- Synthesis, aerobic cytotoxicity, and radiosensitizing activity of novel 2,4-dinitrophenylamine tethered 5-fluorouracil and hydroxyurea
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Two novel dual functional agents, 3[3-(2,4-dinitro-phenylamino)-propyl]-5-fluoro-1H-pyrimidine-2,4-dione 7 and N-[3-(2,4-dinitro-phenylamino)-propoxy]urea 8, resulting from linkage of 2,4-dinitrophenylamine through three carbon atoms with 5-fluorouracil 5
- Khalaj, Ali,Doroudi, Ali Reza,Ostad, Seyed Nasser,Khoshayand, Mohammad Reza,Babai, Mohammad,Adibpour, Neda
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- KINETIC STUDIES AND MICELLAR EFFECT ON THE AMINOLYSIS OF CERTAIN O-ARYL OXIMES
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Rate constants for the aminolysis of a few O-aryl oximes with several primary alkyl amines, CH3NH2-------C6H12NH2 in 1:1 water-acetonitrile are reported.Reactions of methylamine with substrates possessing poor nucleofugues are very weakly sensitive to base catalysis while reactions of higher amines are not.Slightly higher rate of long chain amine may be considered as a consequence of hydrophobic interaction.Cationic micelles of cetyltrimethyl ammonium bromide enhance the rate.Magnitude of micellar catalysis increases towards higher amines.
- Jain, Ajay K.,Velu, V. K.,Sarma, K. N.
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- Mechanistic assessment of SNAr displacement of halides from 1-Halo-2,4-dinitrobenzenes by selected primary and secondary amines: Br?nsted and Mayr analyses
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Pseudo-first-order rate constants (kobsd) have been measured spectrophotometrically for nucleophilic substitution reactions of 1-X-2,4-dinitrobenzenes (1a-d, X = F, Cl, Br, I) with various primary and secondary amines in MeCN and H2O
- Um, Ik-Hwan,Im, Li-Ra,Kang, Ji-Sun,Bursey, Samantha S.,Dust, Julian M.
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- Effect of the nature of the nucleophile and solvent on an SNAr reaction
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The reaction of 2,4-dinitrobenzenesulfonyl chloride toward propylamine was kinetically evaluated in 19 organic solvents and 10 ionic liquids as reaction media. This study was compared with a previous study to experimentally show that solvent effects and t
- Gazitúa, Marcela,Tapia, Ricardo A.,Contreras, Renato,Campodónico, Paola R.
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- Low background FRET-substrates for lipases and esterases suitable for high-throughput screening under basic (pH 11) conditions
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FRET-based fluorogenic substrates for lipases and esterases were prepared in four steps from commercially available building blocks. The substrates are pyrenebutyric acid monoesters of aliphatic 1,2-diols bearing a dinitrophenylamino group as a quencher. The most enzyme-reactive substrate is ester 2a. The substrates do not show any measurable background reaction in the absence of enzyme even at pH 11, but react fast and specifically with lipases and esterases. These substrates offer an unprecedented and practical solution to the long-standing problem of a simple yet efficient high-throughput screening tool for lipase activities under basic conditions. The Royal Society of Chemistry 2006.
- Yang, Yongzheng,Babiak, Peter,Reymond, Jean-Louis
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- RETRACTED ARTICLE: Sanger's Reagent Sensitized Photocleavage of Amide Bond for Constructing Photocages and Regulation of Biological Functions
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Photolabile groups offer promising tools to study biological processes with high spatial and temporal control. In the investigation, we designed and prepared several new glycine amide derivatives of Sanger's reagent and demonstrated that they serve as a new class of photocages for Zn2+ and an acetylcholinesterase (AChE) inhibitor. We showed that the mechanism for photocleavage of these substances involves initial light-driven cyclization between the 2,4-dinitrophenyl and glycine methylene groups to form acyl benzimidazole N-oxides, which undergo secondary photoinduced decarboxylation in association with rupture of an amide bond. The cleavage reactions proceed with modest to high quantum yields. We demonstrated that these derivatives can be used in targeted intracellular delivery of Zn2+, fluorescent imaging by light-triggered Zn2+ release, and regulation of biological processes including the enzymatic activity of carbonic anhydrase (CA), negative regulation of N-methyl-d-aspartate receptors (NMDARs), and pulse rate of cardiomyocytes. The successful proof-of-concept examples described above open a new avenue for using Sanger's reagent-based glycine amides as photocages for the exploration of complex cellular functions and signaling pathways.
