- ROTATIONAL ISOMERS OF THE RADICAL-ANIONS OF 2-CARBONYL-CONTAINING DERIVATIVES OF 5-NITROFURAN
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The radical-anions of 2-carbonyl-containing derivatives of 5-nitrofuran were obtained by electrochemical generation.Their ESR spectra indicate the existence of a mixture of O,O-cis and O,O-trans rotational isomers.The parameters of the isomers were identified by INDO calculations.The more polar form (the cis isomer) is more stable in polar media.
- Gavar, R. A.,Baumane, L. Kh.,Stradyn',Ya. P.,Fleischer, M. B.,Chernaeva, M.,Kovach, Ya.
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- N-Nitroheterocycles: Bench-Stable Organic Reagents for Catalytic Ipso-Nitration of Aryl- And Heteroarylboronic Acids
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Photocatalytic and metal-free protocols to access various aromatic and heteroaromatic nitro compounds through ipso-nitration of readily available boronic acid derivatives were developed using non-metal-based, bench-stable, and recyclable nitrating reagents. These methods are operationally simple, mild, regioselective, and possess excellent functional group compatibility, delivering desired products in up to 99% yield.
- Budinská, Alena,Katayev, Dmitry,Passera, Alessandro,Zhang, Kun
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supporting information
(2020/03/30)
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- NITRATION
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The present invention relates to a process for preparing a nitrated compound, comprising the step of reacting a compound (A) comprising at least one substituted or unsubstituted aromatic or heteroaromatic ring, wherein said heteroaromatic ring comprises at least one heteroatom selected from the group consisting of oxygen, sulfur, phosphor, selenium and nitrogen, with a compound of formula (I) wherein Y is selected from the group consisting of hydrogen and nitro.
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Page/Page column 36; 39; 55
(2020/05/28)
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- Bioreductively activatable prodrug conjugates of phenstatin designed to target tumor hypoxia
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A variety of solid tumor cancers contain significant regions of hypoxia, which provide unique challenges for targeting by potent anticancer agents. Bioreductively activatable prodrug conjugates (BAPCs) represent a promising strategy for therapeutic intervention. BAPCs are designed to be biologically inert until they come into contact with low oxygen tension, at which point reductase enzyme mediated cleavage releases the parent anticancer agent in a tumor-specific manner. Phenstatin is a potent inhibitor of tubulin polymerization, mimicking the chemical structure and biological activity of the natural product combretastatin A-4. Synthetic approaches have been established for nitrobenzyl, nitroimidazole, nitrofuranyl, and nitrothienyl prodrugs of phenstatin incorporating nor-methyl, mono-methyl, and gem-dimethyl variants of the attached nitro compounds. A series of BAPCs based on phenstatin have been prepared by chemical synthesis and evaluated against the tubulin-microtubule protein system. In a preliminary study using anaerobic conditions, the gem-dimethyl nitrothiophene and gem-dimethyl nitrofuran analogues were shown to undergo efficient enzymatic cleavage in the presence of NADPH cytochrome P450 oxidoreductase. Each of the eleven BAPCs evaluated in this study demonstrated significantly reduced inhibitory activity against tubulin in comparison to the parent anti-cancer agent phenstatin (IC50?=?1.0?μM). In fact, the majority of the BAPCs (seven of the eleven analogues) were not inhibitors of tubulin polymerization (IC50?>?20?μM), which represents an anticipated (and desirable) attribute for these prodrugs, since they are intended to be biologically inactive prior to enzyme-mediated cleavage to release phenstatin.
- Winn, Blake A.,Shi, Zhe,Carlson, Graham J.,Wang, Yifan,Nguyen, Benson L.,Kelly, Evan M.,Ross, R. David,Hamel, Ernest,Chaplin, David J.,Trawick, Mary L.,Pinney, Kevin G.
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p. 636 - 641
(2017/01/17)
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- Ethylammonium nitrate (EAN)/Tf2O and EAN/TFAA: Ionic liquid based systems for aromatic nitration
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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.
- Aridoss, Gopalakrishnan,Laali, Kenneth K.
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experimental part
p. 8088 - 8094
(2011/11/13)
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- Novel functionalized melamine-based nitroheterocycles: Synthesis and activity against trypanosomatid parasites
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Human African trypanosomiasis (HAT), caused by the protozoan parasite Trypanosoma brucei spp., is a major health problem in sub-Saharan Africa. New drugs are urgently required for the disease. Selective uptake of toxic compounds into trypanosomes has been achieved by exploiting plasma membrane transporters. For example, the P2 aminopurine transporter, along with other transporters, selectively concentrates melamine and benzamidine moieties into trypanosomes. We have previously reported the use of the melamine motif to selectively target nitrofuran to the trypanosome. In this paper we report the further investigation of the structure activity relationships and the effect of the introduction of different functionalized substituents onto the melamine unit. Most of the compounds tested in vitro for their trypanocidal activity showed activities in the submicromolar range against T. b. rhodesiense. The Royal Society of Chemistry 2009.
- Baliani, Alessandro,Peal, Valerie,Gros, Ludovic,Brun, Reto,Kaiser, Marcel,Barrett, Michael P.,Gilbert, Ian H.
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experimental part
p. 1154 - 1166
(2009/05/30)
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- The Preparation and Thermal Fragmentation of 2-Acyl-5-azidofurans
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The reaction of the nitrofurans (1)-(4) with sodium azide in Me2SO gave the thermally unstable azidofurans (5)-(8), which decompose to give nitrogen and the (Z)-dioxoalkenenitriles (32) and (15)-(17) respectively.The azides (6)-(8), the (Z)-nitriles (15)-
- Barnes, Bradley J.,Newcombe, Peter J.,Norris, Robert K.
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p. 963 - 976
(2007/10/02)
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