Patents by Inventor Hermann-Dieter Krall

Hermann-Dieter Krall 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 dimeric aromatic acyl cyanides
    Patent number: 4792606
    Abstract: A process for the preparation of a dimeric aromatic acyl cyanide of the formula ##STR1## in which Ar is optionally substituted phenyl, naphthyl or hetaryl,comprising reaction an acyl halide of the formulaAr--CO--Halin whichHal is fluorine, chlorine or bromine, with an alkali metal cyanide in a two-phase system comprising water and a water-immiscible or only sparingly water-miscible aliphatic ketone, and in the presence of a phase-transfer catalyst. The products are known intermediates for pesticides.
    Type: Grant
    Filed: July 16, 1987
    Date of Patent: December 20, 1988
    Assignee: Bayer Aktiengesellschaft
    Inventors: Reinhard Lantzsch, Hermann-Dieter Krall
  • Process for preparing diphenylamines
    Patent number: 4057581
    Abstract: Diphenylamines having the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and are hydrogen, alkyl with up to 4 C atoms or alkoxy with up to 4 C atoms,Are prepared by catalytically dehydrogenating the corresponding wholly or partially hydrogenated diphenylamines. The catalyst used is a nickel/chromium catalyst containing manganese and/or aluminum and/or copper and/or sulphates of the alkali metals or alkaline earth metals.
    Type: Grant
    Filed: April 15, 1976
    Date of Patent: November 8, 1977
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hermann-Dieter Krall, Oskar Weissel, Hans-Helmut Schwarz
  • Process for preparing azomethines
    Patent number: 4045486
    Abstract: Azomethines having the formula ##STR1## wherein R is hydrogen, alkyl or alkoxy,m denotes an integer of from 1 to 4, andThe m R radicals are the same or different,Are prepared by condensing cyclohexanone and a primary aromatic amine in the presence of an acid ion exchanger.
    Type: Grant
    Filed: May 12, 1976
    Date of Patent: August 30, 1977
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hermann-Dieter Krall, Hans-Helmut Schwarz