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Substituted Diphenylamine

Zifeng Zhang, Ed Sverko, Shirley Anne Smyth, Christopher H Marvin
Owing to their stability at high temperature, low biodegradation, low water solubility, and low vapor pressure, substituted diphenylamines are used as antioxidants in rubber, foamed polymers, and as high-temperature functional fluids (e.g., lubricants, gear oils, and hydraulic fluids). There are few existing environmental measurements of these substances in any environmental medium. In this study, a method was developed for the determination of 10 substituted diphenylamines in wastewater, biosolids, and sediments using gas chromatography-tandem mass spectrometry (GC-MS/MS)...
November 2016: Analytical and Bioanalytical Chemistry
Zhe Lu, Amila O De Silva, Thomas E Peart, Cyril J Cook, Gerald R Tetreault, Mark R Servos, Derek C G Muir
Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs), previously under reported classes of organic contaminants, were determined in sediment, water, and freshwater biota in an urban creek in Canada. SDPAs and BZT-UVs were frequently detected in all matrices including upstream of the urban area in a rural agricultural/woodlot region, suggesting a ubiquitous presence and bioaccumulation of these emerging contaminants. Spatial comparisons were characterized by higher levels of SDPAs downstream compared with the upstream, implying a possible influence of the urban activities on the antioxidant contamination in the sampling area...
September 6, 2016: Environmental Science & Technology
Zhe Lu, Thomas E Peart, Cyril J Cook, Amila O De Silva
Analytical methods were developed for the determination of eight substituted diphenylamines (SDPAs) and six benzotriazole UV stabilizers (BZT-UVs) in blood plasma and fish homogenate matrices. Liquid-liquid extraction by methyl tert-butyl ether and denaturation by KOH following silica gel packed column clean-up was employed for blood plasma preparation. For the fish homogenate samples, ultrasonic assisted solvent extraction combined with automated gel permeation chromatography and silica gel packed column clean-up was used...
August 26, 2016: Journal of Chromatography. A
David J Stewart, Matthew J Dalton, Stephanie L Long, Ramamurthi Kannan, Zhenning Yu, Thomas M Cooper, Joy E Haley, Loon-Seng Tan
The two-photon absorbing dye AF240 [1, (7-benzothiazol-2-yl-9,9-diethylfluoren-2-yl)diphenylamine] is modified by adding bulky alkyl groups to the diphenylamino moiety. Three new compounds are synthesized which have ethyl groups in both ortho positions of each phenyl ring (2), t-butyl groups in one ortho position of each phenyl ring (3), and t-butyl groups in the para position of each phenyl ring (4). The dyes are examined in several aprotic solvents with varying polarity to observe the effects of the sterically hindering bulky groups on the ground and excited-state photophysical properties...
February 21, 2016: Physical Chemistry Chemical Physics: PCCP
Yue Jiang, Denis Gindre, Magali Allain, Ping Liu, Clément Cabanetos, Jean Roncali
A small push-pull molecule involving a diphenylamine substituted by an oligo-oxyethylene chain is described. The compound exhibits aggregation-induced emission with solvent-dependent emission wavelength. Spin-cast deep-red amorphous films rapidly self-reorganize into colorless crystalline films which exhibit mechanofluorochromism and aggregation-induced second-harmonic generation.
August 5, 2015: Advanced Materials
Panuwat Padungros, Alexander Wei
Oxidation-sensitive N,N-diaryl dithiocarbamates (DTCs) are synthesized in good yields by the generation of metal amide salts from N-benzoyl precursors, followed by addition of CS2. para-Substituted diphenylamines are prepared by electrophilic aromatic substitution of diphenylbenzamide and saponification. Deacylation of electron-rich species such as bis(p-dimethylaminophenyl)benzamide is challenging because of the oxidative sensitivity of the anionic intermediate but could be achieved in good yield by using n-BuLi to generate a hemiaminal adduct, prior to acidification...
2014: Synthetic Communications
Luca Valgimigli, Derek A Pratt
Hydrocarbon autoxidation, the archetype free radical chain reaction, challenges the longevity of both living organisms and petroleum-derived products. The most important strategy in slowing this process is via the intervention of radical-trapping antioxidants (RTAs), which are abundant in nature and included as additives to almost every petroleum-derived product as well as several other commercial products. Accordingly, a longstanding objective of many academic and industrial scientists has been the design and development of novel RTAs that can outperform natural and industrial standards, such as α-tocopherol, the most biologically active form of vitamin E, and dialkylated diphenylamines, respectively...
April 21, 2015: Accounts of Chemical Research
Mohammednoor Altarawneh, Bogdan Z Dlugogorski
This contribution presents pathways for the formation of the three nitrogenated dioxin-like species, carbazole, phenoxazine, and phenazine via unimolecular rearrangements of diphenylamine (DPA) and its nitro substituents (NDPA). The latter represent major structural entities appearing in formulations of explosives and propellants. Intramolecular H transfer from the amine group to one of the two O atoms in the nitro group denotes the most accessible route in the unimolecular decomposition of NDPA. Further unimolecular rearrangements afford phenazine and carbazole...
