- Specific para-hydroxylation of nitronaphthalenes with cumene hydroperoxide in basic aqueous media
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A synthetic method for specific para-hydroxylation of nitroarenes has been developed. The reaction of nitronaphthalenes with cumeme hydroperoxide in basic aqueous media produces exclusively para-hydroxy nitronaphthalenes in good yield. The selectivity of ortho and para hydroxylation is mediated by water content. The rationale for water-controlled orientation of hydroxylation has been briefly discussed. (C) 2000 Elsevier Science Ltd.
- Zhu, Lei,Zhang, Lin-Hua
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Read Online
- Light-Controlled Tyrosine Nitration of Proteins
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Tyrosine nitration of proteins is one of the most important oxidative post-translational modifications in vivo. A major obstacle for its biochemical and physiological studies is the lack of efficient and chemoselective protein tyrosine nitration reagents. Herein, we report a generalizable strategy for light-controlled protein tyrosine nitration by employing biocompatible dinitroimidazole reagents. Upon 390 nm irradiation, dinitroimidazoles efficiently convert tyrosine residues into 3-nitrotyrosine residues in peptides and proteins with fast kinetics and high chemoselectivity under neutral aqueous buffer conditions. The incorporation of 3-nitrotyrosine residues enhances the thermostability of lasso peptide natural products and endows murine tumor necrosis factor-α with strong immunogenicity to break self-tolerance. The light-controlled time resolution of this method allows the investigation of the impact of tyrosine nitration on the self-assembly behavior of α-synuclein.
- Long, Tengfang,Liu, Lei,Tao, Youqi,Zhang, Wanli,Quan, Jiale,Zheng, Jie,Hegemann, Julian D.,Uesugi, Motonari,Yao, Wenbing,Tian, Hong,Wang, Huan
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supporting information
p. 13414 - 13422
(2021/05/12)
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- Method for preparing 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate
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The invention discloses a method for preparing 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate. The method comprises the following steps: carrying out a nitrosation reaction on 2-naphthol serving as a raw material, sodium nitrite and dilute sulfuric acid in a tubular reactor to generate 1-nitroso-2-naphthol, carrying out catalytic hydrogenation on the 1-nitroso-2-naphthol and hydrogen in a Raney nickel immobilized fixed bed reactor to generate 1-amino-2-naphthol, carrying out sulfonation diazotization cyclization on 1-amino-2-naphthol and nitrosyl sulfuric acid in the tubular reactor, and nitrifying with nitric acid to obtain the final product 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate. According to the novel synthesis method of the 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate, hydrogen is used for reduction in the route, nitrosyl sulfuric acid is used for sulfonation diazotization cyclization, so the problem that a large amount of solid waste is generated in a traditional route is avoided, the atom utilization rate is high, the yield is increased, the safety coefficient is increased by using a tubular process, and the method is suitable for industrial production.
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Paragraph 0008; 0032-0034; 0041-0043
(2020/06/17)
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- Ruthenium-Catalyzed Tandem Carbene/Alkyne Metathesis/N-H Insertion: Synthesis of Benzofused Six-Membered Azaheterocycles
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The Cp*RuCl-based catalyst enables expedient access to a variety of benzofused six-membered azaheterocycles from unprotected o-alkynylanilines and trimethylsilyldiazomethane through an unprecedent tandem carbene/alkyne metathesis/N-H insertion reaction. The transformation takes place under mild reaction conditions (room temperature, 15 min) and with excellent functional group tolerance. The synthetic utility of the final products and a mechanistic rationale are also discussed.
- Padín, Damián,Saá, Carlos,Varela, Jesús A.
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supporting information
(2020/03/30)
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- Ring-Fused 1,4-Dihydro[1,2,4]triazin-4-yls through Photocyclization
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Halogen lamp irradiation of benzo[e][1,2,4]triazines 2[X] in CH2Cl2 solutions leads to planar ring-fused 1,4-dihydro[1,2,4]triazin-4-yl radicals 1 through a novel, potentially general, cyclization mechanism. The scope and efficiency of the method were established for unsubstituted and ortho-substituted (X = NH2, Br, NO2) phenoxy, naphthyloxy, and quinolinoxy derivatives 2[X]. The regioselectivity of 2[X] photocyclization was rationalized with DFT computational methods. Radicals 1 were characterized by spectroscopic (UV-vis, EPR), electrochemical, and XRD methods.
- Bartos, Paulina,Kaszyński, Piotr,Young, Victor G.
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supporting information
(2020/05/22)
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- 3-(Ethoxycarbonyl)-1-(5-methyl-5-(nitrosooxy)hexyl)pyridin-1-ium cation: A green alternative to tert-butyl nitrite for synthesis of nitro-group-containing arenes and drugs at room temperature
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Due to their remarkable properties, task-specific ionic liquids have turned out to be progressively popular over the last few years in the field of green organic synthesis. Herein, for the first time, we report that a new task-specific nitrite-based ionic liquid such as 3-(ethoxycarbonyl)-1-(5-methyl-5-(nitrosooxy)hexyl)pyridin-1-ium bis(trifluoromethanesulfonyl)imides (TS-N-IL) derived from biodegradable ethyl nicotinate indeed acted as an efficient and eco-friendly reagent for the synthesis of highly valuable nitroaromatic compounds and drugs including nitroxynil, tolcapone, niclofolan, flutamide, niclosamide and nitrazepam. The bridging of an ionic liquid with nitrite group not only increases the yield and rate of direct C[sbnd]N bond formation reaction but also allows easy product separation and recyclability of a byproduct. Nonvolatile nature, easy synthesis, merely stoichiometric need and mildness are a portion of the extra focal points of TS-N-IL while contrasted with tert-butyl nitrite an outstanding and highly-flammable reagent utilized largely in organic synthesis.
