- Silica supported dodecatungstophosphoric acid (DTP/SiO2): An efficient and recyclable heterogeneous catalyst for rapid synthesis of quinoxalines
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A facile synthesis of quinoxalines by the cyclocondensation of substituted phenacyl bromides with o-pheneylenediamines using silica-supported dodecatungstophosphoric acid (DTP/SiO2) as a recyclable heterogeneous catalyst is unveiled in this res
- Hebade, Madhav J.,Deshmukh, Tejshri R.,Dhumal, Sambhaji T.
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p. 2510 - 2520
(2021/06/17)
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- Meta-Selective CAr-H Nitration of Arenes through a Ru3(CO)12-Catalyzed Ortho-Metalation Strategy
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The first example of transition metal-catalyzed meta-selective CAr-H nitration of arenes is described. With the use of Ru3(CO)12 as the catalyst and Cu(NO3)2·3H2O as the nitro source, a wide spectrum of arenes bearing diversified N-heterocycles or oximido as the directing groups were nitrated with meta-selectivity exclusively. Mechanism studies have demonstrated the formation of a new 18e-octahedral ruthenium species as a key ortho-CAr-H metalated intermediate, which may be responsible for the subsequent meta-selective electrophilic aromatic substitution (SEAr). Moreover, this approach provides a fast-track strategy for atom/step economical synthesis of many useful pharmaceutical molecules.
- Fan, Zhoulong,Ni, Jiabin,Zhang, Ao
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supporting information
p. 8470 - 8475
(2016/07/26)
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- Recyclable acidic br?nsted ionic liquid catalyzed synthesis of quinoxaline
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The acidic ionic liquid, 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate [MimC4SO3H]HSO4 catalyzed two-component condensation reaction of phenacyl bromide and o-phenylenediamine to afford corresponding quinoxaline derivatives. The inexpensive and non-toxic ionic liquids can be reused several times without any perceptible loss of their activities.
- Tejeswararao
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p. 2843 - 2845
(2016/07/12)
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- Synthesis of quinoxaline using silica supported phosphomolybdic acid as reusable heterogeneous catalyst
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Using phosphomolybdic acid on silica as recyclable catalyst we have developed methodology for the synthesis of quinoxalines by condensation of phenacyl bromides and o-phenylene diamines in ClCH2CH2Cl at 80°C. The phosphomolybdic acid
- Tejeswararao
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p. 2353 - 2356
(2016/10/12)
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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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- Quinoxaline derivatives: Novel and selective butyrylcholinesterase inhibitors
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Alzheimer's disease (AD) is a progressive brain disorder which occurs due to lower levels of acetylcholine (ACh) neurotransmitters, and results in a gradual decline in memory and other cognitive processes. Acetycholinesterase (AChE) and butyrylcholinesterase (BChE) are considered to be primary regulators of the ACh levels in the brain. Evidence shows that AChE activity decreases in AD, while activity of BChE does not change or even elevate in advanced AD, which suggests a key involvement of BChE in ACh hydrolysis during AD symptoms. Therefore, inhibiting the activity of BChE may be an effective way to control AD associated disorders. In this regard, a series of quinoxaline derivatives 1-17 was synthesized and biologically evaluated against cholinesterases (AChE and BChE) and as well as against achymotrypsin and urease. The compounds 1-17 were found to be selective inhibitors for BChE, as no activity was found against other enzymes. Among the series, compounds 6 (IC50 = 7.7 ± 1.0μM) and 7 (IC50 = 9.7 ± 0.9 μM) were found to be the most active inhibitors against BChE. Their IC50 values are comparable to the standard, galantamine (IC50 = 6.6 ± 0.38 μM). Their considerable BChE inhibitory activity makes them selective candidates for the development of BChE inhibitors. Structure-activity relationship (SAR) of this new class of selective BChE inhibitors has been discussed.
- Zeb, Aurang,Hameed, Abdul,Khan, Latifullah,Khan, Imran,Dalvandi, Kourosh,Choudhary, M. Iqbal,Basha, Fatima Z.
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p. 724 - 729
(2015/04/14)
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- Sodium dodecylsulfate induced synthesis of quinoxalines
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A simple and efficient sodium dodecylsulfate (SDS) induced method for the synthesis of quinoxalines in excellent yields in water at room temperature by the reaction of phenacyl bromide and o-phenylene diamines has been developed. Simple reaction conditions, wide compatibility and high yields are the advantages of this protocol.
- Emmadi, Narender Reddy,Atmakur, Krishnaiah
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p. 1500 - 1504
(2014/01/23)
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- Synthesis of functionalized benzimidazoles and quinoxalines catalyzed by sodium hexafluorophosphate bound Amberlite resin in aqueous medium
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A very simple, eco-friendly, and versatile method for the selective synthesis of 1,2-disubstituted benzimidazoles and quinoxalines in water-methanol (1:1) mixture with the aid of resin bound hexafluorophosphate ion as catalyst is reported. The method is also effective for the incorporation of quinoxaline nucleus at the A ring of pentacyclic triterpenoid, friedelin. A plausible mechanism for the formation of disubstituted benzimidazole has also been suggested.
- Ghosh, Pranab,Mandal, Amitava
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supporting information
p. 6483 - 6488,6
(2012/12/12)
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- Synthesis of functionalized benzimidazoles and quinoxalines catalyzed by sodium hexafluorophosphate bound Amberlite resin in aqueous medium
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A very simple, eco-friendly, and versatile method for the selective synthesis of 1,2-disubstituted benzimidazoles and quinoxalines in water-methanol (1:1) mixture with the aid of resin bound hexafluorophosphate ion as catalyst is reported. The method is also effective for the incorporation of quinoxaline nucleus at the A ring of pentacyclic triterpenoid, friedelin. A plausible mechanism for the formation of disubstituted benzimidazole has also been suggested.
- Ghosh, Pranab,Mandal, Amitava
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supporting information
p. 6483 - 6488
(2013/01/15)
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- Synthesis of libraries of quinoxalines through eco-friendly tandem oxidation-condensation or condensation reactions
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A facile and expeditious solid-phase synthesis of libraries of quinoxalines promoted on KF-alumina surface via tandem oxidation-condensation or condensation reactions is reported. The reaction protocol is operationally simple and mild. Moreover, solvent-free reaction condition makes the reaction procedure eco-friendly and economically viable.
- Paul, Susmita,Basu, Basudeb
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experimental part
p. 6597 - 6602
(2012/01/03)
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