- Preparation method of 2-amino-4-nitrophenol
-
The invention provides a preparation method of 2-amino-4-nitrophenol, which comprises the steps of (1) dissolving 2-aminophenol in a solvent to react with concentrated sulfuric acid to generate 2-aminophenol sulfate, and passivating an amino group; (2) carrying out nitration reaction on the generated 2-aminophenol hydrogen sulfate and a mixed acid of concentrated sulfuric acid and concentrated nitric acid, and selectively nitrating at the 4 position to obtain 2-amino-4-nitrophenol; and (3) finally, processing the 2-amino-4-nitrophenol crude product into a 2-amino-4-nitrophenol refined product. According to the method provided by the invention, the defects of poor selectivity of sulfide, hydrazine hydrate or palladium carbon and the like can be avoided; and the preparation method provided by the invention is simple to operate, and the prepared product is good in appearance, good in quality and high in yield and has a good industrial prospect.
- -
-
Paragraph 0037-0079
(2021/05/29)
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- 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
-
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.
-
supporting information
(2020/03/23)
-
- Hydroxyl Assisted Rhodium Catalyst Supported on Goethite Nanoflower for Chemoselective Catalytic Transfer Hydrogenation of Fully Converted Nitrostyrenes
-
Control of chemoselectivity is a special challenge for the reduction of nitroarenes bearing one or more unsaturated groups. Here, we report a flower-like Rh/α-FeOOH catalyst for the chemoselective hydrogenation of nitrostyrene to vinylaniline over full conversion, which benefits the new functionalized aminostyrene because the multisubstituted aminostyrenes are usually commercially unavailable. This catalyst does not only show desirable selectivity for the vinylanilines, but also exhibits the inertness to various other reducible groups over wide reaction duration. The catalytic selectivity for the reduction of the nitro group towards vinyl group was investigated by the control experiments and FT-IR analysis. We have found that the abundant hydroxyl groups in the α-FeOOH may contribute to the improvement of catalytic activity and selectivity. Furthermore, the catalyst exhibits excellent stability and keeps its catalytic performance even after 6 cycles. (Figure presented.).
- Hu, Zenan,Ai, Yongjian,Liu, Lei,Zhou, Junjie,Zhang, Gang,Liu, Hongqi,Liu, Xiangyu,Liu, Zhibo,Hu, Jianshe,Sun, Hong-bin,Liang, Qionglin
-
supporting information
p. 3146 - 3154
(2019/05/10)
-
- Method for synthesizing benzoxazole compound by using nitration by-products of aromatic hydrocarbon and application of benzoxazole compound
-
The invention discloses a method for synthesizing a benzoxazole compound by using nitration by-products of aromatic hydrocarbon and application of the benzoxazole compound. The method comprises the main process: performing step-by-step crystallization on nitration products of a 2,4-dinitrochlorobenzene production enterprise so as to obtain 2,4-dinitrochlorobenzene, 2,6-dinitrochlorobenzene (I) anda small amount of residues, adopting the obtained 2,6-dinitrochlorobenzene (I) as the main starting material, and performing hydrolysis, selective catalytic hydrogenation reduction, cyclization, halogenation, carbon-carbon coupling and other processes so as to synthesize the benzoxazole compound, wherein the obtained compound can be used as a main raw material to synthesize a series of chemical intermediates with important application, and the chemical intermediates include o-aminophenol, 2-amino-4-nitrophenol, 2-amino-5-nitrophenol and hydrochloride of o-aminophenol, 2-amino-4-nitrophenol, 2-amino-5-nitrophenol. Through the method, the industrial by-products are converted into high value-added aromatic aminophenol products, industrial hazardous waste of the 2,4-dinitrochlorobenzene production enterprise is reduced, the scope of products of the enterprise is widened, and the economic benefits of enterprise are increased.
