H3PW12O40: An Efficient and Green Catalyst for the Facile and Selective Oxidation of Sulfides to Sulfoxides, Applied to the Last Step of the Synthesis of Omeprazole

Abstract

<em>Omeprazole, (6-methoxy-2-((4-methoxy-3,5-dimethylpyridin-2-yl)methylsulfinyl)-1H-benzimidazole is a well-established prescribed drug,</em> <em>exhibits proton pump inhibitor activity. In this work, a novel, facile, economical and selective oxidation approach</em> <em>using H₃PW₁₂O₄₀ as Keggin type heteropolyacids along with H₂O₂ in the last step of the conventional synthesis of this compound as well as its derivatives under environmental-benign conditions, is reported. This protocol can be</em><em>well adopted for pilot plant scale giving a high pure pharmacopeia grade material.</em> <em>Our synthetic route</em><em> involves the use of various heteropolyacids as heterogeneous catalysts.</em> <em>Due to the obtained results, it was concluded that Keggin type heteropolyacid , is</em> <em>an effective catalyst for this purpose. </em><em>The optimized condition for the last step of this synthesis was applied to the synthesis of lansoprazole,</em><em> pantoprazole, and rabeprazole.</em>