- Visible light promoted tandem dehydrogenation-deaminative cyclocondensation under aerobic conditions for the synthesis of 2-aryl benzimidazoles/quinoxalines fromortho-phenylenediamines and arylmethyl/ethyl amines
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Visible light promoted domino synthesis of 2-aryl benzimidazoles is reported through the reaction ofortho-phenylenediamines and arylmethyl amines under aerobic conditions. The methodology has wide substrate scope and tolerates a wide range of functional groups affording the products in high yields. The use of arylethyl amines instead of arylmethyl amines gives 2-aryl quinoxalines.
- Sofi, Firdoos Ahmad,Sharma, Rohit,Rawat, Ravi,Chakraborti, Asit K.,Bharatam, Prasad V.
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supporting information
p. 4569 - 4573
(2021/03/22)
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- Thiazolo[5,4-f]quinoxalines, Oxazolo[5,4-f]quinoxalines and Pyrazino[b,e]isatins: Synthesis from 6-Aminoquinoxalines and Properties
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The regioselective iodination of different 2-mono-, 3-mono- and 2,3-disubstituted 6-aminoquinoxalines, which takes place at their 5-position, was rationalized on the basis of Hückel theory calculations. Oxazolo- and thiazolo[5,4-f]quinoxaline analogues of
- Bach, Stéphane,Dorcet, Vincent,El Osmani, Nour,Erb, William,Fajloun, Ziad,Lassagne, Frédéric,Mongin, Florence,Mongin, Olivier,Picot, Laurent,Richy, Nicolas,Robert, Thomas,Roisnel, Thierry,Sims, Joshua M.,Thiéry, Valérie
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supporting information
p. 2756 - 2763
(2021/06/25)
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- Organocatalytic Green Approach Towards the Fabrication of Fused Benzo N,N-containing Heterocycles Facilitated by Ultrasonic Irradiation
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The development of a metal-free protocol for transformations in organic synthesis offers a significant potential environmental benefit. This article reports the exploration of meglumine, a nontoxic and biodegradable amino sugar, as an organocatalyst for the synthesis of biologically active 1H-dibenzo[b,e][1,4]diazepin-1-ones, highly regioselective benzimidazole derivatives and derivatives of quinoxalines. Operational simplicity, mild reaction conditions, shorter reaction times, and use of green solvents are the highlights of this protocol. The advantage of ultrasonic irradiation has been significantly explored for the synthesis of the aforesaid compounds. Furthermore, the multifaceted use of o-phenylenediamine has also been accentuated in the study.
- Nongrum, Ridaphun,Kharmawlong, George Kupar,Rani, Jims World Star,Rahman, Noimur,Dutta, Arup,Nongkhlaw, Rishanlang
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- Copper-catalyzed aerobic oxidative coupling of o-phenylenediamines with 2-aryl/heteroarylethylamines: direct access to construct quinoxalines
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A copper-catalyzed oxidative coupling reaction of o-phenylenediamines with 2-aryl/heteroarylethylamines using molecular oxygen as an oxidant has been developed. This approach provides a practical and direct access to construct quinoxalines in excellent yields at room temperature. The reaction has a broad substrate scope and exhibits excellent functional-group tolerance. This method could be easily scaled up and applied to the synthesis of biologically active molecules bearing a quinoxaline structural scaffold.
- Gopalaiah, Kovuru,Saini, Anupama,Chandrudu, Sankala Naga,Rao, Devarapalli Chenna,Yadav, Harsh,Kumar, Binay
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p. 2259 - 2268
(2017/03/20)
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- Metal free synthesis of quinoxalines from alkynes via a cascade process using TsNBr2
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A metal free protocol for the synthesis of quinoxalines from alkynes has been developed. The reaction was carried out by treating alkynes with TsNBr2in presence of O-phenylenediamines in a mixture of acetonitrile and water (9:1). This one-pot reaction proceeds via an oxidative transformation of alkynes to α,α-dibromoketones in presence of TsNBr2and eventually to quinoxalines in presence of 1,2-diamines in a cascade process.
