Home  About us  Contact
 

Heterocyclic System (heterocyclic + system)

Distribution by Scientific Domains
Chemistry100%

Kinds of Heterocyclic System

  • new heterocyclic system
    		•

    Selected Abstracts

    Application of Selective Palladium-Mediated Functionalization of the Pyrido[3,,2,:4,5]pyrrolo[1,2- c]pyrimidine Heterocyclic System for the Total Synthesis of Variolin B and Deoxyvariolin B,

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 29 2010
    Alejandro Baeza
    Abstract The reaction of protected 3-bromo-2-(bromomethyl)-4-methoxypyrrolo[2,3- b]pyridine and tosylmethyl isocyanide (TosMIC) afforded a pyrido[3,,2,:4,5]pyrrolo[1,2- c]pyrimidine derivative in good yield. This compound was transformed through installation of the pyrimidine moiety in the C5 position, hydrolysis, and decarboxylation in an advanced intermediate for the total or formal synthesis of the naturalalkaloid variolin B. Reaction of 3-bromo-2-(bromomethyl)-4-chloropyrrolo[2,3- b]pyridine with N -tosylmethyl dichloroformimide as a synthetic TosMIC equivalent afforded trihalo-substituted pyrido[3,,2,:4,5]pyrrolo[1,2- c]pyrimidine. This compound was used in a new total synthesis of the alkaloid variolin B by selective and sequential C,N, C,C, and C,O palladium-mediated functionalization at the C9, C5, and C4 positions of the pyrido[3,,2,:4,5]pyrrolo[1,2- c]pyrimidine system. A formal synthesis of deoxyvariolin B is also described by using the same synthetic strategy. [source]

    ChemInform Abstract: Synthesis of 7,8-Dihydro-6H-pyrazolo[5,,1,:3,4][1,2,4]triazino[6,5-d] [1,2]diazepin-6-one, a New Heterocyclic System.

    CHEMINFORM, Issue 47 2009
    V. V. Didenko
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source]

    ChemInform Abstract: Condensed Bridgehead Nitrogen Heterocyclic System: Synthesis and Pharmacological Activities of 1,2,4-Triazolo-[3,4-b]-1,3,5-thiadiazole Derivatives of Ibuprofen and Biphenyl-4-yloxy Acetic Acid.

    CHEMINFORM, Issue 28 2009
    Mohd. Amir
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source]

    ChemInform Abstract: Synthesis of Benzo[b]thieno[3,2-e]benzimidazoles, First Representatives of a New Heterocyclic System.

    CHEMINFORM, Issue 23 2009
    T. E. Khoshtariya
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source]

    ChemInform Abstract: Synthesis of a Novel Heterocyclic System , 7-Methyl-1,2-dihydro[1,2,4]triazino[3,4-b][1,2,4,5]tetrazine-6-thione.

    CHEMINFORM, Issue 19 2009
    M. M. Heravi
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source]

    Synthesis of a New Heterocyclic System , Pyrrolo[1,2-a][4,1]benzoxazepine

    CHEMINFORM, Issue 9 2004
    N. S. Kistanova
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Synthesis of New Compounds Containing the 2,3-Dihydro[1,4]dioxino[2,3-b]pyridine Heterocyclic System as a Substructure.

    CHEMINFORM, Issue 36 2003
    M. Soukri
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Synthesis of a Novel Heterocyclic System: Quinoxalino[1,2-a]pyrrolo[2,3-b][1,5]benzothiazepine (III).

    CHEMINFORM, Issue 34 2003
    A. N. Maslivets
    No abstract is available for this article. [source]

    New Condensed Heterocyclic System (III) with a Bridgehead Phosphorus Atom.

    CHEMINFORM, Issue 52 2002
    V. V. Ivanov
    No abstract is available for this article. [source]

    ChemInform Abstract: 7,12-Dihydroisoquino[3,2-c]-1,2,4-benzothiadiazine, a New Heterocyclic System.

    CHEMINFORM, Issue 32 2001
    V. M. Kisel'
    Abstract ChemInform 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. [source]

    ChemInform Abstract: Pyridine-Functionalized MCM-41 as an Efficient and Recoverable Catalyst for the Synthesis of Pyran Annulated Heterocyclic Systems.

