23132-52-7Relevant academic research and scientific papers
Regioselective nitration of aromatics with nanomagnetic solid superacid SO42-/ZrO2-MxOy-Fe 3O4 and its theoretical studies
Wang, Peng Cheng,Zhu, Jie,Liu, Xiang,Lu, Ting Ting,Lu, Ming
, p. 310 - 317 (2013/08/23)
A series of micro- and nanosulfated zirconia loaded on Fe3O 4 or other metal oxides (SO42-/ZrO 2-MxOy-Fe3O4 (M=Ti 4+, V5+, and Zn2+)) was prepared, characterized, and used in nitration. The nitration conditions with these solid superacids were then optimized to achieve the best regioselectivity and improve the performances of the catalysts as well. In the experimental results, SZTF (SO42-/ZrO2-TiO2-Fe 3O4) showed excellent catalytic activity and it increased the surface area of SO42-/ZrO2 by up to 15 %. The increase not only facilitated the generation of NO2+, but also provided more opportunities for metal ions to interact with aromatic compounds. With chlorobenzene as substrate, theoretical research on its geometric parameters, electron clouds, and electron spin density was used to investigate the interaction between transition metals and chlorobenzene.
Rare earth metal triflates catalyzed electrophilic nitration using N 2O5
Ma, Xiao Ming,Li, Bin Dong,Lu, Ming,Lv, Chun Xu
experimental part, p. 73 - 76 (2012/03/26)
A mild, efficient and eco-friendly process for the electrophilic nitration is described using N2O5 as a green nitrating agent in the presence of rare earth metal triflates [RE(OTf)3] under mild conditions.
Reusable and efficient polystryrene-supported acidic ionic liquid catalyst for mononitration of aromatic compounds
Li, Li Xia,Ling, Qi Long,Liu, Zu Liang,Xing, Xiao Dong,Zhu, Xiao Qin,Meng, Xiao
, p. 3373 - 3377 (2013/01/15)
A series of polystyrene-supported 1-(propyl-3-sulfonate)-3-methyl- imidazolium hydrosulfate acidic ionic liquid (PS-[SO3H-PMIM][HSO 4]) catalysts were prepared and tested for mononitration of simple aromatics compounds with nitric acid. It was found that the reactivity of the catalysts increased with increasing [SO3HPMIM][ HSO4] content. The para-selectivity was not only related to the [SO 3H-PMIM][HSO4] content but also the substituent groups in aromatics. A reaction mechanism of nitration over this new catalyst was proposed. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.
Regioselectivity nitration of aromatics with N2O5 in PEG-based dicationic ionic liquid
Wang, Peng-Cheng,Lu, Ming
supporting information; experimental part, p. 1452 - 1455 (2011/05/16)
Regioselective mononitration of simple aromatic compounds has been investigated with N2O5 as nitrating agent and a new PEG200-based dicationic acidic ionic liquid (PEG200-DAIL) as catalyst. The results of experiments show that this nitration system can significantly improve the para-selectivity of alkyl-benzenes and the ortho-selectivity of halogenated-benzenes. The PEG200-DAIL exhibits recyclable temperature-dependant phase behavior in CCl4 solvent, and it can be recycled without apparent loss of catalytic activity, and only 5% loss of weight is observed after six times recycling.
Electrophilic nitration of aromatics in ionic liquid solvents
Laali,Gettwert
, p. 35 - 40 (2007/10/03)
Potential utility of a series of 1-ethyl-3-methylimidazolium salts [emim][X] with X = OTf-, CF3COO-, and NO3- as well as [HNEtPri2][CF3COO] (protonated Huenig's base) ionic liquids were explored as solvent for electrophilic nitration of aromatics using a variety of nitrating systems, namely NH4NO3/TFAA, isoamyl nitrate/BF3·Et2O, isoamyl nitrate/TfOH, Cu(NO3)/TFAA, and AgNO3/Tf2O. Among these, NH4NO3/TFAA (with [emim][CF3COO], [emim][NO3]) and isoamyl nitrate/BF3·Et2O, isoamyl nitrate/TfOH (with [emim][OTf]) provided the best overall systems both in terms of nitration efficiency and recycling/reuse of the ionic liquids. For [NO2][BF4] nitration, the commonly used ionic liquids [emim][AlCl4] and [emim][Al2Cl7] are unsuitable, as counterion exchange and arene nitration compete. [Emim][BF4] is ring nitrated with [NO2][BF4] producing [NO2-emim][BF4] salt, which is of limited utility due to its increased viscosity. Nitration in ionic liquids is surveyed using a host of aromatic substrates with varied reactivities. The preparative scope of the ionic liquids was also extended. Counterion dependency of the NMR spectra of the [emim][X] liquids can be used to gauge counterion exchange (metathesis) during nitration. Ionic liquid nitration is a useful alternative to classical nitration routes due to easier product isolation and recovery of the ionic liquid solvent, and because it avoids problems associated with neutralization of large quantities of strong acid.
