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  • Organic Chemistry  (10)
  • General Chemistry  (6)
  • 1975-1979  (9)
  • 1960-1964  (7)
  • 1955-1959
  • 1
    Electronic Resource
    Electronic Resource
    (Perhalogenmethylthio)heterocyclen. XIX. Mitt.: s. [1].. Säurekatalysierte Substitutionen an (Perchlorfluormethylthio)pyrrolen und deren agrobiologische Wirkung (1979)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 62 (1979), S. 1442-1450 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Perhalomethylthio)heterocycles. XIX. Mitt.: s. [1]. . Acid-catalyzed substitutions on (perchlorofluoromethylthio)pyrroles and their agro-biological activitiesIn the presence of C4F9SO3H the (perhalomethylthio)pyrroles 1a-c react with Cl3-nFnCSCl (n = 1-3) to give mixtures of the 2,5- and 2,4-disubstituted pyrroles 2a-f and 3a-h. 2a and 3a react with CF3SCl (catalyst CF3SO3H) yielding 2,3,5-tris (trifloromethylthio)pyrrole (4a), which under similar conditions reacts further to give 2,3,4,5-tetrakis (trifluoromethylthio)pyrrole (5). As a by-product during the conversion of 3a to 4a 2,3,4-tris (trifluoromethylthio)pyrrole (4b) is formed. The pyrroles 2a, 4a and 5 form the mercury salts 6a-c; compound 5 yields also a silver salt 7. The 1H- and 19F-NMR. spectra are discussed and the agro-biological properties of the compounds investigated.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19790620508
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  • 2
    Electronic Resource
    Electronic Resource
    Die Reaktion von α,β-Dihalogen-propionitrilen mit monosubstituierten Hydrazinen - einfache Synthese 1-substituierter 3- bzw. 5-Amino-pyrazole (1979)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 321 (1979), S. 93-101 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Reaction of α,β-Dihalogeno-propionitriles with Monosubstituted Hydrazines  -  A Simple Synthesis of 1-Substituted 3- or 5-Amino-pyrazolesIn methanol hydrazines 3, and α,β-dihalogeno-propionitriles 1, 2 even at 0°C irreversibly yield 3 · HX, and α-halogenoacrylonitriles 4, 5 (A1). Fast addition of alkyl- and aralkyl- hydrazines 3 to 4, 5 (C) gives 1-substituted 1-(2′-halogeno-2′-cyan-ethyl)-hydrazines 6, the addition of arylhydrazines 3 to 4, 5 (D) 1-aryl-2-(2′-halogeno-2′-cyan-ethyl)-hydrazines 8. In methanol 6 spontaneously cyclise (E) to hydrogen halides 7 · HX of 1-alkyl- and 1-aralkyl-3-amino-pyrazoles, 8 with 2 moles of acids (F) to salts 10 · 2HY of 1-aryl-4-halogeno-5-imino-pyrazolidines, and the free 10 spontaneously (G) to hydrogen halides 9 · HX of 1-aryl-5-amino-pyrazoles. Mechanisms (A1), (C), (D), (E), (F), and (G) are proved by t.l.c., 1H-n.m.r., and isolation of intermediates, the structures of 7 resp. 9, using the significant 1H-n.m.r.-parameter ΔHMPTCDCl3. Simple general syntheses are described for 3-amino-pyrazoles 7 (R = H, alkyl, aralkyl) or 5-amino-pyrazoles 9 (R = aryl) starting with α,β-dihalogeno-propionitriles 1, 2, and for α-bromo-acrylonitrile 5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19793210112
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  • 3
    Electronic Resource
    Electronic Resource
    Allgemeine Synthesen und rationelle Strukturparameter isomerer Derivate von [3,4]-kondensierten Pyrazolen (1979)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 321 (1979), S. 881-898 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: General Syntheses and Rational Parameters for Structural Assignment of Isomeric Derivatives of [3,4]-fused Pyrazoles4 isomeric 1- or 2-methyl-, and 1- or 2-benzyl-pyrazolo[3,4-b]pyridones, i.e. the 4-oxo-types 17a, b or 11a, b and the 6-oxo-types 16a, b or 10a, b, are synthesized unambiguously. Cyclisation of 1-substituted 3- or 5-(1-methyl-2-ethoxycarbonyl-vinylamino)-pyrazoles 9a, b or. 15a, b, which were synthesized from 1-substituted 3- or 5-amino-pyrazoles and ethyl acetoacetate yields 11a, b or 17a, b in downtherm, but 10a, b or 16a, b in presence of acidic catalysts. The acidic cyclisation is preceded by a new rearrangement of 9 or 15 into 1- substituted 3- 27 or 5-amino-4-(1-methyl-2-ethoxycarbonyl-vinyl)-pyrazoles 30; mechanism and concurring reactions are explained. Because of their higher electron densities at C-4 it is easier to cyclise derivatives of 5-amino-pyrazoles compared to 3-amino-pyrazoles. All isomeric 1- or 2-substituted 4(6)-chloro-6(4)-methyl-pyrazolo-[3,4-b]pyridines are formed with POCl3 from the corresponding oxo-compounds.The position of a substituent at N-1 or N-2 of [3,4]-fused pyrazoles can be assigned using the significant 1H-n.m.r.