- Hazarika, Debojit,Phukan, Prodeep
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p. 1374 - 1379
(2017/02/15)
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- One-Pot Protocol for the Synthesis of Imidazoles and Quinoxalines using N-Bromosuccinimide
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N-bromosuccinimide (NBS)-mediated one-pot, green, efficient and practical synthesis of substituted imidazoles and quinoxalines has been achieved by the reaction of styrenes with N-arylbenzamidines and o-phenylenediamines, respectively, in a water:1,4-dioxane mixture. The reaction involves formation of an α-bromo ketone as an intermediate in the presence of NBS and water, followed by condensation with the N-arylbenzamidine and o-phenylenediamine. Use of an inexpensive NBS as a bromine source as well as an oxidant, water as a solvent and readily available starting materials makes this protocol environmentally benign and economically viable. Substituted imidazoles and quinoxalines were obtained in good to excellent yields with wide functional group compatibility. (Figure presented.).
- Pardeshi, Sachin D.,Sathe, Pratima A.,Vadagaonkar, Kamlesh S.,Chaskar, Atul C.
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supporting information
p. 4217 - 4226
(2017/12/07)
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- Nano Copper(0)-Stabilized on Alumina: Efficient and Recyclable Heterogeneous Catalyst for Chemoselective Synthesis of 1,2-Disubstituted Benzimidazoles and Quinoxalines in Aqueous Medium
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Abstract: The present communication elicits the use of copper nanoparticles on aluminium oxide derived from Cu–Al hydrotalcite as a heterogeneous catalyst in the green and operationally simple approach for the synthesis of selective 1,2-disubstituted benzimidazoles and quinoxaline. Wide ranges of substituted o-phenylenediamines and aldehydes or α-bromo ketones were used to achieve the desired products using water as the reaction medium. The recoverability and reusability of the catalyst are the significant features in this eco-friendly green protocol. Graphical Abstract: A simple and efficient process for the synthesis of benzimidazoles and quinoxaline in presence of Cu(0)/Al2O3 catalyst at room temperature is described.
- Pogula, Jaya,Laha, Soumi,Likhar, Pravin R.
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p. 2724 - 2735
(2017/09/14)
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- New 6-Aminoquinoxaline Derivatives with Neuroprotective Effect on Dopaminergic Neurons in Cellular and Animal Parkinson Disease Models
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Parkinson's disease (PD) is a neurodegenerative disorder of aging characterized by motor symptoms that result from the loss of midbrain dopamine neurons and the disruption of dopamine-mediated neurotransmission. There is currently no curative treatment for this disorder. To discover druggable neuroprotective compounds for dopamine neurons, we have designed and synthesized a second-generation of quinoxaline-derived molecules based on structure-activity relationship studies, which led previously to the discovery of our first neuroprotective brain penetrant hit compound MPAQ (5c). Neuroprotection assessment in PD cellular models of our newly synthesized quinoxaline-derived compounds has led to the selection of a better hit compound, PAQ (4c). Extensive in vitro characterization of 4c showed that its neuroprotective action is partially attributable to the activation of reticulum endoplasmic ryanodine receptor channels. Most interestingly, 4c was able to attenuate neurodegeneration in a mouse model of PD, making this compound an interesting drug candidate for the treatment of this disorder.