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- Ultrafine FeCu Alloy Nanoparticles Magnetically Immobilized in Amine-Rich Silica Spheres for Dehalogenation-Proof Hydrogenation of Nitroarenes
-
A novel core–shell structured nanocatalyst (Fe3O4@SiO2-NH2-FeCu nanoparticles) with ultrafine FeCu alloy NPs magnetically immobilized in porous silica has been fabricated. The obtained catalyst revealed excellent activity and chemoselectivity for catalyzing the hydrogenation of nitroarenes to corresponding anilines using hydrazine hydrate as the hydrogen source, and the reaction could be carried out smoothly in water, which is an environmentally friendly solvent. The FeCu alloy effectively prevented the dehalogenation of halonitroarenes, and X-ray photoelectron spectroscopy (XPS) study showed that it resulted from the electron-enrichment of Fe from Cu. A kinetics study indicated that the reaction order was about 1.5 towards 4-CNB and the apparent active energy (Ea) was 48.1 kJ mol?1, which is a relatively low value. Furthermore, the FeCu NPs are magnetically immobilized in the silica spheres (Fe3O4@SiO2), therefore the catalyst can be easily recovered by use of an external magnet and also possesses a long life time.
- Bao, Hongjie,Li, Yunong,Liu, Lei,Ai, Yongjian,Zhou, Junjie,Qi, Li,Jiang, Ruihang,Hu, Zenan,Wang, Jingting,Sun, Hongbin,Liang, Qionglin
-
supporting information
p. 14418 - 14424
(2018/09/12)
-
- Porous silica-encapsulated and magnetically recoverable Rh NPs: A highly efficient, stable and green catalyst for catalytic transfer hydrogenation with "slow-release" of stoichiometric hydrazine in water
-
A core-shell structured nanocatalyst (Fe3O4@SiO2-NH2-RhNPs@mSiO2) that is encapsulated with porous silica has been designed and prepared for catalyzing the transfer hydrogenation of nitro compounds into corresponding amines. Rh nanoparticles serve as the activity center, and the porous silica shell plays an important role in the "slow-release" of the hydrogen source hydrazine. This reaction can be carried out smoothly in the green solvent water, and the atom economy can be improved by decreasing the amount of hydrazine hydrate used to a stoichiometric 1.5 equivalent of the substrate. Significantly, high catalytic efficiency is obtained and the turnover frequency (TOF) can be up to 4373 h-1 in the reduction of p-nitrophenol (4-NP). A kinetics study shows that the order of reaction is ~0.5 towards 4-NP, and the apparent active energy Ea is 58.18 kJ mol-1, which also gives evidence of the high catalytic efficiency. Additionally, the excellent stability of the catalyst has been verified after 15 cycles without any loss of catalytic activity, and it is easily recovered by a magnet after reaction due to the Fe3O4 nucleus.
- Zhou, Junjie,Li, Yunong,Sun, Hong-Bin,Tang, Zhike,Qi, Li,Liu, Lei,Ai, Yongjian,Li, Shuang,Shao, Zixing,Liang, Qionglin
-
supporting information
p. 3400 - 3407
(2017/07/28)
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- Method for recovering 2,4-dinitrophenol hydrogenation reduction byproduct to prepare 2-amino-4-acetamidoanisole
-
The invention discloses a method for recovering 2,4-dinitrophenol hydrogenation reduction byproduct to prepare 2-amino-4-acetamidoanisole. The method comprises the following steps: separating a 2-amino-4-nitrophenol and 2-nitro-4-aminophenol mixture to obtain a 2-nitro-4-aminophenol single component; mixing the 2-nitro-4-aminophenol with an alkylation reagent, and carrying out a phenolic hydroxyl group alkylation reaction and an amino group acylation reaction to obtain 2-nitro-4-acetamidoanisole; and carrying out nitro group reduction on the 2-nitro-4-acetamidoanisole to obtain the 2-amino-4-acetamidoanisole. The method provides a brand new method for the synthesis of the fine chemical engineering intermediate 2-amino-4-acetamidoanisole with important uses, reduces the content of organic matters in 2-amino-4-nitrophenol production wastewater, reduces the treatment difficulty of enterprises' industrial wastewater, converts wastewater components into the fine chemical engineering intermediate with important production uses, and increases the enterprises' economy income.