- Chaudhary, Renu,Natarajan, Palani,Rani, Neetu,Sakshi,Venugopalan, Paloth
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supporting information
(2019/12/30)
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- 2-Methyl-1,3-disulfoimidazolium polyoxometalate hybrid catalytic systems as equivalent safer alternatives to concentrated sulfuric acid in nitration of aromatic compounds
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Ionic liquid-derived polyoxometalate salts [mdsim]3[PM12O40] (where M?=?W and Mo) of two heteropolyacids H3PW12O40.nH2O and H3PMo12O40.nH2O were synthesized using 2-methyl-1,3-disulfoimidazolium chloride ([mdsim][Cl]) ionic liquid and the corresponding heteropolyacids. Three equivalents of [mdsim][Cl] were treated with the respective Keggin-structured heteropolyacids (one equivalent) in aqueous medium at room temperature to afford the water-stable ionic polyoxometalates as acidic solids. They were completely characterized using spectroscopic and other analytical techniques including thermal analysis and Hammett acidity studies. The inherent Br?nsted acidic properties of ─SO3H group of these polyoxometalate salts were studied for the nitration of aromatic compounds with 69% HNO3 at normal temperature and 80°C without use of any external concentrated sulfuric acid. These strongly acidic polyoxometalates display good recyclability and efficient reusability.
- Saikia, Susmita,Borah, Ruli
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- Iodine(III)-Catalyzed Electrophilic Nitration of Phenols via Non-Br?nsted Acidic NO2+ Generation
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The first catalytic procedure for the electrophilic nitration of phenols was developed using iodosylbenzene as an organocatalyst based on iodine(III) and aluminum nitrate as a nitro group source. This atom-economic protocol occurs under mild, non-Br?nsted acidic and open-flask reaction conditions with a broad functional-group tolerance including several heterocycles. Density functional theory (DFT) calculations at the (SMD:MeCN)Mo8-HX/(LANLo8+f,6-311+G) level indicated that the reaction proceeds through a cationic pathway that efficiently generates the NO2+ ion, which is the nitrating species under neutral conditions.
- Juárez-Ornelas, Kevin A.,Jiménez-Halla, J. Oscar C.,Kato, Terumasa,Solorio-Alvarado, César R.,Maruoka, Keiji
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supporting information
p. 1315 - 1319
(2019/03/07)
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- Silica-supported perchloric acid and potassium bisulfate as reusable green catalysts for nitration of aromatics under solvent-free microwave conditions
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Silica-supported perchloric acid and bisulfate (SiO2/HClO4 and SiO2/KHSO4) have been developed as reusable green catalysts for nitration of aromatic compounds using NaNO2 in acetonitrile medium under conventional and solvent-free microwave conditions. The reaction times under microwave irradiation are significantly shorter than conventional method even though the yields obtained in microwave-assisted reactions are comparable with those obtained under reflux conditions.
- Kumar, M. Satish,Sriram, Y. Hemanth,Venkateswarlu,Rajanna,Sudhakar, M. Sai,Venkanna, Purugula,Saiprakash
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supporting information
p. 59 - 67
(2017/12/26)
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- Preparation method of 1-nitro-2-naphthol derivative
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The invention belongs to the field of organic synthesis and in particular relates to a preparation method of a 1-nitro-2-naphthol derivative. The preparation method comprises the following steps: adding a 2-naphthol derivative shown as a formula I-1, tert-butyl nitrite and a certain amount of water into a dry reactor; adding a certain amount of an organic solvent and stirring at room temperature (commonly referring to 20 DEG C to 25 DEG C) for a period of time; after reacting, filtering an reaction solution through a glass dropper filled with silica gel; washing a filter cake with ethyl acetate; spinning and drying filtrate; carrying out silica gel column chromatography separation to obtain a target product with a formula I. A reaction formula can be shown in the description.
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Paragraph 0031-0034
(2017/08/30)
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- Preparation method of 2-nitro-1-naphthol derivative
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The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of a 2-nitro-1-naphthol derivative. The preparation method comprises the following steps: adding a 1-naphthol derivative shown in Formula II-1, tert-butyl nitrite and a certain amount of water into a dry reactor, then adding a certain amount of organic solvent, and stirring at room temperature (generally 20-25 DEG C) for some time; and after the reaction is completed, filtering the reaction solution through a silica gel loaded glass dropper, flushing the filter cake with ethyl acetate, performing spin drying on the filtrate, and performing silica gel column chromatographic separation to obtain a target product shown in Formula II. The reaction formula is shown in the specification.