- Le Douaron, Gael,Ferrié, Laurent,Sepulveda-Diaz, Julia E.,Amar, Majid,Harfouche, Abha,Séon-Méniel, Blandine,Raisman-Vozari, Rita,Michel, Patrick P.,Figadère, Bruno
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p. 6169 - 6186
(2016/07/26)
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- I2 catalyzed tandem protocol for synthesis of quinoxalines via sp3, sp2 and sp C-H functionalization
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One-pot, atom-economic synthesis of quinoxalines has been achieved through generation of arylglyoxal from easily available ethylarenes, ethylenearenes and ethynearenes, and subsequent condensation with o-phenylenediamines. Catalytic I2 with TBHP as an oxidant in DMSO is the system of choice for this domino reaction involving C-H functionalization/oxidative cyclization. This metal-free, mechanistically distinct and functional group tolerant tandem approach could be a powerful complement to traditional approaches for the synthesis of quinoxalines. This journal is
- Vadagaonkar, Kamlesh S.,Kalmode, Hanuman P.,Murugan, Kaliyappan,Chaskar, Atul C.
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p. 5580 - 5590
(2015/02/05)
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- A selective, expeditious and sustainable entry en route to benzopyrazines and bis-benzopyrazines
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A convenient green synthesis of benzopyrazines and bis-benzopyrazines has been performed by the condensation of diversely substituted diamines and dicarbonyl compounds in water using indium powder as catalyst under controlled microwave exposure. The effects of microwave power, and temperature on this reaction are investigated in detail to identify the best condition. A wide range of diversely substituted diamines and dicarbonyl compounds produce excellent yield of the corresponding benzopyrazines and bis-benzopyrazines. A comparative study has also been made between microwave-induced procedure and conventional method. The present method is atom-economical, environmentally friendly, and affords synthetically useful and challenging products very rapidly.
- Bandyopadhyay, Debasish,Mukherjee, Sanghamitra,Banik, Bimal K.
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- Catalyst-free synthesis of quinoxalines
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Quinoxalines are a class of important heterocycles, so to explore a facile and practical new synthetic method is always demanded. We have developed a new catalyst-free domino synthesis of quinoxalines from phenacyl halides and 1,2-diaminoarenes. Phenacyl
- Lu, Dongming,Xiang, Qinjie,Zhou, Lihong,Zeng, Qingle
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p. 2639 - 2641
(2015/12/12)
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- Catalytic application of recyclable silica-supported bismuth(III) chloride in the benzo[N,N]-heterocyclic condensation
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Silica-supported bismuth(III) chloride (BiCl3/SiO2) has been successfully employed in the condensation of 1,2-dicarbonyls with a variety of arene-1,2-diamines bearing either electron withdrawing or donating functional groups. The catalyzed reaction proceeded smoothly under ambient temperature in methanol to give the corresponding quinoxaline and pyrido[2,3-b]pyrazine compounds in good to excellent yields. The catalyst exhibited remarkable reusable activity and higher catalytic performance than homogeneous BiCl3. A plausible mechanism for the catalytic action of BiCl3/SiO2 has been introduced. Moreover, the crystal structure of the prepared unsymmetrical benzo[N,N]-heterocycles has been determined by single crystal X-ray diffraction.
- Aghapoor, Kioumars,Mohsenzadeh, Farshid,Shakeri, Atena,Darabi, Hossein Reza,Ghassemzadeh, Mitra,Neumüller, Bernhard
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p. 170 - 178
(2013/10/08)
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- Heterogeneous SnCl2/SiO2 versus homogeneous SnCl 2 acid catalysis in the benzo[N,N]-heterocyclic condensation
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The scope of homogeneous Lewis acid-catalyzed benzo[N,N]-heterocyclic condensation was expanded to include the use of various metal salts not reported in the literature and SnCl2·2H2O was finally selected. Among various solid supports activated with SnCl2, heterogeneous SnCl2/SiO2 proved to be the most effective and significantly higher conversions were achieved compared to SnCl 2·2H2O itself. The results of TG-DTA and BET indicated that dispersed SnCl2 coordinates with surface hydroxyl groups of silica leading to formation of stable Lewis acid sites. Low catalyst loading, operational simplicity, practicability and applicability to various substrates render this eco-friendly approach as an interesting alternative to previously applied procedures.
