- Light-emitting analogues based on triphenylamine modified quinoxaline and pyridine[2,3-b]pyrazine exhibiting different mechanochromic luminescence
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A series of light-emitting analogues, [4-(2,3-diphenyl-quinoxalin-6-yl)-phenyl]-diphenyl-amine (TPA-DPQ) and [4-(2,3-diphenyl-pyrido[2,3-b]pyrazin-7-yl)-phenyl]-diphenyl-amine (TPA-DPP) are synthesized and characterized.TPA-DPQandTPA-DPPpossess similar do
- Ge, Yuxi,Huang, Bin
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- Palladium-catalyzed cross-coupling reactions of 7-bromo-2,3-diphenyl- pyrido[2,3-b]pyrazine
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First examples of palladium-catalyzed cross-coupling reactions, such as Suzuki, Sonogashira, Heck and Buchwald-Hartwig reactions, are reported in the pyrido[2,3-b]pyrazine series. This methodology circumvents problems found in uncatalyzed nucleophilic sub
- Yin, Lunxiang,Liebscher, Juergen
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- Synthesis and biological evaluation of novel pyrido[2,3-b]pyrazines inhibiting both erlotinib-sensitive and erlotinib-resistant cell lines
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A series of novel pyrido[2,3-b]pyrazines were synthesized as potential antitumor agents for erlotinib-resistant tumors. Known signal inhibitor compounds from our Nested Chemical Library were tested in phenotypic assays on erlotinib-sensitive PC9 and erlotinib-resistant PC9-ER cell lines to find a compound class to be active on erlotinib resistant cell lines. Based on the screening data, novel pyrido[2,3-b]pyrazines were designed and synthesized. The effect of the substituent position of the heteroaromatic moiety in position 7 and the importance of unsubstituted position 2 of the pyridopyrazine core were explored. Compound 7n had an IC50 value of 0.09 μM for the inhibition of PC9 and 0.15 μM for the inhibition of PC9-ER. We found that some lead compounds of these structures overcome erlotinib-resistance which might become promising drug candidates to fight against NSCLC with EGFR T790M mutation. The signaling network(s) involved in the mechanism(s) of action of these novel compounds in overcoming erlotinib resistance remain to be elucidated.
- Kékesi, László,Sipos, Anna,Németh, Gábor,Pató, János,Breza, Nóra,Baska, Ferenc,?rfi, László,Kéri, Gy?rgy
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- Pyrido[2,3-b]pyrazine-based full-color fluoresent materials for high-performance OLEDs
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High photoluminescence quantum efficiency (PLQY) and simple molecular structure in a full-color emitting material system are two crucial issues for cost-effective multicolor display applications. Herein, a new tailor-made fluorescent core (pyrido[2,3-b]py
- Luo, Jiajia,Ma, Dongge,Wu, Zhongbin,Xie, Guohua,Yang, Chuluo,Yu, Ling,Zou, Yang
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p. 12445 - 12449
(2020/10/06)
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- Synthesis of quinoxaline, benzimidazole and pyrazole derivatives under the catalytic influence?of biosurfactant-stabilized iron nanoparticles in water
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Abstract: We have reported the synthesis, characterization, and catalytic applications of amorphous iron nanoparticles (FeNPs) using aqueous leaves extract of renewable natural resource Boswellia serrata plant. Synthesized FeNPs were stabilized in situ by the addition of aqueous pod extracts of Acacia concinna as a biosurfactant (pH 3.11). The structural investigation of biosynthesized nanoparticles was performed using UV–visible spectroscopy, X-ray diffraction analysis, selected area electron diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and BET analysis. The FeNPs were amorphous in nature with average particle size ~ 19?nm and successfully employed as heterogeneous catalyst for the synthesis of quinoxaline, benzimidazole, and pyrazole derivatives in aqueous medium at ambient conditions. The FeNPs could be recycled up to five times with modest change in the catalytic activity. Graphic abstract: [Figure not available: see fulltext.].
- Arde, Satyanarayan M.,Patil, Audumbar D.,Mane, Ananda H.,Salokhe, Prabha R.,Salunkhe, Rajashri S.
