Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 60 (1995), S. 2807-2811 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 36 (2000), S. 327-333 
    ISSN: 1573-1111
    Keywords: Schiff base ; calixarene ; upper rim ; complexation ; transition metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The synthesis and properties of upperrim Schiff base calix[4]arenes are described in thisarticle. Tetrakis-p-bromomethylcalix[4]arene(1) reacts with hexamethylenetetramine to givetetrakis-p-formylcalix[4]arene (2) in highyield. Then upper rim Schiff base calix[4]arenes 3 can be easily synthesized by 2 reacting withappropriate alkylamines. The complexation ability of3 toward transition metals Pb2+, Cu2+and Co2+ was studied by UV-VIS spectrophotometry.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclische β-Enaminoester, 341). Neue Typen von Spiro-Verbindungen durch Additions- und Ringschlußreaktionen von 3-(2-Imidazolidinyliden)- und 3-(Tetrahydro-2(1H)-pyrimidinyliden)dihydro-2(3H)-furanonen mit Acrylsäure-methylester und Acetylendicarbonsäure-dimethylesterDie 2(3H)-Furanone 1a - e reagieren mit Acrylsäure-methylester in Benzol- oder Dioxanlösung in einer Additions- und Cyclokondensations-Sequenz zu den Spiro-Verbindungen 2a - e. 1a, b ergeben mit Acetylendicarbonsäure-dimethylester die Additionsprodukte 3a, b; hingegen resultieren aus 1c - e in einer verwandten Additions-Cyclokondensationssequenz die Spiro-Verbindungen 4a - c.
    Notes: The 2(3H-furanones 1a - e react with methyl acrylate in benzene or dioxane solution to afford the spiro compounds 2a - e in an addition and cyclocondensation reaction sequence. With dimethyl acetylenedicarboxylate 1a, b give merely the addition products 3a, b, while 1c - e yields the spiro compounds 4a - c in a related addition-cyclocondensation step.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclische β-Enaminoester, 33. Additions- und Ringschlußreaktionen der 3-(2-Imidazolidinyliden)- und 3-(Hexahydro-2-pyrimidinyliden)-2(3H)-furanone mit Chlorwasserstoffsäure, Halogenen und Propiolsäure-methylesterDie 3-(2-Imidazolidinyliden)- und 3-(Hexahydro-2-pyrimidinyliden)-2(3H)-furanone 1a - e reagieren unter syn-Addition mit Propiolsäure-methylester in Benzol oder Dioxan zu den Addukten 2a - e. In Alkoholen findet Ringschluß zu den Imidazo[1,2-a]pyridinen und Pyrido-[1,2-a]pyrimidinen 3a - j statt unter Öffnung des γ-Lactonrings. In alkoholischer Lösung entstehen 3a - j direkt. In Abhängigkeit von der Substitution reagieren 1a - e mit Brom oder Chlor zu den halogenierten Hydrohalogeniden 4a - c, 5a - c und 6; sie werden ferner mit Chlorwasserstoffsäure glatt zu den Immoniumsalzen 7a - e protoniert.
    Notes: The 3-(2-imidazolidinylidene)- and 3-(hexahydro-2-pyrimidinylidene)-2(3H)-furanones 1a - e react with methyl propiolate in benzene or dioxane solution to afford the adducts 2a - e via syn- addition. In the presence of alcohols 2a - e are cyclized to give the imidazo[1,2-a]pyridines and pyrido[1,2-a]pyrimidines 3a - j with ring cleavage of the γ-lactone ring; in turn 3a - j are directly formed from 1a - e in alcoholic solution. Upon treatment with bromine or chlorine 1a - e give the halogenated hydrohalides 4a - c, 5a - c, or 6 depending on the individual substituents; they are furthermore smoothly protonated with hydrochloric acid to form the immonium salts 7a - e.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 622-632 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclische β-Enaminoester, 321). Zur Reaktion aliphatischer Diamine und von Methylamin mit 2-Amino-4,5-dihydro-3-furancarbonsäureestern. Revidierte Konstitutionsvorschläge durch 13C-NMR-AnalyseDie 13C-NMR-Spektren der Reaktionsprodukte von 2-Amino-4,5-dihydro-3-furancarbonsäure-ethylestern 3a - e mit Ethylendiamin und 1,3-Diaminopropan wurden vermessen und die Konstitutionen mit Hilfe der Gated Decoupling Technik als 3-(2-Imidazolidinyliden)- bzw. 3-(Hexahydro-2-pyrimidinyliden)dihydro-2(3H)-furanone 1a - i und nicht als Furo[2,3-e]-1,4-diazepinone bzw. Furo[2,3-b][1,5]diazocinone 2a - i gesichert. - 3b - e reagieren mit Methylamin zu einem Gemisch aus E- und Z-Isomeren der 3-[Amino(methylamino)methylen]-4,5-dihydro-2(3H)-furanone 6b - e und 6'b - e. Unabhängig von der Substitution beträgt das E-/Z-Verhältnis ungefähr 40:60.
