Thiophene Analogues Research Articles

On the selectivity in the bromination of selenophene‐2‐carbonyl derivatives in the presence of aluminum trichloride

AbstractBromination reactions of 2‐selenophenecarbaldehyde and 2‐acetylselenophene in the presence of aluminum trichloride have been investigated and the reactivity and positional selectivity compared with those of the analogous thiophene derivatives.

Doped polymers by oxidative polymerization, 3. Electrochemical synthesis of poly[trans‐1,2‐di(2‐furyl)ethylene

AbstractRedoxable poly[trans‐1,2‐di(2‐furyl)ethylene] films (PDFE) were synthesized by electrochemical polymerization of trans‐1,2‐di(2‐furyl)ethylene (DFE). Acetonitrile, benzonitrile, nitromethane and propylene carbonate proved to be useful solvents for this polymerization reaction. Suitable supporting electrolytes are tetrabutylammonium perchlorate (TBAP), tetrabutylammonium tetrafluoroborate and lithium perchlorate. To avoid irreversible overoxidation of the polymer, the potential should not exceed 1,15 V (vs. Ag/AgCl). The maintenance of the furan rings in the polymer can be gathered from the reflection IR spectrum. The redoxability of the polymer can be proved by means of the UV/Vis spectrum, which shows a shift of maximum absorption from 310 nm in the reduced state to 345 nm in the oxidized state. PDFE shows an electrochromic behaviour. The potential of oxidation of DFE lies in the same range as the analogous thiophene derivative trans‐1,2‐di(2‐thienyl)ethylene (DTE). A comparison of the polymer PDFE and its corresponding thiophene derivative poly[trans‐1,2‐di(2‐thienyl)ethylene] (PDTE) shows that PDFE is more sensitive to overoxidation, and its electrical conductivity is several orders of magnitude lower.

Cyclometallation of N,N-dimethylbenzo[ b]furan-2-carbothio (and seleno) amides with palladium(II), ruthenium(II) and rhodium(III)

N,N-Dimethylbenzo[ b]furan-2-carbothio (and seleno) amides (abbreviated as Hzft and Hzfs) were prepared from the corresponding carboxamide upon reaction with Lawesson's reagent and phenyldichlorophosphine selenide, respectively. Both Hzft and Hzfs were cyclopalladated with lithium tetrachloropatladate(II) and cyclorhodated with hexachlorotetrakis(tri-n-butylphosphine)dirhodium(IlI), while cycloruthenation with tetrachlorohexacarbonyldiruthenium(II) occurred only with Hzft. These cyclometallated products were spectroscopically characterized. The benzofuran ring was metallated at position 3 and the amide groups were coordinated through the sulfur or selenium atom to form a five-membered metallathia (of selena) heterocycle. The corresponding benzo[ b]thiophene (thianaphthene) analogues were not cyclometallated under similar conditions. The structures of Hzfs, [PdCl(zfs)(PBu 3)], and [RuCl(zft)(CO) 2(PBu 3)] were determined by X-ray analysis.

Studies of the Reaction of Triaminophosphines with α,β-Unsaturated Nitriles

Tris(dialkylamino)phosphines IIIa and IIIb react with furfurylidenemalonitrile (Ia) and its thiophene analogue Ib to give a mixture of 1 : 1 adducts IV and V. Compounds IV have aminophosphonium dipolar ion structure, while compounds V are the ylide forms. The ratio of the products depends on the reaction conditions. Some reactions of IV and V are described.

Novel electron acceptors derived from isothianaphthene

The synthesis and properties of 1,3-dihydro-1,3-bis(dicyanomethylene)isothianaphthene 1 and its higher homologue 1,3-bis(1,3-dicyanovinylene)isothianaphthene 2 are reported; these compounds, which are the first electron acceptors of the isothianaphthene series, show electrochemical behaviour that contrasts with that of their thiophene analogues; the molecular structure of 1 was determined by X-ray analysis.