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Paragraph 0030; 0031; 0032; 0033; 0034
(2017/07/19)
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- Potassium Periodate/NaNO2/KHSO4-Mediated Nitration of Aromatic Compounds and Kinetic Study of Nitration of Phenols in Aqueous Acetonitrile
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Synthesis and kinetics of potassium periodate(KIO4)/NaNO2/KHSO4)-initiated nitration of aromatic compounds have been studied in aqueous acetonitrile medium. Synthesis of nitroaromatic compounds is achieved under conventional and solvent-free microwave conditions. Reaction times in microwave-assisted reaction are comparatively less than in conventional reaction. The reaction kinetics for the nitration of phenols in aqueous bisulfate and acetonitrile medium indicated first-order dependence on [phenol], [NaNO2], and [KIO4]. An increase in [KHSO4] accelerated the rate of nitration under otherwise similar conditions. The rate of nitration increased in the solvent of high dielectric media (solvents with high dielectric constant (D)). Observed results were in accordance with Amis and Kirkwood plots [log k′ vs. (1/D) and [(D ? 1)/(2D + 1)]. These observations probably indicate the participation of anionic species and molecular or (dipolar) species in the rate-determining step. In addition, the plots of (log k′) versus volume% of organic solvent were also linear, which probably indicate the importance of both electrostatic and nonelectrostatic forces, solvent–solute interactions during nitration of phenols. Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups, but results could not be quantitatively correlated with Hammett's equation and depicted deviations from linearity. These deviations could probably be attributed to cumulative effects arising inductive, resonance, and steric effects. Leffler's plot (ΔH# vs. ΔS#) was found linear indicating the compensation (cumulative) effect of both enthalpy and entropy parameters in controlling the mechanism of nitration.
- Sriram, Y. Hemanth,Fatima, Touheeth,Rajanna,Kumar, M. Satish,Raju, R. Madhusudan
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supporting information
p. 622 - 632
(2017/06/30)
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- Prussian Blue/NaNO2 as an Efficient Reagent for the Nitration of Phenols in Aqueous Bisulfate and Acetonitrile Medium: Synthetic and Kinetic Study
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The reaction kinetics of Prussian blue (PB)/NaNO2 initiated for the nitration of phenols by in aqueous bisulfate and acetonitrile medium indicated first-order dependence on [phenol], [NaNO2], and [PB]. An increase in [KHSO4] accelerated the rate of nitration under otherwise similar conditions. The rate of nitration was faster in the solvent of higher dielectric constant (D). Observed results were in accordance with Amis and Kirkwood plots [log k′ vs. (1/D) and [(D ? 1)/(2D + 1)]. These findings together with the linearity of plots, log k′ versus (vol% of acetonitrile (ACN)) and mole fraction of (nx) ACN, probably indicate the importance of both eloctrostatic and nonelctrostatic forces, solvent–solute interactions during nitration of phenols. Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups, which are interpreted by Hammett's theory of linear free energy relationship. Hammett's reaction constant (ρ) is a fairly large negative (ρ 0) value, indicating attack of an electrophile on the aromatic ring. Furthermore, an increase in temperature decreased the reaction constant (ρ) values. This trend was useful in obtaining isokinetic temperature (β) from Exner's plot of ρ versus 1/T. Observed β value (337.8 K) is above the experimental temperature range (303–323 K), indicating that the enthalpy factors are probably more important in controlling the reaction.
- Srinivas, Pasnoori,Suresh, Muppidi,Rajanna,Krishnaiah
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supporting information
p. 209 - 218
(2017/02/05)
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- Room-Temperature, Water-Promoted, Radical-Coupling Reactions of Phenols with tert -Butyl Nitrite
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A radical-radical cross-coupling reaction of phenols with tert -butyl nitrite has been developed with the use of water as an additive. This method allows the construction of C-N bonds under an air atmosphere at room temperature, providing the ortho -nitrated phenol derivative in moderate to good yields.
- Wei, Wen-Ting,Zhu, Wen-Ming,Liang, Weida,Wu, Yi,Huang, Hui-Yan,Huang, Yi-Ling,Luo, Junfei,Liang, Hongze
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supporting information
p. 2153 - 2156
(2017/09/26)
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- Nitration of arenes by 1-sulfopyridinium nitrate as an ionic liquid and reagent by in situ generation of NO2
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1-Sulfopyridinium nitrate was synthesized as a potent nitrating agent for the nitration of arenes without the need for any co-catalysts. A variety of nitro compounds were synthesized and fully characterized by IR, 1H NMR, 13C NMR, thermal gravimetric analysis (TGA), differential thermal gravimetry (DTG), CHN analysis and mass spectroscopy. Mechanistically, in situ generated nitrogen dioxide as a radical from the reagent is proposed for the presented nitration protocol.
