528-29-0Relevant articles and documents
Nitration of deactivated aromatic compounds via mechanochemical reaction
Wu, Jian-Wei,Zhang, Pu,Guo, Zhi-Xin
supporting information, (2021/05/05)
A variety of deactivated arenes were nitrated to their corresponding nitro derivatives in excellent yields under high-speed ball milling condition using Fe(NO3)3·9H2O/P2O5 as nitrating reagent. A radical involved mechanism was proposed for this facial, eco-friendly, safe, and effective nitration reaction.
Mass production method of phenylenediamine from high purity dinitrobenzene
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Paragraph 0028-0032; 0035-0038, (2020/04/09)
The present invention relates to a method for producing phenylenediamine using the high purity of dinitrobenzene, which may manufacture meta-phenylenediamine having a high yield since dinitrobenzene can be produced without aniline as a byproduct. Meta-phenylenediamine is manufactured based on a cost effective raw material by using a process as above without a separate purification process, thereby drastically reducing a manufacturing cost compared to an existing process. Therefore, stable reaction can be induced in a synthetic process, thereby easily and safely manufacturing meta-phenylenediamine.COPYRIGHT KIPO 2020
Transition-State Interactions in a Promiscuous Enzyme: Sulfate and Phosphate Monoester Hydrolysis by Pseudomonas aeruginosa Arylsulfatase
Van Loo, Bert,Berry, Ryan,Boonyuen, Usa,Mohamed, Mark F.,Golicnik, Marko,Hengge, AlVan C.,Hollfelder, Florian
, p. 1363 - 1378 (2019/03/11)
Pseudomonas aeruginosa arylsulfatase (PAS) hydrolyzes sulfate and, promiscuously, phosphate monoesters. Enzyme-catalyzed sulfate transfer is crucial to a wide variety of biological processes, but detailed studies of the mechanistic contributions to its catalysis are lacking. We present linear free energy relationships (LFERs) and kinetic isotope effects (KIEs) of PAS and analyses of active site mutants that suggest a key role for leaving group (LG) stabilization. In LFERs PASWT has a much less negative Br?nsted coefficient (βleaving groupobs-Enz = 0.33) than the uncatalyzed reaction (βleaving groupobs = 1.81). This situation is diminished when cationic active site groups are exchanged for alanine. The considerable degree of bond breaking during the transition state (TS) is evidenced by an 18Obridge KIE of 1.0088. LFER and KIE data for several active site mutants point to leaving group stabilization by active site K375, in cooperation with H211. 15N KIEs and the increased sensitivity to leaving group ability of the sulfatase activity in neat D2O (βleaving groupH-D = +0.06) suggest that the mechanism for S-Obridge bond fission shifts, with decreasing leaving group ability, from charge compensation via Lewis acid interactions toward direct proton donation. 18Ononbridge KIEs indicate that the TS for PAS-catalyzed sulfate monoester hydrolysis has a significantly more associative character compared to the uncatalyzed reaction, while PAS-catalyzed phosphate monoester hydrolysis does not show this shift. This difference in enzyme-catalyzed TSs appears to be the major factor favoring specificity toward sulfate over phosphate esters by this promiscuous hydrolase, since other features are either too similar (uncatalyzed TS) or inherently favor phosphate (charge).
PROCESS FOR THE MANUFACTURE OF (PER) FLUOROPOLYETHERS WITH AROMATIC END GROUPS
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, (2015/12/11)
The invention relates to a process which comprises the reaction of a (per)fluoropolyether peroxide with an optionally substituted aromatic or heteroaromatic compound. The process allows to obtain (per)fluoropolyether compounds having two chain ends, wherein one or both chain ends is a —CF2— group covalently bound to an optionally substituted aromatic or heteroaromatic group through a -carbon-carbon- bond. The invention further relates to the use of these compounds and to their derivatives as additives for perfluorinated oils and greases.
Click chemistry inspired facile synthesis and bioevaluation of novel triazolyl analogs of Ludartin
Lone, Shabir H.,Bhat, Khursheed A.,Majeed, Rabiya,Hamid, Abid,Khuroo, Mohd A.
