Search results

Search for "5-aminopyrazoles" in Full Text gives 16 result(s) in Beilstein Journal of Organic Chemistry.

Catalytic multi-step domino and one-pot reactions

  • Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

Graphical Abstract
  • facile stereoselective tandem reaction based on the asymmetric conjugate addition of dialkylzinc reagents to unsaturated acylimidazoles, followed by trapping of the intermediate zinc enolate with carbocations [12]. A practical one-pot synthesis of fluorescent pyrazolo[3,4-b]pyridin-6-ones by reacting 5
  • -aminopyrazoles with azlactones under solvent-free conditions, through subsequent elimination of a benzamide molecule in a superbasic medium, is described by the Fisyuk group [13]. A further facile one-pot process toward a new series of copper(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrin analogues is described
PDF
Album
Editorial
Published 08 Feb 2024

Cyanothioacetamides as a synthetic platform for the synthesis of aminopyrazole derivatives

  • Valeriy O. Filimonov,
  • Alexandra I. Topchiy,
  • Vladimir G. Ilkin,
  • Tetyana V. Beryozkina and
  • Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2023, 19, 1191–1197, doi:10.3762/bjoc.19.87

Graphical Abstract
  • : deposit@ccdc.cam.ac.uk). Examples of bioactive pyrazoles for the protection of cultivated plants and drugs containing a thiocarbonyl group. Structures of starting materials. Syntheses of 4,5-diamino- and 4-thiocarbamoyl-5-aminopyrazoles. Synthesis of 3,5-diaminopyrazoles 4а–с and thiocarbamoyl-NH
PDF
Album
Supp Info
Full Research Paper
Published 08 Aug 2023

New one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones based on 5-aminopyrazoles and azlactones

  • Vladislav Yu. Shuvalov,
  • Ekaterina Yu. Vlasova,
  • Tatyana Yu. Zheleznova and
  • Alexander S. Fisyuk

Beilstein J. Org. Chem. 2023, 19, 1155–1160, doi:10.3762/bjoc.19.83

Graphical Abstract
  • Ave., 55a, 644077 Omsk, Russian Federation 10.3762/bjoc.19.83 Abstract An effective one-pot strategy was developed for the synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones from pyrazolo[3,4-b]pyridin-6-ones, obtained by reacting 5-aminopyrazoles with 4-arylidene-2-phenyloxazol-5(4H)-ones (azlactones
  • UV light, are used in forensics, in protection against forgery of banknotes, securities, and other important documents [34]. Conclusion In summary, we developed a simple one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones, based on the solvent-free reaction of the available starting compounds 5
  • -aminopyrazoles 1, 5, 6 and azlactones 2a–i, followed by heating the resulting intermediate in DMSO in the presence of t-BuOK. Photophysical properties of the obtained compounds were studied. Biologically active 4-arylpyrazolo[3,4-b]pyridin-6-ones. Normalized absorption and fluorescence spectra of solutions of
PDF
Album
Supp Info
Full Research Paper
Published 02 Aug 2023
Graphical Abstract
  • 3-indolyl-substituted aza-quaternary stereocenter. Here the stereoselectivity was attributed to an H-bonding interaction between the catalyst and the substrates (Scheme 21) [50]. In 2022, Lin and co-workers reported an unusual aza-Friedel–Crafts reaction using N-aryl-5-aminopyrazoles 92 as potential
PDF
Album
Review
Published 28 Jun 2023

Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities

  • Viktor A. Zapol’skii,
  • Isabell Berneburg,
  • Ursula Bilitewski,
  • Melissa Dillenberger,
  • Katja Becker,
  • Stefan Jungwirth,
  • Aditya Shekhar,
  • Bastian Krueger and
  • Dieter E. Kaufmann

Beilstein J. Org. Chem. 2022, 18, 524–532, doi:10.3762/bjoc.18.54

Graphical Abstract
  • group forming a six-membered ring system that upon reaction with 7-chloro-4-hydrazinylquinoline formed 5-aminopyrazoles 5a,l–o. Here, a nucleophilic attack of the NH2 group of the arylhydrazine on the C3 position of the butadiene chain is observed due to the sterically hindered rigidized six-membered
  • ring system in the dienes 4a,l–o (Scheme 4). The obtained 5-aminopyrazoles 5a,l–o show the following 13C NMR shifts of the pyrazole ring and the dichloromethyl group: 149.5–149.9 ppm (C-NHR), 114.7–116.1 ppm (C-NO2), 147.0–147.2 ppm (C=N), and 62.2–62.3 ppm (CHCl2). On the other hand, the dienes 4b–k
  • the butadiene chain is more likely due to the possibility of a rotation around the C1–C2 bond in 4b–k. The 3-aminopyrazoles 5b–k show considerable differences of the 13C shifts of C-NO2-, C-CHCl2- and CHCl2-groups in comparison with the corresponding 13C shifts of 5-aminopyrazoles 5a,l–o. The 13C NMR
PDF
Album
Supp Info
Full Research Paper
Published 09 May 2022

Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines

  • Yana I. Sakhno,
  • Maryna V. Murlykina,
  • Oleksandr I. Zbruyev,
  • Anton V. Kozyryev,
  • Svetlana V. Shishkina,
  • Dmytro Sysoiev,
  • Vladimir I. Musatov,
  • Sergey M. Desenko and
  • Valentyn A. Chebanov

Beilstein J. Org. Chem. 2020, 16, 281–289, doi:10.3762/bjoc.16.27

Graphical Abstract
  • . Therefore, the present work is devoted to the study of multicomponent reactions involving 3-amino-1,2,4-triazole or 5-aminopyrazoles, aromatic aldehydes, and pyruvic acid or its esters under ultrasonication. Results and Discussion It was discovered that MCRs involving 3-amino-1,2,4-triazole or 5-amino-1H
  • . However, the reaction time had to be increased to 24 h, and the yields and purity of the compounds 4 decreased (as seen via TLC and NMR analysis), obviously due to the worse homogenization and mass transfer compared to ultrasonication. Literature data [17][26][27][33][34][35] indicates that 5
  • -aminopyrazoles bearing an electron-withdrawing substituent in the 4-position, such as a carbonitrile group, often behave similar to 3-amino-1,2,4-triazole; therefore, we studied the latter under the same reaction conditions. We showed that the pseudo four-component heterocyclization of two equivalents of 3-amino
PDF
Album
Supp Info
Full Research Paper
Published 27 Feb 2020

Molecular iodine-catalyzed one-pot multicomponent synthesis of 5-amino-4-(arylselanyl)-1H-pyrazoles

  • Camila S. Pires,
  • Daniela H. de Oliveira,
  • Maria R. B. Pontel,
  • Jean C. Kazmierczak,
  • Roberta Cargnelutti,
  • Diego Alves,
  • Raquel G. Jacob and
  • Ricardo F. Schumacher

Beilstein J. Org. Chem. 2018, 14, 2789–2798, doi:10.3762/bjoc.14.256

Graphical Abstract
  • β-ketonitriles, arylhydrazines and aryl sulfonyl hydrazides as sulfur source [21]. The chemistry of iodine-catalyzed transformations has emerged as a greener, efficient and economical alternative to transition metals in organic synthesis [22][23][24]. However, the synthesis of selenium-containing 5
  • -aminopyrazoles under iodine-catalyzed three-component reaction was not described so far. In view of this, we present a direct and selective multicomponent strategy to synthesize 5-amino-4-(arylselanyl)-1H-pyrazoles 4 by reacting benzoylacetonitrile derivatives 1, arylhydrazines 2 and diorganyl diselenides 3
PDF
Album
Supp Info
Full Research Paper
Published 06 Nov 2018

Synthesis of pyrazolopyrimidinones using a “one-pot” approach under microwave irradiation

  • Mark Kelada,
  • John M. D. Walsh,
  • Robert W. Devine,
  • Patrick McArdle and
  • John C. Stephens

Beilstein J. Org. Chem. 2018, 14, 1222–1228, doi:10.3762/bjoc.14.104

Graphical Abstract
  • [3,4-b]pyridines, pyrazolo[1,5-a]pyrimidines and pyrazolo[1,5-a]pyrimidinones [12][13][14][15][16][17][18]. The majority of methods used in the generation of the pyrazolo[1,5-a]pyrimidinones employ a two-step process, which first requires the synthesis and isolation of the intermediate 5-aminopyrazoles
  • followed by their reaction with an appropriate β-dicarbonyl compound [1][2][3][4][19][20][21][22][23][24][25][26][27][28][29]. A very recent and excellent review by Aggarwal et al. covers the use and versatility of 5-aminopyrazoles in the synthesis of a range of pyrazoloazines [30]. As part of a study into
  • conditions for the microwave-assisted generation of the intermediate 5-aminopyrazoles. Once established, this methodology could be expanded to generate a one-pot synthesis of pyrazolo[1,5-a]pyrimidinones. Typical methods for preparing 5-aminopyrazoles require conventional heating of the appropriate β
PDF
Album
Supp Info
Letter
Published 28 May 2018