-parameter ΔHMPTCDCL3 = δCDCl3  -  - δHMPT (conc. HC - 3). If solvent influences are considered, δ(C = O) is a useful 13C-n.m.r.-parameter to distinguish the 4-oxo-types (11a, b; 17a, b) from the 6-oxo-types (10a, b; 16a, b) of pyrazolo[3,4-b]pyridones. Further own and lit. dates conc. structural assignment (n.m.r., i.r., u.v.) are discussed critically.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19793210602
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  • 4
    Electronic Resource
    Electronic Resource
    Ableitung und Diskussion rationeller 1H-NMR-Struktur-parameter für 1,3-bzw. 1,5-disubstituierte Pyrazolderivate (1977)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 319 (1977), S. 281-296 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Discussion and Rationalization of 1H-n.m.r. Parameters for the Structural Assignment of 1,3- or 1,5- Disubstituted PyrazolesFor 44 1,3-disubstituted (1) or 1,5-disubstituted pyrazoles (2) with growing polarity μ of solvent the 1H-chemical shift δ (HC-5) (for 1) increases considerably more than δ (HC-3) (for 2), and, depending on the 5-substituent, δ (HC-3) often even decreases. This is interpreted in terms of nucleophilic interaction between polar solvent and “pyridine-like” pyrazole-(N-2), in enhancement of the contributions of polar canonical structures, in substituent effects, and in influences of the pyrazole dipole moments μr. Resultant dipole moments μr of disubstituted pyrazoles with the 3-resp. 5-substituents Me, Cl, NH2, and OMe, and their projections μ′r on the H-(C-5)-resp. H-(C-3)- bond axes are calculated.The chloro-pyrazoles 1h, 1i, 2h and 2i, 3-methoxy-, and 5-methoxy-1-benzyl-pyrazole are synthesized unambiguously. is recommended as significant parameter for the structural assignment of 1,3-disubstituted pyrazoles 1 and 1,5-disubstituted pyrazoles 2.
    Notes: Bei 44 1,3-disubstituierten (1) bzw. 1,5-disubstituierten Pyrazolen (2) steigt mit zunehmender Lösungsmittelpolarität μ die 1H-chemische Verschiebung δ (HC-5) (für 1) wesentlich stärker an als δ(HC-3) (für 2), und, abhängig vom 5-Substituenten, nimmt δ (HC-3) oft sogar ab. Dies wird mit nukleophiler Wechselwirkung zwischen polarem Lösungsmittel und „pyridinartigem“ Pyrazol-(N-2), mit Erhöhung des Gewichts polarer Grenzstrukturen mit Substituenteneffekten und mit Einflüssen des Pyrazol-Dipolmoments μr begründet. Gesamtdipolmomente μr disubstituierter Pyrazole mit den 3-bzw. 5-Substituenten Me, Cl, NH2 und OMe und ihre Projektionen μ′r auf die H-(C-5)- bzw. H-(C-3)-Bindungsachse werden berechnet.Die Chlor-pyrazole 1h, 1i, 2h und 2i sowie 3-Methoxy- und 5-Methoxy-1-benzyl-pyrazol werden eindeutig synthetisiert. wird als signifikanter Strukturparameter für 1,3-disubstituierte 1 bzw. 1,5-disubstituierte Pyrazole 2 empfohlen.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19773190216
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  • 5
    Electronic Resource
    Electronic Resource
    Struktur und Isomerisierung der 1,3-dipolaren Cycloaddukte von Malein- und Fumarsäure-dimethylester an Pyrazolidon-(3)-azomethinimineHerrn Prof. Dr. Günter Hilgetag zum 70. Geburtstag gewidmet. (1979)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 321 (1979), S. 565-569 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Structures and Isomerisation of the 1,3-Dipolar Cycloadducts of Dimethyl Maleate and Fumarate to 3-Pyrazolidone-azomethiniminesThe 1,3-dipolar cycloaddition of dimethyl maleate 1b and fumarate 5b to the 3-pyrazolidone-azomethinimine 2 is a stereospecific cisoid reaction yielding the perhydropyrazolo[1,2-a] pyrazoles 3b/4b in the molar ratio of 2:1, and 6b/7b in the molar ratio 1:1. Starting with each of the 4 stereoisomers, epimerization, catalysed by alcoholate, results in all 4 of them 3b, 4b, 6b and 7b with 7b as sterically favoured main product. During the addition reaction no epimerization is occurring. 1H- and 13C-n.m.r. data are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19793210408
