- Method for preparing pantoprazole nitrogen oxide
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The invention provides a preparation method of pantoprazole nitrogen oxide, which is implemented according to the following steps: reacting 2-chloromethyl-3, 4-dimethoxypyridine hydrochloride servingas a raw material with m-chloroperoxybenzoic acid, and carrying out oxidization to prepare pyridine nitrogen oxide; and enabling the pyridine nitrogen oxide to react with 5-difluoromethoxy-2-mercapto-1H-benzimidazole to generate 5-difluoromethoxy-2-[(3, 4-dimethoxy-2-pyridyl) methyl] thio-1H-benzimidazole nitrogen oxide. The genetically toxic impurity pantoprazole nitrogen oxide of the pantoprazole sodium sesquihydrate is prepared by an economical and green method, the operation is simple and convenient, the condition is mild, and the product purity is high.
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Paragraph 0017; 0038-0040; 0043-0045
(2020/05/14)
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- Efficient synthesis of N-Oxide derivatives: Substituted 2-(2-(pyridyl-N-oxide)methylsulphinyl)benzimidazoles
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Different substituted 2-chloromethylpyridyl derivatives (6a-d) were oxidized with mCPBA to give the respective 2-chloromethylpyridine-N-oxide derivatives (7a-d) at low temperature, which on condensation with 2-mercapto-1H-benzimidazole (8a-c) in the presence of aprotic solvents give the 2-[[(pyridin-2-yl-1-oxide)methyl]sulfanyl]-1H-benzimidazole (9a-d) in good yield. Finally, 9a-d oxidized with mCPBA in chlorinated solvent gives a mixture of 2-[[(pyridin-2-yl-1-oxide)methyl]sulfonyl]-1H-benzimidazole (3a-d, 10%) and 2-[[(pyridin-2-yl-1-oxide) methyl]sulfinyl]-1H-benzimidazole (4a-d, 90%) derivatives. Copyright Taylor & Francis Group, LLC.
- Ray, Purna C.,Mittapelli, Vasantha,Rohatgi, Amit,Tyagi, Om Dutt
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p. 2861 - 2868
(2008/02/12)
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