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

  • Ranjana Aggarwal and
  • Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

Graphical Abstract
  • substituted pyrazoloazines by a broad range of organic reactions by means of 5-aminopyrazole as a precursor. Keywords: 5-aminopyrazoles; fused pyrazole derivatives; pyrazolopyridines; pyrazolopyrimidines; pyrazolotriazines; Review Pyrazole and its derivatives are known to exhibit significant biological and
  • resemblance. In addition to the immense biological potential related to fused pyrazoles, their synthetic potential needs to be reviewed for further improvements and extension of interests. Various efforts have been developed for the synthesis of pyrazole-based fused heterocycles. 5-Aminopyrazoles have been
  • ]-1,2,4-triazines 11 [23], pyrazolo[1,5-a]-1,3,5-triazines 12 [24], pyrazolo[3,4-d][1,2,3]triazines 13 [25] (Figure 2). A number of review articles have been published by us and others highlighting the synthetic and biological aspects of 5-aminopyrazoles [26][27][28] as well as on the synthesis of fused
PDF
Album
Review
Published 25 Jan 2018

New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized

  • Maryna V. Murlykina,
  • Maryna N. Kornet,
  • Sergey M. Desenko,
  • Svetlana V. Shishkina,
  • Oleg V. Shishkin,
  • Aleksander A. Brazhko,
  • Vladimir I. Musatov,
  • Erik V. Van der Eycken and
  • Valentin A. Chebanov

Beilstein J. Org. Chem. 2017, 13, 1050–1063, doi:10.3762/bjoc.13.104

Graphical Abstract
  • -binucleophile, acid – catalyst). Literature data indicate [14][25][59][97][98][99][100][101] that 5-aminopyrazoles bearing in the fourth position electron-withdrawing substituents like carboxamide, carboxylate or a carbonitrile group, posses chemical properties being different from other 5-aminopyrazoles but
PDF
Album
Supp Info
Full Research Paper
Published 31 May 2017

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

  • Volodymyr V. Tkachenko,
  • Elena A. Muravyova,
  • Sergey M. Desenko,
  • Oleg V. Shishkin,
  • Svetlana V. Shishkina,
  • Dmytro O. Sysoiev,
  • Thomas J. J. Müller and
  • Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

Graphical Abstract
  • -aminotetrazole [9], 5-aminopyrazoles [11], and 5-amino-1,2,3-triazole [12] have previously been investigated. In some cases when the reaction could proceed in two alternative pathways the conditions enabling to control the interaction direction were determined, which made it possible to obtain the desired
  • azoloazine with high chemo- and regioselectivity [11][13][14][15]. In particular, three-component heterocyclizations involving 3-amino-1,2,4-triazoles or 4-substituted 5-aminopyrazoles yielded either 4,5,6,7-tetrahydroazolo[1,5-a]pyrimidine-6-carboxamides under ultrasonication at room temperature (kinetic
  • control) or 4,7-dihydroazolo[1,5-a]pyrimidine-6-carboxamides at reflux in an applicable solvent (thermodynamic control), respectively (Scheme 1). The behavior of the reaction of 5-aminopyrazoles containing substituents in the position 3 is influenced by the structure of aminoazoles and aldehydes, giving
PDF
Album
Supp Info
Full Research Paper
Published 17 Dec 2014

Facile synthesis of 1H-imidazo[1,2-b]pyrazoles via a sequential one-pot synthetic approach

  • András Demjén,
  • Márió Gyuris,
  • János Wölfling,
  • László G. Puskás and
  • Iván Kanizsai

Beilstein J. Org. Chem. 2014, 10, 2338–2344, doi:10.3762/bjoc.10.243

Graphical Abstract
  • ) inputs (Scheme 1). The transformations of either the 5-aminopyrazoles [28][29], or their 4-substituted ethoxycarbonyl [7][30][31][32] and carbonitrile [28][33][34][35][36] analogues via the GBB-3CR have not been appreciably examined so far. In the relevant literature [7][28][29][31][32][33], the products
  • diversity arising from the pyrazole starting material. As far as we are aware, a one-pot two-step process involving the in situ formation of the desired amino-substituted N-heterocycles such as C4 functionalized 5-aminopyrazoles, followed by GBB-3CR has not been described to date. On the other hand, the
  • protocol allowed the rapid synthesis of a 46-membered 1H-imidazo[1,2-b]pyrazole library with isolated yields up to 83%. Following the microwave-aided formation of functionalized 5-aminopyrazoles, the GBB-3CR transformations occurred during 10–60 min under mild conditions. This protocol offers operationally
PDF
Album
Supp Info
Full Research Paper
Published 08 Oct 2014

Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

  • Yan Sun,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 8–14, doi:10.3762/bjoc.9.2

Graphical Abstract
  • describing that either 2-naphthylamine [22][23][24][25], functionalized 5-aminopyrazoles [26][27][28], or 2-aminobenzothiazoles [29] reacted with isatin and cyclic 1,3-dicarbonyl compounds to give the similar spiro[dihydropyridine-oxindole] (II, III in Figure 2), in which both the amino group and the aryl
PDF
Album
Supp Info
Full Research Paper
Published 03 Jan 2013

Features of the behavior of 4-amino-5-carboxamido-1,2,3-triazole in multicomponent heterocyclizations with carbonyl compounds

  • Eugene S. Gladkov,
  • Katerina A. Gura,
  • Svetlana M. Sirko,
  • Sergey M. Desenko,
  • Ulrich Groth and
  • Valentin A. Chebanov

Beilstein J. Org. Chem. 2012, 8, 2100–2105, doi:10.3762/bjoc.8.236

Graphical Abstract
  • synthesize different types of heterocyclic systems, with a high level of selectivity, from the same starting materials. For example, MCRs or 5-aminopyrazoles containing several nonequivalent nucleophilic reaction centers with aromatic aldehydes and derivatives of 1,3-cyclohexanedione [10][11] or pyruvic
PDF
Album
Supp Info
Full Research Paper
Published 30 Nov 2012

Regioselectivity in the multicomponent reaction of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal under controlled microwave heating

  • Kamal Usef Sadek,
  • Ramadan Ahmed Mekheimer,
  • Tahany Mahmoud Mohamed,
  • Moustafa Sherief Moustafa and
  • Mohamed Hilmy Elnagdi

Beilstein J. Org. Chem. 2012, 8, 18–24, doi:10.3762/bjoc.8.3

Graphical Abstract
  • ., either kinetic or thermodynamic [11][12][13]. It has been reported that the use of microwave or ultrasound irradiation provides an additional parameter for synthetic selectivity [14][15][16][17]. Results and Discussion The multicomponent reaction of 5-aminopyrazoles, dimedone and aromatic aldehydes was
  • investigation concerning the regioselectivity in multicomponent reactions of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal (DMFDMA) under controlled microwave heating. We began this study by treating 5-amino-3-methylpyrazole (1a) and dimedone (2a) with DMFDMA (3) in DMF under
  • single-crystal X-ray diffraction [25][26] (Figure 1, Figure 2 and Table 1, Table 2, Table 3). With this result in hand, we went on to study the scope of such multicomponent reactions with several substituted 5-aminopyrazoles and cyclic 1,3-diketones. Thus, the reaction of 1b–f with 2a,b and 3, under the
PDF
Album
Full Research Paper
Published 04 Jan 2012

Approaches towards the synthesis of 5-aminopyrazoles

  • Ranjana Aggarwal,
  • Vinod Kumar,
  • Rajiv Kumar and
  • Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

Graphical Abstract
  • properties of 5-aminopyrazoles have prompted enormous research aimed at developing synthetic routes to these heterocyles. This review focuses on the biological properties associated with this system. Various synthetic methods developed up to 2010 for these compounds are described, particularly those that
  • involve the reactions of β-ketonitriles, malononitrile, alkylidenemalononitriles and their derivatives with hydrazines, as well as some novel miscellaneous methods. Keywords: alkylidenemalononitriles; 5-aminopyrazoles; hydrazines; β-ketonitriles; malononitriles; Review The 5-aminopyrazole system
  • enter clinical trials [13] (Figure 1). Besides the importance of 5-aminopyrazoles as biologically active agents, they are also useful synthons and building blocks for many heterocyclic products and can act as a binucleophile [14][15][16][17][18]. Cyclocondensation of 5-aminopyrazoles with 1,3
PDF
Album
Review
Published 09 Feb 2011
Other Beilstein-Institut Open Science Activities