Patents by Inventor Lutz Frohn

Lutz Frohn 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 preparing piperidines
    Patent number: 6458954
    Abstract: Piperidines are prepared in an advantageous manner by catalytic hydrogenation of activated pyridines in the presence of palladium catalysts if the palladium catalyst is palladium-on-carbon and the solvents are aromatic hydrocarbons.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: October 1, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Guido Giffels, Herbert Diehl, Georg Martin, Lutz Frohn, Erich Hammerschmidt
  • Method for producing catalysts containing ruthenium and the use thereof for hydrogenation
    Patent number: 6376414
    Abstract: The invention relates to catalysts containing ruthenium and at least one other metal having an atomic number in the range of from 23 to 82 prepared by (a) mixing a suspension of a ruthenium compound having a specific surface area in the range of from 50 to 300 m2/g with a solution of at least one metal compound in which at least one such metal compound contains a metal different from ruthenium and has an atomic number in the range of from 23 to 82, and (b) treating the mixture of the suspension and the solution with a reducing agent.
    Type: Grant
    Filed: July 25, 2000
    Date of Patent: April 23, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Stefan Antons, Lutz Frohn, Jörg-Dietrich Jentsch, Andreas Schulze Tilling, Erich Wolters
  • Process for preparing piperidines
    Publication number: 20010056186
    Abstract: Piperidines are prepared in an advantageous manner by catalytic hydrogenation of activated pyridines in the presence of palladium catalysts if the palladium catalyst is palladium-on-carbon and the solvents are aromatic hydrocarbons.
    Type: Application
    Filed: April 30, 2001
    Publication date: December 27, 2001
    Inventors: Guido Giffels, Herbert Diehl, Georg Martin, Lutz Frohn, Erich Hammerschmidt
  • Preparation of N-phenyl-1-naphthylamine
    Patent number: 6054618
    Abstract: N-phenyl-1-naphthylamine can be prepared by reacting aniline and 1-naphthylamine in the liquid phase at 100-400.degree. C. at a reaction pressure which is higher than atmospheric pressure. Boron and fluorine-containing catalysts, mono or polysulfonic acids, iodine, PCl.sub.3, PCl.sub.5, or POCl.sub.3, for example, may be used as catalysts.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: April 25, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hanspeter Baumgartner, Lutz Frohn, Alexander Klausener, Frank Arndt
  • Process for preparing 2-pyrrolidones
    Patent number: 5912358
    Abstract: 2-Pyrrolidones can be prepared by simultaneous reaction of maleic acid, ammonia or a primary amine and hydrogen at elevated temperature and elevated pressure in the liquid phase over a supported catalyst, with the supported catalyst containing both palladium and rhenium in metallic or bound form.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: June 15, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Lutz Frohn, Jorg-Dietrich Jentsch, Eberhard Zirngiebl
  • Process for preparing hydroxymethylcyclopropane
    Patent number: 5786521
    Abstract: Hydroxymethylcyclopropane is prepared from alkyl cyclopropanecarboxylates by reduction with hydrogen in a process in which use is made of a reduced pelletized catalyst which is obtainable by pressing a mixture of pulverulent copper, zinc and aluminum oxides and subsequent reduction. This process has the advantage that it uses a low-toxicity catalyst which has a long operating life and is particularly suitable for a continuous process and requires relatively low reaction temperatures.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: July 28, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Darsow, Lutz Frohn, Reinhard Langer
  • Process for the preparation of hydroxymethyl-cyclopropane
    Patent number: 5728896
    Abstract: Hydroxymethyl-cyclopropane (cyclopropyl-methanol) can be obtained in a manner which is both economical and environment-friendly by catalytic hydrogenation of cyclopropanecarboxylic acid alkyl esters under increased pressure at elevated temperature if a chromium-free zinc oxide catalyst is employed as the catalyst.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: March 17, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Lutz Frohn, Reinhard Langer, Gerhard Darsow, Eberhard Zirngiebl, Jorg-Dietrich Jentsch, Bernd Pennemann, Christoph Tiburtius