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  • 11
    Electronic Resource
    Electronic Resource
    Reaktionen von 2,3-Dichlormaleinimiden mit methylenaktiven Verbindungen (1979)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 321 (1979), S. 787-796 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of 2,3-Dichloromaleimides with Methyleneactive Compounds2,3-Dichloromaleimides 1 react with activated methylene compounds mainly under monosubstitution to give 2-6. Replacement of the second chloroatom gives 2,3-disubstituted maleimides 9-15 and stable ylides 16-27 with pyridine and triphenylphosphine, respectively. A general synthesis for such maleimid-ylides was found in a one-batch reaction from 2,3-dichloromaleimides 1 with methyleneactive compounds and pyridine or triphenylphosphine.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19793210510
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  • 12
    Electronic Resource
    Electronic Resource
    Die Synthese von s-Triazolo[a]pyrimido-pyrimidinen (1970)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 312 (1970), S. 254-262 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es werden Darstellungs- und Abbaureaktionen von je einem Derivat der vier bisher noch nicht bekannten s-Triazolo[a]pyrimido-pyrimidine beschrieben. Dabei wird in der Reihe der durch Kondensation von 3-Amino-1,2,4-triazol mit Äthoxymethylenmalonsäuredinitril entstehenden s-Triazolo[a]pyrimidine erstmalig an derartigen Ringsystemen eine Dimroth-Umlagerung eines s-Triazolo[1,5-a]pyrimidins in das [4,3-a]-Isomere beobachtet.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19703120208
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  • 13
    Electronic Resource
    Electronic Resource
    Vinyloge Acylverbindungen. XXI. 1H-NMR-spektroskopische Untersuchungen an 3-Chlor-propen-iminiumsalzen (1989)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 331 (1989), S. 111-114 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinylogous Acyl Compounds. XXI. 1H-N.M.R. Spectroscopic Investigations on 3-Chloropropen-iminium SaltsThe 1H-n.m.r. data of a series of 3-aryl-3-chloropropeniminium salts 5 are reported. From the vicinal coupling constants 3J(H1, 2H) as well as from NOE difference spectra follows that salts of type 5 have throughout E(1,2)Z(2,3) configuration.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19893310117
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  • 14
    Electronic Resource
    Electronic Resource
    Tetrazolverbindungen. 5. Synthese und Umaminierung von Enaminoketonen der Tetrazolreihe (1990)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 977-994 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetrazole Compounds. 5. Synthesis and Transamination of Enamino Ketones of the Tetrazole SeriesTetrazole-5-acetaldehyde enamines 5 react with aliphatic and aromatic carboxylic acid chlorides in the presence of an auxiliary base (e.g. pyridine or triethylamine) to give tetrazolylsubstituted enamino ketones 6. The latter can be modified by acid-catalyzed transamination with secondary aliphatic amines (e.g. diethylamine, pyrrolidine, piperidine, morpholine, hexamethylene imine) yielding 5-(1-acyl-2-dialkylamino-vinyl)-1-aryl-1 H-tetrazoles 7. The analogue transamination of 6 with primary alkyl, aralkyl, and aryl amines results in corresponding secondary enamino ketones 8, which exist in solution as an equilibrium mixture of the Z and E form. Acylation of secondary tetrazole-5-acetaldehyde enamines 9 does not lead to 8, but to the isomeric N-acyl derivatives 10. - Characteristic 1H-n.m.r., u.v., and i.r. spectroscopic data of the novel products are reported.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19903320615
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  • 15
    Electronic Resource
    Electronic Resource
    Pyryliumverbindungen. 44 [1]. 2-(2-Hydroxy-3-oxo-cycloalk-1-enyl)-2H-thiopyrane aus 2,4,6-Triaryl-thiopyryliumsalzen und Cycloalkan-1,2-dionen (1989)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 331 (1989), S. 853-858 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. 44. 2-(2-Hydroxy-3-oxo-cycloalk-1-enyl)-2H-thiopyranes from 2,4,6-Triarylthiopyrylium Salts and Cycloalkane-1,2-diones2,4,6-Triarylthiopyrylium salts 5 react with cyclopentane-1,2-dione (2a) or cyclo-hexane-1,2-dione (2b) in the presence of an appropriate acid binding agent (e.g. sodium acetate, piperidine acetate, triethylamine/acetic acid, triethylamine) to give the hitherto unknown 2-(2-hydroxy-3-oxo-cycloalk-1-enyl)-2H-thiopyranes 6. - The structure of the novel compounds was established by n.m.r., i.r. and u.v. spectroscopic methods.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19893310520
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  • 16
    Electronic Resource
    Electronic Resource
