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  • 1
    ISSN: 1434-4475
    Keywords: Carbon-13 NMR ; Diazaphenanthrenes ; Steric shifts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Sterisch bedingte Tieffeldverschiebungen infolge von δ-CH-Molekülteilen und δ-lone pairs von Stickstoffatomen sind in methylierten Diazaphenanthrenen ähnlich. Die gemessenen δ-Effekte dürften auf sterische Deformationen zurückzuführen sein, was als weiteres Indiz für den nahezu gleichgroßen Raumbedarf eines Wasserstoffatoms und eines freien Elektronenpaars am Stickstoff gewertet werden kann.
    Notes: Abstract Steric downfield shifts due to a δ-CH moiety and a δ-nitrogen lone pair are similar in methylated diazaphenanthrenes. Most probably steric distortions are responsible for the δ-effects observed, and this might be quoted as a further evidence for a nearly equal steric requirement of a hydrogen atom and a nitrogen lone pair.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 119 (1988), S. 263-276 
    ISSN: 1434-4475
    Keywords: Phenanthroline ; Aminoether ; Vivakorfen ; Intercalation of DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Wechselwirkung von trizyklischen, azaaromatischen Systemen mit positiver Ladung an Seitenketten mitDNA, der Einfluß der molekularen Struktur des Liganden bei nonkovalenter Bindung und die Stabilität des gebildeten Komplexes wurde bestimmt. Als Liganden wurden mehrere (N,N-diethylamino)alkoxy-Verbindungen von 1,7-, 1,8-, 1,10- und 4,7-Phenanthrolin in protonierter Form benutzt. Es wurde gezeigt, daß die elektronischen und sterischen Faktoren für elektrostatische und intercalative Wechselwirkungen des Ligand undDNA verantwortlich sind. Es wurden Synthesen von (N,N-diethylamino)alkoxy-phenanthrolinen aus entsprechenden Chlorverbindungen ausgearbeitet.
    Notes: Abstract The interaction of the tricyclic angular azaaromatic system having positive charged side chains withDNA, influence of molecular structure of the ligand on the mode of noncovalent binding, and stability of the complex formed were established. Several (N,N-diethylamino)alkoxy derivatives of 1,7-, 1,8-, 1,10- and 4,7-phenanthroline in the protonated form were used as ligand. The electronic and steric factors were shown as responsible for the electrostatic and intercalative interactions of the ligand withDNA. The syntheses of (N,N-diethylamino)alkoxy derivatives from parent phenanthrolines were elaborated.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 324 (1982), S. 735-742 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Komplexe der Dipicolinsäure und verwandter Verbindungen zur Oxidation organischer SubstrateDie Oxidation von methylierten Hydrochinonen zu Chinonen und von α,β-ungesättigten Alkoholen zu Aldehyden in Gegenwart verschiedener Oxidationsmittel wurde untersucht.Günstige Ergebnisse wurden bei der Anwendung des MnO2-Dipikolinsäure-Systems für d'e Oxidation von Allyl- und Benzylalkoholen und des AgO-Dipikolinsäure-Systems für die oxidative Demethylierung von methylierten Hydrochinonen erreicht.Der Einfluß der Struktur von 4-substituierten Dipicolinsäuren auf die katalytischen Eigenschaften wurde untersucht.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 327 (1985), S. 963-967 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The catalytic activity of sodium 1-dodecanesulfonate, sodium dodecyl sulfate, disodium 2-dodecyl-1, 3-propanediyl disulfate (1) and trisodium 2, 2-bis(sulfonatemethyl)tetradecylsulfate (2) was tested in the two-phase oxidation of p-xylene with cerium ammonium nitrate (CAN). Also various toluene derivatives were oxidized with CAN in the presence of sodium dodecyl sulfate. The observed reaction enhancements are discussed in terms of the micelle-substrate interaction. The catalytic oxidation of some toluene derivatives (3) with a subsequent thermal rearrangement of the oxidation product offers a simple synthetic route to benzaldehydes 4.