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p. 5069 - 5086
(2020/09/02)
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- HBTU-catalyzed simple and mild protocol for the synthesis of quinoxaline derivatives
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HBTU-catalyzed, simple, mild, and effective protocol for the synthesis of quinoxalines has been established. The reaction between 1,2-diamines, benzil, and catalytic amount of HBTU in ethanol resulted into quinoxalines. Various aliphatic, aromatic and het
- Bhushan, B. Popatkar,Gangadhar, A. Meshram
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- A zirconium Schiff base complex immobilized on starch-coated maghemite nanoparticles catalyzes heterogeneous condensation of 1,2-diamines with 1,2-dicarbonyl compounds
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A magnetically separable zirconium Schiff base nanocatalyst was synthesized under ultrasonic agitation. TEM images revealed a uniform spherical particle shape with average size of 10-14 nm for the as-prepared catalyst. The catalytic performance of ZrOL2@SMNP in the heterogeneous condensation of various 1,2-diamines and 1,2-dicarbonyls for the synthesis of heterocyclic compounds in ethanol has been explored.
- Jafarpour, Maasoumeh,Rezaeifard, Abdolreza
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p. 205 - 211
(2016/02/20)
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- Synthesis of quinoxalines and pyrido[2,3-b]pyrazines by SuzukiMiyaura cross-coupling reaction
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Abstract: Bromo-substituted quinoxalines and pyrido[2,3-b]pyrazines were synthesized by condensation reactions of aromatic 1,2-diamino and 1,2-diketone compounds. These compounds were used as common intermediates for postcondensation modification by SuzukiMiyaura coupling reaction to form aryl-substituted quinoxalines and pyrido[2,3-b]pyrazines. High-efficiency with improved product yield of aryl-substituted quinoxalines and pyrido[2,3-b]pyrazine derivatives was achieved by conducting a coupling reaction in presence of Pd(dppf)Cl2·CH2Cl2 in tetrahydrofuran (THF) using K2CO3 as base at reflux temperature. Graphical abstract: [Figure not available: see fulltext.].
- Kumbhar, Arjun,Jadhav, Sanjay,Salunkhe, Rajashri
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p. 5431 - 5440
(2016/06/01)
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- Bipolar compound containing pyridopyrazine unit and preparation method and application of compound
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The invention provides a bipolar compound containing a pyridopyrazine unit. A preparation method of the bipolar compound containing the pyridopyrazine unit comprises the step that the pyridopyrazine unit with an electron-withdrawing effect serves as the b
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Paragraph 0052; 0053
(2017/01/12)
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- A novel protocol for selective synthesis of monoclinic zirconia nanoparticles as a heterogeneous catalyst for condensation of 1,2-diamines with 1,2-dicarbonyl compounds
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ZrO2 nanocatalyst has been obtained successfully using novel and safe agents through a simple and safe sol-gel method (polymerizing-complexing) and characterized by XRD, FT-IR, Raman spectroscopies and transmission electron microscopy (TEM). Raman spectroscopies and XRD results indicated only formation of monoclinic zirconia. TEM images revealed spherical nanoparticles with 20-40 nm diameter range. The spectral and analysis data confirmed the effectiveness of the method for preparation of monoclinic zirconia by preventing grain growth or agglomeration of particles. The nanostructured ZrO2 exhibited high efficiency in catalyzing condensation of various 1,2-diamine and 1,2-dicarbonyl compounds for the synthesis of heterocyclic compounds. The recovery of the title heterogeneous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from the bulk one.
