524-42-5Relevant articles and documents
Environmental photochemistry on semiconductor surfaces: Photosensitized degradation of a textile azo dye, Acid Orange 7, on TiO2 particles using visible light
Vinodgopal,Wynkoop, Darrel E.,Kamat, Prashant V.
, p. 1660 - 1666 (1996)
Photosensitized degradation of a textile azo dye, Acid Orange 7, has been carried out on TiO2 particles using visible light. Mechanistic details of the dye degradation have been elucidated using diffuse reflectance absorption and FTIR techniques. Degradation does not occur on Al2O3 surface or in the absence of oxygen. The dependence of the dye degradation rate on the surface coverage shows the participation of excited dye and TiO2 semiconductor in the surface photochemical process. Diffuse reflectance laser flash photolysis confirms the charge injection from the excited dye molecule into the conduction band of the semiconductor as the primary mechanism for producing oxidized dye radical. The surface-adsorbed oxygen plays an important role in scavenging photogenerated electrons, thus preventing the recombination between the oxidized dye radical and the photoinjected electrons. Diffuse reflectance FTIR was used to make a tentative identification of reaction intermediates and end products of dye degradation. The intermediates, 1,2-naphthoquinone and phthalic acid, have been identified during the course of degradation. Though less explored in photocatalysis, the photosensitization approach could be an excellent choice for the degradation of colored pollutants using visible light.
RuCl3 Catalyzed and Uncatalyzed Oxidative Decolorization of Acid Orange 7 Dye with Chloramine-B in Acid Medium: Spectrophotometric, Kinetic and Mechanistic Study
Manjunatha, Adalagere Somashekar,Puttaswamy
, p. 1312 - 1321 (2015)
Acid orange 7, chemically known as sodium 4-[(2E)-2-(2-oxonaphthalen-1-ylidene)hydrazinyl]benzenesulfonate, is extensively used for dyeing textiles, paper and leather. The discharge of wastewater containing this dye, causes environmental and health related problems. Therefore, in the present research, we have developed optimum conditions for the facile oxidative decolorization of this dye with sodium N-chlorobenzenesulfonamide or chloramine-B (CAB). The kinetics and mechanism of oxidative decolorization of acid orange 7 dye with CAB in acidic medium have also been studied spectrophotometrically at 303 K in the presence and absence of RuCl3 catalyst. Under similar experimental conditions, the reaction exhibits a first-order dependence of rate each on [CAB]o and [dye]o, and an inverse-fractional-order dependence on [H+] for both the RuCl3 catalyzed and uncatalyzed reactions. The order with respect to RuCl3 is fractional. Activation parameters have been computed. Dielectric effect is negative in both the cases. Oxidation products of the acid orange 7 dye are identified as 1,2-naphthoquinone and benzenesulfonic acid by GC-MS data. The RuCl3 catalyzed reaction is about four fold faster than the uncatalyzed reaction. The chemical oxygen demand value of the dye was determined. The mechanistic pathways and kinetic modelings have been computed based on experimental results. The developed oxidative decolorization method is expected to be helpful to treat acid orange 7 dye present in wastewater after suitable modifications. (Chemical Equation Presented).
Microwave-assisted selenium dioxide mediated selective oxidation of 1-tetralones to 1,2-naphthoquinones
Gelman, Danny M.,Perlmutter, Patrick
, p. 39 - 40 (2009)
We report an improved procedure for the selective transformation of substituted 1-tetralones to 1,2-naphthoquinones by microwave-assisted selenium dioxide oxidation. The reaction time is effectively reduced from hours to seconds without any loss of yield (40-70%) or selectivity.
One-pot multistep synthesis of bipolar carbazolo-phenazines: Hydrogen bond control of Diels-Alder cycloaddition and application for fluoride sensing
Mishra, Abhaya Kumar,Mukhopadhyay, Arindam,Moorthy, Jarugu Narasimha
, p. 2210 - 2216 (2017)
Access to novel bipolar carbazolo-phenazines is demonstrated by one-pot IBX-initiated multistep cascade, which involves oxidation of 2-naphthols to 1,2-naphthoquinones, Diels-Alder cycloaddition, aerial dehydroaromatization and cyclocondensation. With unprotected dienic indolylacrylates, N[sbnd]H?O hydrogen bonding in the transition state controls the product selectivity almost exclusively in favor of Diels-Alder cycloaddition over the competing Michael addition. The utility of one of the carbazolo-phenzines as applied to selective naked-eye sensing of fluoride is demonstrated.
1,2-Dihydro-1,2-dihydroxynaphthalene dehydrogenase containing recombinant strains: Preparation, isolation and characterisation of 1,2- dihydroxynaphthalenes and 1,2-naphthoquinones
Cavallotti, Camilla,Orsini, Fulvia,Sello, Guido,Di Gennaro, Patrizia,Galli, Enrica,Bestetti, Giuseppina
, p. 4467 - 4480 (1999)
1,2-Dihydroxynaphthalenes are produced by dehydrogenation of the corresponding 1,2-dihydro-1,2-dihydroxynaphthalenes using an Escherichia coli recombinant strain containing the dihydrodiol naphthalene dehydrogenase gene cloned from Pseudomonas fluorescens N3. Conversions are led in carefully controlled conditions to minimise product polymerisation. A multistep procedure using a weakly basic resin permits isolation of good product amounts, solving the toxicity problem. Products are isolated and characterised as t-butyldimethylsilyl derivatives that are stable compounds. The transformation of the 1,2-dihydroxynaphthalenes into the corresponding 1,2-naphthoquinones is also reported.