February 17, 2015: Environmental Science & Technology
Vanessa Casas-Rua, Patricia Tomas-Martin, Aida M Lopez-Guerrero, Ignacio S Alvarez, Eulalia Pozo-Guisado, Francisco Javier Martin-Romero
STIM1 is a key regulator of store-operated calcium entry (SOCE), and therefore a mediator of Ca²⁺ entry-dependent cellular events. Phosphorylation of STIM1 at ERK1/2 target sites has been described as enhancing STIM1 activation during intracellular Ca²⁺ emptying triggered by the inhibition of the sarco(endo)plasmic Ca²⁺ -ATPase with thapsigargin. However, no physiological function is known for this specific phosphorylation. The present study examined the role of STIM1 phosphorylation in cell signaling triggered by EGF...
January 2015: Biochimica et Biophysica Acta
Chang-Jiang Yao, Hai-Jing Nie, Wen-Wen Yang, Jiang-Yang Shao, Jiannian Yao, Yu-Wu Zhong
Nine cyclometalated ruthenium complexes with a redox-active diphenylamine unit in the para position to the RuC bond were prepared. MeO, Me, and Cl substituents on the diphenylamine unit and three types of auxiliary ligands-bis(N-methylbenzimidazolyl)pyridine (Mebip), 2,2':6',2''-terpyridine (tpy), and trimethyl-4,4',4''-tricarboxylate-2,2':6',2''-terpyridine (Me3 tctpy)--were used to vary the electronic properties of these complexes. The derivative with an MeO-substituted amine unit and Me3 tctpy ligand was studied by single-crystal X-ray analysis...
December 22, 2014: Chemistry: a European Journal
Guanyi Huang, Hexin Yan, Shoudong Ye, Chang Tong, Qi-Long Ying
STAT3 can be transcriptionally activated by phosphorylation of its tyrosine 705 or serine 727 residue. In mouse embryonic stem cells (mESCs), leukemia inhibitory factor (LIF) signaling maintains pluripotency by inducing JAK-mediated phosphorylation of STAT3 Y705 (pY705). However, the function of phosphorylated S727 (pS727) in mESCs remains unclear. In this study, we examined the roles of STAT3 pY705 and pS727 in regulating mESC identities, using a small molecule-based system to post-translationally modulate the quantity of transgenic STAT3 in STAT3(-/-) mESCs...
May 2014: Stem Cells
Jonathan A Kitchen, Juan Olguín, Rafal Kulmaczewski, Nicholas G White, Victoria A Milway, Guy N L Jameson, Jeffery L Tallon, Sally Brooker
Seven new dinuclear iron(II) complexes of the general formula [Fe(II)2(PMRT)2](BF4)4·solvent, where PMRT is a 4-substituted-3,5-bis{[(2-pyridylmethyl)-amino]methyl}-4H-1,2,4-triazole, have been prepared in order to investigate the substituent effect on the spin crossover event. Variable temperature magnetic susceptibility and (57)Fe Mössbauer spectroscopy studies show that two of the complexes, [Fe(II)2(PMPT)2](BF4)4·H2O (N(4) substituent is pyrrolyl) and [Fe(II)2(PM(Ph)AT)2](BF4)4 (N(4) is N,N-diphenylamine), are stabilized in the [HS-HS] state between 300 and 2 K with weak antiferromagnetic interactions between the iron(II) centers...
October 7, 2013: Inorganic Chemistry
Rui F Munhá, Ryan A Zarkesh, Alan F Heyduk
A family of tantalum compounds was prepared to probe the electronic effects engendered by the addition of electron-donating or electron-withdrawing groups to the 4/4' positions of the redox-active ligand derived from bis(2-isopropylamino-4-X-phenyl)amine [(X,iPr)(NNN(cat))H3, X = F, H, Me, (t)Bu]). A general synthetic procedure for the (X,iPr)(NNN(cat))H3 ligand family was developed starting from the 4/4' disubstituted diphenylamine derivative. A second ligand modification, incorporation of aromatic substituents at the flanking nitrogen moieties, was achieved via palladium-catalyzed cross-coupling to afford bis(2-3,5-dimethylphenylamino-4-methoxy-phenyl)amine (OMe,DMP)(NNN(cat))H3 (DMP = 3,5-C6H3Me2), allowing a comparative study to the less sterically hindered isopropyl derivative...
