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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2898-2912 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ringfission of Cyclic Azo Compounds, VI. Photolysis of 8-Oxo-8H-quinazolino[3.2-c]1.2.3-benzotriazine Preparation of New DiazocinesPhotolysis of 8-Oxo-8H-quinazolino[3.2-c]1.2.3-benzotriazine (1) in inert solvents leads to 11-oxo-11H-benz[3.4]azeto[2.1-b]quinazoline (2) and to diphenylamin-2.2′-dicarboximide (7) via 5-oxo-5H-benz[3.4]azeto[1.2-a]quinazoline (6), which has been detected spectrophoto-metrically and by trapping experiments. In the presence of nucleophiles under similar conditions the substituted dibenzo diazocines 7, 13 and 15 are formed. HMO-calculations of 2 and 6 give with the structurally similar heterocycles A-C and A'-C' a good correlation of the pC=o-π-bond orders and the carbonyl frequencies and can explain the preferred addition of nucleophiles to the C=N-double bond of 6 compared to the C=N-double bond of 2.
    Notes: Bei der Photolyse des 8-Oxo-8H-chinazolino[3.2-c]1.2.3-benzotriazins (1) in indifferenten Lösungsmitteln entsteht 11-Oxo-11H-benz[3.4]azeto[2.1-b]chinazolin (2) und über das in Lösung sowohl spektroskopisch als auch durch Abfangreaktionen nachgewiesene 5-Oxo-5H-benz[3.4]azeto[1.2-a]chinazolin (6) Diphenylamin-dicarbonsäure-(2.2′)-imid (7). In Gegenwart nucleophiler Agenzien bilden sich unter denselben Photolysebedingungen aus 6 die benzokondensierten substituierten Diazocine 7, 13 und 15. HMO-Berechnungen für 2 und 6 ergeben mit den strukturverwandten Heterocyclen A-C und A'-C' eine gute Korrelation zwischen pC=O-π-Bingungsordnung und Carbonylwellenzahlen und vermögen die bevorzugte Addition von Nucleophilen an die C=N-Doppelbindung von 6 im Vergleich zur C=N-Doppelbindung von 2 zu erklären.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 656-674 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Five-Membered Heterocycles, VI. - 3-Organylamino-1,3-thiazolin-2-ones and -2-thionesS-Potassium (N'-organylhydrazino)monothio- and potassium (N-organylhydrazino)dithioformates 1A and 1B are alkylated at the mercapto sulfur atom with α-halo ketones to form the acylmethyl (hydrazino)thioformates 2 A and 2B, which can be obtained pure, or their cyclic derivatives 2'A and 2'B, respectively. In acidic solution these products are transformed into 3-organylamino-1,3-thiazolin-2-ones 3A or -2-thiones 3B, respectively. Proof for the five-membered ring structure comes from chemical reactions and UV spectroscopy. The syn-anti-diastereomeric S,S'-dialkyl dithiocarbonate tosylhydrazones Z-5 and E-5 have been prepared and their stereochemistry assigned.
    Notes: S-Kalium-[(N-organylhydrazino)monothio- und Kalium-[(N-organylhydrazino)dithioformiate] 1A bzw. 1B lassen sich mit α-Halogenketonen am Mercapto-Schwefel zu rein isolierbaren (Hydrazino)thioameisensäure-acylmethylestern 2Abzw. 2B oder deren cyclischen Derivaten 2'A bzw. 2'B alkylieren. Diese ergeben in saurer Lösung 3-Organylamino-1,3-thiazolin-2-one 3A bzw. -2-thione 3B. Der Beweis für das Vorliegen der fünfgliedrigen Ringstruktur wurde durch chemische Reaktionen und UV-spektroskopisch erbracht. Die syn-anti-diastereomeren Dithio-kohlensäure-S,S'-dialkylester-tosylhydrazone Z-5 und E-5 wurden hergestellt und zugeordnet.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ring-Fission of Cyclic Azo Compounds, VII1). - 6-Fluoro- and 6-Nitro-3-phenyl-3,4-dihydro-1,2,3-benzotriazin-4-one and their Photolysis; Nucleophilic Substitution as a Test of Suschitzky's Fluorine Labelling MethodThe photolysis of the fluorine- and nitro-substituted benzotriazinones 1a, 1b was investigated with a view to obtaining direct proof of the diazonium intermediate 2β. The products 3, 4, 5, 6 and 7 substituted at C-6 correspond to those reported previously to occur in the photolysis of the unsubstituted benzotriazinone 1c, whereas the compounds 1d-1h are formed by interactions of 1a and amines or methanolate in dark reactions. The fluorine-substitution occurs according to scheme 2 (route a), and not with the intermediacy of an intramolecular diazonium anilide ion pair (route b). Reasons which make it unlikely that the diazonium anilide ion pair 2β is involved in the photofragmentation reaction of 1 are reported.
    Notes: Die Photolyse der fluor- und nitrosubstituierten Benzotriazinone 1a bzw. 1b wurde im Hinblick auf einen direkten Nachweis der Diazoniumzwischenstufe 2β untersucht. Die am C-6 substituierten Produkte 3, 4, 5, 6 und 7 entsprechen denjenigen, über die kürzlich als Photolyseprodukte der unsubstituierten Verbindung 1c berichtet wurde. Die Produkte 1d-1h entstammen dagegen einer Dunkelreaktion von 1a mit Aminen oder Methylat. Die Fluorsubstitution erfolgt gemäß Schema 2, Weg a und nicht über ein intramolekulares Diazoniumanilid-Ionenpaar 2βa (Weg b). Gründe, die es unwahrscheinlich machen, daß bei der Photofragmentierung von 1 das Diazoniumanilid-Ionenpaar 2β auftritt, werden genannt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Five-Membered Heterocycles, IV.  -  Ring Contraction of 5-Aryl-6H-1,3,4-thiadiazin-2(3H)- ones to 4-Aryl-1,2,3-thiadiazoles5-Aryl-6H-1,3,4-thiadiazin-2(3H)-ones 3α have been prepared via two different routes (A and B). Oxidation with chlorine-containing tert-butyl hypochlorite led via ring contraction and extrusion of carbon dioxide to the 4-aryl-1,2,3-thiadiazoles 9.
    Notes: 5-Aryl-6H-1,3,4-thiadiazin-2(3H)-one 3α wurden auf zwei verschiedenen Wegen (A und B) dargestellt. Die Oxidation mit chlorhaltigem tert-Butylhypochlorit führte unter Ringverengung und Abspaltung von Kohlendioxid zu den 4-Aryl-1,2,3-thiadiazolen 9.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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