- Synthetic process of anti-hyperglycemic drug intermediate R-3-amino-piperidine dihydrochloride
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The invention relates to a synthetic process of an anti-hyperglycemic drug intermediate R-3-amino-piperidine dihydrochloride. The synthetic process comprises the steps: using inexpensive L-glutamic acid as a starting material, and performing esterification, amino protection, reduction, hydroxyl protection, substitution, cyclization and removal of protecting groups for amino groups so as to obtainthe R-3-amino-piperidine dihydrochloride. Compared with the prior art, the synthetic process has cheap and easily available raw materials, good selectivity, good atomic economy, high total yield and mild reaction conditions, and is suitable for industrial production.
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- Intermediate argues a row sandbank R-3-amino piperidine dihydrochloride preparation method
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The invention aims to provide a preparation method for an alogliptin intermediate R-3-aminopiperidine dihydrochloride. The method has a brief route and is environmentally friendly and low-cost. A racemic compound 3- piperidine carboxamide which is cheap and easy to get is taken as a raw material, and is subjected to Hoffmann rearrangement reaction under the action of 1- fluoronaphthalene, hydrogen peroxide and fluoboric acid, which is similar to acid amides, to obtain 3-aminopiperdine which has one less carbon than the substrate. The method has simple reaction conditions, can be implemented at the room temperature, has simple operations in process, and is easy to monitor. The solvents are an ethanol-water mixture, and are low-cost and environmentally friendly. The carbon-lessened product 3-aminopiperidine is acidized and salified by concentrated hydrochloric acid. The hydrochloride is separated and salified by D-tartaric acid to obtain the target product R-3-aminopiperidine dihydrochloride. The chirality purity is high. The ee value is more than 99.5%. The reaction overall yield can reach 89%-93%. The cost is low. The method is suitable for industrial mass production.
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Paragraph 0018; 0019
(2018/02/04)
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- PROCESS FOR THE PREPARATION OF ENANTIOMERICALLY ENRICHED 3-AMINOPIPERIDINE
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The present invention relates to a process for the preparation of enantiomerically enriched 3-aminopiperidine, and in particular of its R-enantiomer (R)-3-aminopiperidine. The invention also relates to an enantiomerically enriched intermediate of said process and to specific acid-addition salts of 3-aminopiperidine (hereinafter also APIP) that are useful for obtaining a single enantiomer of APIP, and to crystalline (R)-3-aminopiperidine-dihydrochloride-monohydrateand crystalline (S)-3-aminopiperidine-dihydrochloride-monohydrate.
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Page/Page column 34
(2014/09/03)
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- A catalytic version of hypervalent aryl-λ3-iodane-induced Hofmann rearrangement of primary carboxamides: Iodobenzene as an organocatalyst and m-chloroperbenzoic acid as a terminal oxidant
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The first catalytic version of hypervalent aryl-λ3- iodane-induced Hofmann rearrangement of primary carboxamides, which probably involves in situ generation of a tetracoordinated bis(aqua)(hydroxy)phenyl- λ3-iodane complex as an active oxidant from a catalytic amount of iodobenzene by the reaction with m-chloroperbenzoic acid in the presence of HBF4 in dichloromethane-water under mild conditions, was developed.
- Miyamoto, Kazunori,Sakai, Yuuta,Goda, Shunsuke,Ochiai, Masahito
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supporting information; experimental part
p. 982 - 984
(2012/02/04)
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- PROCESS FOR THE PREPARATION OF A SINGLE ENANTIOMER OF 3-AMINOPIPERIDINE DIHYDROCHLORIDE
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A process comprising: (a) reduction of N-acetyl-3-aminopyridine (2): or its salt in the presence of hydrogen and a palladium catalyst deposited on solid support; (b) converting racemic N-acetyl-3-aminopiperidine (3) or its salt produced in step (a) to rac-3-aminopiperidine (rac-4) or its salt; (c) resolution of the racemic 3-aminopiperidine (rac-4) or its salt produced in step (b) with a chiral acid.
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Page/Page column 12-13
(2012/01/06)
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