- Darabi, Hossein Reza,Aghapoor, Kioumars,Mohsenzadeh, Farshid,Jalali, Mohammad Reza,Talebian, Shiva,Ebadi-Nia, Leila,Khatamifar, Ehsan,Aghaee, Ali
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experimental part
p. 213 - 218
(2011/11/06)
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- Application of metalloporphyrins as new catalysts for the efficient, mild and regioselective synthesis of quinoxaline derivatives
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A simple, highly efficient and green procedure for the condensation of aryl and alkyl 1,2-diamines with α-diketones in the presence of catalytic amounts of metalloporphyrins at room temperature is described. Using this method, quinoxaline derivatives as biologically interesting compounds are produced in high to excellent yields and short reaction times. In this report, the effects of central metal in porphyrin core and substituents on tetraphenylporphyrin skeleton have been studied.
- Mohammadi, Khosro,Hasaninejad, Alireza,Niad, Mahmud,Najmi, Mojtaba
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experimental part
p. 1052 - 1058
(2011/11/14)
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- A mild and convenient synthesis of quinoxalines via cyclization-oxidation process using DABCO as catalyst
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An efficient and general method has been described for the synthesis of quinoxalines by the reaction of 1,2-diamines with phenacyl bromides in the presence of DABCO. The method is suitable for the preparation of functionalized quinoxalines.
- Meshram,Santosh Kumar,Ramesh,Chennakesava Reddy
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experimental part
p. 2580 - 2585
(2010/07/04)
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- 2-Phenyl-(6(7)-R-substituted quinoxalines N-oxides. Synthesis, structure elucidation and antimicrobial activity
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A certain number of isomeric 2-phenylquinoxalines N-oxides bearing substituents at position 6/7 were prepared in order to investigate anti-microbial activity. The effect of some electron-withdrawing groups seem to increase an anti-Trichomonas vaginalis ac
- Loriga,Nuvole,Paglietti,Fadda,Zanetti
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p. 527 - 532
(2007/10/02)
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- REACTION OF PHENACYLDIMETHYLSULFONIUM IODIDE WITH o-PHENYLENEDIAMINES
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The reaction of o-phenylenediamines with phenacyldimethylsulfonium iodide gave 2-phenylquinoxaline.The same reaction by use of 3,4-diaminotoluene and 1,2-diamino-4-chlorobenzene instead of o-phenylenediamine afforded a mixture of the corresponding 6- and 7-substituted 2-phenylquinoxalines.In the case of 1,2-diamino-4-nitrobenzene, 6-nitro-2-phenylquinoxaline was obtained On the other hand, the reaction of 1,2-diamino-4-methoxybenzene and phenacyldimethylsulfonium iodide gave 7-methoxy-2-phenylquinoxaline.Furthermore, condensation of maleonitrile with phenacyldimethylsulfonium iodide gave 2,3-dicyano-6-phenylpyrazine.
- Kano, Shinzo,Yuasa, Yoko
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p. 1449 - 1452
(2007/10/02)
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- Synthesis of Quinoxaline Derivatives through Condensation of 1,2-Diaminobenzenes with β-Keto Sulfoxides
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The reaction of o-phenylenediamine with α-methylsulfinylcyclohexanone and α-methylsulfinylcyclopentanone in the presence of acetic acid afforded 1,2,3,4-tetrahydrophenazine and 2,3-dihydro-1H-cyclopentaquinoxaline, respectively. 3,4-Diaminotoluene and 3,4-diaminochlorobenzene were reacted with α-methylsulfinylacetophenone to give a mixture of the corresponding 6- and 7-substituted 2-phenylquinoxaline.Condensation of 3,4-diaminomethoxybenzene with α-methylsulfinylacetophenone gave 7-methoxy-2-phenylacetophenone, whereas, the same reaction between 3,4-diaminonitrobenzene and α-methylsulfinylacetophenone yielded 6-nitro-2-phenylquinoxaline.
- Kano, Shinzo,Shibuya, Shiroshi,Yuasa, Yoko
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p. 1559 - 1561
(2007/10/02)
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