- Wei, Tingwen,Lu, Sheng,Sun, Jiahui,Xu, Zhijun,Yang, Xiao,Wang, Fang,Ma, Yang,Shi, Yun Stone,Chen, Xiaoqiang
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supporting information
p. 3806 - 3813
(2020/03/10)
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- Synthesis of o-Nitroarylamines via Ipso Nucleophilic Substitution of Sulfonic Acids
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A mild, efficient, and eco-friendly method for the synthesis of o-nitroarylamine from o-nitroaryl sulfonic acid via ipso nucleophilic aryl substitution by amine is described. The products have been obtained with good yields at room temperature without the assistance of any metal, activating agent, or toxic oxidant. This method is useful for racemization-free synthesis of N-aryl amino acid esters.
- Manne, Srinivasa Rao,Chandra, Jyoti,Mandal, Bhubaneswar
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supporting information
p. 636 - 639
(2019/01/21)
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- “Zero VOC” Synthetic Strategy – Aromatic Amination Reactions in Deep Eutectic Solvents
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Rising concern for environment hazards resulting from the use of volatile organic compounds (VOCs) is prompting many chemists to use “green” solvents like water, polyethylene glycol, ionic liquids and deep eutectic solvents (DES). With a few notable exceptions, many of these processes still need to use volatile organic solvents for the workup and isolation of products. In the present report, we demonstrate a “zero VOC” protocol which eliminates the need to use organic solvents for any stage of the reaction. As a proof of concept, nucleophilic aromatic substitution reactions of 1-halo-2,4-dinitrobenzene with secondary amines were carried out in deep eutectic solvents. The reaction workup involved the addition of water for separating the product from the DES. Evaporation of water led to recovery of the DES, which exhibited good recyclability. The reaction in deep eutectic solvents was much faster than that in many other solvents, as confirmed by the kinetic studies. An attempt was made to elucidate the origin of this rate enhancement based on analysis activation parameters and correlation with the polarity parameters. The results show that use of deep eutectic solvents can take chemists a step closer towards the “zero VOC” synthetic strategy.
- Valvi, Arun,Tiwari, Shraeddha
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p. 4933 - 4939
(2018/09/11)
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- The influence of steric effects on the kinetics and mechanism of SNAr reactions of 1-phenoxy-nitrobenzenes with aliphatic primary amines in acetonitrile
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Rate constants are reported for the reactions of 1-phenoxy-dinitrobenzenes, 3, 1-phenoxy-dinitrotrifluoromethylbenzenes, 4, with n-propylamine, and 1-methylheptylamine in acetonitrile as solvent. The results are compared with results reported previously f
- Isanbor, Chukwuemeka
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- Specific nucleophile-electrophile interactions in nucleophilic aromatic substitutions
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We herein report results obtained from an integrated experimental and theoretical study on aromatic nucleophilic substitution (SNAr) reactions of a series of amines towards 1-fluoro-2,4-dinitrobenzene in water. Specific nucleophile-electrophile interactions in the title reactions have been kinetically evaluated. The whole series undergoes SNAr reactions where the formation of the Meisenheimer complex is rate determining. Theoretical studies concerning specific interactions are discussed in detail. It is found that H-bonding effects along the intrinsic reaction coordinate profile promote the activation of both the electrophile and the nucleophile. Using these results, it is possible to establish a hierarchy of reactivity that is in agreement with the experimental data. Second order energy perturbation energy analysis highlights the strong interaction between the ortho-nitro group and the acidic hydrogen atom of the amine. The present study strongly suggests that any theoretical analysis must be performed at the activated transition state structure, because the static model developed around the reactant states hides most of the relevant specific interactions that characterize the aromatic substitution process.
