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  • 1
    Electronic Resource
    Electronic Resource
    Synthese neuartig substituierter Pyridazin-6(1H)-one (1995)
    Springer
    Monatshefte für Chemie 126 (1995), S. 341-347 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00816103
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  • 2
    Electronic Resource
    Electronic Resource
    New syntheses of 2,4-diaminopyrroles and aminopyrrolinones (1997)
    Springer
    Monatshefte für Chemie 128 (1997), S. 933-943 
    Details
    ISSN: 1434-4475
    Keywords: Thorpe-Ziegler cyclization ; (Oxazolin-2-yliden)malononitrile ; 2,4-Diamino-pyrrole ; 2-Amino-4-oxo-pyrrol-3-carbonitrile ; 4-Amino-2-oxo-pyrrol-3-carbonitrile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Oxazolin-2-yliden-malononitrile3a–d. die aus Thioketenaminalen und α-Halogenketonen erhalten wurden, reagieren mit primären und sekundären Aminen zu den 2,4-Diaminopyrrolen5a–h. Mercaptobenzol als nukleophiles Reagens liefert 4-Amino-2-phenylthiopyrrol (5j). Analog wurden Cyan-(3,5-diphenyl-3H-oxazol-2-yliden)-essigsäuremethylester als Zwischenprodukte für die Synthese der 2-Amino-4-oxo-pyrroline10a–d hergestellt. Die isomeren 4-Amino-2-oxo-pyrroline13a–d können aus den 4-Amino-2-methoxy-pyrrolen11a,b erhalten werden, was als Nachweis für die Position der Substituenten dient. Die Verbindungen wurden1H- und13C NMR-spektroskopisch untersucht.
    Notes: Summary Oxazolin-2-ylidene-malononitriles3a–d, obtainable from thioketenaminals and α-halogen-ketones, react with primary and secondary amines to afford 2,4-diamino-pyrroles5a–h. Mercaptobenzen as nucleophilic agent gives the 4-amino-2-phenylthio-pyrrole5j. Analogously, cyano-(3,5-diphenyl-3H-oxazol-2-ylidene)-acetic acid methyl esters were prepared as intermediates for the synthesis of 2-amino-4-oxo-pyrrolines10a–d. The isomeric 4-amino-2-oxo-pyrrolines13a–d can be obtained from 4-amino-2-methoxy-pyrroles, which serves as proof for the position of substituents. The structures were investigated by1H and13C NMR spectroscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00807103
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  • 3
    Electronic Resource
    Electronic Resource
    Zur Chemie der 4-Amino-thiazolin-2-thione, 2. Mitt. (1994)
    Springer
    Monatshefte für Chemie 125 (1994), S. 1129-1143 
    Details
    ISSN: 1434-4475
    Keywords: Pyrimidine-5-thioles ; Thiazolidine-2,4-diones ; Thiazoline-2-ones ; Thiazoline-2-thiones ; Thiazolo[4,5-e]isothiazoles ; Thiazolo[4,5-d]pyrimidines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 6-Amino-thiazolo[4,5-c]isothiazole derivatives4 are obtained by addition of hydrogen sulfide to the 4-Amino-thiazoline-5-carbonitrile2 followed by cyclooxidation of the intermediate thioamides3. In the presence of sodium sulfite the hydrolysis of the4-amino-2-methylthio-thiazolium salts5 derived from the title compounds1 yields the4-amino-thiazolin-2-ones6. By their further hydrolysis the 2,4-dioxo-thiazolidin-5-carboxamides8 are formed. The 2-oxo-and 2-thioxo-thiazolo [4,5-d]pyrimidin-7-ones and -thiones available from1 undergo ring opening by hydrolysis