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  • 1
    Electronic Resource
    Electronic Resource
    Synthese von substituierten 2-(Ethoxycarbonyl-formyl-methylen)-2H-benzopyranen und ihre Überführung in Polymethinderivate (1994)
    Springer
    Monatshefte für Chemie 125 (1994), S. 61-70 
    Details
    ISSN: 1434-4475
    Keywords: 3-Chloro-2-ethoxycarbonyl crotonic aldehyde ; 2H-Benzopyrans ; Pyrylium salts ; Polymethin dyes ; Grob-Fragmentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 3-Chloro-2-ethoxycarbonyl crotonic aldehydeC reacts with several 2-hydroxybenzene carbaldehydes and 2-hydroxy-naphthalene-1-carbaldehyde, respectively, to give 2-(ethoxycarbonyl-formyl-methylene)-2H-benzopyrans1a–h under mild conditions. With exception of1c and1d these compounds are mixtures ofE–Z isomers.1a–h easily undergo reactions, e.g. with aniline and derivatives to give2a–e, with various CH-acidic compounds to give3a–h and with 2-alkyl-4,6-diphenyl pyrylium salts to give4a–e. In the presence of alcoholic hydrochloric acid, compounds1 are converted into symmetrical 2,2′-benzopyrylotrimethine salts5a–e which exhibit longwave absorptions from 640–705 nm. These polymethine dyes with ester groups in the methine chain exhibit a remarkable thermal stability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811675
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  • 2
    Electronic Resource
    Electronic Resource
    Synthese neuer, 3-substituierter 2H-Thiopyran-Derivate via [4+2]-Cycloaddition mittels acceptorsubstituierter Enaminothione (1994)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 336 (1994), S. 434-438 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of New 3-Substituted 2H-Thiopyran Derivatives via [4+2] Cycloaddition Reactions using Acceptor Substituted Enaminothiones3- and 4-Nitro acetophenones as well as 3- and 4-trifluoromethyl acetophenones react with POCl3/DMF (Vilsmeier reagent) to give dimethyliminium perchlorates 1a-d after addition of perchloric acid to the reaction mixture. Substitution of the chloro atom in 1 by using sodium sulfide nonahydrate occurs under mild conditions (in case of nitro compounds at -5°C) leading to enaminothiones 2a-d. Reactions with acroleine and methylvinylketone in refluxing benzene give exclusively 2H-thiopyran derivatives 4a-h, which were isolated in good yields after spontaneous fast elimination of dimethylamine. In contrast, the introduction of 1-nitro-2-phenylethene as the dienophile allows stepwise reaction to give stable adducts 3k and 3l, respectively, and also 3m under mild conditions (reaction at room temperature). 1H n.m.r. spectroscopic data as well as the elimination of dimethylamine to 4k-m permit the elucidation of the structure of adducts 3k-m.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19943360510
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  • 3
    Electronic Resource
    Electronic Resource
    Reaktionen von β-Chlor-vinylaldehyden, I. 2- und 2.3-substituierte 1H-1.5-Benzodiazepine durch Kondensation von β-Chlor-vinylaldehyden mit o-Phenylendiamin (1967)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 100 (1967), S. 584-590 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aus β-Chlor-zimtaldehyden, 1-Chlor-2-formyl-cycloalkenen und partiell hydrierten hetero-cyclischen β-Chlor-aldehyden werden durch Kondensation mit o-Phenylendiamin 2- und 2.3-substituierte sowie 2.3-alicyclisch und -heterocyclisch kondensierte 1H-1.5-Benzodiazepin-Salze heregestellt. β-Chlor-zimtaldehyde bilden mit o-Phenylendiamin in neutraler alkoholischer Lösung Azomethine, die in 2-aryl-substituierte Diazepinsalze übergeführt werden.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19671000227
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  • 4
    Electronic Resource
    Electronic Resource
    Heterocyclisch [c]-anellierte Cumarine aus 4-Azido-3-cumarincarbaldehyden (1992)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1992 (1992), S. 23-28 
    Details
    ISSN: 0170-2041
    Keywords: Coumarins, 4-chloro-3-formyl-, 3-acyl-4-azido- ; Isoxazoles ; Pyrazoles ; 1,5-Diazepines ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Heterocyclic [c]-Condensed Coumarins from 4-Azido-3-coumarincarbaldehydes4-Azido-3-coumarincarbaldehydes 2a-d are useful starting materials for syntheses of a variety of 3,4-disubstituted coumarins as well as heterocyclic [c]-fused coumarins, e. g. isoxazoles, pyrazoles and 1,5-diazepines, under mild conditions. In these reactions, 2a-d are - despite of their thermolability  -  superior to the corresponding 4-chloro-3-coumarincarbaldehydes 1a-d, from which they were prepared. An improved method for the preparation of 1a-d from 4-hydroxy-coumarins is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199219920106
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  • 5
    Electronic Resource
    Electronic Resource
    Über acylierende Oxydation von Cyclo-olefinen und -ketonen mit Quecksilber(II)-acetat, III (1960)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 93 (1960), S. 1374-1379 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quecksilber(II)-acetat wurde mit phenylsubstituierten Fünf-, Sechs- und Siebenring-olefinen und -ketonen umgesetzt. Aus Δ1.1′-Bicyclohexenyl-(1.1′) wurde mit Quecksilber(II)-acetat stufenweise das Mono- und Diacetoxyderivat dargestellt. Letzteres wurde in Dicyclohexenofuran übergeführt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19600930621