    Notes: 13C NMR spectra of the reaction products of ethyl 2-amino-4,5-dihydro-3-furancarboxylates 3a - e with ethylenediamine and 1,3-diaminopropane, respectively, were measured, and the constitutions were confirmed with the aid of gated decoupling technique to be 3-(2-imidazolidinylidene)- and 3-(hexahydro-2-pyrimidinylidene)dihydro-2(3H)-furanones 1a - i, instead of furo[2,3-e]-1,4-diazepinones and furo[2,3-b][1,5]diazocinones 2a - i, respectively. - The reaction of 3b - e with methylamine has been studied, and a mixture of E- and Z-isomers of 3-[amino(methylamino)methylene]-4,5-dihydro-2(3H)-furanones 6b - e and 6'b - e has been obtained. The ratios of E- and Z-isomers are approximately 40:60, irrespective of the different substituents.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese von Ketenaminalen mit Imidazolidinring durch Kondensation von 4,5-Dihydro-2-(methylthio)-1H-imidazolen mit CH-aciden Methylenverbindungen und einige Additions-und Cyclokondensations-Reaktionen4,5-Dihydro-2-(methylthio)-1H-imidazole 1a, b reagieren mit aktiven Methylenverbindungen 2a-f unter Eliminierung von Methanthiol zu den entsprechend substituierten Methylenimidazolidinen 3a-f und 4c-f. Die Verbindungen 2g-j, die eine aktivere Carbonylgruppe enthalten, ergeben mit 1a unter Eliminierung einer Methylthio- und Acylgruppe 3g-i. 3a, g-i reagieren mit Estern ungesättigter Säuren in einer Additions- und Cyclokondensations-Sequenz zu den entsprechenden Imidazo[1,2-a]pyridinen 5,6 und 7, ergeben aber mit Azodicarbonsäure-diethylester nur die Additionsprodukte 8.
    Notes: The 4,5-dihydro-2-(methylthio)-1H-imidazoles 1a,b react with active methylene compounds 2a-f to afford the corresponding substituted methyleneimidazolidines 3a-f and 4c-f by elimination of methanethiol. The reaction of compounds 2g-j, which contain a more active carbonyl group, with 1a gives 3g-i by elimination of a methylthio group as well as an acyl group, too. 3a,g-i react with esters of α,β-unsaturated acids to afford the corresponding imidazo[1,2-a]pyridines 5,6, and 7 in an addition and cyclocondensation reaction sequence, but with diethyl azodicarboxylate only to give the addition product 8.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1042-7163
    Keywords: Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Heterocyclic ketene aminals reacted with aryl isothiocyanates to give products of addition to the β-carbon. By oxidative cyclization of these addition products by the action of bromine, isothiazole-fused heterocycles or benzothiazole-substituted heterocyclic ketene aminals were formed according to the influence of the different substituents.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Heteroatom Chemistry 7 (1996), S. 285-288 
    ISSN: 1042-7163
    Keywords: Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: α-Aroyl substituted bis-ketene N,S-acetals 3-6 with a polymethylene linkage, N,N′-bis(1-methylthio-2-aroyl)vinyl polymethylene diamines, were synthesized by reactions between α-aroyl ketene dithioacetals 1 and polymethylene diamines 2 in moderate yields. © 1996 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 122 (1989), S. 95-100 
    ISSN: 0009-2940
    Keywords: Diazaheterocycles, γ-lactam-fused ; Ketene aminals, heterocyclic ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkylierung von Heterocyclischen Keten-aminalen mit Benzylchlorid und Bromessigsäure-ethylester. Synthese von Heterobicyclen bestehend aus γ-Lactam-verknüpften DiazaheterocyclenHeterocyclische Keten-aminale 1-3 reagieren mit Benzylchlorid zu den Benzyl-substituierten Verbindungen 4-6. Bromessigsäure ethylester liefert analoge Alkylierungsprodukte, die zu den γ-Lactamen 9-11 cyclisieren.
    Notes: Heterocyclic ketene aminals 1-3 react with benzyl chloride to give the benzyl-substituted compounds 4-6. With ethyl bromoacetate, 1-3 react smoothly, and γ-lactam-fused heterobicycles 9-11 are obtained by further cyclocondensation of the alkylation products.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 541-547 
    ISSN: 0009-2940
    Keywords: Ketene N,S-acetals / 1H-Pyrido[2,1-b]benzothiazole, derivatives ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ketene dithioacetals 2 react with 2-aminothiophenol to afford the corresponding substituted 2(3H)-methylenebenzothiazoles 3. Some compounds 3 react with α,β-unsaturated esters to give 1H-pyrido[2,1-b]benzothiazole derivatives 4 and 5 by an electrophilic addition and cyclocondensation sequence.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...