- Method for preparing esomeprazole impurity
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The invention discloses a method for preparing an esomeprazole impurity. 5-methoxy-2-[(S)-[(4-chloro-3,5-dimethyl-2-pyridyl)methyl]sulfinyl]-1H-benzimidazole (II) is obtained through demethylation, halogenation, condensation and asymmetric oxidation by taking 2-chloromethyl-4-methoxy-3,5-dimethylpyridine hydrochloride as a starting raw material. According to the method disclosed by the invention,a synthesis route is simple and short, the starting raw material is easy to obtain, the reaction conditions are gentle, the operation is simple and convenient, and the impurity can be obtained withoutcolumn chromatography; the purity of the prepared impurity can be up to 99 percent or above, the ee (Enantiomeric Excess) value can be up to 99 percent or above, and the impurity can be used as reference substance in quality research.
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- ISOTOPICALLY SUBSTITUTED PROTON PUMP INHIBITORS
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The invention relates to benzimidazoles of Formula (1) and to pharmaceutical compositions comprising these compounds, further to intermediates of Formula (2 and 3).
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Page/Page column 29
(2008/06/13)
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- 4-chloro-3,5-dimethyl-2-sulfonyl pyridines
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2-Sulfonylpyridine derivatives can be industrially produced efficiently by reacting a sulfonyl cyanide derivative with an α,β-unsaturated carbonyl compound and a 2-{[(2-pyridyl)methyl]thio}-1H-benzimidazole skeleton can be formed in one step in a good yield by reacting this type of the 2-sulfonylpyridine derivative with a 2-methylthio-1H-benzimidazole derivative in the presence of an organolithium compound.
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- Method for producing 2-sulfonylpyridine derivatives and method for producing 2-{[(2-pyridyl)methyl]thio}-1H-benzimidazole derivatives
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2-Sulfonylpyridine derivatives can be industrially produced efficiently by reacting a sulfonyl cyanide derivative with an α, β-unsaturated carbonyl compound and a 2-{[(2-pyridyl)methyl]thio}-1H-benzimidazole skeleton can be formed in one step in a good yield by reacting this type of the 2-sulfonylpyridine derivative with a 2-methylthio-1H-benzimidazole derivative in the presence of an organolithium compound.
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- A process for the preparation of omeprazol
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The process starts by reacting 2,3,5 trimethylpyridine with hydrogen peroxide in the presence of catalysts, giving new reactive ionic species allowing the number of required steps to be substantially reduced. In the final important step, oxidation to omeprazol, there are used new salts of 5-methoxy-2-((3,5-dimethyl-4-methoxy-2-pyridine)methylthio)-1H-benzimidazole which, as the oxidation evolves, precipitate the omeprazol. The new oxidation method avoids superoxidations, provide for faster oxidation, high purity and yields of over 90%.
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