to give the substituted 4-amino-6-oxo- and 4-amino-6-thioxo-pyrimidine-5-thiols15a–h and13i–e. They have been isolated as their disulfides14 or 5-alkyl derivativesi.e. the substituted 4-amino-5-alkylthiopyrimidin-6-ones and -thiones16. In analogy, the intermediate 6-amino-7-oxo-thiazolo[4,5-d] pyrimidin-2-thione18 and the 7-amino-thiazolo[4,5-d]-pyrimidin-2-thione24 derived from1 react by ring cleveage to yield the 1,4-and 4,6-diamino-pyrimidin-5-thiole derivatives22 and27, respectively, isolated as their disulfides or alkylthio-derivatives. From the pyrimidine16b the pyrimido[5,4-b]1,4-thiazine derivative18 can be obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811521
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  • 4
    Electronic Resource
    Electronic Resource
    Substituierte 2-Alkoxy-5-amino- und-2,5-diamino-imidazole aus Oxazol-2-yliden-cyanamiden (1996)
    Springer
    Monatshefte für Chemie 127 (1996), S. 313-318 
    Details
    ISSN: 1434-4475
    Keywords: (2-Alkoxy-5-amino-imidazol-4-yl)-ketones ; N-Cyano-S-methyl-isothioureases ; (2.5-Di-amino-imidazol-4-yl)-ketones ; α-Halogenketones ; Oxazol-2-yliden-cyanamides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary N-Cyano-S-methyl-isothio-ureases (1) react with α-halogen ketones (2) by ring closure yielding the (3H-oxazol-2-yliden)-cyanamides3. by ring transformation, 2-Alkoxy-5-amino-1-phenyl-3H-imidazol-4-yl)-ketones (4) are formed. Primary and secondary amines react with3 to give 2-N-alkylated (2,5-Diamino-1-phenyl-3H-imidazol-4-yl)-ketones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813797
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  • 5
    Electronic Resource
    Electronic Resource
    Syntheses with pyridinium and sulfonium salts of acylated β-enaminonitriles (1995)
    Springer
    Monatshefte für Chemie 126 (1995), S. 711-723 
    Details
    ISSN: 1434-4475
    Keywords: Malononitrile ; Benzoles ; Pyridines ; Thiophenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Pyridinium- und Sulfoniumsalze2a–e, die aus 3-Amino-2-(α-halo-acetyl)-crotonsäurenitril und 3-Amino-2-(α-halo-acetyl)-zimtsäurenitril hergestellt werden können, reagieren mit Malonsäuredinitril in Gegenwart einer Base zu 3-Amino-2-pyridinio-phenolaten3a,b und 3-Amino-2-sulfonio-phenolaten3c–e. In Analogie wurden 3-Amino-2-(diethyloxyphosphoryl)-phenol5a und 3-Amino-2-(p-tolyl-sulfonyl)-phenol5b erhalten. 2,3-Diamino-phenole6a,b werden aus den Pyridiniumsalzen3a,b gebildet. Das Verhalten der Pyridiniumsalze2a,b gegenüber Heterokumulenen ist untersucht worden. Cyanamid führt zum (2-Amino-4-hydroxy-pyrid-3-yl)-pyridiniumsalz8c. Phenylisothiocyanat liefert die 3-Pyridinio-2-thioxo-pyridin-4-olate9a,b. In Abhängigkeit vom Substituenten in der Position 6 entsteht bei der Reaktion mit Schwefelkohlenstoff ein 3-Pyridinio-2-thioxo-pyridin-4-olat10 oder ein 3-Pyridinio-2-thioxo-thiopyran-4-olat11. Phenylisocyanat reagiert zum Pyrimidin-2,4-dion12 unter Verlust von N-Methyl-pyridiniumchlorid. S-Methylierung von9a und Spaltung des Pyridiniumringes ergibt das 3-Amino-2-methylthio-pyrid-4-on14. Die Verbindungen wurden1H- und13C-NMR-spektroskopisch untersucht.
