103-76-4Relevant articles and documents
Selective deprotective method using palladium-water soluble catalysts
Lemaire-Audoire,Lemaire-Audoire, Sandrine,Savignac,Savignac, Monique,Blart,Blart, Errol,Pourcelot,Pourcelot, Guy,Genet,Genet, Jean Pierre,Bernard,Bernard, Jean-Marie
, p. 8783 - 8786 (1994)
Allylcarboxy and Allyloxycarbonyl groups can be removed without affecting dimethylallylcarboxy and cinnamylcarboxy groups in the same molecule. using Pd(O) water soluble catalyst prepared in situ, with diethylamine as allyl scavenger. Homogeneous or biphasic media are suitable: the yields of deprotection are quantitative.
Synthesis method for co-production of N-hydroxyethyl piperazine and N-ethyl piperazine
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Paragraph 0008; 0029-0087, (2021/03/11)
The invention discloses a method for co-production of N-hydroxyethyl piperazine and N-ethyl piperazine. The method comprises the following steps: reacting methyl glycolate serving as a process intermediate for preparing ethylene glycol by a coal method with piperazine to generate an intermediate product carbonyl hydroxyethyl piperazine, then in the presence of a hydrogenation catalyst, carrying out hydrogenation reduction and dehydration under certain pressure and temperature conditions to obtain N-hydroxyethyl piperazine, and simultaneously co-producing part of N-hydroxyethyl piperazine. Themethod is simple and convenient, low in cost, high in total yield, good in selectivity, easy in product separation and environment-friendly.
Synthesis method of N-hydroxyethylpiperazine
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Paragraph 0027-0078, (2020/06/20)
The invention discloses a synthesis method of N-hydroxyethylpiperazine, which comprises the following steps: by using piperazine and hydroxyacetaldehyde as raw materials and carrying out intermolecular dehydration condensation with hydrogen in the presence of a catalyst to generate N-hydroxyethylpiperazine; wherein the catalyst is composed of a Raney skeleton element and other auxiliary elements (at least one of iron, manganese, zinc, chromium, zirconium and cobalt) loaded on the Raney skeleton element. The method is simple in process operation, high in conversion rate, good in selectivity, simple in post-treatment and environment-friendly. Some examples prove that the yield of the method can reach about 90%, so that the method has a good industrial prospect.
Synthesis method of dasatinib intermediate
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Page/Page column 3; 4, (2018/07/28)
The invention discloses a synthesis method of a dasatinib intermediate. The dasatinib intermediate is 1-(2-hydroxyethyl)piperazine; the synthesis method comprises the following step: carrying out one-step temperature control reaction synthesis by utilizing bi(2-chloroethyl)amine and ethanolamine under the action of a acid-bonding agent to obtain the dasatinib intermediate. Compared with a method in the prior art, the synthesis method has the advantages of improved yield, simple steps, convenience for operation and few byproducts. According to the synthesis method, reaction is carried out without the need of adopting a high-pressure reaction kettle; the requirements on production equipment are lower and industrial production is facilitated.
Biocatalytic Access to Piperazines from Diamines and Dicarbonyls
Borlinghaus, Niels,Gergel, Sebastian,Nestl, Bettina M.
, p. 3727 - 3732 (2018/04/14)
Given the widespread importance of piperazines as building blocks for the production of pharmaceuticals, an efficient and selective synthesis is highly desirable. Here we show the direct synthesis of piperazines from 1,2-dicarbonyl and 1,2-diamine substrates using the R-selective imine reductase from Myxococcus stipitatus as biocatalyst. Various N- and C-substituted piperazines with high activity and excellent enantioselectivity were obtained under mild reaction conditions reaching up to 8.1 g per liter.