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 328 (1986), S. 419-429 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,4-Benzoquinones and 1,4-naphthoquinones carrying 3′,3′-dimethyloxiranyl, dimethylacetyl or oxiranylmethyloxy substituents (1, 2 or 3) have been synthesized. The methods presented involved epoxidation of a sterically overcrowded double bond as a crucial step for synthesis of (3′,3′-dimethyloxiranyl)quinones 1. Reaction of aryllithium derivatives with 2-chloro-2-methyl-propanol unexpectedly led to (dimethyl)acetylarenes 11 subsequently oxidized to (dimethylacetyl)-quinones 2. High cytotoxicity of 1 against KB cells has been revealed contrary to significantly lower activity of 2 and 3. The structure-activity relationship was discussed in terms of current theory of biologically activated alkylating agents.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 605-610 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,4-Benzoquinones and 1,4-naphthoquinones bearing 2′-methyloxiranyl substituents have been synthesized as new bioreductive alkylating agents. The method presented here involved the synthesis of 2-acetyl-1,4-dimethoxybenzenes 6a, b, d and -naphthalenes 6c, e, f, conversion of the acetyl group into 2′-methyloxirane ring using trimethylsulfonium chloride and sodium hydroxide in anhydrous medium, and oxidative demethylation of these intermediates 7a-f to quinones 8a, c, e, f with silver(II) dipicolinate.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 327 (1985), S. 808-822 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of 1,4-benzoquinones and 1,4-naphthoquinones 3a-j carrying substituents such as methoxyl, ally or oxiranyl was substantially improved. The 1-methoxy-4-methoxy-methyloxy 2a-d, g-k or 1,4-bis(methoxymethyloxy) derivatives 2e-f were used, as a substrates instead of 1,4-dimethoxy derivatives 1a-j hitherto used and they were oxidized with silver(II) dipicolinate. Among numerous examples, the synthesis a of new analog of ubiquinone 3d with the oxiranyl substituent, being a new bioactivated alkylating agent, is reported.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 338 (1996), S. 65-68 
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It has been revealed that N,N-dimethylhydrazones (1a-c, 3a,b) derived from kojic acid analogs, such as substituted furans (3a,b), 4-pyrones (1a,b) and 4-pyridine (1c), on oxididation with 3-chloroperoxybenzoic acid afford the corresponding nitriles (2a-c, 4a,b). The method has preparative value. The mechanism of the reaction is presented.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0947-3440
    Keywords: Amino acids ; 1,2-Benzisoselenazol-3(2H)-ones ; Cytokine inducers ; Ebselen ; Nitric oxide synthase inhibitors ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A convenient synthesis of the 2-carboxyalkyl-1,2-benzisoselenazol-3(2H)-ones 4a-k and their esters 41-p from 2-(chloroseleno)benzoyl chloride (2) and amino acids or their carboxy esters is reported. In similar way other 2-substituted 1,2-benzisoselenazol-3(2H)-ones 4q-u were synthesized. The related bis[2-(carbamoyl)phenyl] diselenides 5 were obtained by reductive conversion of 1,2-benzisoselenazol-3(2H)-ones 4 or directly by the reaction of bis[2-(chlorocarbonyl)phenyl] diselenide (3) with compounds having a primary amino group. It was found that some of compounds 4 and 5 are modest cytokine (TNF, IFN) inducers in human peripheral blood leucocyte cultures and block the constitutive endothelial nitric oxide synthase (ce NOS).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1434-193X
    Keywords: 1,3,2-Benzothiaselenazole 1,1-dioxides ; Cytokine inducers ; Diselenobis(benzenesulfonamides) ; Diselenides ; Sulfonamides ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -A convenient method for the synthesis of 2,2′-diselenobis(benzenesulfonamides) 4 and 2-substituted 1,3,2-benzothiaselenazole 1,1-dioxides 2, has been elaborated. It is based on the conversion of 2-aminobenzenesulfonic acid into bis[2-(chlorosulfonyl)phenyl] diselenide (6), and reaction with ammonia or primary amines to give the sulfonamides 4. Finally, cyclization of these sulfonamides by oxidation with benzoyl peroxide or by treatment of their sodium or potassium salt with elemental bromine produces 1,3,2-thiaselenazole 1,1-dioxides 2.
    Type of Medium: Electronic Resource
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