Patents by Inventor Werner Praetorius

Werner Praetorius 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).

  • Continuous preparation of adiptic acid
    Patent number: 4360695
    Abstract: In a process for the continuous preparation of adipic acid by hydrolysis of C.sub.1 -C.sub.4 -alkyl adipates with water at an elevated temperature in the presence of a strongly acidic ion exchanger, the improvement that the esters and excess water are fed to the middle section of a column, reaction mixture is taken off at a plurality of trays of the column below the feed point, passed over a strongly acidic ion exchanger and recycled, alkanols or alkanol/water mixtures are taken off at the top of the column and an aqueous solution of adipic acid is taken off at the bottom of the column.
    Type: Grant
    Filed: January 7, 1982
    Date of Patent: November 23, 1982
    Assignee: BASF Aktiengesellschaft
    Inventors: Peter Magnussen, Volker Schumacher, Wolfgang Gebert, Heinrich Reitz, Werner Praetorius
  • Preparation of imidazoles
    Patent number: 4340744
    Abstract: Imidazoles are prepared by reacting 2-imidazolines at from 250.degree. to 500.degree. C. in the presence of molybdenum oxide and nickel oxide and/or cobalt oxide and aluminum oxide, silicon dioxide and/or silicates as catalysts.The imidazoles obtainable by the process according to the invention are valuable starting materials for the preparation of dyes, crop protection agents, textile auxiliaries, catalysts for polyurethanes and epoxy resins, surfactants and drugs, for example the corresponding nitroimidazoles.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: July 20, 1982
    Assignee: BASF Aktiengesellschaft
    Inventors: Helmut Schwarz, Toni Dockner, Uwe Kempe, Herbert Krug, Werner Praetorius, Peter Magnussen, Ewald Gallei, Erich Fehr
  • Preparation of 2-imidazolines
    Patent number: 4340745
    Abstract: 2-Imidazolines are prepared by reacting N,N'-diformyl-1,2-diamines in the gas phase at 200.degree.-350.degree. C., in the presence of certain amounts of an inert gas, over zinc oxide of a particular structure or over a mixture of this zinc oxide and aluminum oxide, as the catalyst.The 2-imidazolines obtainable by the process according to the invention are valuable starting materials for the preparation of dyes, crop protection agents and drugs.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: July 20, 1982
    Assignee: BASF Aktiengesellschaft
    Inventors: Toni Dockner, Uwe Kempe, Herbert Krug, Peter Magnussen, Werner Praetorius
  • Preparation of 2-imidazolines
    Patent number: 4298748
    Abstract: A novel process for the preparation of 2-imidazolines by reacting 1,2-diamines with nitriles or carbonyl compounds in the gas phase at from 200.degree. to 450.degree. C. in the presence of an oxide or phosphate of a metal of group 3 or 4 of the periodic table and/or in the presence of silicon dioxide.The 2-imidazolines obtainable by the process of the invention are valuable starting materials for the preparation of dyes, crop protection agents and drugs.
    Type: Grant
    Filed: November 27, 1979
    Date of Patent: November 3, 1981
    Assignee: BASF Aktiengesellschaft
    Inventors: Toni Dockner, Uwe Kempe, Herbert Krug, Peter Magnussen, Werner Praetorius, Hans J. Szymanski