- A Common, Facile and Eco-Friendly Method for the Reduction of Nitroarenes, Selective Reduction of Poly-Nitroarenes and Deoxygenation of N-Oxide Containing Heteroarenes Using Elemental Sulfur
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A transition metal-free, environment-friendly and practical protocol was developed either for the reduction of nitroarenes or for the deoxygenation of N-oxide containing heteroarenes. The reaction proceeded with the use of a non-toxic and cheap feedstock as elemental sulfur in aqueous methanol under relatively mild conditions. Green chemistry credentials were widely favorable compared to traditional and industrial protocols with good E-factors and a low production of waste. The strategy allowed the efficient reduction of a large variety of substituted-nitroarenes including various o-nitroanilines as well as selective reduction of various poly-nitroarenes in excellent yields with a broad substrate scope. The protocol was successfully extended to the deoxygenation of some N-oxide containing heteroarenes, like benzofuroxans, phenazine N,N'-dioxides, pyridine N-oxides, 2H-indazole N1-oxides, quinoxaline N1,N4-dioxides and benzo[d]imidazole N1,N3-dioxides. A gram-scale example for the synthesis of luminol, in green conditions, was reported. A solid mechanism of reaction was proposed from experimental evidences.
- Cerecetto, Hugo,Romero, Angel H.
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supporting information
(2020/03/23)
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- Compound of diaminopyridazine 3- methotrexate -5,10- with a hydroxyl group in the range -2- of not more than one hydroxyl group (by machine translation)
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The structural formula of the compound is shown 3 - in the specification, and the structural formula of the compound is shown in the specification. The structure has the advantages of simple synthetic route, strong electron donating ability, high fluorescence intensity and the like, can be used as an organic chemical intermediate and can be used as an organic chemical intermediate, and has a good application prospect. (by machine translation)
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Paragraph 0008-0009
(2019/12/02)
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- A mild and simple method for the synthesis of substituted phenazines
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A mild, simple, and general method has been developed for the synthesis of phenazines by cross-coupling of benzoquinones with o-phenylenediamines. Benzoquinones and o-phenylenediamines reacted smoothly to give the corresponding cross-coupled products in good to excellent yields. 1,4-Naphthoquinone also coupled with o-phenylenediamines in the presence of copper acetate at 50? °C to give the corresponding benzo[a]phenazines. All reactions could be carried out under air. Georg Thieme Verlag Stuttgart New York.
- Kour, Harpreet,Paul, Satya,Singh, Parvinder Pal,Gupta, Rajive
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p. 495 - 500
(2014/03/21)
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- Derivatives of phenazine useful to treat cancer
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The present invention relates to derivatives of phenazine having a general formula (I) as follows: for use as an agent for treating cancer.
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Page/Page column 12
(2011/10/12)
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- Efficient methods for the synthesis of 2-hydroxyphenazine based on the Pd-catalyzed N-arylation of aryl bromides
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(Chemical Equation Presented) Substituted diphenylamines can be synthesized by Pd(0)-catalyzed N-arylation using o-nitroanilines and nitro-substituted aryl bromides for a substrate. Cyclization of the diphenylamines by various methods, including the intramolecular Pd(0)-catalyzed N-arylation, produces 2-methoxyphenazine which can easily be deprotected to give 2-hydroxyphenazine. This phenazine is required to synthesize methanophenazine, a novel redoxactive cofactor isolated from methanogenic archaea.
- Tietze, Mario,Iglesias, Alberto,Merisor, Elena,Conrad, Juergen,Klaiber, Iris,Beifuss, Uwe
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p. 1549 - 1552
(2007/10/03)
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- Deoxygenation of Quinoxaline and Phenazine N-Oxides by Catalytic Transfer Reduction and by Iodide in the Presence of Pyridine/Sulfur Trioxide Complex
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Quinoxaline and phenazine di-N-oxides are deoxygenated under mild conditions by catalytic transfer reduction or by treatment with sodium iodide in the presence of pyridine/sulfur trioxide complex.
- Demirdji, S. H.,Haddadin, M. J.,Issidorides, C. H.
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p. 1735 - 1737
(2007/10/02)
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- Rates of Formation of Some Phenazines by Cyclization of Di- and Monoimines of N-(2-Aminophenyl)-p-benzoquinone
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The spectrophotometrically determined rates for cyclization of N-(2-aminophenyl)-p-benzoquinonediimine and its 5-methyl and 5-chloro derivatives in buffered aqueous media are reported in Table I for the pH range 6-9.The first-order rate equation involves protonated diimine.At higher pH these diimines hydrolyze to the corresponding monoimines which then undergo cyclization.The first order rate expression for cyclization for monoimine 3 (kL) involves the neutral monoimine and under the conditions used for the reaction is faster than the second-order hydrolysis (kh) of diimine 1a.Around pH 1 the diimines hydrolyze at the nonterminal imine nitrogen to the corresponding p-benzoquinone monoimine and o-phenylenediamine, which react further.Monoimine 3 undergoes a similar hydrolysis.
- Loveless, Norman P.,Brown, Keith C.,Horrocks, Robert H.
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p. 1182 - 1185
(2007/10/02)
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- Di-(2-hydroxy-1-phenazinyl)methane - A Compound of Novel Structure from Pseudomonas aureofaciens
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The structure elucidation of di-(2-hydroxy-1-phenazinyl)methane from Pseudomonas aureofaciens is described.In addition to the phenazine derivatives isolated earlier from this bacterium 2,3,4-trihydroxyphenazine-1-carboxylic acid and phenazine-1,6-dicarboxylic acid could be identified. - Keywords: Di-(2-hydroxy-1-phenazinyl)methane, Phenazines, Bacterial Constituents, Pseudomonas aureofaciens
- Neuenhaus, W.,Roemer, A.,Budzikiewicz, H.,Korth, H.,Pulverer, G.
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p. 385 - 388
(2007/10/02)
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