Patents by Inventor Sten K. Kristensson

Sten K. Kristensson 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).

  • Selective acylation process
    Patent number: 4592869
    Abstract: This invention relates to a selective acylation process for the preparation of phenolic N-disubstituted carbamate esters of steroids, comprising reacting in an inert solvent an acylating agent being a carbamoyl halogenide, a 4-(tertiary amino)-pyridine, or a complex thereof, optionally as a part of a polymer and a steroid having at least two free hydroxy groups, where at least one is phenolic and at least one is alcoholic, optionally in the presence of an acid acceptor.
    Type: Grant
    Filed: September 28, 1984
    Date of Patent: June 3, 1986
    Assignee: Aktiebolaget Leo
    Inventors: Sten K. Kristensson, Anders R. Stamvik
  • Steroid esters preparation
    Patent number: 4537722
    Abstract: This invention relates to an improved steroid ester synthesis in which carbodiimides and catalytic amounts of 4-(tertiary amino)-pyridines, in combination with acid catalysts, are used as condensing agents, resulting in pure, non discolored compounds in high yields.
    Type: Grant
    Filed: May 29, 1984
    Date of Patent: August 27, 1985
    Assignee: Ab Leo
    Inventors: Anders R. Stamvik, Sten K. Kristensson, Karl-Erik Lundvall