October 7, 2013: Inorganic Chemistry
Ming Jin, Haoran Xu, Hong Hong, Jean-Pierre Malval, Yuan Zhang, Aimin Ren, Decheng Wan, Hongting Pu
New sulfonium salts with diphenylamino asymmetrically substituted stilbene as a D-π-A conjugated system have been synthesized. The resulting photoacid generators exhibit a highly efficient acid photogeneration process by either one-photon 405 nm or two-photon 800 nm excitation.
October 4, 2013: Chemical Communications: Chem Comm
Ingo V Hartung, Marion Hitchcock, Florian Pühler, Roland Neuhaus, Arne Scholz, Stefanie Hammer, Kirstin Petersen, Gerhard Siemeister, Dominic Brittain, Roman C Hillig
Using PD325901 as a starting point for identifying novel allosteric MEK inhibitors with high cell potency and long-lasting target inhibition in vivo, truncation of its hydroxamic ester headgroup was combined with incorporation of alkyl and aryl ethers at the neighboring ring position. Whereas alkoxy side chains did not yield sufficient levels of cell potency, specifically substituted aryloxy groups allowed for high enzymatic and cellular potencies. Sulfamide 28 was identified as a highly potent MEK inhibitor with nanomolar cell potency against B-RAF (V600E) as well as Ras-mutated cell lines, high metabolic stability and resulting long half-lives...
April 15, 2013: Bioorganic & Medicinal Chemistry Letters
Doaa Ezzat Abdel Rahman
Synthesis of 2,5-disubstituted-1,3,4-oxadiazole (2a-c), 3-substituted aminomethyl-5-substituted-1,3,4-oxadiazole-2(3H)-thione (4a-m) and 2-substituted thio-5-substituted-1,3,4-oxadiazole (5a, b) had been described. All the synthesized derivatives were screened for anticancer activity against HT29 and MCF7 cancer cell lines using Sulfo-Rodamine B (SRB) standard method. Most of the tested compounds exploited potent antiproliferative activity against HT29 cancer cell line rather than MCF7 cancer cell line. Compounds 2a-c, 4f and 5a exhibited potent cytotoxicity (IC(50) 1...
2013: Chemical & Pharmaceutical Bulletin
Haesun Youn, Song-Hee Kim, Kyung Ah Choi, Sungtae Kim
Establishment of mouse spermatogonial stem cell (SSC) culture systems offers a useful stem cell model for studies of proliferation and self-renewal of mammalian germline stem cells. In addition, spontaneous development of pluripotent stem cells from cultured SSCs emphasizes their possible applications in regenerative medicine as a substitute for embryonic stem cells (ESCs). These pluripotent stem cells termed multipotent germline stem cells (mGSCs) or germline-derived pluripotent stem cells (gPSCs) exhibit almost identical properties in terms of morphology and gene expression patterns to mouse ESCs (mESCs)...
April 2013: Journal of Cellular Biochemistry
Sarah G Pati, Kwanghee Shin, Marita Skarpeli-Liati, Jakov Bolotin, Soren N Eustis, Jim C Spain, Thomas B Hofstetter
Dioxygenation of aromatic rings is frequently the initial step of biodegradation of organic subsurface pollutants. This process can be tracked by compound-specific isotope analysis to assess the extent of contaminant transformation, but the corresponding isotope effects, especially for dioxygenation of N-substituted, aromatic contaminants, are not well understood. We investigated the C and N isotope fractionation associated with the biodegradation of aniline and diphenylamine using pure cultures of Burkholderia sp...
November 6, 2012: Environmental Science & Technology
Jason J Hanthorn, Luca Valgimigli, Derek A Pratt
We recently reported a preliminary account of our efforts to develop novel diarylamine radical-trapping antioxidants (Hanthorn, J. J. et al. J. Am. Chem. Soc. 2012, 134, 8306-8309) wherein we demonstrated that the incorporation of ring nitrogens into diphenylamines affords compounds which display a compromise between H-atom transfer reactivity to peroxyl radicals and stability to one-electron oxidation. Herein we provide the details of the synthetic efforts associated with that report, which have been substantially expanded to produce a library of substituted heterocyclic diarylamines that we have used to provide further insight into the structure-reactivity relationships of these compounds as antioxidants (see the accompanying paper, DOI: 10...
August 17, 2012: Journal of Organic Chemistry
Jason J Hanthorn, Riccardo Amorati, Luca Valgimigli, Derek A Pratt
We recently reported a preliminary account of our efforts to develop novel diarylamine radical-trapping antioxidants (Hanthorn et al. J. Am. Chem. Soc.2012, 134, 8306-8309), wherein we demonstrated that the incorporation of ring nitrogens into diphenylamines affords compounds that display a compromise between H-atom transfer reactivity to peroxyl radicals and stability to one-electron oxidation. Herein, we report the results of thermochemical and kinetic experiments on an expanded set of diarylamines (see the accompanying paper, DOI: 10...
August 17, 2012: Journal of Organic Chemistry
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