A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3′-dimethylbiphenyl and the oxidation of the acetyl derivatives

Salam JJ Titinchi, Fadhil S. Kamounah, Hanna S. Abbo, Ole Hammerich

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

    Resumé

    Background: Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3'-dimethylbiphenyl (3,3'-dmbp) have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and derivatives that are of interest in cancer treatment.

    Findings: The effect of solvent and temperature on the selectivity of monoacetylation of 3,3'-dmbp by the Perrier addition procedure was studied using stoichiometric amounts of reagents. 4-Ac-3,3'-dmbp was formed almost quantitatively in boiling 1,2-dichloroethane and this is almost twice the yield hitherto reported. Using instead a molar ratio of substrate: AcCl:AlCl3 equal to 1: 4: 4 or 1: 6: 6 in boiling 1,2-dichloroethane, acetylation afforded 4,4'- and 4,6'-diacetyl-3,3'-dmbp in a total yield close to 100%. The acetyl derivatives were subsequently converted to the carboxylic acids by hypochlorite oxidation. The relative stabilities of the isomeric products and the corresponding s-complexes were studied by DFT calculations and the data indicated that mono-and diacetylation followed different mechanisms.

    Conclusions: Friedel-Crafts acetylation of 3,3'-dmbp using the Perrier addition procedure in boiling 1,2-dichloroethane was found to be superior to other recipes. The discrimination against the 6-acetyl derivative during monoacetylation seems to reflect a mechanism including an AcCl: AlCl3 complex or larger agglomerates as the electrophile, whereas the less selective diacetylations of the deactivated 4-Ac-3,3'-dmbp are suggested to include the acetyl cation as the electrophile. The DFT data also showed that complexation of intermediates and products with AlCl3 does not seem to be important in determining the mechanism.
    OriginalsprogEngelsk
    TidsskriftChemistry Central Journal
    Vol/bind6
    ISSN1752-153X
    DOI
    StatusUdgivet - 2012

    Bibliografisk note

    Artikel nr. 52

    Citer dette

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    title = "A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3′-dimethylbiphenyl and the oxidation of the acetyl derivatives",
    abstract = "Background: Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3'-dimethylbiphenyl (3,3'-dmbp) have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and derivatives that are of interest in cancer treatment. Findings: The effect of solvent and temperature on the selectivity of monoacetylation of 3,3'-dmbp by the Perrier addition procedure was studied using stoichiometric amounts of reagents. 4-Ac-3,3'-dmbp was formed almost quantitatively in boiling 1,2-dichloroethane and this is almost twice the yield hitherto reported. Using instead a molar ratio of substrate: AcCl:AlCl3 equal to 1: 4: 4 or 1: 6: 6 in boiling 1,2-dichloroethane, acetylation afforded 4,4'- and 4,6'-diacetyl-3,3'-dmbp in a total yield close to 100{\%}. The acetyl derivatives were subsequently converted to the carboxylic acids by hypochlorite oxidation. The relative stabilities of the isomeric products and the corresponding s-complexes were studied by DFT calculations and the data indicated that mono-and diacetylation followed different mechanisms. Conclusions: Friedel-Crafts acetylation of 3,3'-dmbp using the Perrier addition procedure in boiling 1,2-dichloroethane was found to be superior to other recipes. The discrimination against the 6-acetyl derivative during monoacetylation seems to reflect a mechanism including an AcCl: AlCl3 complex or larger agglomerates as the electrophile, whereas the less selective diacetylations of the deactivated 4-Ac-3,3'-dmbp are suggested to include the acetyl cation as the electrophile. The DFT data also showed that complexation of intermediates and products with AlCl3 does not seem to be important in determining the mechanism.",
    author = "Titinchi, {Salam JJ} and Kamounah, {Fadhil S.} and Abbo, {Hanna S.} and Ole Hammerich",
    note = "Artikel nr. 52",
    year = "2012",
    doi = "10.1186/1752-153X-6-52",
    language = "English",
    volume = "6",
    journal = "Chemistry Central Journal",
    issn = "1752-153X",
    publisher = "BioMed Central Ltd.",

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    A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3′-dimethylbiphenyl and the oxidation of the acetyl derivatives. / Titinchi, Salam JJ; Kamounah, Fadhil S.; Abbo, Hanna S.; Hammerich, Ole.

