Patents by Inventor Ulrich Fechtel

Ulrich Fechtel 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).

  • Method for producing L-ascorbic acid
    Patent number: 6573393
    Abstract: The invention relates to a method for producing L-ascorbic acid from 2-keto-L-gulonic acid or 2,3-4,6-diacetone-2-keto-L-gulonic acid. The reaction is carried out in the presence of water and hydrogen halide and the concentration of the hydrogen halide in water is greater than 37 wt. %.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: June 3, 2003
    Assignee: Merck KGAA
    Inventors: Ulrich Fechtel, Wolfgang Heinz, Klaus Beschmann, Bernd Müller, Jöran Stoldt
  • 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
  • Process for preparing 2-arylbenzimidazole-5-sulfonic acids
    Patent number: 5473079
    Abstract: The invention relates to an improved process for preparing 2-arylbenzimidazole-5-sulfonic acids of the formula I, ##STR1## in which Ar is unsubstituted phenyl or phenyl substituted by one or more C.sub.1 -C.sub.6 alkyl or alkoxy groups andm is 1, 2 or 3,wherein o-phenylenediamine is reacted in the presence of sulfuric acid at between room temperature and 250.degree. C. with a benzoic acid derivative of the formula IIAr(--X).sub.
    Type: Grant
    Filed: October 1, 1993
    Date of Patent: December 5, 1995
    Assignee: Merck Patent Gesellschaft Mit Beschrankter Haftung
    Inventors: Ulrich Heywang, Ingeborg Stein, Ulrich Fechtel, Michael Casutt, Gerald Faller, Hartmut Hartner