- Ormazábal-Toledo, Rodrigo,Contreras, Renato,Tapia, Ricardo A.,Campodónico, Paola R.
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supporting information
p. 2302 - 2309
(2013/04/10)
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- Nucleotides. Part LXXVIII: Double labeling of nucleosides and nucleotides
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Several N(-hydroxyalkyl)-2,4-dinitroanilines were transformed into their phosphoramidites (see 5 and 6 in Scheme 1) in view of their use as fluorescence quenchers, and modified 2-aminobenzamides (see 9, 10, 18, and 19 in Scheme 1) were applied in model re
- Maier, Thomas,Pfleiderer, Wolfgang
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experimental part
p. 2365 - 2392
(2011/02/18)
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- Synthesis of (alkylamino)nitroarenes by oxidative alkylamination of nitroarenes
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The viability of the oxidative alkylamination process for the derivatization of electron-deficient carboaromatics has been investigated. 1,3-Dinitrobenzene, 1-nitronaphthalene, and 1,5- and 1,8-dinitronaphthalenes have shown to react with a wide range of alkylamines in the presence of an oxidant (KMnO4, AgMnO4, AgPy2MnO4) to give access to the corre sponding N-alkyl-nitroarenamines in moderate to good yields. Nitroarenes are more reactive than azines towards alkylamines.
- Gulevskaya, Anna V.,Verbeeck, Stefan,Burov, Oleg N.,Meyers, Caroline,Korbukova, Inna N.,Herrebout, Wouter,Maes, Bert U. W.
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experimental part
p. 564 - 574
(2009/09/06)
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- A new leaving group in nucleophilic aromatic substitution reactions (S NAr)
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Nucleophilic aromatic substitution of a 2,4-dinitrophenyl substituted pyrazole 1 with primary amines leads to substitution of the pyrazolo substituent. In these nucleophilic aromatic substitution reactions (S NAr), 5-amino-1H-4- pyrazolecarbonitrile (3) acts as a new leaving group.
- Bakavoli, Mehdi,Pordel, Mehdi,Rahimizadeh, Mohammad,Jahandari, Pooneh
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experimental part
p. 432 - 433
(2009/06/30)
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- Effect of substituent on regioselectivity and reaction mechanism in aminolysis of 2,4-dinitrophenyl X-substituted benzenesulfonates
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(Chemical Equation Presented) We report on a kinetic study for the nucleophilic substitution reactions of 2,4-dinitrophenyl X-substituted benzensulfonates (X = 4-MeO, 1a, and X = 4-NO2, 1c) with a series of primary amines in 80 mol % H2O/20 mol % DMSO at 25.0 °C. The reactions proceed through S-O and C-O bond fission pathways competitively. The fraction of the S-O bond fission increases as the attaching amine becomes more basic and the substituent X changes from 4-MeO to 4-NO2, indicating that the regioselectivity is governed by the electronic nature of the substituent X as well as the basicity of amines. The S-O bond fission has been suggested to proceed through an addition intermediate with a change in the rate-determining step (RDS) at pK°a = 8.9 ± 0.1. The electronic nature of the substituent X influences kNS-O and k1 values, but not the k2/k-1 ratios and the pK°a value significantly. Stabilization of the ground state (GS) through resonance interaction between the electron-donating substituent and the electrophilic center has been suggested to be responsible for the decreased reactivity of 1a compared to 1c. The second-order rate constants for the C-O bond fission exhibit no correlation with the electronic nature of the substituent X. The distance effect and the nature of the reaction mechanism have been suggested to be responsible for the absence of the correlation.
- Um, Ik-Hwan,Hong, Jin-Young,Seok, Jin-Ah
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p. 1438 - 1444
(2007/10/03)
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- 15N NMR and FTIR studies of 2,4-dinitroanilines and their salts
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Twenty-two 2,4-dinitroanilines were synthesised and their pK(a) values were determined. The 2,4-dinitroanilines and their protonated forms were studied by 15N NMR spectroscopy. The relations between the 15N NMR chemical shifts and the pK(a) values of the 2,4-dinitroanilines and their salts were found to be linear. The deprotonation reaction of N-methyl-2,4- dinitroanilines and N-methyl-2,4,6-trinitroaniline by MTBD was successful only for the latter and yielded protonated MTBD molecule and the anion in which the electrons are strongly delocalised. The kinetic parameters of the 2,4-dinitroanilines in reactions with hydroxide ions in mixed solvent DMSO:water (95:5, v/v) were determinated and discussed. (C) 2000 Elsevier Science B.V.