    I: Chemistry Central Journal, Bind 6, 2012.

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

    TY - JOUR

    T1 - A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3′-dimethylbiphenyl and the oxidation of the acetyl derivatives

    AU - Titinchi, Salam JJ

    AU - Kamounah, Fadhil S.

    AU - Abbo, Hanna S.

    AU - Hammerich, Ole

    N1 - Artikel nr. 52

    PY - 2012

    Y1 - 2012

    N2 - Background: Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3'-dimethylbiphenyl (3,3'-dmbp) have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and derivatives that are of interest in cancer treatment. Findings: The effect of solvent and temperature on the selectivity of monoacetylation of 3,3'-dmbp by the Perrier addition procedure was studied using stoichiometric amounts of reagents. 4-Ac-3,3'-dmbp was formed almost quantitatively in boiling 1,2-dichloroethane and this is almost twice the yield hitherto reported. Using instead a molar ratio of substrate: AcCl:AlCl3 equal to 1: 4: 4 or 1: 6: 6 in boiling 1,2-dichloroethane, acetylation afforded 4,4'- and 4,6'-diacetyl-3,3'-dmbp in a total yield close to 100%. The acetyl derivatives were subsequently converted to the carboxylic acids by hypochlorite oxidation. The relative stabilities of the isomeric products and the corresponding s-complexes were studied by DFT calculations and the data indicated that mono-and diacetylation followed different mechanisms. Conclusions: Friedel-Crafts acetylation of 3,3'-dmbp using the Perrier addition procedure in boiling 1,2-dichloroethane was found to be superior to other recipes. The discrimination against the 6-acetyl derivative during monoacetylation seems to reflect a mechanism including an AcCl: AlCl3 complex or larger agglomerates as the electrophile, whereas the less selective diacetylations of the deactivated 4-Ac-3,3'-dmbp are suggested to include the acetyl cation as the electrophile. The DFT data also showed that complexation of intermediates and products with AlCl3 does not seem to be important in determining the mechanism.

    AB - Background: Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3'-dimethylbiphenyl (3,3'-dmbp) have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and derivatives that are of interest in cancer treatment. Findings: The effect of solvent and temperature on the selectivity of monoacetylation of 3,3'-dmbp by the Perrier addition procedure was studied using stoichiometric amounts of reagents. 4-Ac-3,3'-dmbp was formed almost quantitatively in boiling 1,2-dichloroethane and this is almost twice the yield hitherto reported. Using instead a molar ratio of substrate: AcCl:AlCl3 equal to 1: 4: 4 or 1: 6: 6 in boiling 1,2-dichloroethane, acetylation afforded 4,4'- and 4,6'-diacetyl-3,3'-dmbp in a total yield close to 100%. The acetyl derivatives were subsequently converted to the carboxylic acids by hypochlorite oxidation. The relative stabilities of the isomeric products and the corresponding s-complexes were studied by DFT calculations and the data indicated that mono-and diacetylation followed different mechanisms. Conclusions: Friedel-Crafts acetylation of 3,3'-dmbp using the Perrier addition procedure in boiling 1,2-dichloroethane was found to be superior to other recipes. The discrimination against the 6-acetyl derivative during monoacetylation seems to reflect a mechanism including an AcCl: AlCl3 complex or larger agglomerates as the electrophile, whereas the less selective diacetylations of the deactivated 4-Ac-3,3'-dmbp are suggested to include the acetyl cation as the electrophile. The DFT data also showed that complexation of intermediates and products with AlCl3 does not seem to be important in determining the mechanism.

    U2 - 10.1186/1752-153X-6-52

    DO - 10.1186/1752-153X-6-52

    M3 - Journal article

    VL - 6

    JO - Chemistry Central Journal

    JF - Chemistry Central Journal

    SN - 1752-153X

    ER -