ and inner tubule K+, which is blocked by PPI, thereby treating peptic ulcer. Some impurities could emerge during the process of production and storage, which directly or indirectly affect product quality and purity. As a result, it plays a pivotal role that comprehensive and accurate grasping of drug-related impurities to ensure the safety and effectiveness of medicines.In this work, two known omeprazole impurities (impurity E: 4-methoxy-2-[[(RS)-(5-methoxy-1H-benzo-pyrazol-2-yl)sulfinyl]methyl]-3,5-dimethylpyridinel-oxide and impurity H: 2-[(RS)-[(4-chloro-3,5-dimethylpyridin-2-yl)methyl]sulfinyl]-5-methoxy-1H-benzimidazole) a nd one rabeprazole impurity (2-(((1H-benzimidazol-1-2-yl)sulfinyl)methyl)-4-(3-methoxyprop oxy)-3-methylpyridine-1-oxide) have been successfully prepared by modifying and optimizi ng the literature method. In particularly, the pyridine-N-oxide impurities of omeprazole (i mpurity E) and rabeprazole were obtained by a newly designed one-pot biphase reaction procedure that significantly simplifies the reaction steps and improve reaction efficiency. All compounds have been fully characterized by 1H-NMR, ESI-MS, UV-VIS, IR and HP LC technique to confirm their target structures.