- Moosavi-Zare, Ahmad Reza,Zolfigol, Mohammad Ali,Zarei, Mahmoud,Noroozizadeh, Ehsan,Beyzavi, M. Hassan
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p. 89572 - 89577
(2016/10/03)
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- Tertiary Butyl Nitrite Triggered Nitration of Phenols: Solvent- and Structure-Dependent Kinetic Study
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Nitration of phenols with tertiary butyl nitrite (TBN) obeyed second-order kinetics with a first-order dependence on [TBN] and [phenol] under acid-free conditions. Reaction rates were significantly altered by a change in the dielectric constant and other physical properties of solvent. The rate of nitration increased with an increase in temperature (303-323 K) in different solvent media (acetonitrile, dichloroethane, CCl4, dimethyl formamide (DMF), and toluene). The rates of nitration (log k) could not fit into either Amis or Kirkwood plots [log k' vs. (1/D) or [(D - 1)/(2D + 1)], but the trends were better explained by the basic form of multivariate linear solvent energy relationships (MLSER) suggested by the Koppel and Palm approach on the one hand and the Kamlet and Taft approach on the other hand. These observations probably substantiate that cumulative contributions of basic solvent parameters (equilibrium as well as frictional solvent effects) and solvent-solute interactions for solvation of transition state during nitration of phenols. Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups. Accordingly, the reactivity of structurally different phenols was found to follow the following sequence: p-OH > p-MeO > p-Me > H > m-Me > p-Cl > p-Br > m-Cl > p-NO2 > m-OH. The results are interpreted by Hammett's theory of linear free energy relationship. The reaction constant (Hammett's ρ) is a measure of the sensitivity of the reaction toward the electronic effects of the substituent. The rho (ρ) values obtained from the present experiments are fairly large negative values (ρ CH3) versus σ? or, Es or combined Taft's relationship. However, Charton's MLRA of the log k with polar, resonance, steric, hydrophobicity, and molar refractivity showing a very good linear relationship was obtained. It is of interest to note that when log kexp values are correlated with log kcal a perfect linearity is obtained with a correlation coefficient of unity, indicating the consonance between experimental and calculated rate constants in the present work.
- Kumar, M. Satish,Rajanna,Venkateswarlu,Rao, K. Lakshman
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supporting information
p. 171 - 196
(2016/04/09)
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- N-methyl-2-chloropyridinium iodide/NaNO2/Wet SiO2: Neutral reagent system for the nitration of activated aromatic compounds under very mild conditions
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Mononitration of activated aromatic compounds using N-methyl-2-chloro-pyridinium iodide (Mukaiyama reagent)/NaNO2/wet SiO2 reagent system under neutral, very mild and environmentally safer reaction condition has been developed. Various structurally diverse aromatic rings are subjected in this condition and the corresponding nitro-aromatic compounds are prepared in moderately high yields.
- Azadi, Roya,Nazari-Far, Zahra
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p. 136 - 140
(2015/06/22)
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- Ultrasonically Assisted Rate Enhancements in Trichloroisocyanuric Acid/DMF/NaNO2 Triggered Nitration of Aromatic Compounds and Decarboxylative Nitration of α,β-Unsaturated Acids
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An efficient and safe method for nitration of aromatic compounds and decarboxylative nitration of α,β-unsaturated acids was developed using trichloroisocyanuric acid (TCICA)/dimethylformamide (DMF) in the presence of NaNO2. The reaction times of conventional protocol reduced from 8-10 h to 1.0-1.5 h (60-90 min) under sonication, even though the yields are comparable under both the conditions.
- Kumar, Mukka Satish,Rajanna, Kamatala Chinna,Venkateswarlu, Marri,Venkanna, Purugula,Saiprakash, Pondichery Kuppuswamy
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p. 2251 - 2258
(2015/09/22)
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- Improved Protocol for Mononitration of Phenols with Bismuth(III) and Iron(III) Nitrates
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A simple and efficient multigram procedure was developed for the selective mononitration of various activated phenols. The reaction proceeded smoothly with 0.5 equivalents of Bi(NO3)3 · 5H2O or Fe(NO3)3 · 9H2O in acetone at ambient temperature or at reflux. The desired products were isolated in 62-93% total yield and essentially no overnitrated compounds were detected.
- W?sińska, Ma?gorzata,Korczewska, Anna,Giurg, Miros?aw,Skarzewski, Jacek
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supporting information
p. 143 - 150
(2015/10/20)
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- ONE POT PROCESS FOR THE CONVERSION OF AROYL CHLORIDES TO ACYL THIOUREAS
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The present invention disclose an improved one pot process for synthesis of acyl thioureas of formula (I), with yield greater than 80%, from aroyl chlorides of formula (I) wherein, R' is an aryl or a heteroarylene group substituted with one or more groups selected from hydrogen, alkyl, alkylene, alkynyl, alkoxy, alkenyloxy, halo, hydroxyl, nitro, amino, carboxyl, ester, halogenated hydrocarbon or an aryl or heteroaryl; R" and R"' are selected independently from hydrogen, alkyl, alkylene, alkynyl, alkoxy, alkenyloxy, halo, hydroxyl, nitro, amino or halogenated hydrocarbon.
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Page/Page column 8; 13
(2014/06/24)
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- Vanadium pentoxide as a catalyst for regioselective nitration of organic compounds under conventional and nonconventional conditions
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Vanadium pentoxide is used as an efficient catalyst for regioselective nitration of aromatic compounds under conventional and nonconventional conditions such as ultrasonically assisted (USAR) and microwave-assisted reactions (MWAR). The reactions underwent smoothly and afforded good yields of products with high regioselectivity. Observed longer reaction times (about 8 h) in V2O5 catalyzed reactions reduced to (0.5/30 min) under sonication and (90 s) in the case of MWAR. When ortho position is blocked, para derivatives are obtained as end products while ortho nitro products are obtained when para position is blocked.