METHOD FOR PRODUCING CIS- AND TRANS-ENRICHED MDACH
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, (2017/09/23)
A process for preparing trans-enriched MDACH, including: distilling an MDACH starting mixture in the presence of an auxiliary, which is an organic compound having a molar mass of 62 to 500 g/mol, a boiling point at least 5° C. above the boiling point of cis,cis-2,6-diamino-1-methylcyclohexane, and 2 to 4 functional groups, each of which is independently an alcohol group or a primary, secondary or tertiary amino group. The MDACH starting mixture includes 0 to 100% by weight of 2,4-MDACH and 0 to 100% by weight of 2,6-MDACH, based on the total amount of MDACH present in the MDACH starting mixture. The MDACH starting mixture includes both trans and cis isomers. Trans-enriched MDACH includes 0 to 100% by weight of 2,4-MDACH and 0 to 100% by weight of 2,6-MDACH, where the proportion of trans isomers in the mixture is higher than the proportion of trans isomers in the MDACH starting mixture.
Preparation method of manidipine hydrochloride
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Paragraph 0035; 0036; 0044; 0045; 0054; 0055; 0064; 0065, (2017/12/06)
The invention discloses a preparation method of manidipine hydrochloride and belongs to the technical field of medicine preparation. Piperazine serving as a starting raw material is used for synthesis of N-(2-hydroxyethyl)piperazine, then 1-diphenylmethyl-4-(2-hydroxyethyl)piperazine is synthesized, and 2-(4-diphenylmethyl-1-piperazinyl)ethyl acetoacetic ester is synthesized; 2-(4-diphenylmethyl-1-piperazinyl)ethyl acetoacetic ester, m-nitrobenzaldehyde and methyl 3-aminocrotonate are dissolved in isopropanol, the mixture is subjected to heating reflux, a solvent is removed through steaming, residues are dissolved in trichloromethane, the mixture is dried with anhydrous sodium sulfate and filtered, a solvent of the filtrate is recovered under reduced pressure, residues are mixed with methanol to be completely dissolved, hydrogen chloride is introduced in an ice bath, the solvent is removed through steaming, residues are mixed with methanol, activated carbon is added for decoloration, filtering is performed, filtrate is cooled, and manidipine hydrochloride is obtained. The preparation method of manidipine hydrochloride is simple in process, the yield is high, the cost is low, and the product purity is high.
1-(2-hydroxy ethyl) piperazine synthetic method
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Paragraph 0029; 0030; 0033; 0034; 0037; 0038, (2017/08/28)
The invention discloses a 1-(2-hydroxy ethyl) piperazine synthetic method. The 1-(2-hydroxy ethyl) piperazine synthetic method includes the steps that 2-molindone and 2-chlorohydrin are reacted, and 2-keto-4-(2-hydroxy ethyl)-morpholine is generated; then the 2-keto-4-(2-hydroxy ethyl)-morpholine and ammonia are reacted to generate 1-(2-hydroxy ethyl) piperazine. According to the 1-(2-hydroxy ethyl) piperazine synthetic method, the raw materials are simple and easy to obtain, the reaction yield is high, aftertreatment is easy, and industrial production is easy to achieve. The formula is defined in the description.
N - alkylpiperazine purification of
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Paragraph 0054, (2017/02/28)
PROBLEM TO BE SOLVED: To provide a purification method of N-alkyl piperazines, capable of providing high purity N-alkyl piperazines with low cost and having a high recovery rate.SOLUTION: A mixture of N-alkyl piperazines and a piperazine is distilled in the presence of a polar organic solvent having a higher boiling point than that of the piperazine.
NMR study of the composition of aqueous 2-aminoethanol solution used for absorption of carbon dioxide from fuel gases
Talzi
, p. 927 - 931 (2016/09/04)
The compositions of aqueous 2-aminoethanol solutions used in industry for absorption of carbon dioxide resulting from combustion of natural gas have been determined by1H and13C NMR spectroscopy. The absorption process does not involve generally accepted paths of thermal decomposition of the absorbent in the reaction with carbon dioxide, but the main path is non-oxidative decomposition of 2-aminoethanol into ammonia and ethylene oxide. Splitting of the NMR signals of carbamate anion formed by reaction of 2-aminoethanol with carbon dioxide has been rationalized by specific structure of the anion due to intramolecular hydrogen bonding.