Vanadium(v) oxytrinitrate, VO(NO3)3. A powerful reagent for the nitration of aromatic compounds at room temperature under non-acidic conditions
Dove, Michael F. A.,Manz, Berthold,Montgomery, John,Pattenden, Gerald,Wood, Simon A.
, p. 1589 - 1590 (2007/10/03)
Vanadium(v) oxytrinitrate is an easy to handle reagent which can be used to nitrate a range of substituted aromatic compounds in dichloromethane at room temperature, leading to >99% yields of nitration products in most cases.
A novel method for the nitration of simple aromatic compounds
Smith, Keith,Musson, Adam,DeBoos, Gareth A.
, p. 8448 - 8454 (2007/10/03)
Simple aromatic compounds such as benzene, alkylbenzenes, halogenobenzenes, and some disubstituted benzenes are nitrated in excellent yields with high regioselectivity under mild conditions using zeolite β as a catalyst and a stoichiometric quantity of nitric acid and acetic anhydride. The zeolite can be recycled, and the only byproduct is acetic acid, which can be separated easily from the nitration product by distillation; the process is inexpensive and represents an attractive method for the clean synthesis of a range of nitroaromatic compounds. For example, nitration of toluene gives a quantitative yield of mononitrotoluenes, of which 79% is 4-nitrotoluene; fluorobenzene gives a quantitative yield of mononitro compounds, of which 94% is 4-nitrofluorobenzene; and 2-fluorotoluene gives a 96% yield of mononitro products, of which 90% is the 5-nitro isomer and 10% is the 4-nitro isomer.
Synthesis of functionalized carbamates through a palladium-catalyzed reductive carbonylation of substituted nitrobenzenes
Wchman, Petra,Borst, Leo,Kamer, Paul C. J.,Van Leeuwen, Piet W. N. M.
, p. 13 - 21 (2007/10/03)
The palladium-catalyzed reductive carbonylation of ortho and para-substituted nitrobenzenes has proven to be an attractive route for the synthesis of functionalized carbamates. For the Pd(1,10-phenanthroline)2(triilate}2 catalyst system, the scope of the reaction has been studied. Substrates with electron-donating substituents at the para position were found to decrease the catalytic activity, most probably as a result of their relatively low oxidizing capacity. The selectivity towards the desired carbamate, however, was increased for these substrates. Under the influence of electron-withdrawing substituents the azoxybenzene and azobenzene derivatives became important side products. Introduction of large steric hindrance at the ortho position of the nitro substrates gave rise to an interesting side reaction, viz. methoxylation of the aromatic ring. The methoxylation reaction appeared to occur on an intermediate species in the catalytic cycle. Several functionalities have shown to be resistant to the reaction conditions required for the conversion of the nitro group. Especially with 4-nitrobenzoic acid, an extremely high activity and selectivity was found, thus yielding a very convenient synthesis for N-protected amines containing carboxylic acid functions. VCH Verlagsgesellschaft mbH.
Iron(III)-catalysed nitration of non-activated and moderately activated arenes with nitrogen dioxide-molecular oxygen under neutral conditions
Suzuki, Hitomi,Yonezawa, Shuji,Nonoyama, Nobuaki,Mori, Tadashi
, p. 2385 - 2389 (2007/10/03)
In the presence of molecular oxygen and a catalytic amount of tris(pentane-2,4-dionato)iron(III), non-activated and moderately activated arenes, which include alkylbenzenes, halogenobenzenes, phenolic ethers, naphthalene and derivatives, can be nitrated with nitrogen dioxide at ice-bath temperature or below to give the corresponding nitro derivatives in fair to good yields. An electron-transfer mechanism has been proposed, where an activated NO2-FeIII complex plays a key role in the cyclic process for converting arenes into nitroarenes.
Hydrocarbons and chloroaromatics from anilines and n-butyl nitrite
Giumanini, Angelo G.,Verardo, Giancarlo,Gorassini, Fausto,Strazzolini, Paolo
, p. 311 - 316 (2007/10/02)
A single reagent, i.e. n-butyl nitrite, can be used to oxidize an aromatic amine, or the corresponding N-methylene derivative, to a diazo compound followed by its subsequent reduction to hydrocarbon in a single batch.Alternatively, a chloro derivative can be obtained if carbon tetrachloride is used as the solvent.The reactions appear to be general and complete product identification was accomplished.