    Notes: Summary Pyridinium and sulfonium salts2a–e which can be prepared from 3-amino-2-(α-haloacetyl)-crotonitriles and 3-amino-2-(α-halo-acetyl)-3-phenyl-acrylonitriles react with malononitrile in the presence of a base to 3-amino-2-pyridinio-phenolates3a,b and 3-amino-2-sulfonio-phenolates3c–e. In an analogous way, 3-amino-2-(diethyloxyphosphoryl)-phenol5a and 3-amino-2-(p-tolyl-sulfonyl)-phenol5b have been prepared. 2,3-Diamino-phenoles6a,b are formed from the pyridinium salts3a,b. The behaviour of the pyridinium salts2a,b towards heterocumulenes has been investigated. Cyanamide leads to the (2-amino-4-hydroxy-pyrid-3-yl)-pyridinium salt8c. Phenylisothiocyanate gives the 3-pyridinio-2-thioxo-pyridin-4-olates9a,b. Carbon disulfide gives rise to 3-pyridinio-2-thioxo-pyridin-4-olate10 or 3-pyridinio-2-thioxo-thiopyran-4-olate11, depending on the substituent at the 6-position. Phenylisocyanate reacts to the pyrimidin-2,4-dione12 with loss of N-methyl-pyridinium chloride. S-methylation of9a and cleavage of the pyridine moiety yields the 3-amino-2-methylthio-pyrid-4-one14. The structures were investigated by1H and13C NMR spectroscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00807162
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  • 6
    Electronic Resource
    Electronic Resource
    Synthese und Reaktionen von 2-Arylhydrazono-2-cyan-N,N-dialkyl-acetamidinen (1991)
    Springer
    Monatshefte für Chemie 122 (1991), S. 195-207 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00809365
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  • 7
    Electronic Resource
    Electronic Resource
    Methods for the synthesis of 2-aminothiophenes and their reactions (review) (1976)
    Springer
    Chemistry of heterocyclic compounds 12 (1976), S. 1077-1090 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract 2-Aminothiophenes are readily formed as a result of various cyclization reactions. The method of preparation of derivatives of 2-aminothiophene-3-carboxylic acids and 2-amino-3-acylthiophenes from carbonyl compounds, nitriles that have an active methylene group, and sulfur is particularly simple and rich in possibilities. The aminothiophenes can be converted to other thiophene derivatives and used primarily for the preparation of condensed thiophenes such as thionaphthenes, thienopyrroles, thienothiazoles, thienoisothiazoles, thienopyrimidines, thienopyridines, and thienodiazepines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00945583
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  • 8
    Electronic Resource
    Electronic Resource
    5,6-Condensed 3-nitropyridines from heterocyclic amines and nitromalonaldehyde (1983)
    Springer
    Chemistry of heterocyclic compounds 19 (1983), S. 1163-1166 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reaction of nitromalonaldehyde with 2-aminothiophenes leads to 5-nitrothieno-[2,3-b]pyridines. The analogous reaction with 3-aminopyrroles leads to 6-nitropyrrolo [3,2-b]pyridines. The analogous reaction with 4- and 5-aminopyrazoles leads to 6-nitropyrazolo[4,3-b]pyridines and 5-nitropyrazolo[3,4-b]pyridines, respectively. Enamines are formed as intermediates. 3- and 5-Aminopyrazoles which are unsubstituted at N-1 are converted to 3-nitropyrazolo[1,5-a]pyrimidines. The nitro derivatives obtained may be reduced to the corresponding amines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00515347
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  • 9
    Electronic Resource
    Electronic Resource
    Einfache Synthese von 2,4-Diamino-chinolin-3-carbonitrilen (1992)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 334 (1992), S. 89-91 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Simple Synthesis of 2,3-Diamino-quinoline-3-carbonitriles
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19923340118
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  • 10
    Electronic Resource
    Electronic Resource
    Amino-thieno[2,3-c]pyrazole und Amino-thieno[2,3-b]pyrrole (1995)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 337 (1995), S. 472-477 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Amino-thieno[2,3-c]pyrazoles and Amino-thieno[2,3-b]pyrrolesThe synthesis of thieno[2,3-c]pyrazoles and thieno[2,3-b]pyrroles is described. From the dithioliumsalt (1) and potassium hydroxide the potassium-(2,2-dicyan-1-methylthio-ethen-1-yl)-thiolate (2) is formed. This reacts with hydrazine hydrate to form the 3-amino-5-thioxo-pyrazol-4-carbonitrile (3) S-Alkylation with α-chlorocarbonyl compounds yielding (6a-c) leads via Thorpe-Ziegler-cyclization to 3,4-diamino-thieno[2,3-c]pyrazoles (9) if the position 1 is alkylated (8). Acetyl acetone yields 2-mercapto-pyrazolo[1,5-a]pyrimidine (5). After S-alkylation (10a-d) are immediately cyclized to thieno [2′,3′:3,4]pyrazolo[1,5-a]pyrimidine (11a-d). The ketone (6a) can be cyclized to the pyrazolo [5,1-b]thiazole (12). 3 reacts with oxalyl chloride to form the 2,3-dioxo-6-thioxo-imidazo[1,2-b]pyrazole (13) of which S-phenacyl derivative (14) because the NH-proton cannot be cyclized. The 5-amino-3,4-dicyano-pyrrol-2-thiolate (16) shows the analogous behaviour. The S-alkylation is followed by cyclization, and 3,5-diamino-thieno[2,3-b]pyrroles (18a-b) arise. Reaction of 5-amino-2-alkylthio-pyrrol-3,5-dicarbonitrile (17) with acetyl acetone provides pyrrolo[1,2-a]pyrimidine (20a-c) which can be cyclized to form thieno[3′,2′:4,6]pyrimidines (21a-c) very easily.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.199533701101
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