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-
Paragraph 0019-0022
(2017/07/22)
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- Method for preparing 2-amino-4-nitrophenol through selective catalytic hydrogenation reduction
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The invention discloses a method for preparing 2-amino-4-nitrophenol through selective catalytic hydrogenation reduction. The method roughly comprises the processes of obtaining a 2,4-sodium dinitrobenzene water solution through reaction of 2,4-dinitrochlorobenzene and a 10%-30% sodium hydroxide solution, mixing the 2,4-sodium dinitrobenzene water solution with an acid and an organic solvent to obtain a mixed solution of 2,4-dinitrophenol and an organic solvent; and mixing the mixed solution of 2,4-dinitrophenol and an organic solvent with hydrogen in the presence of a noble metal catalyst, and producing 2-amino-4-nitrophenol through selective catalytic hydrogenation reduction. According to the method, the problems that 2-amino-4-nitrophenol is high in salinity, much in wastewater and high in production cost in an existing production method of 2-amino-4-nitrophenol are solved, and an environment-friendly method which is low in production cost is provided for production of high-quality 2-amino-4-nitrophenol.
- -
-
Paragraph 0008; 0018-0020
(2017/08/31)
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- 2-amino-4-nitrophenol synthesis method
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The invention discloses a 2-amino-4-nitrophenol synthesis method, comprising the following specific steps: 1, in an organic solvent, enabling 2-aminophenol (I) to react with hydrochloric acid or sulfuric acid to synthesize a compound (II), and directly performing the next step without recycling the organic solvent; 2, in the organic solvent, performing nitration on the compound (II) by using nitric acid at low temperature to obtain a compound (III), and finishing the reaction; 3, adding liquid caustic soda into a system, recovering the organic solvent by distillation, mixing distillation residues with inorganic acid, and performing solid and liquid separation to obtain a compound (IV), performing distillation and concentration on mother liquor to obtain a commercialized by-product, sodium chloride or sodium sulfate, and recycling and reusing distillation cooling water for reaction. The process is basically shown as a chemical equation shown in the description, wherein R is chloridion and hydrogen sulfate radical ions. The method provided by the invention has the advantages that the technological continuous operability is high, the safety is high, waste is avoided, the required production equipment is common reaction equipment, and the industrialization is easier to realize.
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-
Paragraph 0026; 0027; 0028; 0029; 0030; 0031; 0032-0056
(2017/08/31)
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- Visible Light as a Sole Requirement for Intramolecular C(sp3)-H Imination
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A novel, simple, and practical visible-light-mediated intramolecular α-C(sp3)-H imination of tertiary aliphatic amines containing β-O-aryl oximes leading to N-heterocycles has been developed. The reaction was performed well at rt with tolerance of some functional groups. Importantly, the selective C-H functionalization did not require added catalyst, oxidant, additive, acid, and base; visible light was the sole requirement.
- Li, Jingjing,Zhang, Pengxiang,Jiang, Min,Yang, Haijun,Zhao, Yufen,Fu, Hua
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p. 1994 - 1997
(2017/04/28)
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- Preparation method for 2-amino-4-nitrophenol
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The invention discloses a preparation method for 2-amino-4-nitrophenol. The preparation method for the 2-amino-4-nitrophenol, provided by the invention, comprises the following step: subjecting 2,4-dinitrophenol and hydrazine hydrate to a reduction reaction in the presence of a catalyst, thereby preparing the 2-amino-4-nitrophenol, wherein the catalyst is a combination of ferric chloride hexahydrate (FeCl3.6H2O) and activated charcoal. The preparation method disclosed by the invention has the advantages of milder reaction conditions, no byproduct, economical efficiency, environment-friendliness, simple aftertreatment and high reaction yield, thereby being adaptable to industrial production.