    CHEMINFORM, Issue 30 2010
    Ahmad Shaabani
    Abstract ChemInform 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. [source]

    ChemInform Abstract: Zipper-Mode Double C,H Activation: Palladium-Catalyzed Direct Construction of Highly Fused Heterocyclic Systems.

    CHEMINFORM, Issue 14 2008
    Hiroaki Ohno
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source]

    Synthesis of Derivatives of a New Heterocyclic Systems , 7-Thia-5,8,11-triazaindeno[1,2-c]fluorene.

    CHEMINFORM, Issue 52 2007
    V. V. Dotsenko
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Synthesis of Fused Nonaromatic Heterocyclic Systems Based on Dioxolanones (I) and Hydrazine.

    CHEMINFORM, Issue 45 2007
    Yu. B. Chudinov
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Fused Heterocyclic Systems with s-Triazine Ring.

    CHEMINFORM, Issue 13 2007
    Part 4.
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Synthesis of S-Triazolo[3,4-a]phthalazine and Related Polynuclear Heterocyclic Systems.

    CHEMINFORM, Issue 51 2005
    A. A. Aly
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Synthesis of New Heterocyclic Systems: 3,4-Dihydro-1-isoquinolinyl- and Spiro[4,5]benzo[8,9]-6-azadec-6-en-7-ylthieno[2,3-b]pyridine-3-amines.

    CHEMINFORM, Issue 8 2005
    E. A. Kaigorodova
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    ChemInform Abstract: Novel Bridgehead Nitrogen Heterocyclic Systems: Synthesis and Antimicrobial Activity of Imidazo[2,1-b]-1,3,4-thiadiazolo[2,3-c]-s-triazoles, s-Triazolo[3,4-b][1,3,4]thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline and Bis-(s-triazolo[3,4-b][1,3,4]thiadiazolo[3,2-b][imidazo [4,5-b]-cyclohexane]-5a,6a-diene).

    CHEMINFORM, Issue 31 2001
    Jag Mohan
    Abstract ChemInform 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. [source]

    A Joint Theoretical and Experimental Insight into the Electronic Structure of Chromophores Derived from 6H,12H -5,11-Methanodibenzo[b,f][1,5]diazocine

    HELVETICA CHIMICA ACTA, Issue 11 2007
    Vincent Lemaur
    Abstract We report on the synthesis and electronic spectra of the chiral, donor-acceptor (push-pull) chromophores (±)- 4 and (±)- 5 with a 6H,12H -5,11-methanodibenzo[b,f][1,5]diazocine scaffold (Scheme,1 and Fig.,2). The electronic structures of these compounds were investigated at a quantum-chemical level (Figs.,2 and 3). The chemical reactivity of 6H,12H -5,11-methanodibenzo[b,f][1,5]diazocine ((±)- 11) towards aromatic electrophilic substitution (Scheme,2 and Table) provided additional information about its electronic structure and confirmed nonnegligible delocalization of the lone pair of the bridge-head N-atoms in this heterocyclic system. [source]

    Synthesis of some pyrazolo[1,5- c][1,3]benzoxazines and a new 5H -pyrazolo[1,5-c][1,3,2]benzoxazaphosphorine ring system

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2005
    Jan Svetlik
    Condensations of 5-(2-hydroxyphenyl)pyrazoline 3a with 4-carboxybenzaldehyde, glyoxylic acid and N,N -carbonyldiimidazole leading to pyrazolobenzoxazine derivatives were studied. The observed diastere-oselectivity is discussed. Reaction of 3a with Lawesson reagent gave rise to a new 5H -pyrazolo[1,5-c]-[1,3,2]benzoxazaphosphorine heterocyclic system. [source]

    First synthesis and x-ray crystal structure of hexahydrobenzo[b]pyrido[3,4,5- de]-1,6-naphthyridines

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2005
    Leonid G. Voskressensky
    The reaction of 10-carboxamido tetrahydrobenzo[b][1,6]naphthyridines 1-3 with activated terminal alkynes in DMF/methanol resulted with the formation of hexahydrobenzo[b]pyrido[3,4,5- de]-1,6-naph-thyridines 7-10 - representatives of a new heterocyclic system. [source]

    Ring transformations of heterocyclic compounds.

