Patents by Inventor Leon F. Christensen

Leon F. Christensen 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).

  • Patent number: 4138547
    Abstract: 1-.beta.-D-Ribofuranosyl-1,2,4-triazole-3-carboxamide is prepared by a process wherein a suitably substituted formimidic acid hydrazide is condensed with a blocked derivative of D-ribose and the intermediate is ring closed with a reagent which donates one carbon atom to yield a 3-substituted-1-(blocked .beta.-D-ribofuranosyl)-1,2,4-triazole. Treatment of this intermediate with ammonia and/or removal of the blocking group yields the product.
    Type: Grant
    Filed: December 22, 1977
    Date of Patent: February 6, 1979
    Assignee: ICN Pharmaceuticals, Inc.
    Inventors: Leon F. Christensen, Joseph T. Witkowski
  • Patent number: 3968101
    Abstract: Novel compounds of the general formula ##SPC1##Wherein X is H or NH.sub.2 ; R' is C.sub.1 to C.sub.8 alkyl, C.sub.1 to C.sub.8 substituted alkyl, benzyl, C.sub.1 to C.sub.8 acyl, benzoyl, carbamoyl, are disclosed as well as a novel free radial alkylation and acylation process for making such compounds. The compounds of the invention display activity comparable to or superior to their naturally occurring analogue while resisting phosphodiesterase degradation. In some cases the compounds of this invention actually inhibit enzymatic degradation of the natural analogue.
    Type: Grant
    Filed: December 20, 1974
    Date of Patent: July 6, 1976
    Assignee: ICN Pharmaceuticals, Inc.
    Inventors: Leon F. Christensen, Roland K. Robins