7466-48-0Relevant academic research and scientific papers
Synthesis method of dihydropyridine drug degradation impurity
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Paragraph 0029-0031; 0034-0036; 0039-0041; 0044-0046, (2021/07/01)
The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing dihydropyridine drug degradation impurities, which comprises the following steps of: reacting 3-nitrobenzaldehyde and acetone dimethyl phosphate serving as raw materials to obtain an intermediate 1, and then sequentially reacting with methyl acetoacetate and polyphosphoric acid to finally obtain a degradation impurity I and a degradation impurity II, the yield of the degraded impurity I is 30-35%, the purity of the degraded impurity I reaches 97% or above, the yield of the degraded impurity II is 25-30%, and the purity of the degraded impurity II reaches 97% or above. The high-purity dihydropyridine drug degradation impurity I and the high-purity dihydropyridine drug degradation impurity II are prepared through a chemical synthesis method and can be further used for pharmacological and toxicological research on the degradation impurity I and the degradation impurity II, and sample support is provided for research on side effects of dihydropyridine drug impurities. Meanwhile, the compound can be used as an impurity working standard substance for HPLC analysis of related substances of dihydropyridine drugs.
Organocatalytic diastereo- And enantioselective oxa-hetero-Diels-Alder reactions of enones with aryl trifluoromethyl ketones for the synthesis of trifluoromethyl-substituted tetrahydropyrans
Pasha, Maira,Tanaka, Fujie
supporting information, p. 9242 - 9250 (2021/11/16)
Tetrahydropyran derivatives are found in bioactives, and introduction of the trifluoromethyl group into molecules often improves biofunctions. Here we report diastereo- and enantioselective oxa-hetero-Diels-Alder reactions catalyzed by amine-based catalyst systems that afford trifluoromethyl-substituted tetrahydropyranones. Catalyst systems and conditions suitable for the reactions to provide the desired diastereomer products with high enantioselectivities were identified, and various trifluoromethyl-substituted tetrahydropyranones were synthesized with high diastereo- and enantioselectivities. Mechanistic investigation suggested that the reactions involve a [4 + 2] cycloaddition pathway, in which the enamine of the enone acts as the diene and the ketone carbonyl group of the aryl trifluoromethyl ketone acts as the dienophile. In this study, tetrahydropyran derivatives with the desired stereochemistry that are difficult to synthesize by previously reported methods were concisely obtained, and the range of tetrahydropyran derivatives that can be synthesized was expanded. This journal is
Access to Spirocyclic Benzothiophenones with Multiple Stereocenters via an Organocatalytic Cascade Reaction
Formánek, Bed?ich,Tauchman, Ji?í,Císa?ová, Ivana,Vesely, Jan
, p. 8510 - 8521 (2020/07/16)
The present report describes an organocatalytic cascade reaction between 2-alkylidene benzo[b]thiophenone derivatives and enones in the presence of the Cinchona alkaloid amine. Spirobenzothiophenonic cyclohexane derivatives containing three stereocenters were prepared via one-step synthesis in yields ranging from 88 to 96% and in enantioselectivities (enantiomeric excess (ee)) ranging from 85 to 97%, with diastereoselectivities of approximately 14/2/1. Therefore, this method provides an efficient route for the synthesis of a new class of optically active 2-spirobenzothiophenones.
Chemoselective and metal-free reduction of α,β-unsaturated ketones by: In situ produced benzeneselenol from O -(tert -butyl) Se-phenyl selenocarbonate
Ballarotto, Marco,Siciliano, Carlo,Temperini, Andrea
, p. 33706 - 33717 (2020/10/22)
The carbon-carbon double bond of arylidene acetones and chalcones can be selectively reduced with benzeneselenol generated in situ by reacting O-(tert-butyl) Se-phenyl selenocarbonate with hydrochloric acid in ethanol. This mild, metal-free and experimentally simple reduction procedure displays considerable functional-group compatibility, products are obtained in good to excellent yields, and the use of toxic Se/CO mixture and NaSeH, or the smelly and air-sensitive benzeneselenol, is avoided. This journal is
An access to α, β-unsaturated ketones via dual cooperative catalysis
Syamala, Lakshmi V.R. Babu,Khopade, Tushar M.,Warghude, Prakash K.,Bhat, Ramakrishna G.
supporting information, p. 88 - 91 (2018/12/05)
A dual cooperative organocatalytic approach for the synthesis of α, β-unsaturated ketones is described. This one pot transformation is realized via a domino Knoevenagel-Michael-retro Michael reaction sequence. Various aliphatic ketones reacted smoothly with aromatic as well as aliphatic aldehydes in presence catalytic amount of Meldrum's acid and bifunctional amine. The highlights of this protocol are the easy availability of catalysts, high selectivity, and functional group tolerance. The reaction proved to highly E-selective with no side products emanating from self-condensation, unlike the base-mediated reactions.