- Gierczyk,Leska,Nowak-Wydra,Schroeder,Wojciechowski,Bartl,Brzezinski
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p. 217 - 225
(2007/10/03)
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- Synthesis of 1-Alkoxy-2-Alkyl-Benzimidazoles from 2-Nitroanilines via Tandem N-Alkylation-Cyclization-O-Alkylation
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Substituted 2-nitroanilines react with benzylic, allyl and alkyl halides to give 2-aryl-1-benzyloxy-, 1-allyloxy-2-vinyl- and 1-alkoxy-2-alkyl-benzimidazoles, in a one-pot cascade process involving 1-alkylation-cyclization-O-alkylation. 2-Aryl-1-benzyloxy- and 1-allyloxy-2-vinyl- derivatives are obtained in high yields (79-98percent), while with simple alkyl halides, yields of the benzimidazoles are substrate dependent.An X-ray crystal structure of 2,4-dimethyl-1-ethoxybenzimidazole is presented.
- Gardiner, John M.,Loyns, Colin R.,Schwalbe, Carl H.,Barrett, Garry C.,Lowe, Philip R.
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p. 4101 - 4110
(2007/10/02)
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- Aromatic Nucleophilic Substitution Reactions of Oxime Ethers with Aliphatic Primary and Secondary Amines in Benzene
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Reactions of various oxime ethers with the primary alkylamines propyl-, butyl-, pentyl-, and hexylamine and with pyrrolidine, a secondary alkyl amine, have been studied in benzene at 35 +/- 0.1 deg C.These reactions have all been found to be wholly base catalysed.Some reactions, especially those involving strong nucleophiles and substrates with poor leaving groups , exhibit a third-order dependence on amine concentration which has been explained on the basis of a cyclic transition-state mechanism.These reactions also show an inverse-temperature effect. Reactions with substrates which have good leaving groups and weaker nucleophiles show a second-order dependence on amine concentration.These reactions show normal temperature effects with low energy of activation.This low energy of activation and high negative entropy of activation support the cyclic transition-state mechanism invoked to explain these data.
- Jain, Ajay K.,Gupta, Vinod K.,Kumar, Anurag
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- Aminolysis of Oxime Ethers in Protic and Aprotic Solvents
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Reactions of oxime ethers with the primary amines, n-propyl-, n-butyl-, n-pentyl-, and n-hexylamine in DMSO, DMF, and MeCN are strongly catalysed by general bases.The observed second-order rate constants (kA) exhibit a curvilinear dependence on amine concentration leaving a positive intercept.The reactions of piperidine in DMSO follow a wholly catalysed pathway.A plot of kA versus is linear and passes through the origin.No base catalysis is observed for the reactions of n-butylamine in methanol and 1:1 (v/v) methanol-acetonitrile.The participation of the hydrogen- bond donor solvent molecule in the intermediate may account for absence of base catalysis in these solvents.
- Jain, Ajay K.,Kumar, Anurag,Sarma, Kula N.
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p. 153 - 158
(2007/10/02)
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- UNUSUAL DEALKYLATIONS AND REARRANGEMENTS IN AROMATIC NUCLEOPHILIC SUBSTITUTION
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The reaction of 2,4-dinitrohalobenzenes with di-isopropylamine produces mainly N-(2,4-dinitrophenyl)-isopropylamine and N-(2,4-dinitrophenyl)-n-propylamine instead of the expected straightforward substitution product.Dealkylations are also observed in the reactions with isopropylcyclohexylamine and dicyclohexylamine.A carbanionic mechanism is proposed.
- Nudelman, N. Sbarbati,Socolovsky, S. E.
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p. 3331 - 3334
(2007/10/02)
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