Formation and [4 + 2] cycloaddition reactions of 2,3‐dimethylene‐2,3‐dihydrothiophene

Abstract2,3‐Dimethylene‐2,3‐dihydrothiophene (1), the thiophene analog of o‐xylylene (o‐quinodimethane), was generated in situ from the (trialkylammoniomethyl)‐(trimethylsilylmethyl)thiophene iodides 4 or 5 by fluoride‐induced 1,4 climination, and was trapped by [4 + 2] cycloadditions with a series of dienophiles. The reaction of 1 with dimethyl fumarate was considerably faster than with dimethyl maleate. Unsymmetrical dienophiles gave mixtures of regio‐isomers. In the absence of dienophiles, 1 formed [4 + 2] spiro dimers, of which 15a is the major component, as determined by 1H‐NMR comparison with a tetradeutero analog of 15a. The syntheses of the new precursors of 1 and dideutero‐1: compounds 4, 5a,b, as well as the 3.4‐isomer of 4, are described.

ChemInform Abstract: Synthesis and Preliminary Study of the Activity of Thiophene Analogues of Pyrovalerone on the Neuronal Uptake of the Monoamines.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Dynamic behaviour of [2] metacyclo [2] (3,4) thiophenophane

AbstractThe conformational analysis of dimethyl [2] metacyclo [2] (3,4)thiophenophane (1), which is the thiophene analogue of [2.2] orthometacyclophane, is described. The comparison between the dynamic NMR spectra of 1 and the computer‐simulated spectra led to the energy barrier between syn and anti conformers of 1. This is the first conformational analysis of a [2,2] orthometa‐type cyclophane.

Rearrangement of dimethyl(furylmethyl)ammonium and dimethyl(thienylmethyl)ammonium N-methylides. Isolation and reaction of nonaromatic intermediates

3-[(Dimethylamino)methyl]-2-methylene-2,3-dihydrofuran (5o) and 2-[(dimethylamino)methyl]-3-methylene-2,3-dihydrofuran (12o) and their thiophene analogues 5s and 12s were prepared in high yields by fluoride-ion induced desilylation of N,N-dimethyl-N-[(trimethylsilyl)methyl](2-furylmethyl)ammonium (3o) and -(3-furylmethyl)ammonium iodides (10o) and their thienylmethyl analogues 3s and 10s

Synthesis and structure-activity relationships of heterocyclic analogues of the functional M 1 selective muscarinic agonist hexyloxy-TZTP

Isothiazole ( 8a,b), isoxazole ( 14) and thiophene ( 19a,b) analogues of the potent, M 1 selective muscarinic agonist, hexyloxy-TZTP, 1b, were synthesized and tested |in vitro for muscarinic receptor affinity and M 1 efficacy. All the analogues had lower affinity and efficacy at the M 1 muscarinic receptors than 1b.

Sulfonylureas: a new class of cancer chemotherapeutic agents.

This study summarizes the antitumor properties of a number of sulofenur thiophene analogs against subcutaneously implanted 6C3HED lymphosarcoma with structural modification of the aryl moiety of the sulfonamide portion of the diarylsulfonylureas. The spectrum of activity of N-(p-chlorophenyl)-N'- [(5-methoxy-2-thienyl)sulfonyl]urea in the HXGC3, VRC5, CX-1, and LX-1 cell lines is also presented.

Reactions of diene-conjugated 1,3-dipolar intermediates: the formation of cyclopropa[c]isoquinolines from benzonitrile o-alkenylbenzyl ylides and their rearrangements to benzazepines

The diene-conjugsted nitrile ylides 19, generated by the 1,3-dehydrochlorination of imidoyl chlorides 18, cyclise at room temperature to give the cyclopropa[c]isoquinolines 21 in a stereospecific reaction. Thermal decomposition of the latter when R1 or R2= H involves an equilibration between exo and endo isomers (Scheme 4) accompanied by a slower ring expansion to give 1H-2-benzazepines. In cases where neither R1 or R2= H the thermal decomposition follows another path (Scheme 5) to give 5H-2-benzazepines. In contrast 32 and 38, the thiophene analogues of 19, do not give cyclopropa[b]thienopyridines 33 and 39, respectively but instead give the thienoazepines 35 and 41.

Synthesis and preliminary pharmacological study of thiophene analogues of the antipyretic and analgesic agent ethenzamide.