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-
Paragraph 0005; 0040
(2017/04/06)
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- Synthetic method for acebutolol drug intermediate 2-amino-4-nitrophenol
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The invention discloses a synthetic method for acebutolol drug intermediate 2-amino-4-nitrophenol. The synthetic method includes adding 2, 4-dinitrophenol into a mixed solution comprising 3-fluorine-5-(trifluoromethyl) acetophenone and a sodium carbonate solution, increasing the temperature, adding 2-(thiophene-2-yl) pyrrolidine dropwise, continuing to stir after adding, precipitating solids after filtration and temperature reduction, dissolving the solids in a dimethylsulfoxide solution, adding an oxalic acid solution, and performing molecular sieve decoloration, suction filtration, washing and recrystallization to obtain the crystal 2-amino-4-nitrophenol. Compared with conventional synthetic methods, the synthetic method has the advantages that reaction yield is increased greatly, and a new synthetic path is provided to lay a good foundation for further increasing the reaction yield.
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-
Paragraph 0021-0024
(2017/04/03)
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- Method for preparing 2-amino-4-nitrophenol through liquid catalytic hydrogenation
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The invention relates to a method for preparing 2-amino-4-nitrophenol, in particular to a method for preparing 2-amino-4-nitrophenol through liquid catalytic hydrogenation. 2,4-dinitrochlorobenzene is hydrolyzed to obtain industrial 2,4-dinitrochlorobenzene serving as a raw material, and 5 percent of Pd/C is used as a catalyst, so that the 2-amino-4-nitrophenol is prepared by performing catalytic hydrogenation on a liquid phase system. Compared with original sodium sulfide reduction, the liquid catalytic hydrogenation process disclosed by the invention has the advantages of low pollution, high yield and high quality; meanwhile, the catalytic hydrogenation system takes water serving as a solvent to replace an alcohol solvent which is low in boiling point and easy to volatilize, so that the problem of solvent recycling in the catalytic hydrogenation process is solved, and the safety of production is improved.
- -
-
Paragraph 0048; 0049
(2016/11/17)
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- Effect of viscosity on photodegradation rates in complex secondary organic aerosol materials
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This work explores the effect of environmental conditions on the photodegradation rates of atmospherically relevant, photolabile, organic molecules embedded in a film of secondary organic material (SOM). Three types of SOM were studied: α-pinene/O3/
- Hinks, Mallory L.,Brady, Monica V.,Lignell, Hanna,Song, Mijung,Grayson, James W.,Bertram, Allan K.,Lin, Peng,Laskin, Alexander,Laskin, Julia,Nizkorodov, Sergey A.
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p. 8785 - 8793
(2016/04/09)
-
- Ligand- and base-free synthesis of phenols by rapid oxidation of arylboronic acids using iron(III) oxide
-
Fe2O3 catalyzed rapid oxidation of arylboronic acids to obtain phenols in excellent yields (90-95%) in the presence of atmospheric oxygen under solar VIS-light irradiation using α-Fe2O3 as a catalyst in ligand- and base-free conditions is presented.
- Sawant, Sanghapal D.,Hudwekar, Abhinandan D.,Aravinda Kumar,Venkateswarlu, Vunnam,Singh, Parvinder Pal,Vishwakarma, Ram A.
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p. 811 - 814
(2015/03/03)
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- Homoleptic ruthenium(iii) chalcogenolates: A single precursor to metal chalcogenide nanoparticles catalyst
-
Eight homoleptic metal(iii) arylchalcogenolate polymers [M(EPh-p-X) 3]n (M = Ru, Cr, and Mo) were characterized by PXRD. Structural solution of [Ru(SPh-p-tBu)3]n1 was achieved by Rietveld refinement of the PXRD data. Pyrolysis of [Ru(SePh)3] n4 produced nanostructured RuSe2, which selectively catalyzed the reduction of nitro compounds in the presence of other functionalities.
