Library

X
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
    Darstellung und Struktur von Pyrazolyl-Kationen mit Polymethin- und Methan-Gerüst (1983)
    Springer
    Monatshefte für Chemie 114 (1983), S. 219-225 
    Details
    ISSN: 1434-4475
    Keywords: Cyanine dyes ; Dipyrazolylmethanes ; Heterocycles ; N-15-NMR ; O-17-NMR ; Phenazon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The 4-pyrazoline-3-one1 reacts with 4-dimethylaminobenzaldehyde to yield the stable asymmetric cyanine dye2b which reacts with1 to give the colorless (aryl) (dipyrazolyl) methane3b. Using aldehydes with less cationstabilizing groups the polymethines2 are not isolated but only the methanes3. The structures of2b and3 are discussed by1 H,13C and Hetero NMR spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00798325
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Thion- und Dithioester, XXX. Reaktionen von Isocyaniden mit Thiooxalestern (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 3107-3114 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiono and Dithio Esters, XXX. Reactions of Isocyanides with ThiooxalatesDimethyl tetrathiooxalate (1) reacts with all isocyanides 2 investigated to form 2-imino-1,3-dithioles 4 in high yield. Complex mixtures of products, however, are obtained from O,O-dimethyl dithiooxalate (5) and isocyanides. The main product is always the 1,3-thiazetidine 7, by-products are the azetidinethiones 8 and the 3,3′-biazetidine-2,2′-dithiones 6.
    Notes: Tetrathiooxalsäure-dimethylester (1) bildet mit allen untersuchten Isocyaniden 2 in einheitlicher Reaktion die 2-Imino-1,3-dithiole 4. Komplexe Produktgemische entstehen hingegen bei der Umsetzung von Dithiooxalsäure-O, O-dimethylester (5) mit Isocyaniden. Hauptprodukt ist stets das 1,3-Thiazetidin 7, Nebenprodukte sind die Azetidinthione 8 und 3,3′-Biazetidin-2,2′-dithione 6.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150916
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Gekreuzt-konjugierte polychlorierte Cycloheptatrienderivate aus Octachlorcycloheptatrien und Hexachlortropon (1988)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 1595-1600 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cross-Conjugated Polychlorinated Derivatives of Cycloheptatriene from Octachlorocycloheptatriene and HexachlorotroponeA new convenient synthesis of hexachlorotropone (6) and some condensation reactions of 6 are described, yielding novel polychlorinated cross-conjugated derivatives of cycloheptatriene. Treatment of octachlorocycloheptatriene (5) with benzene/CF3SO3Ag and phenylmalononitrile (28) leads to the first stable [1.6.7]quinarenes 19 and 29, respectively. The structure of 19 is proved by X-ray diffraction and a mechanism is proposed for the reaction. The influence of polychlorination on stability and electronic spectra is discussed.
    Notes: Wir beschreiben eine neue, ergiebige Synthese von Hexachlortropon (6) und einige Kondensationsreaktionen von 6 zu neuen polychlorierten, gekreuzt konjugierten Cycloheptatrienderivaten. Umsetzungen von Octachlorcycloheptatrien (5) mit Benzol/CF3SO3Ag bzw. mit Phenylmalononitril (28) führen zu ersten stabilen [1.6.7]Chinarenen 19 und 29. Die Struktur von 19 wird mit Hilfe einer Röntgenstrukturanalyse bewiesen und ein Bildungsweg vorgeschlagen. Der Einfluß der Polychlorierung auf Stabilität und Elektronenspektren wird diskutiert.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19881210910
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    15N-NMR-Studien der Tautomerie in N-monosubstituierten Amidinen und in N,N′-Diphenylguanidin (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1101-1104 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 15N NMR Studies of the Tautomeric Equilibrium of N-Monosubstituted Amidines and of N,N′-Diphenylguanidine15N NMR data are reported for tautomeric N-monosubstituted amidines 1a and b and for N,N′-diphenylguanidine (6). In order to elucidate the position of the tautomeric equilibrium, the nitrogen resonances of the salts of 1a, b and 6 were also determined. For comparison, chemical shifts δ15N were measured of non-tautomeric amidines 2 - 5. The preferred tautomers for N-phenylbenzamidine (1a) and for 6 have the C=N double bond conjugated with the phenyl group. Replacement of an NH proton with an alkyl group, as in 1b, has little effect on the tautomeric equilibrium of amidines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190331
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Zur Tautomerie von O-Alkylidenpropandinitril- und O-Alkylidencyanamid-Gruppen in O-substituierten Acetylacetonen (1989)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 122 (1989), S. 669-675 
    Details
    ISSN: 0009-2940
    Keywords: Acetylacetonates, O-substituted ; (Alkenyloxymethylene)cyanamide derivatives ; (Alkenyloxymethylene)-propanedinitrile derivatives ; Tautomerism ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tautomerism of O-Alkylidenepropanedinitrile and O-Alkylidenecyanamide Groups in O-Substituted AcetylacetonesReaction of the sodium salt of acetylacetone (1) with (α-chlorobenzylidene)propanedinitrile (2, R = Ph) leads to the C-substitution product 4 as the cis-enol. The trans-enol 5 is only obtained as an intermediate (e.g. photochemically) yielding immediately the 2-pyridone 6. Acetylacetone (7) as such reacts with 2 (R = Ph) or with N-cyanobenzimidoyl chloride (9) in the presence of triethylamine/DMAP to give the O-substitution products 8 and 10 as mixtures of their E/Z-isomers. The Z-isomers show a rapid degenerate (O → O) migration. By heating, 8Z rearranges irreversibly to the benzoic acid enol ester 11. 3-Phenylacetylacetone or its thallium(I) salt 16 reacts with (1-chloroalkylidene)propanedinitriles 2 or with N-cyanobenzimidoyl chloride (9) to yield the O-substitution products 14, 15, 17a, and 17b. 8Z, 17a, and 17b were investigated by DNMR spectroscopy.
