- Asymmetric hydrogenation of maleic anhydrides catalyzed by Rh/bisphosphine-thiourea: efficient construction of chiral succinic anhydrides
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Asymmetric hydrogenation of various 3-substituted maleic anhydrides catalyzed by Rh/bisphosphine-thiourea (ZhaoPhos) under mild conditions was successfully developed. A wide range of 3-alkyl and 3-aryl maleic anhydrides were hydrogenated well to provide the desired products 3-substituted succinic anhydrides in one hour with excellent results (full conversions, up to 99% yield, 99% ee, 3000 TON). Importantly, we developed a creative and efficient synthetic route to construct the key intermediate of the hypoglycemic drug mitiglinide through our catalytic system.
- Han, Zhengyu,Wang, Rui,Gu, Guoxian,Dong, Xiu-Qin,Zhang, Xumu
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p. 4226 - 4229
(2017/04/21)
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- Novel mitiglinide calcium preparing method
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The invention provides a novel mitiglinide calcium preparing method. According to the method, (S)-2-benzyl succinic acid is taken as the raw material, and deacidification is conducted to generate (S)-2-benzyl succinic anhydride; amidation is conducted between (S)-2-benzyl succinic anhydride and cis-hexahydroisoidolin to generate mitiglinide acid and an isomer byproduct; the isomer byproduct is separated out and subjected to isomerization to generate mitiglinide acid; acid-base salifying and salt exchange are conducted on the obtained mitiglinide acid to generate the product mitiglinide calcium. Compared with an existing anhydride-method technology, the method has the advantage that the purity of the product is improved remarkably. Compared with an active ester method and an amide method, the method has the advantages that the technology is simple, the yield is high, and production cost is low.
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Paragraph 0042; 0043
(2016/10/10)
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- Identification, synthesis and characterization of impurities of (S)-Mitiglinide calcium dihydrate
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(S)-Mitiglinide Calcium dihydrate (1), an important potent hypoglycemic agent. During laboratory optimization and later in bulk synthesis the formation of various impurities was observed. The method of preparation of most of these impurities is not availa
- Umasankara Sastry,Nageswara Rao,Appi Reddy,Gandhi
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p. 2417 - 2421
(2014/06/09)
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