- Cyrhetrenylaniline and new organometallic phenylimines derived from 4- and 5-nitrothiophene: Synthesis, characterization, X-Ray structures, electrochemistry and in vitro anti-T. brucei activity
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A novel series of cyrhetrenyl (3a-4a) and ferrocenyl (3b-4b) Schiff bases were synthesized through a condensation reaction, between the known 4-ferrocenylaniline (2b) or the unreported 4-cyhretrenylaniline (2a) with 4- or 5-nitrothiophenecarboxaldehyde. The structure of 2a and the new Schiff bases have been elucidated using conventional spectroscopic techniques (FT-IR, 1H and 13C NMR), mass spectrometry, and single-crystal X-ray diffraction analysis of compounds 2a, 4a and 3b. Cyclic voltammetry of organometallic phenylimines derived from 5-nitrothiophene showed NO2 group reduction potentials (E1/2 ≈ ?0.575 V) that were more anodic than those registered for their 4-nitro analogues (E1/2 ≈ ?0.981 V). All organometallic imines were tested against the bloodstream form of Trypanosoma brucei. Evaluation indicated that the most active complexes are the 5-nitrothiophene derivatives, 4a, which were remarkably more active than nifurtimox. In addition, complex 4b resulted in less toxicity to host L6 cells than nifurtimox. The results revealed that the electronic effects of cyrhetrene and ferrocene are not an influential factor in E1/2 and anti-Trypanosoma brucei activity for these new imines, which is probably due to the non-coplanarity of the [(η5-C5H4)-C6H4-N=CH-(C4H2S)] system.
- Toro, Patricia,Suazo, Constanza,Acu?a, Alejandra,Fuentealba, Mauricio,Artigas, Vania,Arancibia, Rodrigo,Olea-Azar, Claudio,Moncada, Mauricio,Wilkinson, Shane,Klahn, A. Hugo
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- Synthesis method of 5-nitrothiophene-2-formaldehyde
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The invention relates to the technical field of chemistry, in particular to a synthesis method of 5-nitrothiophene-2-formaldehyde. The method comprises the steps of mixing 2-thiophenecarboxaldehyde and acetic anhydride, carrying out nucleophilic addition reaction to generate (acetyloxy) (2-thiophene) methyl acetate, and adding a nitrating agent to carry out nitration reaction to prepare 5-nitrothiophene-2-yl methylene diacetate; and carrying out a hydrolysis reaction on the obtained 5-nitrothiophene-2-yl methylene diacetate in a solvent to prepare 5-nitrothiophene-2-formaldehyde. The method has the beneficial effects that (1) cheap and easily available raw materials are used, the process is simple, the production cost is low, and the method is suitable for industrial production; and (2) the total yield and the total purity of the product are high.
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Paragraph 0035; 0037-0039; 0041-0043; 0045-0046
(2021/06/13)
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- Synthesis, protolytic equilibria, and antimicrobial action of nifuroxazide analogs
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The present paper reports on the synthesis of four hydrazones derived from 5-nitro-2-furfural, 5-nitro-2-thiophenal, isoniazid, 2,4- and 3,4-dihydroxy-N′-methylenebenzohydrazide. The acid-base dissociation constants of these compounds were determined in an aqueous solution. The protolytic equilibria-related ability of hydrazones to “sense” anions in dimethyl sulfoxide-containing water of different concentrations is studied using spectrophotometry, NMR spectroscopy, and quantum chemistry methods. The antimicrobial action of the hydrazones was tested and compared with that of the known drug nifuroxazide.
- Gamov,Kiselev,Murekhina,Zavalishin,Aleksandriiskii,Kosterin, D.Yu.
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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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- SMALL MOLECULE INHIBITORS OF PROTEIN ARGININE METHYLTRANSFERASES (PRMTS)
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The present invention relates to compounds that are useful as inhibitors of protein arginine methyltransferase that have a formula selected from Formula (I), Formula (II) and Formula (III), as well as racemic mixtures, diastereomers, enantiomers and tautomers thereof and N-oxides, hydrates, solvates, pharmaceutically acceptable salts, prodrugs and complexes thereof as defined herein. Said compound are useful as inhibitors of PRMTs and/or CARM-I. The invention further relates to compositions comprising such compounds and methods for their use.
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Page/Page column 46
(2008/12/08)
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- Clean and selective oxidation of aromatic alcohols using silica-supported Jones' reagent in a pressure-driven flow reactor
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By exploiting the high surface to volume ratio obtained within continuous flow reactors, we are able to oxidise selectively an array of primary alcohols to either the aldehyde or carboxylic acid, depending on the flow rates employed, demonstrating a degree of reaction control unattainable in traditional stirred reactors.
- Wiles, Charlotte,Watts, Paul,Haswell, Stephen J.
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p. 5261 - 5264
(2007/10/03)
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- Synthesis of the fused heterobicycles 5-pyridin-2-yl-thieno[3,2-b]pyridine, 6-pyridin-2-yl-thieno[2,3-b]pyridine and 6-pyridin-2-yl-thieno[3,2-c]pyridine
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Three new pyridyl thienopyridines, 5-pyridin-2-yl-thieno[3,2-b]pyridine, 6-pyridin-2-yl-thieno[2,3-b]pyridine and 6-pyridin-2-yl-thieno[3,2-c]pyridine, have been synthesized, each through a different synthetic sequence. Overall yields ranged from 8% to 32%. Georg Thieme Verlag Stuttgart.