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  • 6
    Electronic Resource
    Electronic Resource
    Vilsmeier-Reaktion an Dimedon (1979)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 321 (1979), S. 671-674 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vilsmeier-Reaction on Dimedone.The Vilsmeier-reaction has been studied in detail for a special cyclic β-diketone, dimedone. It was shown, that the first step in this reaction is the formation of the corresponding β-chlorovinylketone. 3-Chloro-5,5-dimethyl-cyclohex-2-en-one-(1) 2, 2,4-dichloro-6,6-dimethyl-1-formyl-cyclohexa-1,3-diene 3 und 2,4-dichloro-1,5-diformyl-6,6-dimethyl-cyclohexa-1,4-diene 4 were isolated in equal parts. The symmetrical enolether 6 was identified as condensation-product of the diformylated compound 5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19793210420
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  • 7
    Electronic Resource
    Electronic Resource
    Pyryliumverbindungen. XXIII. 2-Dialkylamino-2H-pyrane aus tetra- und pentasubstituierten Pyryliumsalzen (1984)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 657-666 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. XXIII. 2-Dialkylamino-2H-pyrans from Tetra- and Pentasubstituted Pyrylium Salts.Tetra- and pentasubstituted pyrylium salts of type 6 react with secondary alkyl amines to give stable crystalline 2-dialkylamino-2h-pyrans 7. In the case of tetrasubstituted pyrylium salts 6, R′ = Me, R″ = H the reaction occurs regioselectively leading to 2H-pyrans with Me at C-3 of the heterocyclic ring. The structure of the reaction products was established by n.m.r., i.r., u.v. and mass spectroscopic methods. Electrophilic agents like protons, carboxylic acid chlorides or methyl iodide regenerate the original pyrylium cations from 7. In refluxing methanol 7a is converted into the 2-methoxy-2H-pyran derivative 8, whereas in aqueous acetone the pseudobase 9 and with ammonia the pyridine 10 are formed. Reaction of 7a with nitromethane or ethyl cyanoacetate provides the benzene derivatives 11 and 12, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19843260420
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  • 8
    Electronic Resource
    Electronic Resource
    Reaktionen von β-Chlorvinylaldehyden, III. Synthese und Eigenschaften von β-Thioketoaldehyden (1973)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 873-880 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: β-Thioketoaldehyde 1 werden durch Umsetzungen von β-Chlorvinylaldehyden mit Na2S · 9 H2O präparativ dargestellt. Von den möglichen tautomeren Formen dominiert im Gleichgewicht sowohl im festen Zustand als auch in Schwefelkohlenstofflösung der Enthiolaldehyd. Zur Charakterisierung eignen sich die leicht zugänglichen Nickelchelate. Folgereaktionen von 1 mit Phenylhydrazin, Anilin, Alkylhalogeniden und α-Halogencarbonylverbindungen führen zu Pyrazolen, S-haltigen SCHIFFschen Basen, Alkylmercaptovinylaldehyden und Thiophenen, die im einzelnen beschrieben werden.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19733150509
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  • 9
    Electronic Resource
    Electronic Resource
    Reaktionen von β-Chlorvinylaldehyden. IV [1]. Synthesen von 2-Formylmethylen-2H-1-benzopyranen und Benzopyrylocyaninfarbstoffen aus β-Chlorvinylaldehyden (1978)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 320 (1978), S. 497-507 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of β-Chlorovinylaldehydes. IV. Syntheses of 2-Formylmethylene-2H-1-benzopyranes and Benzopyrylocyaninedyes from β-Chlorovinylaldehydesα-Alkyl-β-chlorocrotonaldehydes react with salicylaldehyde in methanolic solution of potassium hydroxide forming 2-formyl-methylene-2H-1-benzopyranes 1. The corresponding benzopyryliumsalts 2 which are easily available from 1 and strong acids, exist in the enolic form. They react at room temperature in alcoholic solution with elimination of ethyl formiate, yielding dark blue compounds which were identified as 2,2′-benzopyrylotrimethincyanindyes 3. The structure of 3 has been elucidated by means of 1H-n.m.r.-spectra.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19783200402
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  • 10
    Electronic Resource
    Electronic Resource
    Über Umsetzungen von 2-Hydroxymethylencyclanonen mit Diaminen. Die Synthese von 2,3-Benzo-5,6-cyclano-1,4-diazepinen (1963)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 20 (1963), S. 117-124 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Hydroxymethylencyclanone wurden unter verschiedenen Bedingungen mit Äthylendiamin bzw. o-Phenylendiamin kondensiert. In neutraler Lösung entstanden Bis-Kondensationsprodukte unterschiedlicher Stabilität. Die Reaktion im sauren Medium führte mit o-Phenylendiamin zu 2,3-benzkondensierten bicyclischen Diazepiniumsalzen, die auch aus den Bis-Kondensationsprodukten der 2-Hydroxymethylencyclanone hergestellt werden konnten. Cyclisierungsversuche mit den Äthylendiaminderivaten schlugen fehl.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19630200303
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