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2002

    2,4,6-Triarylpyrylium perchlorates 1 react with methyleneindolines 3in situ generated from the corresponding methylindolium salts 2, which are spiro-fused with a cycloalkane, benzanellated cycloalkene or a heterocyclic system. These diastereoselective 2,5-[C4+C2] pyrylium ring transformations are carried out in the presence of triethylamine/acetic acid in boiling ethanol to give the dispiroindolines 4 with a trans configuration of the more bulky substituents at the cyclohexadiene ring. By the same type of transformation the dispiro compounds 7/10 with an additional fused benzene ring are obtained from the pyrylium salt 1a and 6/9, the benzo-fused analogues of 3. Spectroscopic data of the transformation products as well as their mode of formation are discussed. [source]

    Synthesis and Biological Evaluation of Some Polymethoxylated Fused Pyridine Ring Systems as Antitumor Agents

    ARCHIV DER PHARMAZIE, Issue 10 2009
    Sherif A. F. Rostom
    Abstract A series of 3,5- bis(arylidene)-4-piperidones like chalcone analogues carrying variety of methoxylated aryl groups, pyrazolo[4,3- c]pyridines, pyrido[4,3- d]pyrimidines, and pyrido[3,2- c]pyridines, carrying an arylidene moiety, and some pyrano[3,2- c]pyridines, like flavone and coumarin isosteres, were synthesized and screened for their in-vitro antitumor activity at the National Cancer Institute (NCI, USA). The tested compounds 7, 9, 10, 12, 13, 15, 17, and 19 exhibited a broad spectrum of antitumor activity. Compounds belonging to the pyrazolo[4,3- c]pyridine series proved to be more active than those of the pyrido[3,2- c]pyridine and pyrano[3,2- c]pyridine analogues, in which the monomethoxylated derivatives showed better antitumor activity when compared with their corresponding dimethoxylated congeners. Compound 7 is considered to be the most active member identified in this study with a broad spectrum of activity against 22 different tumor cell lines belonging to the nine subpanels employed, and a particular effectiveness against the breast cancer T-47D cell line (GI 54.7%). The pyrano[3,2- c]pyridine heterocyclic system 19 proved to be the most active antitumor agent among the six-membered fused pyridines, with variable activity against 18 different tumor cell lines, and special activity against the non-small cell lung cancer Hop-92 and ovarian cancer OVCAR-4 cell lines (GI values 63.9 and 48.5%, respectively). [source]

    ChemInform Abstract: Efficient One-Pot Synthesis of 6-Arylpyrrolo[3,2-d]pyrimidines from 6-Arylethynyl-5-nitropyrimidines.

    CHEMINFORM, Issue 36 2010
    Inga Cikotiene
    Abstract The synthesis of the biologically important heterocyclic system involves conjugative addition of diethylamine to ethynylpyrimidines (I) and subsequent reductive cyclization. [source]

    Fused Tetracyclic Heterocycles by Thermally Initiated Intramolecular Criss-Cross Cycloaddition of 3-Substituted Homoallenylaldazines

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2005
    Hana Zachová
    Abstract The thermally initiated intramolecular criss-cross cycloaddition of 3-substituted homoallenylaldazines 5 has been explored. Their cyclization led to interesting new fused heterocyclic systems 6 consisting of four five-membered rings with two nitrogen heteroatoms. The azines were prepared by the reaction of homoallenyl aldehydes 4 with hydrazine. The homoallenyl aldehydes 4 were synthesized by the Claisen rearrangement of new N,N -disubstituted 4-[(2-methylprop-1-en-1-yl)oxy]but-2-yn-1-amines 3a,f prepared by Mannich reaction of 2-methylprop-1-en-1-yl prop-2-yn-1-yl ether (2). The success of the reaction was based on the improved solvent-free synthesis of 1-chloro-2-methylpropyl prop-2-yn-1-yl ether (1) and its conversion to isolable 2-methylprop-1-en-1-yl prop-2-yn-1-yl ether (2) in high yield. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