- Nurkkala, Lasse J.,Steen, Robert O.,Dunne, Simon J.
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p. 1295 - 1300
(2007/10/03)
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- COMBRETASTATIN DERIVATIVES WITH CYTOTOXIC ACTION
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The invention described herein relates to new combretastatin derivatives obtained by total synthesis and having the following general formula (I) in which the groups are as defined in the description here below. Said compounds, though chemically related to the structure of cis/trans-combretastatin, do not always bind tubulin, but nevertheless exhibit cytotoxic activity of interest in the oncological field as anticancer and/or antiangiogenic agents.
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- Cerebral antihypoxic activity of new thienyldihydropyridines
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New thienyldihydropyridines were synthesized according to Hantzsch's method. The antihypoxic activity of these compounds was compared with that of three reference phenyldihydropyridines by means of the skin conductance reaction (SCR)-hypoxia test.
- Boulouard,Louchahi-Raoui,Heude,Quermonne,Cugnon de Sevricourt,Rault,Robba
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p. 162 - 165
(2007/10/02)
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- New 2-alkylidenemethyl-5-nitrothiophenes: Preparation vis S(RN)1 reactions and in vitro antiprotozoan activity
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The reaction of 2-chloromethyl-5-nitrothiophene with the 2-nitropropane anion has been reinvestigated and extended to various nitronate anions to afford good yields of new 5-nitrothiophenes bearing a trisubstituted ethylenic double bond at the 2-position. These compounds were evaluated as potential antiprotozoan agents and some derivatives were found to have the same activity as that of reference compounds.
- Vanelle,Ghezali,Maldonado,Crozet,Delmas,Gasquet,Timon-David
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- Substitution Reactions of Nitrothiophenes. 6. Disparate Mechanisms for Substitution Reactions at Neopentyl Carbons Bearing 4- and 5-Nitrothienyl Groups
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The reaction of the (5-nitro-2-thienyl)- and (4-nitro-2-thienyl)neopentyl chlorides (9 and 10) with p-toluenesulfinate, azide, and p-toluenethiolate ions proceed smoothly and in high yield (70-95percent) under mild conditions (20 deg C, Me2SO) to give the sulfones 14 and 15, the azides 16 and 17, and the sulfides 18 and 19, respectively.The mechanisms of these substitutions are quite different, however.The substitutions in the 5-nitro series take place by the SRN1 mechanism, whereas those in the 4-nitro series take place by the ionic SN(AEAE) process, which involves initial attack of a nucleophile at the 5-position of the thiophene ring.
- Flower, Felicity I.,Newcombe, Peter J.,Norris, Robert K.
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p. 4202 - 4205
(2007/10/02)
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- Oxotetrahydrothiophenes
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Biological activity is retained while reducing toxicity to animals, particularly mammals, e.g. humans, when a physiologically-active and pharmacologically-acceptable compound (having or structurally modified to have an aldehyde function) is condensed with any of the six (mono)amino(mono)oxotetrahydrothiophenes, e.g. homocysteine thiolactone, to form a Schiff Base (a 4-butyrothiolactone-2-imine or γ-thiobutyrolactone-α-imine). The invention is directed to every Schiff Base which is a condensate of a physiologically-active and pharmacologically-acceptable compound with a (mono)amino(mono)oxotetrahydrothiophene. These Schiff Bases have a unifying common property in reduced toxicity, while maintaining the biological properties "carried" by the imine substituents. They concurrently have at most an insignificant adverse affect on pharmacological activity.
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- INVESTIGATION OF THE KINETICS OF THE NITRATION OF THIOPHENE DERIVATIVES
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The kinetics of the nitration of thiophene derivatives with nitric acid in acetic anhydride were investigated.The nitration of 2-substituted thiophenes is a second-order reaction.The rate constants and activation parameters of the reaction were calculated.The possibility of the Hammett and Yukawa-Tsuno equations for this reaction series is demonstrated.An isokinetic dependence is observed.
- Freidlin, G. N.,Glushkova, A. A.,Solop, K. A.
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p. 127 - 130
(2007/10/02)
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- Substitution Reactions of Nitrothiophens. IV Limitations in Scope of the SN(AEAE) Reaction in Thienylalkyl Derivatives
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The reactions of 5-nitro-3-thienylethyl chloride and acetate with lithium 2-nitropropan-2-ide (1) give excellent yields of the C-alkylate, 4-(1,2-dimethyl-2-nitropropyl)-2-nitrothiophen, by the SN(AEAE) mechanism.The cyano group is not a sufficiently activating substituent to support the SN(AEAE) process and 4-cyano-2-thienyl-methyl and -ethyl chlorides with the salt (1) give O-alkylated products by an SN2 mechanism.The occurence of SN(AEAE) reactions with other nucleophiles is difficult to prove but benzenethiolate and 4-nitro-2-thienylmethyl acetate do react b y this mechanism to give a moderate yield of 4-nitro-2-thienylmethyl phenyl sulfide.
- Newcombe, Peter J.,Norris, Robert K.
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p. 1879 - 1886
(2007/10/02)
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