A preliminary pharmacological study of a thiophene analogue 1b of the analgesic and antipyretic agent Ethenzamide and of a closely related compound 1a showed that a great similarity exists among Ethenzamide and the thiophenic compounds for analgesic, antipyretic, ulcerogenic, hypothermic, and sedative effects. However, the acute toxicity in mice for the thiophenic compounds is notably higher than that of Ethenzamide.

Researches on antibacterial and antifungal agents, XIV: Thiophene analogues of bifonazole.

Some thiophene analogues of bifonazole have been synthesized by standard procedures and their antifungal activity has been tested against Candida albicans. Among test derivatives biphenyl-4-yl-5-chloro-thien-2-ylimidazol-1-ylmethane and its 5-deschlorothien-2-yl analogue resulted to be the most active. Their antifungal potency was almost comparable to that of control substances, such as miconazole, ketoconazole, and bifonazole. Replacement of benzene by the pyrrole ring in the biphenyl portion retained almost quantitatively the antifungal activity, whereas substitution with other azoles and with nitrogen alicyclic rings led always to less potent derivatives.

Thiophene as a structural element of physiologically active substances. 20. Thiophene analogs of the leukotriene D4 antagonist Ro 23-3544

The synthesis of 6-Acetyl-7-[[5-(5-acetyl-4-hydroxy-3-propyl-2-thienyl- oxy)pentyl]oxy]-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid (1), a thiophene analogue of the leukotriene antagonist Ro 23-3544, is described. Compound 1 shows almost no effect on leukotriene D4 induced broncho-constriction on anesthesized guinea pigs.

Oxidation of molybdenum dithiolene complexes yields thiophene analogs of urothione and molybdopterin form B

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxidation of molybdenum dithiolene complexes yields thiophene analogs of urothione and molybdopterin form BCheryl L. Soricelli, Veronika A. Szalai, and Sharon J. Nieter BurgmayerCite this: J. Am. Chem. Soc. 1991, 113, 26, 9877–9878Publication Date (Print):December 1, 1991Publication History Published online1 May 2002Published inissue 1 December 1991https://doi.org/10.1021/ja00026a038RIGHTS & PERMISSIONSArticle Views183Altmetric-Citations21LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (303 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Thiophene systems. 12. Analogues of ketanserin and ritanserin as selective 5-HT 2 antagonists

A series of thieno[3,2- d]-, [3,4- d]- and [2,3- d]pyrimidinedione derivatives was prepared with N-3 substitution containing the side chains of ketanserin and ritanserin. The best of these thiophene analogues were the isosteres of ketanserin which were up to 20-fold more potent than the standards in 5-HT 2 binding assays. More importantly, in addition to their increased potency, these derivatives were more selective than the standards in that they had less affinity for 5-HT 1A and α 1 binding sites. This selectivity is especially noted as the ratio of α 1 5-HT 2 wherein the most interesting thiophene isostere ( 2) in this study had a binding selectivity > 12-fold of ketanserin or ritanserin.

ChemInform Abstract: Synthesis and Pharmacological Study of a Thiophene Analogue of Moprolol and Related Compounds.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Spectral and quantum-chemical study of some heteroanalogs of 1,4-bis(5-phenyl-2-azolyl)benzenes

The effect of structural changes in the molecules of thiophene and furan analogs of 1,4-bis(5-phenyl-2-azolyl)benzenes on their electronic spectra was studied by the MO LCAO method within the π-electron approximation.

Role of the spacer in conferring .kappa. opioid receptor selectivity to bivalent ligands related to norbinaltorphimine

The thiophene 2 and pyran 3 analogues of the kappa-selective opioid antagonist norbinaltorphimine (1a, norBNI) were synthesized and tested in an effort to determine the contribution of the spacer to the interaction of bivalent ligands at different opioid receptor types. Both 2 and 3 were found to be selective kappa opioid receptor antagonists in smooth muscle preparations, and they bound selectively to kappa-recognition sites. The thiophene analogue 2 displayed binding selectivity that was of the same order of magnitude as that of 1a, while 3 was considerably less selective for kappa site. This is consistent with the fact that the second pharmacophore in 1a and 2 displayed a greater degree of superposition than 1a and 3. The results of this study suggest that the pyrrole moiety of norBNI functions primarily as an inert spacer to rigidly hold the basic nitrogen in the second pharmacophore at an "address" subsite that is unique for the kappa opioid receptor.