Patents by Inventor Karl Bischofberger

Karl Bischofberger 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 production of 3-1(1-amino-1,3-dicarboxy-3-hydroxy-but-4-yl) indole
    Patent number: 5128482
    Abstract: The invention provides a process for the production of 3-(1-amino-1,3-dicarboxy-3-hydroxy-but-4-yl) indole and certain salts and internal condensation products thereof. An unsaturated indolyl ester is reacted with ethylchloro(hydroxyimino)acetate in the presence of triethylamine in an organic solvent to cause a 1,3-dipolar addition reaction to form a di-ester. The di-ester is saponified to form a di-acid which di-acid is then reduced to form either the product indole or a salt thereof.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: July 7, 1992
    Assignee: Technology Finance Corporation (Proprietary) Limited
    Inventors: Johan Olivier, Karl Bischofberger