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  • 6
    Electronic Resource
    Electronic Resource
    Konstitution und Bildung der Arylsulfonyl-Derivate von AminoheterocyclenErweiterte Fassung zweier Vorträge: 15. 10. 1959, Symposium für Arzneimittelsynthesen, Weimar (H. Dorn) und 3. 12. 1960, Kolloquium der Chemischen Institute der Deutschen Akademie der Wissenschaften, Berlin (H. Dorn). (1961)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 73 (1961), S. 560-577 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wird eine zusammenfassende Darstellung der Arylsulfonierung von α-Amino-N-Heterocyclen gegeben. Konstitution, chemisches Verhalten und Bildungsmechanismus einer Reihe von Mono- und Diarylsulfonyl-Verbindungen werden eindeutig festgelegt, bisherige Unklarheiten bereinigt. Die von den Amino-heterocyclen werden durch eine Diskussion der Tautomerie der α-Amino-N-Heterocyclen und ihrer Monoarylsulfonyl-Derivate begründet. IR- und UV-Spektroskopie sowie der Mechanismus der Umamidierung von Diarylsulfonyl-Derivaten werden abgehandelt. Die untersuchten Verbindungen sind z. T. als Sulfonamid-Zwischenprodukte technisch wichtig.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19610731603
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  • 7
    Electronic Resource
    Electronic Resource
    Bildung und Verhalten der 2.3.5.6-Tetrahydro-7-aryl-imidazo[2.1-b]thiazolium-Salze [1] (1964)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 76 (1964), S. 301-301 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19640760704
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  • 8
    Electronic Resource
    Electronic Resource
    Zur Struktur des Wolframoxydchlorids (1964)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 76 (1964), S. 587-587 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19640761363
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  • 9
    Electronic Resource
    Electronic Resource
    Synthese von 3(5)-Amino-pyrazol und 1-Alkyl-5-amino-pyrazolen [1] (1964)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 76 (1964), S. 920-921 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19640762206
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  • 10
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Indols, XIII1) Synthesen in der β-Carbolinreihe, II; (±)-Yohimban und (±)-Epialloyohimban durch eine neue Indolsynthese (1979)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 1643-1656 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Indole, XIII1). - Syntheses in the β-Carboline Series, II; (±)-Yohimban and (±)-Epialloyohimban by a Novel Indole SynthesisThe hydrindanone derivative 17 undergoes Schmidt rearrangement to yield selectively after reduction by LiAlH4 the perhydroisoquinolines 20, which have been alkylated at N-2′ by ethyl bromoacetate to give 21. Compound 21 has been cyclized by polyphosphoric anhydride via the acid 22 to yield the yohimban-6-ones 23 which on treatment with LiAlH4 give the title compounds 24a and b. To check the new synthesis the racemate of the natural substance 7 was synthesized.
    Notes: Durch Schmidt-Umlagerung des Hydrindanonderivats 17 und Reduktion mit LiAlH4 erhielt man selektiv die Perhydroisochinoline 20, welche am N-2′ mit Bromessigester zu 21 alkyliert und mittels Polyphosphorsäureanhydrid über die Säuren 22 zu den Yohimban-6-onen 23 cyclisiert werden konnten. Mit LiAlH4 entstanden daraus die Titelverbindungen 24a und b. Zuvor wurde zur Erprobung des neuen Syntheseweges das Racemat des Naturstoffs 7 dargestellt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197919791103
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