- Venkatesham,Reddy, K. Rajendar,Rajanna,Veerasomaiah
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p. 921 - 926
(2014/04/03)
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- Oxalylchloride/DMF as an efficient reagent for nitration of aromatic compounds and nitro decarboxylation of cinnamic acids in presence of KNO 3 or NaNO2 under conventional and nonconventional conditions
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Nitration of aromatic compounds and cinnamic acids with oxalylchloride/DMF afforded the corresponding nitro derivatives in the presence of KNO3 or NaNO2 under conventional and nonconventional (ultrasonic and microwave) conditions. The present methodology offers several benefits such as excellent yields, simple work-up procedure, and short reaction times. The yields obtained under present methodology are comparable with those obtained from (POCl3/DMF/KNO3 or NaNO2) and (SOCl 2/DMF/KNO3 or NaNO2) systems followed by shorter reaction times. The reaction times of sonication and microwave conditions are very shorter than those of the conventional conditions.
- Kumar, M. Satish,Reddy, K. Rajendar,Rajanna,Venkanna,Krishnaiah
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p. 977 - 983
(2013/06/05)
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- Ultrasonic and microwave-assisted synthesis of β-nitro styrenes and nitro phenols with tertiary butyl nitrite under acid-free conditions
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Tertiary butyl nitrite (TBN) is an acid-free and safe nitrating agent that provides preferentially β-nitrostyrenes with cinnamic acids and corresponding nitro derivatives with phenols in good yields under classical conditions. However, ultrasonic and microwave-assisted reactions reduced the reaction times substantially and enhanced the yields from good to excellent. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Kumar, M. Satish,Rajanna,Reddy, K. Rajendar,Venkateswarlu,Venkanna
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supporting information
p. 2672 - 2677
(2013/07/26)
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- Design of ionic liquid 3-methyl-1-sulfonic acid imidazolium nitrate as reagent for the nitration of aromatic compounds by in situ generation of NO 2 in acidic media
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3-Methyl-1-sulfonic acid imidazolium nitrate ([Msim]NO3) as a new Bronsted acidic ionic liquid and nitrating agent was prepared and used for the efficient nitration of aromatic compounds (even aniline derivatives). The dramatic effect of this reagent by in situ generation of nitrogen dioxide as a radical on aromatic compounds to give nitroarenes has been studied.
- Zolfigol, Mohammad A.,Khazaei, Ardeshir,Moosavi-Zare, Ahmad R.,Zare, Abdolkarim,Kruger, Hendrik G.,Asgari, Zhila,Khakyzadeh, Vahid,Kazem-Rostami, Masoud
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experimental part
p. 3640 - 3645
(2012/06/15)
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- Heteropolyacids as an efficient and reusable catalytic system for the regiospecific nitration of phenols with metal nitrates
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Highly regiospecific mononitration of phenols and substituted phenols is accomplished employing a metal nitrate and a catalytic amount of heteropolyacid in acetonitrile. An xclusive ortho-selectivity was observed with excellent yields. A variety of metal nitrates were used to obtain o-nitrophenols exclusively in good to excellent yields. The use of heteropolyacid is key for the selectivity observed.
- Baghernejad, Bita,Heravi, Majid M.,Oskooie, Hossein A.,Bamoharram, Fatemeh F.
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experimental part
p. 145 - 152
(2012/04/18)
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- Nitration of phenolic compounds by antimony nitrate
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Antimony nitrate is new compound to be an efficient nitration reagent in the nitration of phenolic compounds with high yields. This producerworks efficiently onmost of the examples, as a grinding nitration reaction, proceed very fast (～1 min) and thermogenic. Copyright Taylor & Francis Group, LLC.
- Jirandehi, Hassan Fathinejad,Mirzaeian, Marjan
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experimental part
p. 284 - 286
(2011/07/08)
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- Cellulose-supported Ni(NO3)2.6H2O/2,4,6- trichloro-1,3,5-triazine (TCT) as a mild, selective, and biodegradable system for nitration of phenols
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Nitration of certain phenols and naphthols in the presence of biodegradable cellulose-supported Ni(NO3)2.6H2O/2,4,6- trichloro-1,3,5-triazine was carried out in acetonitrile at room temperature. Ortho nitrated phenols were obtained regioselectively within a short reaction time with good yields. The reaction condition was mild, and the employed cellulose could be recovered several times for further use. Copyright
- Nemati, Firouzeh,Kiani, Hossein,Hayeniaz, Yaser Saeidi
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experimental part
p. 2985 - 2992
(2011/08/22)
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- Design and mechanism of iron catalyzed carbon-carbon bond cleavage and N-oxidation processes of hazardous dyes for selective synthesis of nitroarenes and aminoarenecarboxylic acids
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An efficient iron catalyzed oxidative degradation process has been developed for selective conversion of environmentally hazardous azo and indigo dyes into nitroarenes and aminoarenecarboxylic acids (anthranilic acids) respectively, using polymer supported tribromide reagent at an alkaline pH. The in situ generated and the isolated (defined) chloro-iron(II)-terpyridine- pyridine carboxylate [Fe(tpy)(pic)Cl] catalyst system has been developed and its catalytic function was invented for the degradation process. The different nitrogenous and oxygen ligands have been screened out for the development of best catalyst system, and eventually we explored pyridine 2-carboxylic acid and terpyridine ligands together, were found to be the best. Notably, the in situ generated and the defined catalyst systems have found to be more effective with similar catalytic activities towards the oxidative degradation of both the dyes. As a result, the whole oxidative degradation process has been carried out with Fe(tpy)(pic)Cl catalyst system and the general process utilizes the efficient catalytic method for the selective oxidation of -NN- and -CC- bonds of azo and indigo dyes respectively. The detailed catalysis, mechanistic and kinetic investigations have been made for the reactions. Interestingly, both the dyes proceed with a common oxidative degradation mechanism under identical kinetic patters. A common oxidative degradation mechanism which operates in both the dyes has been proposed and an identical related kinetic model was designed. The main interesting aspect of the present work pertains to the catalytic conversion of environmentally hazardous compounds into useful molecules; such are anthranilic acids and nitrobenzenes. Other special aspect related to catalytic activity of iron and potentially, iron catalyst accelerates the reaction rates with 15-20-fold faster. The reactions were also carried out with different polymer supported trihalide and inter-halide reagents. Notably, trichloride and inter-halide regents were found to be more reactive. The catalytic method developed for the degradation process was found to be very efficient and the involvement of cost-effective reagents makes the reaction simple, and can be conveniently scalable to industrial/technological operations with suitable modifications.
