- Extracting preparing method for R-3-Aminobutanol
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The invention relates to an extracting preparing method for R-3-Aminobutanol. R-3-aminobutyric acid is adopted as a raw material, an esterification reaction is performed to obtain R-3-amino-crotonic acid ester, then, a reduction reaction, resin extraction and an alkali reaction performed to obtain the R-3-Aminobutanol with high quality and purity is obtained. The method has the advantages of recycling resin, reducing the waste salt and waste residue generation amount, being high in yield and product quality and the like, the problem that products are not directly extracted from water easily issuccessfully solved, and the problems that a traditional technology is large in water steam energy consumption and not sufficient in solvent extraction are solved.
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Paragraph 0064-0065; 0066-0067; 0077-0078; 0079-0119
(2019/07/16)
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- A chiral 2 - substituted - 4 - piperidone - 1 - carboxylic acid tert-butyl synthetic method
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The invention discloses a synthetic method of chiral 2-substitute-4-piperidone-1-carboxylic acid tert-butyl ester. The synthetic method comprises the following steps: (1) an esterification reaction: carrying out a reaction between chiral beta-amino acid, and thionyl chloride and methanol to obtain chiral beta-amino acid methyl ester hydrochloride; (2) a Michael addition and tert-butyloxycarboryl protecting reaction: carrying out a Michael addition reaction between chiral beta-amino acid methyl ester hydrochloride and methyl acrylate to obtain a substance, and then carrying out a reaction between the substance and di-tert-butyl dicarbonate to obtain chiral 3-substitute-3-(tert-butyloxycarboryl(3-methyl propionate)amino)methyl propionate; (3) a lactone condensation and decarboxylation reaction: conducting lactone condensation and decarboxylation on chiral 3-substitute-3-(tert-butyloxycarboryl(3-methyl propionate)amino)methyl propionate to obtain chiral 2-substitute-4-piperidone-1-carboxylic acid tert-butyl ester. The synthetic method is simple to operate, higher in yield, low in raw material cost, highly available, and suitable for industrialized production.
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Paragraph 0046; 0048
(2017/08/26)
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- A 3 (R) / (S)-amino-1-butanol method for the preparation of
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The invention provides a method for preparing 3(R)/(S)-amidogen-1-butanol. The method comprises the steps that firstly, benzamide reacts with acetoacetic ester under the catalyzing action of p-toluenesulfonic acid, so that 3-benzamido-2-butene acid ester is generated; secondly, catalytic hydrogenation is conducted by using a chiral rhodium-diphosphine ligand compound as a catalyst for enantioselective hydrogenation, so that 3(R)/(S)-benzamide butyrate is generated highly selectively; thirdly, benzoyl is removed by means of mixed solvent of concentrated hydrochloric acid and alcohol, so that 3(R)/(S)-amino-crotonic acid ester hydrochloride is generated; finally, optically pure 3(R)/(S)-amidogen-1-butanol is obtained after ester carbonyl is reduced by means of hydronoron. According to the method, the raw materials are low in cost and easy to obtain, the technological operation is easy and convenient, resolution is not needed, the yield is high, cost is low, environmental friendliness is achieved, the optical purity of product is high, and the method is more suitable for industrial production.
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Paragraph 0081; 0082
(2017/01/17)
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- Synthesis of chiral non-racemic intermediates and Arg-Gly-Asp mimetics by CaLB-catalyzed resolution
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The reactivity of both the ester and amine functions present in β-amino esters was tested in order to obtain the synthesis of enantiopure αvβ3 and α5β1 integrin ligands. CaLB successfully catalyzed both the enantioselective transesterification and the N-acylation of racemic β-amino esters, allowing the isolation of intermediates for the preparation of Arg-Gly-Asp (RGD) mimetic compounds. In particular, a CaLB-catalyzed amidation reaction with unprotected p-aminobenzylamine reduced the number of synthetic steps, thus avoiding protection and deprotection of the intermediate compounds. Following this procedure, RGD mimetics were isolated with high yields and enantiomeric purities.
- Cardillo, Giuliana,Gennari, Arianna,Gentilucci, Luca,Mosconi, Elisa,Tolomelli, Alessandra,Troisi, Stefano
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experimental part
p. 96 - 102
(2010/04/06)
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- Enantioselective Synthesis of β-Amino Acids. 2. Preparation of the like Stereoisomers of 2-Methyl- and 2-Benzyl-3-aminobutanoic Acid
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An improved procedure for the preparation of (R)- and (S)-3-aminobutanoic acids (2a) through diastereomer separation of the corresponding (1'S)-N-phenethyl derivatives 1 is reported.From 2a, the four possible stereoisomeric perhydropyrimidin-4-ones 4 were prepared through the amide 2c and the Schiff base 3.In the cyclization of 3, the cis products 4 predominate ca. 95:5.These heterocycles can be alkylated (LDA, RX), as demonstrated by methylation and benzylation, with formation of a single diastereoisomer (5, 6).Hydrolysis (6 N aqueous HCl) of these 5,6-dialkylperhydropyrimidin-4-ones leads to the free amino acids 7-10.
- Juaristi, Eusebio,Escalante, Jaime,Lamatsch, Bernd,Seebach, Dieter
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p. 2396 - 2398
(2007/10/02)
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