- Process for synthesizing oseltamivir sulfonate from quinic acid
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The invention discloses a process for synthesizing oseltamivir sulfonate from quinic acid. The process specifically comprises the following steps of: S1, adding quinic acid and ethyl acetate into a round-bottom flask, and adding p-toluenesulfonic acid and 2, 2-dimethoxypropane, carrying out reaction to obtain a brown solid 2; S2, adding the brown solid 2 and dichloromethane into the round-bottom flask, dropwise adding methanesulfonyl chloride and triethylamine into the round-bottom flask while performing stirring, and carrying out reaction to obtain an intermediate 3; S3, adding the obtained intermediate 3 into a three-neck flask, adding ethanol and sodium ethoxide for reaction, and removing the dichloromethane after finishing the reaction to obtain an intermediate 4; and S4, adding the intermediate 4 and dichloromethane into the round-bottom flask, dropwise adding the methanesulfonyl chloride and triethylamine into the round-bottom flask while performing stirring, extracting a reaction solution with dichloromethane and water after finishing the reaction, concentrating an obtained organic phase under reduced pressure, adding methanol for crystallization, and performing filtering toobtain a white crystal 5, namely oseltamivir sulfonate.
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- Cyclohexenes derivative or its pharmaceutically acceptable salts and its use
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Belonging to the field of pharmaceutical chemistry, the invention discloses a cyclohexene derivative shown as formula I or its pharmaceutically acceptable salt. The cyclohexene derivative or its pharmaceutically acceptable salt has good inhibitory activit
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Page/Page column 13
(2016/10/09)
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- METHOD FOR PREVENTING OR TREATING ARRHYTHMIA, METHOD FOR PREVENTING OR TREATING ATRIAL FIBRILLATION, MODEL OF SUSTAINED ATRIAL FIBRILLATION, METHOD FOR PRODUCING THE MODEL, AND METHOD FOR SCREENING FOR ATRIAL FIBRILLATION INHIBITOR
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A method for preventing or treating atrial fibrillation, including: administering, to an individual, an atrial fibrillation inhibitor containing a compound expressed by one of the following Structural Formulas (I) to (VI) or a pharmacologically acceptable salt thereof: where in the Structural Formula (III), Gluc refers to glucuronic acid,
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- Industrial synthesis of the key precursor in the synthesis of the anti-influenza drug oseltamivir phosphate (Ro 64-0796/002, GS-4104-02): Ethyl (3R,4S,5S)-4,5-epoxy-3-(1-ethyl-propoxy)-cyclohex-1 -ene-1 -carboxylate
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Starting from (-)-quinic acid, the title compound was synthesized in seven chemical steps and an overall yield of 35-38%. The route of the improved Gilead synthesis was not changed. However, significant improvements in each step led to a doubled overall yield, a 30% reduction in the number of unit operations, and an excellent quality (≥99%) of the resulting epoxide. A highly regioselective method for the dehydration of a quinic acid to a shikimic acid derivative and for the reduction of a cyclic ketal was found. Alternatively, the title compound was synthesized in six chemical steps and 63-65% yield from commercially available (-)-shikimic acid. Compared to the optimized quinic acid route, the production time was reduced by about 50%. The quality of epoxide produced from either natural product was equivalent. Therefore (-)-shikimic acid is the preferred raw material. The absolute configuration of the epoxide was determined by X-ray single crystal structure analysis and it was demonstrated that the epoxide was stereo-isomerically pure.
- Federspiel, Muriel,Fischer, Rolf,Hennig, Michael,Mair, Hans-Jürgen,Oberhauser, Thomas,Rimmler, G?sta,Albiez, Thomas,Bruhin, Jürg,Estermann, Heinrich,Gandert, Carsten,G?ckel, Volker,G?tz?, Stephan,Hoffmann, Ursula,Huber, Gabriel,Janatsch, Günter,Lauper, Stephan,R?ckel-St?bler, Odette,Trussardi, Rene,Zwahlen, Andreas G.
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p. 266 - 274
(2013/09/08)
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