Scalable Multicomponent Synthesis of (Hetero)aryl-Substituted Phenyls: Focus on Metal-Free Halogenated Biaryls, 3-Arylindoles, and Isourolithine A Synthesis
Temperini, Andrea,Lanari, Daniela,Colognese, Francesco,Piazzolla, Francesca
, p. 7711 - 7719 (2019/12/12)
In the context of the growing interest of the scientific community for the development of sustainable synthetic strategies to access aromatic structures, we present a practical and metal-free approach to (hetero)biaryls which exploits the advantages of multicomponent reactions in sustainable solvents. In situ acid-catalysed generation of (hetero)aryl acetoxy dienes from the corresponding (hetero)arylidene acetones in a metal vessel, followed by Diels-Alder reaction using an electron-poor alkyne as dienophile, delivers the expected aromatic products after final oxidation of the cycloadduct. This protocol has been demonstrated as a convenient alternative to the previously reported synthetic strategies, considering its scalability and environmental sustainability and the low cost of substrates and equipment. Moreover, it has been successfully applied to the metal-free regioselective synthesis of (hetero)aryl-substituted-phenyls, 2-unsubstituted-3-aryl-indoles, and to the total synthesis of isourolithine A.
A Mild Procedure for Enone Preparation Catalysed by Bovine Serum Albumin in a Green and Easily Available Medium
Ardanaz, Sebastián M.,Velez Rueda, Ana J.,Parisi, Gustavo,Iribarren, Adolfo M.,Iglesias, Luis E.
, p. 1750 - 1757 (2018/04/24)
Abstract: A simple and mild procedure to obtain α,β-unsaturated ketones from acetone and a set of benzaldehydes is described. The approach applies bovine serum albumin (BSA) catalysis and water or ethanol, this mild reaction medium contrasting with the strong reaction conditions of the classic aldol condensation. Except for the assayed nitrobenzaldehydes, high enone yields (88–97%) were attained. In addition to its mildness, further advantages of this procedure are the use of a green catalyst exhibiting an efficient reuse and the use of eco-friendly and cheap solvents. In order to gain a deeper understanding of the involved catalytic mechanism, computational experiments on BSA structural analysis and molecular docking were carried out.
Catalytic Asymmetric Conjugate Addition of Indolizines to α,β-Unsaturated Ketones
Correia, José Tiago Menezes,List, Benjamin,Coelho, Fernando
supporting information, p. 7967 - 7970 (2017/06/27)
A catalytic enantioselective conjugate addition of indolizines to enones is described. The chiral phosphoric acid (S)-TRIP activates α,β-unsaturated ketones, thereby promoting an enantioface-differentiating attack by indolizines. Using this reaction, several alkylated indolizines were synthesized in good yields and with enantiomeric ratios of up to 98:2.
Traceless OH-Directed Wacker Oxidation-Elimination, an Alternative to Wittig Olefination/Aldol Condensation: One-Pot Synthesis of α,β-Unsaturated and Nonconjugated Ketones from Homoallyl Alcohols
Bethi, Venkati,Fernandes, Rodney A.
, p. 8577 - 8584 (2016/09/28)
A new method for one-pot synthesis of β-substituted and β,β-disubstituted α,β-unsaturated methyl ketones from homoallyl alcohols by sequential PdCl2/CrO3-promoted Wacker process followed by an acid-mediated dehydration reaction has been developed. Remarkably, internal homoallyl alcohols delivered regioselectively nonconjugated unsaturated carbonyl compounds under the same protocol. A new starting material-based synthesis of α,β-unsaturated and nonconjugated methyl ketones is demonstrated.
Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: Chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles
Zhang, Song-Lin,Deng, Zhu-Qin
, p. 7282 - 7294 (2016/08/05)
A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions.
