Patents Represented by Attorney S. D. Frenkel

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  • Process for preparation of 2-vinylnaphthalene
    Patent number: 5191133
    Abstract: The selective formation of 2-acetonaphthalene is achieved by acetylating naphthalene in the presence of liquid hydrogen fluoride. The 2-acetonaphthalene can be separated from the formed 1-acetonaphthalene isomer by successive hydrogenation of the isomer mixture and dehydration. The hydrogenation is selective to the 2-isomer while the 1-acetonaphthalene remains unreacted. Upon completion, 2-vinylnaphthalene can be distilled off from the unreacted 1-acetonaphthalene.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: March 2, 1993
    Assignee: Hoescht Celanese Corporation
    Inventor: Henry C. Linstid, III
  • Synthesis of 1-aminoanthraquinone
    Patent number: 5132437
    Abstract: 1-Aminoanthraquinone (1-AAQ) is synthesized by the reaction of 2-chlorobenzyl chloride and xylene in the presence of a solid acid catalyst to yield 2-chloro dimethyldiphenylmethane, subsequent oxidation of the methyl groups, ring closure to form a 1-chloroanthraquinone carboxylic acid, replacement of the 1-chloro group with ammonia, and decarboxylation.
    Type: Grant
    Filed: February 12, 1991
    Date of Patent: July 21, 1992
    Assignee: Hoechst Celanese Corporation
    Inventors: Mohammad Aslam, Daniel A. Aguilar
  • Synthesis of 1-aminoanthraquinone
    Patent number: 5130448
    Abstract: 1-Aminoanthraquinone (1-AAQ) is synthesized by the condensation of 2-substituted benzoic acid and xylene to yield 2-substituted-dimethylbenzophenone, subsequent oxidation of the methyl groups, ring closure to form a 1-substituted anthraquinone carboxylic acid, replacement of the 1-substituent with ammonia, and decarboxylation.
    Type: Grant
    Filed: February 12, 1991
    Date of Patent: July 14, 1992
    Assignee: Hoechst Celanese Corporation
    Inventors: Mohammad Aslam, Daniel A. Aguilar