Patents by Inventor Leon Krumenacker

Leon Krumenacker has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for the preparation of 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadienone
    Patent number: 4612401
    Abstract: 4-Hydroxy-2,4,6-trimethyl-2,5-cyclohexadienone is made by chlorinating 2,4,6-trimethylphenol with chlorine in an organic solvent in the absence of base while the hydrogen chloride formed is removed as it is formed by physical means and hydrolyzing the reaction mixture with water optionally in the presence of an inorganic base.
    Type: Grant
    Filed: March 19, 1985
    Date of Patent: September 16, 1986
    Assignee: Rhone-Poulenc Sante
    Inventors: Michel Costantini, Francoise Igersheim, Leon Krumenacker
  • Process for the preparation of 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadienone
    Patent number: 4565895
    Abstract: 4-Hydroxy-2,4,6-trimethyl-2,5-cyclohexadienone is prepared by oxidation of 2,4,6-trimethylphenol with a manganese derivative of valency greater than 2 in an aqueous acidic medium.
    Type: Grant
    Filed: September 21, 1984
    Date of Patent: January 21, 1986
    Assignee: Rhone-Poulenc Sante
    Inventors: Michel Costantini, Francoise Igersheim, Leon Krumenacker
  • Process for the preparation of 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadienone
    Patent number: 4560801
    Abstract: 4-Hydroxy-2,4,6-trimethyl-2,5-cyclohexadienone is prepared by treatment of 2,4,6-trimethylphenol with a halogenation agent and water in the presence of an organic solvent which is inert to the halogenation agent.
    Type: Grant
    Filed: July 10, 1984
    Date of Patent: December 24, 1985
    Assignee: Rhone-Poulenc Sante
    Inventors: Michel Costantini, Francoise Igersheim, Leon Krumenacker
  • Process for the preparation of anthraquinone
    Patent number: 3931254
    Abstract: A simple process for preparing anthraquinone in good yield from anthracene is described, which process comprises oxidising anthracene by means of oxygen or an oxygen-containing gas in the liquid phase, in an inert organic diluent, in the presence of a halogen-copper bond free copper derivative.
    Type: Grant
    Filed: May 8, 1974
    Date of Patent: January 6, 1976
    Assignee: Rhone-Poulenc S.A.
    Inventors: Raymond Janin, Leon Krumenacker