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  • 1
    ISSN: 1434-4475
    Keywords: Functional polymers ; 2(2-Hydroxyphenyl)2 H-benzotriazoles ; 2-Hydroxyphenylaceto(benzo)phenones ; Azo coupling ; Reductive cyclization ; Ultraviolet stabilizers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wurden acht Benzotriazole und 4-Methoxybenzotriazole — mono- oder disubstituierte Derivate von 2,4-Dihydroxyaceto(oder benzo)phenonen — über Azokopplung von 4-Methoxy-2-nitrobenzoldiazoniumchlorid mit 2,4-Dihydroxyaceto(oder benzo)phenonen und nachfolgender reduktiver Cyclisierung synthetisiert. Reine monosubstituierte Verbindungen waren sehr schwer herzustellen. Sorgfältige Wahl despH-Wertes für die Azo-Kupplung und geeignete Reagentien für die reduktive Cyclisierung waren dabei wesentlich. Alle Verbindungen wurden mittels UV-, IR-,1H-NMR- und13C-NMR-Spektren und Elementaranalysen charakterisiert. Die synthetisierten Verbindungen besitzen jeweils eine 2-(2-Hydroxyphenyl)-2H-benzotriazol-Einheitund eine 2-Hydroxyaceto(oder benzo)phenon-Einheit im gleichen Molekül und stellen effektvolle und nützliche Ultraviolett-Absorber dar.
    Notes: Abstract Eight benzotriazoles and (4-methoxy)benzotriazoles, mono- or di-substituted derivatives of 2,4-dihydroxyaceto(or benzo)phenone were synthesized by azo coupling of (4-methoxy)2-nitrobenzenediazonium chloride with 2,4-dihydroxyaceto(or benzo)phenone followed by reductive cyclization. Pure mono-substituted compounds were very difficult to prepare. Careful selection of thepH for the azo coupling and selection of the proper reagents for the reductive cyclization were essential. All compounds were characterized by their ultraviolet, infrared1H and13C NMR spectra and their elemental analysis. These compounds have both the 2(2-hydroxyphenyl)2H-benzotriazole unit and a 2-hydroxyaceto(or benzo)phenone unit in the same molecule and are effective and useful ultraviolet absorbers.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1434-4475
    Keywords: 2(2-Hydroxyphenyl)2H-benzotriazoles ; Ultraviolet absorbers ; Condensation copolymers ; Polyamides ; Polyesters ; Polycarbonates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wurden Carboxy- und Carbomethoxy-Derivate von Resorcin mit zwei Benzotriazol-Substituenten dargestellt. 2(2,4-Dihydroxyphenyl)2H-1,3-bis-(4-carboxybenzotriazol) [2,4-Bis(2H-4′-carboxybenzotriazol-2-yl)-1,3-dihydroxybenzol] (DCBDH) wurde über Azokupplung von 4-Carboxy-2-nitrobenzol-diazoniumchlorid mit Resorcin, gefolgt von reduktiver Cyclisierung, synthetisiert. 2(2,4-Dihydroxyphenyl)2H-1,3-bis-(4-carbomethoxybenzotriazol) [2,4-Bis-(2H-4′-carbomethoxybenzotriazol-2-yl)-1,3-dihydroxybenzol] (DCMBDH) erhielt man mittels Veresterung der freien Dicarbonsäure mit Methanol. Die Verbindungen wurden mittels Elementaranalysen und spektroskopisch charakterisiert (IR, UV,1H und13C NMR). Es wurden Copolymerisationen zur Inkorporierung vonDCBDH undDCMBDH in Polyamide und Polyester durchgeführt. Die Kondensationskopolymeren werden kurz charakterisiert.
    Notes: Abstract Carboxy- and carbomethoxy derivatives of resorcinols with two benzotriazole substituents have been synthesized. 2(2,4-Dihydroxyphenyl)2H-1,3-bis-(4-carboxybenzotriazole) [2,4-bis(2H-4′-carboxybenzotriazole-2-yl)-1,3-dihydroxybenzene] (DCBDH) was prepared by azo coupling of 4-carboxy-2-nitrobenzene diazonium chloride with resorcinol followed by reductive cyclization. 2(2,4-Dihydroxyphenyl)2H-1,3-bis(4-carbomethoxy-benzotriazole) [2,4-bis-(2H-4′-carbomethoxy-benzotriazole-2-yl)-1,3-dihydroxybenzene] (DCMBDH) was obtained by esterification of the free dicarboxylic acid with methanol. The compounds were characterized by their elemental analyses and melting points, and by their IR, UV,1H NMR, and13C NMR spectra. Copolycondensations were carried out to incorporateDCBDH orDCMBDH into polyamides or polyesters. The condensation copolymers were briefly characterized.
    Type of Medium: Electronic Resource
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