Development of polyclonal antibodies for detection of protein modification by 1,2-naphthoquinone
Zheng, Jiang,Hammock, Bruce D.
, p. 904 - 909 (1996)
Naphthoquinones have been reported to be toxic to liver cells in vitro. Protein modification is associated with naphthoquinone-induced cytotoxicity. In addition, 1,2-naphthoquinone was found to bind covalently to cysteine residues of proteins of lung Clara cells incubated with naphthalene. To further identify the target proteins of the naphthoquinone, we raised polyclonal antibodies by immunizing rabbits with 1,2-naphthoquinone protein adducts. A high titer of polyclonal antibodies was obtained by antiserum dilution tests. Competitive ELISA showed that the antibodies specifically recognize the 1,2-naphthoquinone N-acetylcysteine adduct. Very weak cross reactivity toward N-acetylcysteine and its 1,4-naphthoquinone as well as naphthalene oxide adducts was observed. For covalent binding studies, we incubated mouse liver homogenates with 1,2-naphthoquinone at concentrations of 1.0 and 10 μM at 37 °C for 1 h. The resulting protein samples were developed by SDS-PAGE, followed by Western blotting and immunostaining using the polyclonal antibodies. Chemiluminescent bands developed with ECL chemiluminescence kit were observed on the poly(vinylidene difluoride) microporous membrane blotted with the mouse liver homogenates exposed to 1.0 and 10 μM 1,2-naphthoquinone. One chemiluminescent band at a molecular weight of 22 kDa was observed in the lane loaded with the protein sample incubated with 1.0μM 1,2-naphthoquinone, and many chemiluminescent bands at a wide range of molecular weights were observed in the lane loaded with the protein sample incubated with 10 μM quinone. As expected, no chemiluminescent bands were detected on the membrane blotted with the proteins exposed to vehicle. We have successfully raised polyclonal antibodies to recognize 1,2-naphthoquinone cysteine adducts and developed immunostaining to detect protein modification by 1,2-naphthoquinone.
One-pot synthesis of phenazines from 2-naphthols with 1, 2-diamines and its biological importance and binding studies
Gajula, Raju,Guguloth, Vijayacharan,Battu, Satyanarayana
, (2021)
Synthesis of phenazine derivatives from the reaction of 2-naphthols with 1, 2-diamino benzenes in presence of K2S2O8 in AcOH and water, through the intermediate formation of 1, 2-naphthoquinones from self-coupling of 2-naphthol and then followed by condensation of 1, 2-diamino benzenes in one pot. The present reaction was compatible with various substituted 2-naphthols as well as substituted 1, 2-diamino benzenes to obtain a variety of substituted phenazine derivatives in good to excellent yields. The reaction was highly regio-selective in the case of unsymmetrical substituted 1, 2-diamino benzenes for providing single regio isomeric phenazine compounds. Reaction conditions were also mild and metal-free and also used green solvents such as AcOH and water. Phenazine derivatives are an important class of heterocycles and occur both in natural and synthetic compounds which shows many biological activities and also present in many important dyestuffs. In meantime, we have also shown our interest in antibacterial, anti-inflammatory activities and molecular docking studies. It is important to note that the phenazine derivatives showed excellent anti-bacterial and anti-inflammatory activities. Graphic abstract: [Figure not available: see fulltext.]
Hypoiodite-catalysed oxidative homocoupling of arenols and tandem oxidation/cross-coupling of hydroquinones with arenes
Uyanik, Muhammet,Nagata, Dai,Ishihara, Kazuaki
supporting information, p. 11625 - 11628 (2021/11/12)
We report the hypoiodite-catalyzed oxidative C-C homocoupling of arenols to biarenols or biquinones using aqueous hydrogen peroxide as an oxidant. In addition, by combining hypoiodite catalysis and lipophilic Lewis acid-assisted Br?nsted acid catalysis under aqueous conditions, we achieved a tandem oxidation/cross-coupling reaction of hydroquinones with electron-rich arenes. These results highlight the substantial scope of hypoiodite/acid co-catalysis for use in oxidative coupling reactions.
Regiodivergent oxidation of alkoxyarenes by hypervalent iodine/oxone system
China, Hideyasu,Tanihara, Kokoro,Sasa, Hirotaka,Kikushima, Kotaro,Dohi, Toshifumi
, p. 2 - 8 (2019/09/10)
We have found that the combination of Oxone with an organoiodine compound, i.e., 2-iodobenzoic acid (2-IB), selectively yields p-quinones from monomethoxyarenes under mild conditions. In this reaction system, an organoiodine compound is immediately oxidized by Oxone to generate cyclic hypervalent iodine (III) species in situ, which serves as the specific mediator for the selective p-quinone synthesis, preventing o-quinone formation.
