Patents by Inventor Karlheinz Wembacher

Karlheinz Wembacher 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 ascorbic acid
    Patent number: 5744618
    Abstract: A process for the preparation of L-ascorbic acid by reacting 2-keto-L-gulonic acid with aqueous mineral acid in a solvent mixture containing an inert organic solvent, an aliphatic ketone and also an acid chloride.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: April 28, 1998
    Assignee: Merck Patent Gesellschaft Mit Beschrankter Haftung
    Inventors: Ulrich Fechtel, Karlheinz Wembacher
  • Method for preparing 3-aminopyridines from 3-nitropyridines
    Patent number: 5518588
    Abstract: The present invention relates to a method for preparing 3-aminopyridines from 3-nitropyridines, in which the nitropyridines are reduced electrochemically in acidic solution.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: May 21, 1996
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Ulrich Fechtel, Karlheinz Wembacher, Heinz-Hermann Bokel