- Jafarpour, Maasoumeh,Rezapour, Elham,Ghahramaninezhad, Mahboobe,Rezaeifard, Abdolreza
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p. 676 - 682
(2014/02/14)
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- PYRIDOPYRAZINES AS ANTICANCER AGENTS
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The present invention relates to pyridopyrazine derivatives and solvates, hydrates and pharmaceutically acceptable salts thereof, the use of them in the prevention and/or the treatment of cancer diseases, as well as pharmaceutical compositions containing at least one of them as pharmaceutically active agent(s) together with pharmaceutically acceptable carrier, excipient and/or diluents, especially for the prevention and/or treatment of cancer diseases.˙
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Page/Page column 14
(2014/07/22)
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- Reusable α-MoO3 nanobelts catalyzes the green and heterogeneous condensation of 1,2-diamines with carbonyl compounds
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Crystalline nanobelts of α-MoO3 have been obtained successfully using novel and safe agents through a simple and safe sol-gel method (polymerizing-complexing) and characterized by XRD, FT-IR, Raman spectroscopies, high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and the temperature programmed desorption (TPD) of ammonia. An orthorhombic lattice system for nano-MoO3 was established. The HRTEM images showed that the nanobelt morphology of α-MoO3 mostly ranged from 20-70 nm in width and 200-400 nm in length. The ammonia TPD profile demonstrated strong acidic sites. The spectral and analysis data confirmed the effectiveness of the method for the preparation of α-MoO3 nanobelts by prevention of grain growth or agglomeration of the particles. The nanostructured MoO3 exhibited a high efficiency in catalyzing the condensation reaction of various 1,2-diamine and carbonyl compounds for synthesis of heterocyclic compounds. The recovery of the title heterogenous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from the bulk material.
- Jafarpour, Maasoumeh,Rezaeifard, Abdolreza,Ghahramaninezhad, Mahboube,Tabibi, Tooba
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p. 2087 - 2095
(2013/10/08)
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- Poly(N,N ′-dibromo-N-ethyl-benzene-1,3-disulphonamide) and N,N,N ′,N ′-tetrabromobenzene-1,3- disulphonamide as novel catalysts for synthesis of quinoxaline derivatives
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Poly(N,N ′ -dibromo-N-ethyl-benzene-1,3-disulphonamide) [PBBS] and N,N,N ′,N ′ -tetrabromobenzene-1,3- disulphonamide [TBBDA] were used as efficient catalysts for the synthesis of quinoxaline derivatives in excellent yields from 1,2-diamines and 1,2-dicarbonyls under aqueous and solvent-free conditions. [Figure not available: see fulltext.]
- Ghorbani-Vaghei, Ramin,Hajinazari, Somaye
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p. 353 - 358
(2013/07/26)
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- Microwave-assisted synthesis of quinoxaline derivatives using glycerol as a green solvent
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A rapid, efficient, and reliable catalyst-free procedure for the synthesis of quinoxaline derivatives in glycerol under focused microwave irradiation was developed. The reaction proceeded in glycerol without any catalyst making this methodology valuable from both economic and environmental viewpoints.
- Zhou,Zhang,Sun,Wang,Wang,Bai
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p. 1244 - 1247
(2014/03/21)
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- Catalyst-free protocol for the synthesis of quinoxalines and pyrazines in PEG
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A facile and simple catalyst-free protocol has been developed for the condensation of 1,2-diketones with aromatic 1,2-diamines in polyethylene glycol (PEG), providing quinoxaline derivatives in good yields. The important features of the methodology are broad substrates scope, simple workup, catalyst free, environmentally benign, and no requirement for metal catalysts. It is noteworthy that the cyclization reaction of 1,2-diketones with aliphatic 1,2-diamines is also conducted smoothly to afford pyrazines in good yields under the standard conditions. In addition, PEG could be recovered easily and was reused without evident loss in activity
- Huang, Tie-Qiang,Qu, Wen-Yan,Ding, Jin-Chang,Liu, Miao-Chang,Wu, Hua-Yue,Chen, Jiu-Xi
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p. 293 - 297
(2013/06/05)
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- Br?nsted acid hydrotrope combined catalyst for environmentally benign synthesis of quinoxalines and pyrido[2,3-b]pyrazines in aqueous medium
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A new Br?nsted acid hydrotrope combined catalyst (BAHC) has been developed and applied in acid catalyzed synthesis of pyrido[2,3-b]pyrazines and quinoxalines in an aqueous medium at ambient temperature with excellent yields. Interestingly, the catalyst ca
- Kumbhar, Arjun,Kamble, Santosh,Barge, Madhuri,Rashinkar, Gajanan,Salunkhe, Rajashri
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experimental part
p. 2756 - 2760
(2012/07/14)
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- Silica tethered Pd-DABCO complex: An efficient and reusable catalyst for suzuki-miyaura reaction
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A palladium-based catalyst supported on DABCO-functionalized silica was successfully prepared by a facile procedure. The prepared heterogeneous catalyst showed a high activity for the Suzuki-Miyaura reaction of aryl bromides, affording excellent yield in all the cases investigated. Interestingly, the catalyst could be quantitatively recovered from the reaction mixture and recycled for five times without any significant loss in activity. Furthermore, this protocol could be extended to the palladium catalyzed synthesis of annulated pyrazines. Springer Science+Business Media, LLC 2012.
