Patents by Inventor Wolfgang Eymann

Wolfgang Eymann 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: 6559340
    Abstract: This invention relates to a process for preparing N-substituted hydroxylamines from N-substituted aryl- or heteroaryloxaziridines by acid hydrolysis and isolation of the N-substituted hydroxylamines in the form of their salts.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: May 6, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Michael Dockner, Wolfgang Eymann, Bernd-Michael König, Helmut Holzem
  • Patent number: 6441254
    Abstract: The present invention relates to a process for preparing trimethylol compounds and formic acid by reaction of formaldehyde and aldehydes in the presence of a nitrogen base and distillation of the resulting reaction mixture in the presence of an auxiliary.
    Type: Grant
    Filed: December 13, 2001
    Date of Patent: August 27, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Frank Döbert, Paul Wagner, Alexander Klausener, Wolfgang Eymann, Rolf Feller
  • Publication number: 20020082453
    Abstract: This invention relates to a process for preparing N-substituted hydroxylamines from N-substituted aryl- or heteroaryloxaziridines by acid hydrolysis and isolation of the N-substituted hydroxylamines in the form of their salts.
    Type: Application
    Filed: December 7, 2001
    Publication date: June 27, 2002
    Inventors: Michael Dockner, Wolfgang Eymann, Bernd-Michael Konig, Helmut Holzem
  • Publication number: 20020077502
    Abstract: The present invention relates to a process for preparing trimethylol compounds and formic acid by reaction of formaldehyde and aldehydes in the presence of a nitrogen base and distillation of the resulting reaction mixture in the presence of an auxiliary.
    Type: Application
    Filed: December 13, 2001
    Publication date: June 20, 2002
    Inventors: Frank Dobert, Paul Wagner, Alexander Klausener, Wolfgang Eymann, Rolf Feller
  • Patent number: 6271415
    Abstract: The invention relates to novel S-(4-biphenyl)-thiosulfuric acids and their salts, to a method for producing them from S-(4-biphenyl)-thiosulfinic acids and their salts, and to a method for producing 4-mercaptobiphenyls from the S-(4-biphenyl)-thiosulfuric acids and their salts.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: August 7, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Friedrich-Wilhelm Ullrich, Helmut Fiege, Wolfgang Eymann
  • Patent number: 6133480
    Abstract: N-Phenyl-1-naphthylamine can be prepared by reaction of aniline and 1-naphthylamine in the liquid phase at 100-400.degree. C. under normal pressure, a catalyst mixture comprising boron and fluorine being employed. Such catalyst mixtures can be obtained, for example, by reaction of hydrogen fluoride, boric acid and aniline and/or 1-naphthylamine. The catalyst is recovered and can be employed again. The reaction can be carried out discontinuously or continuously.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: October 17, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Behre, Helmut Fiege, Wolfgang Eymann, Frank Arndt, Rudolf Wiemers, Alexander Klausener
  • Patent number: 6093852
    Abstract: The invention concerns 4,6-diamino-resorcinol which is prepared in the form of its dihydrochloride by catalytic hydrogenation of 1,3-benzyloxy-4,6-dinitrobenzene on a noble metal contact in a two-phase mixture of dilute aqueous hydrochloric acid and an organic solvent which is not miscible with dilute aqueous hydrochloric acid. This process is carried out at a pressure of between 1 and 200 bar and a temperature of between 0 and 200.degree. C.
    Type: Grant
    Filed: November 17, 1998
    Date of Patent: July 25, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Behre, Helmut Fiege, Heinz Ulrich Blank, Wolfgang Eymann
  • Patent number: 5672708
    Abstract: N-arylaminoacrylic acid derivatives are obtained in good yields and in high purities when benzoylacetic acid derivatives are reacted with N-arylimino ethers. The products thus prepared are used, in particular, for the preparation of 4-quinolone-3-carboxylic acid derivatives, which have an outstanding bactericidal action.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: September 30, 1997
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gunter Rauchschwalbe, Bernhard Beitzke, Wolfgang Eymann, Helmut Fiege
  • Patent number: 5659088
    Abstract: 4-Fluorothiophenol is obtained in outstanding purifies and yields if 4-fluorobenzenesulphonyl chloride is reacted with sodium hydrogen sulphite solution to give a solution of sodium 4-fluorobenzenesulphinate, this solution is reduced with sulphur dioxide to give 4,4'-difluorodiphenyl disulphide and finally this is reacted with sodium borohydride in a water-miscible inert organic solvent to give 4-fluorothiophenol (sodium salt). Free 4-fluorothiophenol can be isolated from the sodium salt solution by acidification.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: August 19, 1997
    Assignee: Bayer Aktiengesellschaft
    Inventors: Helmut Fiege, Ferdinand Hagedorn, Wolfgang Eymann, Otto Neuner, Herbert Muller
  • Patent number: 5574188
    Abstract: 4,6-diaminoresorcinol can be prepared in a plurality of steps in such a way thata) 1,3-dichlorobenzene is nitrated with a mixed acid of HNO.sub.3, H.sub.2 SO.sub.4 and SO.sub.3 at 0 to 40.degree. C. in anhydrous H.sub.2 SO.sub.4,b) the resulting 1,3-dichloro-4,6/2,4-dinitrobenzene isomeric mixture is first reacted with benzyl alcohol in the presence of a strong base at -15.degree. C. to +15.degree. C. and then at 20.degree. to 40.degree. C. to give the dibenzyloxy compound andc) the 1,3-dibenzyloxy-4,6-dinitrobenzene isomer arising in pure form in b) is converted to the 4,6-diaminoresorcinol by catalytic hydrogenation.
    Type: Grant
    Filed: October 27, 1995
    Date of Patent: November 12, 1996
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Behre, Helmut Fiege, Heinz-Ulrich Blank, Uwe Heinz, Wolfgang Eymann