- Chan, Sharon Lai-Fung,Low, Kam-Hung,So, Gary Kwok-Ming,Chui, Stephen Sin-Yin,Che, Chi-Ming
-
supporting information; experimental part
p. 8808 - 8810
(2011/10/02)
-
- A probable hydrogen-bonded meisenheimer complex: An unusually high S NAr reactivity of nitroaniline derivatives with hydroxide ion in aqueous media
-
Observations show that nitroanilines exhibit an unusually high S NAr reactivity with OH- in aqueous media in reactions that produce nitrophenols. SNAr reaction of 4-nitroaniline (2a) in aqueous NaOH for 16 h yields 4-nitrophenol (4a) quantitatively, whereas a similar reaction of 4-nitrochlorobenzene (1a) gave 4a in 2% yield together with recovered 1a in 97%, suggesting that the leaving ability of the NH2 group far surpasses that of Cl under these conditions. An essential feature of SNAr reactions of nitroanilines is probably that the NH2 leaving group participates in a hydrogen-bonding interaction with H 2O. Density functional theory (DFT) calculations for a set of 4-nitroaniline, OH-, and H2O suggest a possible formation of a Meisenheimer complex stabilized by hydrogen-bonding interactions and a six-membered ring structure. The results obtained here contrast with conventional SNAr reactivity profiles in which nitroanilines are nearly unreactive with nucleophiles in organic solvents.
- Imoto, Mitsutaka,Matsui, Yasunori,Takeda, Motonori,Tamaki, Akihiro,Taniguchi, Hisaji,Mizuno, Kazuhiko,Ikeda, Hiroshi
-
experimental part
p. 6356 - 6361
(2011/10/05)
-
- Selective partial hydrogenation of dinitrobenzenes to nitroanilines catalyzed by Ru/C
-
Ru/C was found to be a highly effective catalyst for the selective partial hydrogenation of a range of dinitrobenzenes to their corresponding nitroanilines with excellent selectivity under mild conditions. Furthermore, the effect from other substitute groups of dinitrobenzenes on partial hydrogenation was also explored in this study. Copyright
- Hou, Jie,Ma, Yonghuan,Li, Yuhan,Guo, Fang,Lu, Lianhai
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scheme or table
p. 974 - 975
(2009/04/06)
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- Ferrous sulfide/aqueous ammonia: Simple, efficient, and chemoselective reagent for the conversion of aromatic azide to amine
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A practical, environmentally benign, rapid, and efficient method for the reduction of aromatic azide to amine is described using FeS/aqueous ammonia in the presence of other reducible functionalities. Application of a novel reducing reagent results in aromatic amines with excellent yield and high chemoselectivity, without need of any purification techniques. Copyright Taylor & Francis Group, LLC.
- Gadakh, Amol V.,Karale, Bhausaheb K.
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p. 186 - 191
(2008/03/17)
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- Regulatory molecules for the 5-HT3 receptor ion channel gating system
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Substituted benzoxazole derivatives which possess a nitrogen-containing heterocycle at C2 are selective partial agonists of the 5-HT3 receptor. Alteration of substituents on the benzoxazole nucleus affords both agonist-like and antagonist-like compounds, and uniquely modifies the function of the 5-HT3 receptor ion channel gating system. SAR and corroborative computational docking study for these partial agonists successfully explained structure and function of the 5-HT3 receptor.