- Kumbhar, Arjun,Kamble, Santosh,Jadhav, Sanjay,Rashinkar, Gajanan,Salunkhe, Rajashri
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p. 1388 - 1396
(2013/01/15)
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- Microwave-assisted solvent-free synthesis and in vitro antibacterial screening of quinoxalines and pyrido[2, 3b]pyrazines
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We report herein the microwave assisted synthesis, without solvents and catalysts, of 6-substituted quinoxalines and 7-substituted pyrido[2,3b] pyrazines. The compounds were obtained in good yields and short reaction times using the mentioned procedure and two new structures are reported. A complete 1H-and 13C-NMR assignment was performed using 1D and 2D-NMR. Additionally, an in vitro screening was performed on Gram-positive and Gram-negative bacteria using amoxicillin as positive reference. Compounds bearing a pyridyl group tended to have higher antibacterial activity, but the best activity against Bacillus subtilis and Proteus mirabilis was observed with quinoxaline derivatives.
- Morales-Castellanos, J. Jesus,Ramirez-Hernandez, Karina,Gomez-Flores, Nancy S.,Rodas-Suarez, Oscar R.,Peralta-Cruz, Javier
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experimental part
p. 5164 - 5176
(2012/09/07)
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- Microwave-assisted synthesis of quinoxalines in peg-400
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A rapid and efficient procedure for the synthesis of quinoxaline derivatives has been achieved by condensation of aryl-1,2-diamines with 1,2-dicarbonyl compounds catalyzed by polyethylene glycol under CEM-focused microwave-irradiation conditions. Copyright
- Zhang, Xia-Zhong,Wang, Jin-Xian,Bai, Lin
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experimental part
p. 2053 - 2063
(2011/07/07)
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- Eco-friendly synthesis of quinoxaline derivatives by grinding under solvent-free conditions
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An efficient and facile synthesis of quinoxaline derivatives in excellent isolated yields by the condensation of 1,2-diamines and 1,2-diketones on grinding under solvent-free conditions at ambient temperature has been developed. The important features of this method are that it is reasonably fast, very clean, high yielding, simple workup, and environmentally benign.
- Li, Jun,Jiang, Dan-Na,Chen, Jiu-Xi,Liu, Miao-Chang,Ding, Jin-Chang,Wu, Hua-Yue
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experimental part
p. 403 - 406
(2011/05/14)
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- Synthesis of quinoxaline derivatives catalyzed by PEG-400
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Polyethylene glycol (PEG) was found to be an effective catalyst for the condensation of 1,2-diamines with 1,2-dicarbonyl compounds to afford the corresponding quinoxaline derivatives in excellent yields under mild reaction conditions.
- Zhang, Xia Zhong,Wang, Jin Xian,Sun, Yong Jun,Zhan, Hong Wen
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experimental part
p. 395 - 398
(2010/12/24)
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- Cine and normal substitution reaction on substituted 7-bromo-5-azaquinoxalines by secondary amines
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7-Bromo-3-phenyl-5-azaquinoxaline (I), 7-bromo-2,3-dimethyl-5-azaquinoxaline (II) and 7-bromo-2,3-diphenyl-5-azaquinoxaline (III) have been synthesized and their nucleophilic substitution reactions with pyrrolidine, piperidine, morpholine and diethanolami
- Kumari, Sharda,Ghai, Punit,Sexsena, Archana
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