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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 122 (1991), S. 195-207 
    ISSN: 1434-4475
    Keywords: 5-Dialkylamino-2-aryl-1,2,3-triazoles ; 4-Amino-2,6-dioxo-tetrahydropyrid-3-yl-pyridiniumchloride ; 2-Arylhydrazono-2-cyan-N-chloracetylacetamide ; Arylhydrazono-2-cyan-N,N-dialkylacetamidines ; Arylhydrazonomalononitriles ; 4-Imino-5-arylazo-6-dialkylamino-1,4-dihydropyrimidines ; 13C-NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The title compounds3 were synthesized by reaction of arlyhydrazono-malononitriles1 with secondary amines and used for subsequent cyclization reactions. Thus,3 undergoes cyclooxidation by treatment with CuSO4/pyridine to form the 5-dialkylamino-2-aryl-1,2,3-triazolo-4-carbonitriles4. From4 a and hydrazine hydrate/DMF the 4-(1,3,4-triazolyl-5)-1,2,3-triazole5 c is obtainable. The chloroacetylation of3 is accompanied by hydrolysis of the amino group to yield the arylhydrazono-N-chloracetyl cyanoacetamides6. The quaternisation of6 with pyridins is followed by the Thorpe cyclization to form the 4-amino-5-arylazo-6-hydroxy-3-pyridinio-pyrid-2-on-chlorides8, useful as cationic dyes. The reaction of3 with trichloroacetonitriles yields the 5-arylazo-4-imino-2-trichlormethyl-1,4-dihydropyrimidines10 a–c which can be converted into the 5-arylazo-2-hydrazino-pyrimidine derivatives10 d–f. From10 d the 6-phenylazo-triazolo[4,3-a]pyrimidine derivative11 is obtainable. From3 and phenylisothiocyanate the 5-arylazo-4-imino-1,4-dihydropyrimidin-2-thiones12 arise. The structures were investigated by13C-NMR-spectroscopy.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 126 (1995), S. 341-347 
    ISSN: 1434-4475
    Keywords: Chloroacetic acid chloride ; Phenylhydrazono acetamides ; Pyridines ; Pyridazin-5-ylpyridinium chlorides ; 4,5-Diamino-pyridazin-6(1H)-ones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Arylhydrazono acetamides1 react with chloroacetic acid chloride to give N-chloroacetyl derivatives2. Subsequent reaction with pyridines followed by ring closure yield 1-(4-amino-6-oxo-pyridazin-5-yl)-pyridinium chlorides3. Analogously, 1-(6-oxo-pyridazin-5-yl)-pyridinium chloride (5) and 6-oxo-5-pyridinio-pyridazin-4-olate (4) are formed from phenylhydrazono derivatives and pyridine. Treatment of3 and4 with hydrazinium hydrate gives 4,5-diamino-6-oxo-pyridazin-3-carbohydrazides6 and 5-amino-4-hydroxy-pyridazin-6(1H)-one (8). An analogous ring cleavage of3e and5 gives rise to 4,5-diamino- and 5-amino-pyridazin-6(1H)-ones7. On treatment of the pyridinium salts3 with caustic soda in water, nucleophilic addition of the amino group to the pyridinium ring takes place and stable dehydrated products9 are isolated.
    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. 933-941 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of Methylene Active Nitriles and Cyanamide with Acylated EnaminesThe addition products from enamines onto isocyanates and isothiocyanates, i.e. substituted β-aminoacrylo amides 1 and thioamides 2, react with malononitrile to yield the 6-amino-1-aryl-5-cyano-pyridin-2-ones 3 and -thiones 4 among them 5,6,7,8-tetrahydroisoquinolin-1-ones and -thiones. From ethyl cyanoacetate the 5-cyano-6-hydroxy-pyridin-2-ones 7 and from benzoyl acetonitrile the 6-phenyl-pyridin-2-ones 8 are formed. The replacement of malononitrile by cyanamide yields the 2-amino-3-aryl-pyrimidin-4-ones 5 and -thiones 6 among them 5,6,7,8-tetrahydroquinazolin-4-ones and -thiones. The not isolated β-acyl enamines derived from enamines and acid chlorides react with malononitrile or cyanamide to form the pyridin-2-ones 14 or pyrimidin-2-ones 15 caused by Dimroth-rearrangement.
    Additional Material: 3 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 325 (1983), S. 457-462 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-Amino-thieno[2,3-b]furans and 3-Amino-thieno[3,2-b]furansThe O-alkylation of 2-hydroxy-thiophene-3-carbonitriles (1) with α-bromocarbonyl compounds yields the 2-alkoxy-thiophene-3-carbonitriles (2a-f) among them 2-benzoylmethoxy-thiophene-3-carbonitriles (2a-c) which undergo Thorpe-Ziegler-cyclization to form the 3-amino-2-benzoyl-thieno[2,3-b]furans (3) in low yields. The 2-acyl-3-amino-thieno[3,2-b]furans and ethyl 3-amino-thieno[3,2-b]furan-2-carboxylates (6) are synthesized in similar manner from 3-hydroxy-thiophene-2-carbonitriles (4) and α-halogencarbonyl compounds via 3-acylmethoxy- and 3-ethoxycarbonylmethoxy-thiophene-2-carbonitriles (5) with high yields.
    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 334 (1992), S. 491-496 
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Synthesis of 3-Amino-pyrroles by Thorpe-Ziegler-CyclizationN-Aryl and alkylaminomethylene cyanacetic acid derivatives 1 react with α-halogencarbonyl compounds 2 in the presence of potassium carbonate/sodium ethoxide to yield the substituted 3-amino-pyrroles 6. Using the same principle of cyclization pyrrole derivatives 6 can also be obtained by reaction of β-chloro- and β-alkoxymethylenemalononitriles 4 with β-aminocarbonyl compounds 5. From the malononitrile derivatives 1 containing the methylthio group in the β-position, and α-halogen ketones 7, the 2-dicyanomethylene oxazolines 8 arise which undergo alkoholysis by treatment with sodium alkoxide to form the 3-amino-5-alkoxy-pyrrole derivatives 9.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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