Patents by Inventor Winfried Ludwig

Winfried Ludwig 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 anthranilic acid amides
    Patent number: 4421931
    Abstract: Anthranilic acid amides are prepared by mixing phthalamic acid with a caustic alkali solution, a catalyst and a hypohalite, allowing the mixture to stand for from 1 to 1,000 seconds, then introducing the amine and thereafter addig acid until the pH of the mixture is from 6 to 8.The anthranilic acid amides obtainable by the process of the invention are valuable starting materials for the preparation of dyes, scents and pesticides.
    Type: Grant
    Filed: January 11, 1982
    Date of Patent: December 20, 1983
    Assignee: BASF Aktiengesellschaft
    Inventors: Peter Tonne, Winfried Ludwig, Gerhard Kilpper, Johannes Grimmer