- Preparation method of piperidine alcohol compound
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Discloses a preparation method of a piperidinol compound, wherein the piperidinol is selected from (R)-1 - benzyl -3 - piperidinol. 1 -benzyl -3 - piperidone as reaction raw material and application thereof LiAlH4 A chiral reagent formed by the
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Paragraph 0024-0036
(2021/10/05)
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- Preparation method and application of (R)-3-aminopiperidine dihydrochloride
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The invention provides a preparation method and application of (R)-3-aminopiperidine dihydrochloride. The preparation method comprises the following steps: obtaining (S)-1, 5-dichloro-2-pentanol through the reaction of (S)-epichlorohydrin and 2-chloroethyl magnesium bromide; carrying out an intramolecular cyclization reaction in the presence of an alkaline substance to generate (S)-5-chloro-1, 2-epoxypentane; enabling the (S)-1-benzylamino-5-chloro-2-epoxypentane to react with benzylamine to generate (S)-1-benzylamino-5-chloro-2-pentanol; then obtaining (S)-1-benzyl-3-hydroxypiperidine throughan intramolecular ring closing reaction of (S)-1-benzylamino-5-chloro-2-pentanol; continuing to react with the sulfonyl chloride compound to obtain (R)-1-benzyl-3-sulfonyloxy piperidine; further reacting with benzylamine to obtain (R)-1-benzyl-3-benzylamino piperidine; and finally, under the action of a palladium catalyst, removing benzyl through hydrogenation, thus obtaining the product (R)-3-aminopiperidine dihydrochloride. The preparation method has the advantages of few side reactions, high yield, good product quality, convenient purification, easily available raw materials, low price, mild reaction conditions, high safety, environmental protection, simplicity, practicality, and suitableness for industrial batch production.
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Paragraph 0024; 0085-0086; 0091; 0096; 0101
(2020/12/08)
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- A Bruton tyrosine kinase (Btk) method for the preparation of
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The invention relates to a preparation method of a Bruton's tyrosine kinase (Btk) intermediate (VI). The method comprises the following steps: carrying out benzylamine ring opening on a compound (S)-(+)-5-substituted-2-tetrahydrofurancarboxylic acid to obtain a product, and reacting the product with acyl chloride or acid anhydride to obtain a compound II; reducing the compound II, carrying out salt formation on the reduced compound II by using 1R-(-)-camphorsulfonic acid, and degrading the obtained salt to obtain a compound III; and reducing the compound III, carrying out salt formation on the reduced compound III and AcOH to obtain a compound V, and carrying out Boc addition on the compound V under an alkaline condition to obtain the target compound VI.
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Paragraph 0005; 0006; 0017; 0018
(2017/07/31)
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- Stereo-complementary bioreduction of saturated N-heterocyclic ketones
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The asymmetric bioreduction of several saturated N-heterocyclic ketones is demonstrated in a stereo-complementary fashion using the ketoreductases READH and ChKRED20 for the production of (S)- and (R)-alcohols, respectively. The reaction accepts substrates with a five-, six- or seven-membered ring, and exhibits excellent stereoselectivity when using 2-propanol as both the ultimate reducing agent and cosolvent, achieve >99% ee in the majority of cases for both enantiomers.
- Li, Chao,Liu, Yan,Pei, Xiao-Qiong,Wu, Zhong-Liu
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- Chiral-1-tert-butoxy-carbonyl-3-hydroxy-piperidine, and the preparation of chiral turning method
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The invention relates to preparation of chirality-1-t-butyloxycarboryl-3-hydroxy piperidine and a method for chirality turning. The preparation mainly comprises the following steps: resolving N-benzyl-3-hydroxy piperidine as a raw material to obtain a (S) or (R)-1-benzyl-3-hydroxy piperidine camphorsulfonic acid salt, performing alkali freedom to obtain (S) or (R)-1-benzyl-3-hydroxy piperidine, performing palladium carbon hydrogenation debenzylation/t-butyloxycarboryl protection to obtain (S) or (R)-1-t-butyloxycarboryl-3-hydroxy piperidine, acylating substituting sulfonyl chloride of (R) or (S)-1-substituting-3-hydroxy piperidine as a raw material to obtain (R) or (S)-1-substituting-3-hydroxy piperidine sulfonate, substituting by using substituting carboxylate to obtain (S) or (R)-1-substituting-3-hydroxy piperidine carboxylic ester, and performing alkaline hydrolysis to obtain (S) or (R)-1-substituting-3-hydroxy piperidine. The synthesis route is gentle in reaction condition, and is applicable to industrial large-scale production.