- Jagadeesh, Rajenahally V.,Kiran,Bhagat, Pundlik R.,Kumar, S. Senthil,Nithya,Khan, F. Nawaz,Sivakumar
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experimental part
p. 92 - 104
(2011/05/05)
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- Zn(NO3)2·6H2O/2,4,6-trichloro-1,3,5-triazine (TCT) a mild and selective system for nitration of phenols
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Certain phenols and naphthols were nitrated regioselectively with Zn(NO3)2·6H2O/TCT in acetonitrile as solvent at room temperature and short reaction time in good yields. The reaction condition was mild. TCT is a cheap and commercially available reagent. It performed as an acid catalyst in this transformation.
- Nemati, Firouzeh,Kiani, Hossein
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experimental part
p. 403 - 406
(2010/12/24)
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- Fast and efficient nitration of salicylic acid and some other aromatic compounds over H3PO4/TiO2-ZrO2 using nitric acid
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TiO2-ZrO2 (1/1)-surf with Ti and Zr molar ratio of 1/1 was prepared with surfactant through a sol-gel method. The optimum experimental condition was investigated for nitration of salicylic acid. Then, a number of nitration reactions were carried out with a variety of aromatic compounds in the optimum condition. The 25 wt% H3PO4/TiO2-ZrO2 (1/1)-surf catalyst showed good selectivity and yield in a short time for the nitration of salicylic acid and some other aromatic compounds.
- Kalbasi, Roozbeh Javad,Massah, Ahmad Reza,Zamani, Farzad,Hamid, Javaherian Naghash
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experimental part
p. 397 - 403
(2010/10/20)
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- KHSO4 as an efficient catalytic system for the regiospecific nitration of phenols with metal nitrates
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Highly regiospecific mononitration of phenol and substituted phenols was accomplished employing a metal nitrate and a catalytic amount of KHSO4 in acetonitrile. An exclusive ortho-selectivity was observed with excellent yields. A variety of metal nitrates were used to obtain o-nitrophenols exclusively in good to excellent yields. The use of KHSO4 is key for the selectivity observed.
- Baghernejad, Bita,Oskooie, Hossein A.,Heravi, Majid M.,Beheshtiha, Yahia Sh.
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experimental part
p. 393 - 396
(2010/10/02)
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- Zeolite H-Y-supported copper(II) nitrate: A simple and effective solid-supported reagent for nitration of phenols and their derivatives
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Highly regiospecific mononitration of phenols and substituted phenols is accomplished by employing copper(II) nitrate supported on a catalytic amount of zeolite H-Y in a solid state. Copyright Taylor & Francis Group, LLC.
- Lalitha,Sivakumar
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p. 1745 - 1752
(2008/09/20)
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- Facile, regioselective and green synthesis of ortho-nitrophenoles using NaNO2, KHSO4
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Certain phenols and naphtols were nitrated regioselectively with NaNO 2 in the presence of KHSO4 at 50 °C in high yields.
- Heravi, Majid M.,Oskooie, Hossein A.,Baghernejad, Bita
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p. 767 - 770
(2008/02/13)
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- Mild and selective nitration of phenols by zeofen
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Certain phenols and naphthols were nitrated regioselectively with zeofen in dichloromethane as solvent at room temperature and in a short reaction time to give good yields. Copyright Taylor & Francis Group, LLC.
- Bigdeli, Mohammad A.,Heravi, Majid M.,Nemati, Firouzeh
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p. 2225 - 2230
(2008/02/07)
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- Nitration of some aromatic compounds by sodium nitrate in the presence of benzyltriphenylphosphonium peroxodisulfate
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A simple, mild, and regioselective method for the nitration of some aromatic compounds using sodium nitrate in the presence of benzyltriphenylphosphonium peroxodisulfate in acetonitrile as solvent is reported. Mild reaction conditions and good to excellent yields of the products are the noteworthy advantages of the method. Copyright Taylor & Francis Group, LLC.