- Yoshida, Satoshi,Watanabe, Takashi,Sato, Yasuo
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p. 3515 - 3523
(2008/02/07)
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- New nitronate σ complexes and the mechanism of nucleophilic aromatic photosubstitution para to a nitro group
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Photolysis of 4-nitroanisole with aliphatic amines gives mainly N-substituted 4-nitroanilines. Reactions of this type have been widely attributed to a geminate radical mechanism. We questioned this interpretation and have searched for and found by NMR spectroscopy a new class of stable nitronate adducts generated under the reaction conditions. The adducts imply that photosubstitution by amines para to the nitro group occurs by meta σ complex formation followed by an unprecedented sigmatropic rearrangement.
- Wubbels, Gene G.,Johnson, Kandra M.
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p. 1451 - 1454
(2007/10/03)
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- Ammonium nickel sulphate mediated nitration of aromatic compounds with nitric acid
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Aromatic compounds were efficiently nitrated under mild conditions employing ammonium nickel sulphate and nitric acid as a reagent. This procedure works efficiently at room temperature yielding mononitro derivative in fair to good yield with high regioselectivity.
- Tasneem,Ali,Rajanna,Saiparakash
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p. 1123 - 1127
(2007/10/03)
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- Nitration of o-Aminophenol, o-Anisidine, and o-Benzenediazonium Oxide in Sulfuric Acid
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Entering into a reaction in the protonated form, o-aminophenol is nitrated in 80% sulfuric acid at the para and ortho positions to the hydroxy group to afford a mixture of 4-nitro- and 6-nitro-2-aminophenol and is nitrated and sulfonated in concentrated sulfuric acid, whereas o-anisidine is nitrated at the para positions in both cases, converting into 4-nitro-2-aminoanisole. After diazotization of o-aminophenol and subsequent nitration of o-benzenediazonium oxide, a mixture of the same derivatives as in diazotization of the nitration products of o-aminophenol is formed, but the 6-nitro isomer prevails.
- Gorelik,Shteiman,Shner,Romanskii,Kuznetsova
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p. 348 - 352
(2007/10/03)
-
- Factors controlling regioselectivity in the reduction of polynitroaromatics in aqueous solution
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Regioselectivities in the bisulfide reduction of 10 polynitroaromatics (PNAs) to monoamine products have been determined; four of these compounds have also been reduced by anoxic sediments in heterogeneous aqueous solution, and the same regioselectivities are observed. Analyses of Austin Model 1- Solvation Model 2 electrostatic potential surfaces for the radical anions of these polynitroaromatic compounds provides a reliable method of predicting the regioselectivity of their reduction. In particular, at their minimum- energy geometries in aqueous solution, it is the more negative nitro group that is selectively reduced. This is consistent with a mechanism where regioselection occurs upon kinetic protonation at the site of maximum negative charge in the radical anion formed after the first electron transfer to the neutral PNA. Inclusion of solvation effects is critical in order to confidently predict the electrostatic preference for the reduction of one nitro group over the others. Sterically uncongested nitroaromatic radical anions have gas-phase geometries in which the nitro group is coplanar with the aromatic ring. However, ortho substituents and solvation effects both oppose this tendency and can lead to nitro groups that are rotated out of the ring plane and pyramidalized.
- Barrows, Susan E.,Cramer, Christopher J.,Truhlar, Donald G.,Elovitz, Michael S.,Weber, Eric J.
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p. 3028 - 3038
(2007/10/03)
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- Selective hydrogenation of polynitroaromatic derivatives with noble metal catalysts in the presence of catalytic amounts of iron
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Hydrogen over PtO2, 5%Pd(c), PdCl2, or 5%Rh(al2O3), in the presence of catalytic amounts of iron and under mild reaction conditions, resulted in the selective reduction of a variety of polynitroaromatic compounds in high yields.
- Theodoridis,Manfredi,Krebs
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p. 6141 - 6144
(2007/10/02)
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- PARTIAL REDUCTION OF DINITROARENES TO NITROANILINES WITH HYDRAZINE HYDRATE.