    Notes: Die Umsetzung des Natriumsalzes von Acetylaceton (1) mit (α-Chlorbenzyliden)propandinitril (2, R = Ph) ergibt das C-Substitutionsprodukt 4 als cis-Enol. Das nur als Zwischenstufe (z. B. photochemisch) erhältliche trans-Enol 5 cyclisiert sofort zum 2-Pyridon 6. Acetylaceton (7) selbst liefert mit 2 (R = Ph) oder mit N-Cyanbenzimidoylchlorid (9) in Gegenwart von Triethylamin/DMAP die O-Substitutionsprodukte 8 und 10 als E/Z-Isomerengemische. Die Z-Isomere zeigen eine schnelle entartete (O → O)-Wanderung. 8Z lagert sich bei längerem Erhitzen irreversibel in den Benzoesäure-enolester 11 um. 3-Phenylacetylaceton oder sein Thallium(I)-Salz 16 reagieren mit (1-Chloralkyliden)propandinitrilen 2 oder N-Cyanbenzimidoylchlorid (9) zu den O-Substitutionsprodukten 14, 15, 17a und 17b. 8Z, 17a und 17b werden DNMR-spektroskopisch untersucht.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19891220413
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Zur Kenntnis von Reaktionen des 1,2,4,5-Tetrazin-3,6-dicarbonsäure-dimethylesters mit Nucleophilen (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 683-694 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Dimethyl 1,2,4,5-Tetrazine-3,6-dicarboxylate with NucleophilesThe reaction of water, ammonia or dimethylamine with the tetrazine 1 leads via 1,4-addition of the nucleophile to the hydrazide 4 and the azines 6, 7, respectively. Contrarily methylamine yields the triazine 13. Methanol or methanethiol react to the pyrazoles 19 and 18, respectively. The structure of 18 is proved by X-ray diffraction. Depending on the p-substituents, anilines give triazoles 22 or pyrazolo[3,4-e]triazines 24.
    Notes: Die Reaktion von Wasser, Ammoniak oder Dimethylamin mit dem Tetrazin 1 führt unter 1,4-Addition des Nucleophils zum Hydrazid 4 bzw. zu den Azinen 6 und 7. Mit Methylamin entsteht im Gegensatz dazu das Triazin 13. Methanol oder Methanthiol reagieren zu Pyrazolderivaten 19 bzw. 18. Die Struktur von 18 wird durch eine Röntgenstrukturanalyse belegt. para-Substituierte Aniline lassen sich je nach p-Substituent in Triazole 22 oder Pyrazolo[3,4-e]triazine 24 überführen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150228
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Thion- und Dithioester, XXIX. Reaktionen von Diazoverbindungen mit Thiooxalestern (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 3096-3106 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiono and Dithio Esters, XXIX. Reactions of Diazo Compounds with ThiooxalatesDimethyl tetrathiooxalate (1) reacts with all diazo compounds 2 investigated to form 1,3-dithioles 3 in high yield. Complex mixtures of products, however, are obtained from O,O-dimethyl dithiooxalate (6) and diazo compounds. The reactions of 6 with diazomethane, diazoethane, 2-diazopropane and diphenyldiazomethane were investigated more in detail.
