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  • 1
    Electronic Resource
    Electronic Resource
    A facile synthesis of fluorochlorobromoacetic acid (1990)
    Springer
    Monatshefte für Chemie 121 (1990), S. 31-43 
    Details
    ISSN: 1434-4475
    Keywords: Fluorochlorobromoacetic acid ; 1,1,2-Trifluoro-2-chloroethylene, bromination ; 1,2-Difluoro-1-chloro-2-methoxyethylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Fluorchlorbromessigsäure wurde aus 1,1,2-Trifluor-2-chlorethylen in vier Stufen mit einer Gesamtausbeute von ca. 25% hergestellt. 1,1,2-Trifluor-2-chlorethylen wurde zuerst mit Natriummethoxid zu 1,2-Difluor-1-chlor-2-methoxyethylen umgesetzt, das dann mit elementarem Brom bromiert wurde. Das Reaktionsprodukt daraus ergab nach Behandlung mit konzentrierter Schwefelsäure Methyl-fluorchlorbromacetat, das nach Hydrolyse mit verdünnter Natronlauge zur Zielverbindung führte.
    Notes: Abstract Fluorochlorobromoacetic acid was sythesized in the sequence of four steps from 1,1,2-trifluoro-2-chloroethylene in an overall yield of approximately 25%. 1,1,2-Trifluoro-2-chloroethylene was first allowed to react with sodium methoxide to form 1,2-difluoro-1-chloro-2-methoxyethylene, which was then brominated with elemental bromine and the reaction product treated with concentrated sulfuric acid to give methyl fluorochlorobromoacetate. This compound was hydrolized with a diluted sodium hydroxide solution to fluorochlorobromoacetic acid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00810292
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  • 2
    Electronic Resource
    Electronic Resource
    Head-to-head polymers — XXXII: Toward head-to-head poly(α-methylstyrene): Synthesis of 2,3-dimethyl-2,3-diphenylbutanediol-1,4-ditosylate and 1,4-diphenyl-2,3-dimethylbutadiene-1,3 (1985)
    Springer
    Monatshefte für Chemie 116 (1985), S. 401-412 
    Details
    ISSN: 1434-4475
    Keywords: Phenonium rearrangement ; Nucleophilic displacement ; Stereoisomers ; 1H- and13C NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Ausgehend von 2-Phenylpropionsäure (1) wurde 2,3-Dimethyl-2,3-butandiol-1,4-ditosylat (7) symthetisiert. Das Säurechlorid wurde bromiert und zu Methyl-2-phenyl-2-brom-propionat (4) umgesetzt, das mit Zink/Kupfer zu Dimethyl-2,3-dimethyl-2,3-diphenylsuccinat (5) gekuppelt wurde. Reduktion mitLAH zu 2,3-Dimethyl-2,3-diphenylbutandiol (6) und nachfolgende Tosylierung ergab eine Mischung der meso und racemischen Tosylate7a undb, welche in die reinen Isomere aufgetrennt werden konnten (a Fp. 170 °C undb Fp. 121 °C). Die beiden Verbindungen ergaben bei Behandlung mit Tetraalykylammoniumbromid nicht das erwartete 2,3-Dimethyl-2,3-diphenyl-1,4-dibrombutan (9), sondern 1,4-Diphenyl-2,3-dimethyl-butadien-1,3 (8). Das wurde durch unabhängige Synthese von8 auf anderem Wege, Vergleich der spektroskopischen Eigenschaften und mittels Mischschmelzpunkt nachgewiesen.
    Notes: Abstract 2,3-Dimethyl-2,3-diphenylbutanediol-1,4-ditosylate (7) was synthesized starting from 2-phenylpropionic acid (1). The acid chloride was brominated and transformed into methyl 2-phenyl-2-bromo-propionate (4) which was coupled with a zinc/copper couple to dimethyl 2,3-dimethyl-2,3-diphenylsuccinate (5). Reduction with lithium aluminum hydride to 2,3-dimethyl-2,3-diphenylbutanediol-1,4 (6) was followed by tosylation. The tosylate 7 a mixture of the meso and racemic compounds, could be separated into the pure isomers,a m. p. 170 °C andb m. p. 121 °C. The mixture of each individual pure compound, when treated with tetraalkyl-ammonium bromide, did not give the expected 2,3-dimethyl-2,3-diphenyl-1,4-dibromobutane (9) but rather 1,4-diphenyl-2,3-dimethylbutadiene-1,3 (8). The identity of the compound was established by independent unequivocal synthesis, the comparison of spectral characteristics, and mixed melting point.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00799974
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  • 3
    Electronic Resource
    Electronic Resource
    Head to head polymers. XXV:Part XXIV: M. Malanga and O. Vogl, J. Polym. Sci., Polym. Chem. Ed., in press. Properties of head to head polyisobutylene (1983)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 23 (1983), S. 597-600 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Head-to-head polyisobutylene, prepared by the Grignard coupling reaction of 2,2,3,3-tetramethyl-1,4-dibromobutane had molecular weight of 3,000 to 10,000 and was characterized by wide angle x-ray diffraction, optical microscopy and thermal behavior. Head-to-head polyisobutylene is crystalline, with a crystalline melting point of 187°C and a glass transition temperature of 87°C (measured by DSC at a scan rate of 20°/min.); these values compare to a glass transition temperature of head-to-tail polyisobutylene of similar molecular weight of -61°C and a crystalline melting point of 5°C, which can only be observed when the sample was stretched. The maximum rate of degradation of head-to-head polyisobutylene (20°/min. programmed temperature increase) is at 315°C, 70°C lower than that of head-to-tail polyisobutylene.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760231012
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  • 4
    Electronic Resource
    Electronic Resource
    Functional polymers LI:Part L: Mark D. Purgett and Otto Vogl, J. Polymer Sci., Polymer Chem. Ed., in press. Characterization and property analysis of ω-functionally substituted polyolefins; novel polyolefin ionomers (1987)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 27 (1987), S. 1461-1468 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Homopolymers of 2,6-dimethylphenyl 10-undecenoate and copolymers of 2,6-dimethylphenyl 10-undecenoate with α-olefins, prepared by coordination initiators using aluminum activated titanium trichloride, and the corresponding sodium carboxylate and carboxylic acid derivatives have been characterized. IR and NMR investigations gave the normal; spectral characteristics typical for estersubstituted polyolefins and their derivatives. The thermal behavior of the polymeric esters, investigated by differential scanning calorimetry, showed glass transitions characteristic of poly(α-olefins). Polymeric acids and salts presented quite different behavior; most notably the polymeric salt showed no glass transition, but rather an exothermic transition, resembling a broad melting peak at 250-270°C, which is characteristic of a crystalline polymer. We interpret this behavior as the melting of carboxylate cluster domains, which according to our WAXD analysis has a domain size of about 25 Å.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760271905
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