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Dinitroarenes containing substituents such as hydroxyl and amine groups could be conveniently reduced with 3 molar equivalents of hydrazine hydrate in presence of Raney nickel catalyst in ethanol/1,2-dichloro-ethane solvent mixture to give a product wherein one of the two nitro groups was reduced to the amino group. The yields of the partial reduction products are good. Under similar conditions alkoxyl substitutes in the o,p-position to the nitro groups were displaced by the hydrazine to give 2,4-dinitrophenyl-hydrazine as the main product. The details of the reduction reaction are described.
- Avyyangar,Kalkote,Lugade,Nikrad,Sharma
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p. 3159 - 3164
(2007/10/02)
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- SYNTHESIS OF NITROPHENOLS
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Nitrophenols are prepared from halonitrobenzenes or nitroanilines by treatment with aqueous base.
- Anderson, James S.,Brown, Keith C.
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p. 233 - 236
(2007/10/02)
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- Process for the preparation of 2-amino-4-nitrophenol
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The process of reducing 2,4-dinitrophenol to 2-amino-4-nitrophenol by reduction with a hydrosulfide in aqueous alkaline solution at temperatures from 20°-100° C. is improved by maintaining the pH at 7 to 9.5 during the reduction.
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- 4-Hydroxyquinolone-(2)-azomethine copper complex pigments
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A compound having the formula STR1 wherein A denotes an optionally substituted aromatic, isocyclic or heterocyclic residue; R is H, an alkyl residue having from 1 to 6 carbon atoms, an aryl residue having from 6 to 10 carbon atoms or an aralkyl residue having from 7 to 10 carbon atoms; Q is H or a methyl group; X and Y are the same or different and each is a non-water solubilizing group, or X and Y together form a fused aromatic ring system; and R1 and R2 are the same or different and each is H or an alkyl radical having from 1 to 22 carbon atoms, and R3 is hydrogen, an alkyl radical having from 1 to 22 carbon atoms or an aryl radical having from 6 to 10 carbon atoms, the alkyl radicals in R1, R2 and R3 being unsubstituted and uninterrupted or being substituted by an OH, NH2 or CN group and/or being interrupted by an ethylenic group or an oxygen, sulphur or nitrogen bridge, or two or all three of R1, R2 and R3 may form, together with the nitrogen atom to which they are attached, a heterocyclic residue, is useful for pigmenting high molecular weight organic material such as a natural or synthetic polymer or copolymer, or a coating composition for application to the surface of an article, or a printing liquid medium to yield shades from greenish yellow to red brown, exhibiting good fastness properties.
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- 1:2 Cobalt complex phenol-acetoacetanilide benzene disazo dyestuffs
-
Valuable 1:2-cobalt complex dyestuffs of the disazo compound of formula (1) STR1 had been found, in which R1 is hydrogen, halogen, nitro, lower alkyl or lower alkoxy, R2 is hydrogen, lower alkyl or lower alkoxy, R3 is hydrogen, lower alkyl or lower alkoxy, X is hydroxy or β-sulfoethyl or a group of the formula STR2 wherein R4 is hydrogen or lower alkyl. The novel dyestuffs are well suitable for the dyeing of natural and synthetic polyamide fibres, especially in admixture with hydrophobic fibres, and also especially advantageously with other 1:2-chromium or 1:2 cobalt complex dyestuffs containing one or two sulfonic acid groups per dyestuff molecule, and yield even, strong dyeings of high fastness to wet processing and to use as well as to light. The novel cobalt complex dyestuff can be prepared by cobalting the above disazo compound (1) by means of a cobalt yielding agent.
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- Unsymmetrical 1:2-chromium complexes containing an azo compound and an azomethine compound
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Compounds of the formula: STR1 WHICH ARE EMINENTLY SUITABLE FOR DYEING NATURAL AND SYNTHETIC POLYAMIDES AND FOR COLORING SURFACE COATINGS. Dyeings on textile material are distinguished by very good lightfastness and very good fastness to wet treatments, for example fastness to water, perspiration, sea water and washing.
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