    Studies on organophosphorus compounds: Synthesis and reactions of [1,2,4,3]triaza-phospholo[4,5- a]quinoxaline derivative

    HETEROATOM CHEMISTRY, Issue 5 2008
    Hassan M. Moustafa
    2,4-Bis-(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson's reagent) (1) reacted with 2-hydrazino-3-methyl-quinoxaline (2) to give [1,2,4,3]-triazaphospholo[4,5- a]quinoxaline derivative 3. The Mannich reaction using different amines on compound 3 gave Mannich bases 4a,d. Also, compound 3 reacted with formaldehyde to give the corresponding 2-hydroxymethyl derivative 5, which upon reaction with thionyl chloride gave the corresponding chloromethyl derivative 6. Treatment of compound 6 with some thiols yielded the corresponding sulfides 7a,d. Acylation of compound 3 gave acylated compounds 8a,b. Compound 9, which was prepared through the reaction of compound 3 with ethyl cyanoacetate, was investigated as a starting material for the synthesis of some new heterocyclic systems 10,13. Also, reaction of compound 9 with carbon disulfide and 2 equivalents of methyl iodide in a one-pot reaction yielded the corresponding ketene-S,S-acetal 14, which in turn reacted with bidentates to give some new heterocycles 15,17. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:520,529, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20473 [source]

    Chemistry and heterocyclization of dithiobiurea and thioureidoalkylthiourea

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
    Alaa A. Hassan
    This review summarizes published data on the behavior and reactions of dithiobiurea and thioureidoalkylthiourea derivatives, which lead to the formation of heterocyclic systems, including methods of preparation in addition to synthesis of imidazolidine, thiazole, thioazolidine, triazolidine, thiadiazine, and spiro compounds. J. Heterocyclic Chem., (2010). [source]

    Benzo[1,2- c:3,4- c']bis[1,2,5]selenadiazole, [1,2,5]selenadiazolo-[3,4- e]-2,1,3-benzothiadiazole, furazanobenzo-2,1,3-thiadiazole, furazanobenzo-2,1,3-selenadiazole and related heterocyclic systems

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2004
    Catherine M. Cillo
    The first synthesis of benzo[1,2- c:3,4- c']bis[1,2,5]selenadiazole has been developed starting from commercially available 4-nitrobenzo-2,1,3-selenadiazole. Improved syntheses of the related heterocycles [1,2,5]selenadiazolo[3,4- e]-2,1,3-benzothiadiazole, furazanobenzo-2,1,3-thiadiazole and furazanobenzo-2,1,3-selenadiazole are also reported. [source]

    A robust method for determining 1H,15N long-range correlations: 15N optimized CIGAR-HMBC experiments,

    MAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2003
    Mike Kline
    Abstract An examination of a variety of common nitrogen-containing systems was undertaken to optimize parameters for observation of 1H,15N long-range correlations. Because of the diversity of coupling constants encountered with 1H,15N correlations, a modified accordion-based sequence was used to provide the best results. Optimization of the values for the accordion delay revealed that a range between 3 and 10 Hz provided the best compromise between detection of weak correlations and loss of signal to T2 processes. Multiple bond correlations were readily detected for each class of compound with the exception of anilines. Correlations within heterocyclic systems revealed some general patterns. In general, stronger correlations were observed from protons to ,pyrrole-like' nitrogens than to the ,pyridine-type' nitrogens of imidazoles and pyrazoles. Very long-range (four- and five-bond) correlations were routinely observed between methyl groups and the nitrogens of aromatic heterocycles. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Chromophoric potential of the 4(3H)-quinazolinones: a review

    COLORATION TECHNOLOGY, Issue 3 2004
    Harjinder Singh Bhatti
    The last few decades have seen significant developments in the use of heterocyclic compounds in dyestuff and pigment chemistry. The design of newer heterocyclic systems has been a major target area and has focused on economically viable synthesis, absence of effluent problems and freedom from carcinogenic and mutagenic effects. The present article reviews the chemical and patent literature on the chromophoric potential of the 4(3H)-quinazolinone ring system, including dyes, pigments, fluorescent brightening agents, luminescent inks, electroluminescent devices, photographic couplers, colour formers and photographic fog inhibitors. [source]