Patents by Inventor Hans-Joachim Opgenorth

Hans-Joachim Opgenorth 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).

  • Preparation of indolenines
    Patent number: 4255333
    Abstract: A process for the preparation of an indolenine of the formula ##STR1## where R, X and Y are conventional substituents, by thermal rearrangement of a compound of the formula ##STR2## to give a compound of the formula ##STR3## and cyclization of this compound in the presence of an acid catalyst.
    Type: Grant
    Filed: January 30, 1979
    Date of Patent: March 10, 1981
    Assignee: BASF Aktiengesellschaft
    Inventors: Hans-Joachim Opgenorth, Horst Scheuermann, Harald Laas, Axel Nissen
  • Preparation of indolenines
    Patent number: 4240963
    Abstract: A process for the preparation of an indolenine of the general formula I ##STR1## where R, R.sup.1 and R.sup.2 are aliphatic radicals and R.sup.1 and R.sup.2 may also be linked and the ring A may be additionally substituted, wherein a compound of the formula II ##STR2## is heated in the presence of a Lewis acid and of a halide. The products are valuable starting compounds for the preparation of dyes.
    Type: Grant
    Filed: August 9, 1979
    Date of Patent: December 23, 1980
    Assignee: BASF Aktiengesellschaft
    Inventors: Harald Laas, Axel Nissen, Hans-Joachim Opgenorth, Horst Scheuermann, Hans-Richard Mueller, Wolfgang Schulte
  • Manufacture of benzothiazoles
    Patent number: 4113732
    Abstract: Process for the production of benzothiazoles from N-arylsubstituted thioureas by oxidative ring closure characterized by the use of chlorine as oxidizing agent and by the presence of catalytic amounts of bromine. Yield and quality of the benzothiazoles obtained are very good.
    Type: Grant
    Filed: June 29, 1977
    Date of Patent: September 12, 1978
    Assignee: BASF Aktiengesellschaft
    Inventors: Hans-Joachim Opgenorth, Horst Scheuermann