Patents by Inventor Johann Riegl

Johann Riegl 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).

  • Patent number: 6462219
    Abstract: A process for the production of 3-hydroxypropionitrile is provided. This process includes (a) reacting acrylonitrile with water at a defined molar ratio in the presence of a weak base under specific temperature and pressure conditions until a conversion in the range of about 40% to about 80% has been achieved; (b) after cooling the mixture obtained in (a), separating off its aqueous phase; (c) distilling off the acrylonitrile from the organic phase remaining after (b); (d) subjecting the mixture obtained in (c) to pyrolysis at specific temperature and pressure conditions in the presence of a basic catalyst to obtain a mixture consisting mainly of 3-hydroxypropionitrile and acrylonitrile; and (e) isolating the desired 3-hydroxypropionitrile by fractional distillation from the mixture obtained in (d). Such a process in which the basic aqueous phase and the acrylonitrile that has been distilled off are recycled represents a preferred embodiment.
    Type: Grant
    Filed: January 17, 2001
    Date of Patent: October 8, 2002
    Assignee: Roche Vitamins, Inc.
    Inventors: Bruno Burdet, August Ruettimann, Johann Riegl
  • Patent number: 5892058
    Abstract: A method of producing .alpha.-tocopherol from non-.alpha.-tocopherols is disclosed. In the disclosed method, non-.alpha.-tocopherols are hydroxymethylated and reduced to .alpha.-tocopherol in a single step by reacting formaldehyde or a formaldehyde-producing compound with the non-.alpha.-tocopherol under catalytic reducing conditions in a reaction mixture containing the non-.alpha.-tocopherol, formaldehyde or formaldehyde-producing compound and boric acid or a boric acid-producing compound dispersed in a solvent of an azeotropic mixture of trimethyl borate and methanol and a non-polar organic solvent.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: April 6, 1999
    Assignee: Roche vitamins Inc.
    Inventors: Konrad Bruggemann, Juan Ramon Herguijuela, Thomas Netscher, Johann Riegl