Patents Assigned to Dequssa Akteingesellschaft
  • Method of preparing alkaline earth metal salts of 2-pyrrolidone-5-carboxylic acid
    Patent number: 4921971
    Abstract: Alkaline earth metal salts of 2-pyrrolidone-5-carboxylic acid (pyroglutamic acid) are prepared by heating the corresponding alkaline earth metal salt of glutaminic acid in the solid state to a temperature in a range of 120.degree. C. to 250.degree. C. until the water liberated by the intramolecular condensation (cyclocondensation) has been completely eliminated.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: May 1, 1990
    Assignee: Dequssa Akteingesellschaft
    Inventors: Hans-Peter Krimmer, Karlheinz Drauz, Silvia Werner