    Notes: Tetrathiooxalsäure-dimethylester (1) bildet mit allen untersuchten Diazoverbindungen 2 in einheitlicher Reaktion die 1,3-Dithiole 3. Komplexe Produktgemische entstehen hingegen bei der Umsetzung von Dithiooxalsäure-O, O-dimethylester (6) mit Diazoverbindungen. Näher untersucht wurde die Reaktion von 6 mit Diazomethan, Diazoethan, 2-Diazopropan und Diphenyl-diazomethan.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150915
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Reaktionsprodukte aus N,N-Bis(chlormethyl)carboxamiden und Diaziridinen (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 2947-2949 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction Products from N,N-Bis(chloromethyl)carboxamides and DiaziridinesSpiro[cyclohexane-1,3′-diaziridine] (1) reacts with N,N-bis(chloromethyl)carboxamides (2) to form pentacyclic ditriazolidino-s-hexahydrotetrazines 7.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150826
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    [4 + 2]-Cycloadditionen mit inversem Elektronenbedarf, XVII. Oxepin und 2,7-Dimethyloxepin als Dienophile bei Diels-Alder-Cycloadditionen mit inversem Elektronenbedarf (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 97-102 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [4 + 2] Cycloadditions with Inverse Electron Demand, XVII. Oxepin and 2,7-Dimethyloxepin as Dienophiles in Diels-Alder Cycloadditions with Inverse Electron DemandThe cycloaddition reactions of oxepin (1) with the tetrazine 3 and the triazine 12 yield the dihydrooxepino[4,5-d]pyridazine 5 and the oxepino[4,5-c]pyridine 13, resp., via [2 + 4] cycloaddition as well as the phthalazine 9 and the isoquinoline 14, resp., most probably via [6 + 4] cycloaddition. On the contrary, 2,7-dimethyloxepin (15) only gives the products 16 and 20, which result from [2 + 4] cycloaddition. Oxidation of 16 by silver(I) oxide leads to the oxepino[4,5-d]pyridazine 17, which as well as 20 in hydrochloric acid rearranges to the pseudoazulenes 19 and 21, resp.
    Notes: Cycloadditionsreaktionen von Oxepin (1) mit dem Tetrazin 3 oder dem Triazin 12 führen zum Dihydrooxepino[4,5-d]pyridazin 5 bzw. Oxepino[4,5-c]pyridin 13 via [2 + 4]-Cycloaddition und zum Phthalazin 9 bzw. Isochinolin 14 sehr wahrscheinlich via [6 + 4]-Cycloaddition. Mit 2,7-Dimethyloxepin (15) erhält man im Gegensatz dazu lediglich die Reaktionsprodukte 16 und 20, die aus der [2 + 4]-Cycloaddition resultieren. Durch Oxidation von 16 mit Silber(I)-oxid entsteht das Oxepino[4,5-d]pyridazin 17, das in Salzsäure ebenso wie 20 umgelagert wird in das Pseudoazulen 19 bzw. 21.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831160111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Versuche zur acylotropen und silylotropen Tautomerie bei 1,5-Diacylcyclopentadienen und 6-Aminofulven-1-ketiminen (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 2653-2667 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies of Acylotropic and Silylotropic Tautomerism with 1,5-Diacylcyclopentadienes and 6-Aminofulvene-1-ketiminesThe 1,5-diacyl-1,3-cyclopentadienes 2 react with thallium ethanolate to yield the thallium cyclopentadienides 3, which are transformed by acyl halides or chlorotrimethylsilane into the acyl or silyl enol ethers 4 - 6 According to NMR studies some of these compounds show acylotropic or silylotropic tautomerism up to 140°C. With diphenylboron bromide 3 forms the dioxaborepines 8. Condensation of 2 with heptamethyldisilazane (10) leads to the formation of the 1-acyl-6-(methylamino)fulvenes 11. O-Methylation of 11 and aminolysis of the obtained iminium salts 14 with methylamine gives rise to the isolable 6-(methylamino)fulvene-1-ketimines 17.
    Notes: Aus den 1,5-Diacyl-1,3-cyclopentadienen 2 erhält man mit Thallium-ethanolat die Thallium-cyclopentadienide 3, die mit Acylhalogeniden und Chlortrimethylsilan die Acyl- bzw. Silylenolether 4 - 6 liefern. Diese zeigen nach NMR-spektroskopischen Untersuchungen bis 140°C zum Teil acylotrope und silylotrope Tautomerie. Mit Diphenylborbromid bildet 3 die Dioxaborepine 8. Die Kondensation von 2 mit Heptamethyldisilazan (10) liefert die 1-Acyl-6-(methylamino)fulvene 11. Nach O-Methylierung von 11 setzen sich die erhaltenen Iminiumsalze 14 mit Methylamin zu den 6-(Methylamino)fulven-1-ketiminen 17 um.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831160721
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...