- Tajik, Hassan,Zolfigol, Mohammad Ali,Albadi, Jalal,Eslami, Ramin
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p. 2771 - 2776
(2008/02/12)
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- Highly efficient nitration of phenolic compounds by zirconyl nitrate
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Zirconyl nitrate was found to be an excellent reagent in the nitration of phenol and substituted phenols to give nitrated phenols. This procedure works efficiently on most of the examples at room temperature yielding nitro derivatives in fair to good yields with high regioselectivity.
- Selvam, J. Jon Paul,Suresh,Rajesh,Reddy, S. Ravinder,Venkateswarlu
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p. 2507 - 2509
(2007/10/03)
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- Supported bismuth(III) nitrate on silica sulfuric acid as useful reagent for nitration of aromatic compounds under solvent-free conditions
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A number of aromatic compounds were nitrated to the corresponding nitroaromatic derivatives with the use of supported bismuth(III) nitrate on silica sulfuric acid under solvent-free conditions.
- Hajipour,Zarei,Ruoho
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p. 1493 - 1495
(2007/10/03)
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- Nitrophenol derivatives oxidized by cerium(IV) ammonium nitrate (CAN) and their cytotoxicity
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Oxidation of a series of phenols with cerium(IV) ammonium nitrate (CAN) in acetonitrile undermild conditions yields the mixture of corresponding nitrophenols. In the cases of methylphenols and hydroxy-carboxylic acids, the steric effect may reduce the nitration reaction. Compounds 3 a and 4b showed selective activities to Hep 3B and Hep G2 cancer cell lines, respectively. Compound 2c showed selective activities to Hep G2 and MDA-MB-231 cancer cell lines. Further more, com pound 10b showed selective activities to Hep G2, Hep 3B, MCF-7 and MDA-MB-231 cancer cell lines.
- Pan, Wen-Bin,Wei, Li-Mei,Wei, Li-Lan,Wu, Chin-Chung,Chang, Fang-Rong,Wu, Yang-Chang
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p. 581 - 588
(2007/10/03)
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- Solid-state regioselective nitration of activated hydroxyaromatics and hydroxycoumarins with cerium (IV) ammonium nitrate
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Predominant ortho-selective mononitration of low-melting and liquid phenols and hydroxycoumarins in moderate to high yields has been accomplished upon grinding with solid cerium (IV) ammonium nitrate (CAN). Microwave-assisted expeditious CAN-mediated nitration of relatively high melting phenols and hydroxycoumarins with high efficiency and selectively under solvent-free conditions has been also developed to address the problems of sluggishness and low yield for these reluctant substrates.
- Ganguly, Nemai C.,Dutta, Sanjoy,Datta, Mrityunjoy,De, Prithwiraj
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p. 733 - 735
(2007/10/03)
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- Investigations into the nitric acid mediated dehalonitration of halophenols
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A reaction of nitric acid with bromophenols and iodophenols results in substitution of the halogen with a nitro group. The study indicates moderate reactivity for bromophenols and iodophenols, while chlorophenols were found to be sluggish in this reaction.
- Adimurthy, Subbarayappa,Vaghela, Sanjay S.,Vyas, Punita V.,Bhatt, Anjani K.,Ramachandraiah, Gadde,Bedekar, Ashutosh V.
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p. 6393 - 6395
(2007/10/03)
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- On the role of nitrogen monoxide (nitric oxide) in the nitration of a tyrosine derivative and model compounds
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The nitration of tyrosine derivatives with nitrogen monoxide (nitric oxide) occurs only in the presence of dioxygen, and the hypothesized mechanism involves nitrogen dioxide (.NO2). For better understanding of the reaction mechanism, the nitration of model compounds - such as 1- and 2-naphthols and their corresponding 2- and 1-nitroso derivatives with nitrogen monoxide in the presence and in the absence of dioxygen was studied. The results described here show that tyrosine and naphthols do not undergo nitrosation when they react with .NO, and so nitrosation of tyrosine in biological systems is highly unlikely. In addition, the oxidation of nitrosonaphthols ? isonitrosonaphthols by nitric oxide and its derivatives to the corresponding nitro derivatives does not involve the oxoammonium ion, as reported previously. The mechanistic proposals are supported mainly by ESR investigation and electrochemical data. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Giorgini, Elisabetta,Petrucci, Rita,Astolfi, Paola,Mason, Ronald P.,Greci, Lucedio
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p. 4011 - 4017
(2007/10/03)
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- Chiral Metallosalen Complexes: Structures and Catalyst Tuning for Asymmetric Epoxidation and Cyclopropanation
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Optically active metallosalens are currently one of the most widely used catalysts for asymmetric synthesis. This is mainly due to the following reasons: various salen [N,N′-ethylenebis(salicyldeneaminato)] ligands form complexes with many metal ions and the resulting metallosalens adopt versatile structures, therefore, metallosalens show a variety of catalytic performances. Thus, selection of a metal ion serving the aimed reaction and regulation of ligand conformation to be suitable for the reaction are indispensable for achieving metallosalen-catalyzed asymmetric reactions. Recently, several factors controlling ligand-conformation in metallosalens have been clarified. This article provides selected examples of tuning the structures of metallosalens in compliance to the aimed reaction, by taking asymmetric oxene or carbene transfer reaction as the instance.
