Patents by Inventor Dae Y. Cha

Dae Y. Cha 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).

  • Mercury removal process
    Patent number: 4588529
    Abstract: Oxymercuration reaction products (I) and/or mercury contaminated steroids (I) are purified by dissolving the compound in a suitable solvent and contacting with a metal dust selected from zinc, copper or iron and a suitable acid.
    Type: Grant
    Filed: February 28, 1985
    Date of Patent: May 13, 1986
    Assignee: The Upjohn Company
    Inventor: Dae Y. Cha
  • Process to prepare stabilized monolithium acetylide
    Patent number: 4526720
    Abstract: The process of the present invention uses an amine to prepare monolithium acetylide which is sufficiently stable at up to 0.degree. and yet is sufficiently reactive to react with 16-substituted-17-keto steroids producing the useful 17.alpha.-ethynyl-17.beta.-hydroxy-16-substituted steroids.
    Type: Grant
    Filed: January 5, 1984
    Date of Patent: July 2, 1985
    Assignee: The Upjohn Company
    Inventors: Verlan H. Van Rheenen, Dae Y. Cha