- Direct Transformation of Arylamines to Aryl Halides via Sodium Nitrite and N-Halosuccinimide
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A one-pot universal approach for transforming arylamines to aryl halides via reaction with sodium nitrite (NaNO2) and N-halosuccinimide (NXS) in DMF at room temperature under metal- and acid-free condition is described. This new protocol that is complementary to the Sandmeyer reaction, is suggested to involve the in situ generation of nitryl halide induce nitrosylation of aryl amine to form the diazo intermediate which is halogenated to furnish the aryl halide.
- Mukhopadhyay, Sushobhan,Batra, Sanjay
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supporting information
p. 14622 - 14626
(2018/09/21)
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- Method for preparing hydrobromic acid teneligliptin
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The invention provides a method for preparing hydrobromic acid teneligliptin. The method includes steps of preparing L-hydroxyproline; mixing the L-hydroxyproline and sodium bicarbonate with each other to obtain mixtures, dissolving the mixtures in water, adding acetone into the water, dropping di-tert-butyl dicarbonate into the water, carrying out room-temperature reaction overnight and then treating reaction products to obtain t-butyloxycarboryl-N-hydroxyproline; preparing t-butyloxycarboryl-N-4-oxo-proline from the t-butyloxycarboryl-N-hydroxyproline; preparing (2S)-4-oxo-2-(3-thiazolidine carbonyl)-1-pyrrolidine carboxylic acid tert-butyl ester from the t-butyloxycarboryl-N-4-oxo-proline; preparing compounds III from compounds IV; preparing compounds II from the compounds III; preparing compounds 1-(3-methyl-1-phenyl-1H-pyrazole-5-base) piperazine from the compounds II; preparing intermediates I; preparing the hydrobromic acid teneligliptin from the intermediates I. The method has the advantages that the method is low in cost, and the cost of the method is only two-thirds of the cost of an existing method in the prior art; the yield of the hydrobromic acid teneligliptin is higher than 95%, and the purity of the hydrobromic acid teneligliptin is higher than 98%.
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Paragraph 0043; 0044; 0053; 0054
(2017/07/01)
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- Teneligliptin key intermediate preparation method
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The present invention discloses a preparation method of a teneligliptin key intermediate 1-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazine (compound I), and belongs to the technical field of medicine preparation. According to the method of the present inven
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Paragraph 0019; 0020; 0021
(2016/10/07)
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