- Katsuki, Tsutomu
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p. 131 - 147
(2007/10/03)
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- Regioselectivity of the nitration of phenol by acetyl nitrate adsorbed on silica gel
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The reaction of phenol with acetyl nitrate in chloroform gives nitrophenol with an ortho/para ratio of 1.8. This ratio increase to 13.3 when the reaction was carried out with acetyl nitrate pre-adsorbed on dry silica gel. Silica may be acting as a template to bring phenol close to acetyl nitrate by hydrogen bonds forming a ternary complex, which undergoes a six- center rearrangement to o-nitrophenol. The formation of this ternary complex is evaluated by ab initio molecular orbital calculation.
- Augusto,Rodrigues,De Oliveira Filho, Antonio Pedro,Moran, Paulo J. S.,Custodio, Rogerio
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p. 6733 - 6738
(2007/10/03)
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- Hydroxylation of Nitroarenes with Alkyl Hydroperoxide Anions via Vicarious Nucleophilic Substitution of Hydrogen
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Rhone-Poulenc Polska Ltd., ul. Grzybowska 80/82, 00-844 Warszawa, Poland Garbo- and heterocyclic nitroarenes react with anions of tert-butyl and cumyl hydroperoxides in the presence of strong bases to form substituted o- and p-nitrophenols. The reaction usually proceeds in high yields and is of practical value as a method of synthesis and manufacturing of nitrophenols. Orientation of the hydroxylation can be controlled to a substantial extent by selection of the proper conditions. Basic mechanistic features of this process were clarified.
- Makosza, Mieczyslaw,Sienkiewicz, Krzysztof
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p. 4199 - 4208
(2007/10/03)
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- Reactions of Aromatic Compounds with Nucleophilic Reagents in Liquid Ammonia. XV. Hydroxylation of Aromatic Nitro Compounds with Potassium Peroxide
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Reactions of 1-nitro- and 1,8-dinitronaphthalenes with K2O2 in liquid ammonia at -33°C yield, respectively, mono- and dinitronaphthols. The ratio of the products with 1,2- and 1,4-arrangement of the nitro and hydroxy groups is 1:(1.0-1.3). Lowering the temperature to -60°C results in almost exclusive formation of the 1,4-isomers. Hydroxylation of 1,5-dinitronaphthalene by the action of K2O2 occurs both at the ortho and para positions with respect to the nitro group only in the presence of oxygen. Reactions of 4-chloronitrobenzene and 1,4-dinitrobenzene with K2O2 afford 4-nitrophenol in high yield, whereas nitrobenzene, 4,4′-dinitrobiphenyl, and 1,3-dinitrobenzene do not undergo hydroxylation by the action of K2O2 in liquid ammonia both under argon and in the presence of oxygen.
- Malykhin,Shteingarts
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p. 636 - 643
(2007/10/03)
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- Inhibitory effects of a novel water-soluble cyclophane on the hydrolysis reactions of aromatic esters
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The effects of a novel water-soluble cyclophane (TGCP 44,1) on the hydrolysis reactions of aromatic esters have been studied. TGCP 44 (1) was found to inhibit the hydrolysis of three aromatic esters, p-nitrophenyl chloroacetate (2), glycine p-nitrophenyl ester hydrobromide (3) and 1-nitro-2-naphthyl chloroacetate (4). The hydrolysis rates of the aromatic esters were retarded by 3.0-7.65 fold relative to the spontaneous rates.
- Miyake,Fujimoto
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p. 1938 - 1939
(2007/10/02)
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- Catalytic cyclophanes VII. Esterase activity of a bisimidazolyl-cyclophane
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We report the synthesis of the novel tetraoxaparacyclophane 3 with two imidazole residues attached to the benzene rings of one of the two diphenylmethane spacers that shape the macrocyclic cavity.Four acetic acid residues diverge from the central carbon atoms of the two spacer units and ensure solubility of 3 in water and binary aqueous solvent mixtures.Cyclophane 3 forms stoichiometric inclusion complexes with nitronaphthyl acetates in aqueous phosphate buffers (pH8) and catalyzes the hydrolysis of bound substrates under turnover conditions.
- Chao, Ito,Diederich, Francois
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p. 335 - 338
(2007/10/02)
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- Process for the hydroxylation of electrophilic aromatic compounds
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The invention relates to a generally applicable process for the hydroxylation of electrophilic aromatic compounds, according to which the electrophilic aromatic compounds are reacted with organic hydroperoxides in the presence of bases.
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- Hydroxylation of Nitroarenes with Alkyl Hydroperoxide Anions via Vicarious Nucleophilic Substitution of Hydrogen
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tert-Butyl and cumyl hydroperoxides in strongly basic media react with a variety of nitroarenes to produce o- and/or p-nitrophenols.The reaction proceeds via an addition-base-induced β-elimination pathway analogous to that of vicarious nucleophilic substitution.
- Makosza, Mieczyslaw,Sienkiewicz, Krzysztof
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p. 4979 - 4981
(2007/10/02)
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- Process for producing azo pigment
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A process for producing an azo pigment, which comprises coupling an aromatic diazonium compound with 3-hydroxy-2-naphthoic acid and at least one binaphthol and optionally, laking the resulting pigment.
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