    Pyryliumverbindungen. 43 [1]. Arylsubstituierte 5-(2-Dialkylamino-thiazol-5-yl)-pentadienone aus 2,4,6-Triaryl-pyryliumsalzen und 2-Dialkylamino-4-arylthiazolen (1989)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 331 (1989), S. 843-852 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. 43. Arylsubstituted 5-(2-Dialkylamino-thiazol-5-yl)-pentadienones from 2,4,6-Triarylpyrylium Salts and 2-Dialkylamino-4-aryl-thiazoles2,4,6-Triarylpyrylium salts 1 react with 2-dialkylamino-4-aryl-thiazoles 7 (used in substance or prepared in situ from α-thiocyanato-acetophenones 9) in the presence of an appropriate acid-binding agent (e.g. piperidine acetate or sodium acetate) to give 5-(2-dialkylamino-4-aryl-thiazol-5-yl)-1,3,5-triaryl-penta-2,4-dien-1-ones 8. As reaction medium aliphatic alcohols (ethanol, n-propanol), dipolar aprotic solvents (acetonitrile) or chlorinated hydrocarbons (methylene chloride, chloroform) can be used. On the other hand, under the same conditions 2-amino-4-phenyl-thiazole (10) reacts with salts of type 1 via pyrylium ring transformation yielding 2,4,6-triaryl-1-(4-phenyl-thiazol-2-yl)-pyridinium perchlorates 11.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19893310519
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  • 17
    Electronic Resource
    Electronic Resource
    Tetrazolverbindungen. 4 [1]. Alkylierung von 1-Aryl-5-(2-dimethylamino-vinyl)-1 H-tetrazolen (1989)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 331 (1989), S. 885-892 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetrazole Compounds. 4. Alkylation of 1-Aryl-5-(2-dimethylamino-vinyl)-1 H-tetrazolesAlkylation of 1-aryl-5-(2-dimethylamino-vinyl)-1 H-tetrazoles 1 with dialkyl sulfates or alkyl iodides yields mainly 4-alkyl-1-aryl-5-(2-dimethylamino-vinyl)-1 H-tetrazolium salts which can be isolated free from isomers by separation as perchlorates 2. The reaction proceeds with retention of the E configuration of the vinyl group. In contrast to 1 the methyl groups of the dimethylamino substituent in 2 are magnetically non-equivalent indicating restricted rotation of this residue. On heating 2 with aqueous mineral acids the dimethylaminovinyl moiety undergoes degradation to a methyl group affording 4-alkyl-1-aryl-5-methyl-1 H-tetrazolium salts 4, the structure of which was confirmed by independent synthesis. With hot aqueous alkali hydroxide 2 reacts under ring cleavage to give aryl azide.  -  1H n.m.r. and u.v. spectroscopic data of the tetrazolium salts 2 and 4 are reported.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19893310602
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  • 18
    Electronic Resource
    Electronic Resource
    Substituierte 2-Amino-thiazole aus α-Thiocyanato-acetophenonen und DialkylaminenHerrn Prof. Dr. K. Gewald mit den besten Wünschen zum 60. Geburtstag gewidmet (1990)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 453-460 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Substituted 2-Amino-thiazoles from α-Thiocyanato-acetophenones and Dialkylaminesα-Thiocyanato-acetophenones 1 react with dialkylammonium salts of weak acids (acetates, propionates, benzoates) to give 2-dialkylamino-4-aryl-thiazoles 4. As reaction medium aliphatic alcohols (methanol, ethanol), dipolar-aprotic solvents (acetonitrile, dimethylformamide, dimethyl sulphoxide) or chlorinated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride) can be used. In comparison to known methods for the preparation of the thiazoles 4 the synthesis via α-thiocyanato-acetophenones 1 has the advantage of the simpler accessible starting compounds. - I.r., u.v., n.m.r. and mass spectroscopic data of the thiazoles 4 are reported.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19903320405
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  • 19
    Electronic Resource
    Electronic Resource
    2-Dialkylamino-thiazolin-4-one aus α-Thiocyanato-carbonsäurederivatenHerrn Prof. Dr. G. Zimmermann mit den besten Wünschen zum 60. Geburtstag gewidmet (1990)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 540-546 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Dialkylamino-thiazolin-4-ones from α-Thiocyanato-carboxylic Acid Derivativesα-Thiocyanato-acetic acid esters 1a-c or amide 1d react with dialkylamine salts of weak acids to give 2-dialkylamino-thiazolin-4-ones 2a-f. The reaction can be performed using aliphatic alcohols, dipolar aprotic solvents or halogenated hydrocarbons as reaction medium or by heating the educts at 90°C without any solvent. According to the latter method, the 5-substituted thiazolinones 2g, h are obtained from α-thiocyanatopropionic acid ethyl ester (1d) or α-thiocyanato-phenylacetic acid ethyl ester (1e) and dimethylamine acetate. - I.r., u.v. and n.m.r. data of the thiazolinones 2 are reported.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19903320419
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  • 20
    Electronic Resource
    Electronic Resource
    Tetrazolverbindungen. 1. 1-Aryl-5-(2-dialkylamino-vinyl)-1H-tetrazole aus 3-Chlor-propen-iminiumsalzen (1988)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 330 (1988), S. 963-973 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetrazole Compounds. 1. 1-Aryl-5-(2-dialkylamino-vinyl)-1H-tetrazoles from 3-Chloropropeniminium Salts3-Chloropropeniminium salts 1 react with excess sodium azide in refluxing alcohols to give mainly 1-aryl-5-(2-dialkylamino-vinyl)-1H-tetrazoles 3; in minor quantities isomeric 5-aryl-1-(2-dialkylamino-vinyl)-1H-tetrazoles 4 are formed. The reaction involves splitting off N2 and C → N migration of the aryl and dialkylaminovinyl group, respectively. A cross-over experiment indicated that the rearrangement step proceeds intramolecularly.  -  The i.r., u.v., and n.m.r. spectroscopic data of the novel 1H-tetrazoles 3 as well as the u.v. spectra of some new starting products 1k - v are reported.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19883300617
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