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- NOVEL COMPOUNDS AS ANTI-TUBERCULAR AGENTS
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The present invention relates to novel compounds of formula (1): The present invention also discloses compounds of formula (1) along with other pharmaceutical acceptable excipients and use of the compounds as anti-tubercular agents.
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Page/Page column 39-40
(2015/12/17)
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- Preparation of enantiomerically pure N-heterocyclic amino alcohols by enzymatic kinetic resolution
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Abstract The synthesis of both enantiomers of N-benzyl-3-hydroxypyrrolidine and N-benzyl-3-hydroxypiperidine via enzymatic kinetic resolution of the corresponding racemic esters is described. Various commercially available hydrolases were studied as biocatalysts in native and immobilized form. The best results were obtained with lipases PS, AK, CAL-B and with protease Alcalase, which were active and selective for the kinetic resolutions of racemic esters (E > 100). Under optimized reaction conditions, highly enantiomerically enriched (up to 99.5% ee) resolution products were obtained. Lipase and protease showed opposite enantiopreference on the esters, allowing the preparation of both enantiomers of the target compounds. Semi-continuous reactions in column reactors with immobilized biocatalysts were also performed with high enantioselectivities. Inversion of the configuration at C(3) of N-benzyl-3-hydroxypyrrolidine was quantitatively effected in a short number of steps.
- Tofani, Giorgio,Petri, Antonella,Piccolo, Oreste
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p. 638 - 643
(2015/08/03)
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- An efficient dynamic kinetic resolution of N-heterocyclic 1,2-amino alcohols
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A chemoenzymatic dynamic kinetic resolution (DKR) of N-heterocyclic amino alcohols is described. Various lipases were studied as biocatalysts for the kinetic resolution of N-heterocyclic 1,2-amino alcohols. The influence of the support of the enzymes on t
- Lihammar, Richard,Millet, Renaud,Baeckvall, Jan-E.
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supporting information; scheme or table
p. 2321 - 2327
(2011/10/19)
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- The synthesis of piperidine nucleoside analogs - A comparison of several methods to access the introduction of nucleobases
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This work deals with the synthesis of piperidine and hydroxypiperidine analogs of nucleosides. Starting from commercially available 3-hydroxypiperidine, proline or 4-hydroxyproline, a series of piperidine derivatives of both purine and pyrimidine nucleobases was prepared. Various methods of nucleobase attachment were evaluated. The prepared compounds were tested for cytostatic, antibacterial, and antiviral properties but no significant activity was found.
- Kova?ková, Soňa,Dra?ínsky, Martin,Rejman, Dominik
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p. 1485 - 1500
(2011/04/15)
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- Simple one-pot process for the bioresolution of tertiary amino ester protic ionic liquids using subtilisin
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An efficient hydrolase-catalyzed bioresolution of tertiary amino ester protic ionic liquids has been demonstrated. Protic ionic liquids have been prepared in one step from the corresponding tertiary amino alcohols by treatment with butyric anhydride. Afte
- Brossat, Maude,Moody, Thomas S.,Taylor, Stephen J.C.,Wiffen, Jonathan W.
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experimental part
p. 2112 - 2116
(2010/02/28)
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- Daucus carota mediated-reduction of cyclic 3-oxo-amines
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Carrots (Daucus carota) were used to reduce cyclic amino-ketones in high yields and enantiomeric excesses. This cheap, eco-compatible, and efficient reducing reagent allows the easy access to precursors of biologically active products.
- Lacheretz, Romain,Pardo, Domingo Gomez,Cossy, Janine
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supporting information; experimental part
p. 1245 - 1248
(2009/08/08)
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- Synthesis and pharmacological activity of stereoisomers of 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylic acid methyl 1-(phenylmethyl)-3-piperidinyl ester
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1,4-Dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylic acid methyl 1-(phenylmethyl)-3-piperidinyl ester 1, a highly potent calcium antagonist, was separated into stereo- and optical isomers to investigate the differences of antihypertensive activities between them. Fractional crystallization of the hydrochlorides of 1 gave α- and β-diasterioisomers. The α-isomer (benidipine hydrochloride, KW-3049) showed very strong hypotensive effect, but little activity was observed in the β-isomer. From optically resolved 1,4-dihydro-5-methoxycarbonyl-2,6-dimethyl-4-(3-nitrophenyl)-3-pyridi necarboxylic acids 2, and 1-benzyl-3-piperidinols 3, four optical isomers of 1 were synthesized, and their absolute configurations were deduced. The hypotensive activity of (+)-α, namely (S)-(S)-1, was 30 to 100 times stronger than that of (-)-α in intravenously administered spontaneously hypertensive rats.
- Muto,Kuroda,Kawato,Karasawa,Kubo,Nakamizo
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p. 1662 - 1665
(2007/10/02)
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