, p. 1047 - 1051 (2014/03/21)
A convenient and modular synthesis involving diastereoselective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reaction was carried out to furnish 1,4-disubstituted-1,2,3-triazoles of Ludartin. This reaction scheme involving Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reaction leading to the formation of triazolyl analogs is being reported for the first time. All the triazolyl products were characterised using spectral data analysis. Sulphorhodamine B cytotoxicity screening of the resulting products against a panel of five human cancerous cell-lines revealed that few of the analogs display promising broad spectrum cytotoxic effect. Among all the synthesized compounds, only 3q displayed the best cytotoxic effect with IC50 values of 12, 11, 38, 39 and 8.5 μM but less than the standard Ludartin (1) with IC50 values of 6.3, 7.4, 7.5, 6.9 and 0.5 μM against human neuroblastoma (T98G), lung (A-549), prostate (PC-3), colon (HCT-116) and breast (MCF-7) cancer cell lines, respectively. The present synthesis was designed based on the previous literature reports of Ludartin as an aromatase inhibitor. Our work provides an initial study on structure-activity relationship of triazolyl analogs of sesquiterpene lactones in general and Ludartin (1) in particular.
Competition between electron-donor and electron-acceptor substituents in nitrotoluene isomers: A photoelectron spectroscopy and ab initio investigation
Rondino, Flaminia,Catone, Daniele,Mattioli, Giuseppe,Bonapasta, Aldo Amore,Bolognesi, Paola,Casavola, Anna Rita,Coreno, Marcello,O'Keeffe, Patrick,Avaldi, Lorenzo
, p. 5272 - 5282 (2014/01/23)
We present an investigation of the close relationship between chemical structure, physical properties and reactivity of the three nitrotoluene isomers: a joint experimental and theoretical study, based on X-ray photoelectron spectroscopy (XPS) measurements and ab initio calculations, addressing the complex interplay between the competing electron-donor and electron-acceptor effects of the nitro- and methyl-substituents on the chemical properties of the nitrotoluene isomers. As the main results of the investigation we: (i) point out that accurate ab initio calculations play a key role in the complete assignment of photoemission measurements, as well as in the estimate of proton affinities in the case of all the eligible sites; (ii) revisit, at a more quantitative level, textbook models based on inductive and resonant effects of different substituents of the aromatic ring, as well as on the hyper-conjugative connection of the methyl group to the π-conjugated system; (iii) provide an accurate analysis of correlation patterns between calculated proton affinities and core-ionization energies, which represent a powerful tool, capable of predicting site-specific reactivities of polysubstituted molecules in the case of electrophilic aromatic substitution reactions.
Preparation of heteropoly acid based amphiphilic salts supported by nano oxides and their catalytic performance in the nitration of aromatics
Wang, Peng-Cheng,Yao, Kai,Lu, Ming
, p. 2197 - 2202 (2013/03/14)
A series of Keggin heteropoly acid anion based amphiphilic salts supported by nano oxides were synthesized and used as catalysts in the nitration of aromatic compounds with HNO3. The reaction conditions in the nitration of toluene were optimized and both 92.6% conversion and good para selectivity (ortho:para = 1.09) were obtained.
Preparation, catalytic performance and theoretical study of porous sulfated binary metal oxides shell (SO42 -/M1xO y-M2xOy) using pollen grain templates
Wang, Peng Cheng,Yao, Kai,Zhu, Jie,Liu, Xiang,Lu, Ting Ting,Lu, Ming
, p. 90 - 95 (2013/07/26)
Porous micro-sized particles of binary metal oxide (SO4 2 -/M1xOy-M2xOy) shell were prepared by template-directed synthesis method employing HCl-treated pollen grains. With 150 m2/g high surface area, these solid acids could provide more acid sites and thus obtain better catalytic activity. Using aromatic nitration as the typical reaction, their catalytic performances were evaluated and showed a significant improvement in both conversion and regioselectivity. Then, with chlorobenzene as substrate, theoretical studies were performed to investigate the interaction between transition metals and chlorobenzene. The results showed that the excellent para-selectivity was closely relative to the metal ion in these solid acids.
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.
Ethylammonium nitrate (EAN)/Tf2O and EAN/TFAA: Ionic liquid based systems for aromatic nitration
Aridoss, Gopalakrishnan,Laali, Kenneth K.
experimental part, p. 8088 - 8094 (2011/11/13)
Acting as in situ sources of triflyl nitrate (TfONO2) and trifluoroacetyl nitrate (CF3COONO2), the EAN/Tf 2O and EAN/TFAA systems, generated via metathesis in the readily available ethylammonium nitrate (EAN) ionic liquid as solvent, are powerful electrophilic nitrating reagents for a wide variety of aromatic and heteroaromatic compounds. Comparative nitration experiments indicate that EAN/Tf2O is superior to EAN/TFAA for nitration of strongly deactivated systems. Both systems exhibit low substrate selectivity (K T/KB = 5-10) in (Figure presented) between values reported for covalent nitrates and preformed nitronium salts.
