Patents by Inventor Steven R. Duff

Steven R. Duff 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: 6448419
    Abstract: Disclosed is a method of preparing 2-hydroxy-3,17&bgr;-estradiol derivatives wherein 3,17&bgr;-estradiol is reacted with an organolithium reagent and reacted with either a boron reagent or a silicon reagent to form either a 2-boronyl or a 2-silyl modified estradiol analog represented by the corresponding structural formulae: R1 and R2 are each independently a hydroxyl protecting group. R3, R4 and R5 are selected from the group consisting of halogens, alkyl, aryl, hydroxy, substituted or unsubstituted alkyl, and substituted or unsubstituted aryl.
    Type: Grant
    Filed: August 7, 2001
    Date of Patent: September 10, 2002
    Assignee: Tetrionics, Inc.
    Inventors: Herbert E. Paaren, Steven R. Duff
  • Patent number: 5648540
    Abstract: A method of making (R)-N-[1-(3-methoxyphenyl)ethyl]-3-(2-chlorobenzene)propanamine which involves reducing the appropriate amidyl or iminyl precursor with an appropriate reducing agent. The appropriate amidyl or iminyl precursor is made from a synthesis involving the use of (R)-3-methoxy-.alpha.-methylbenzylamine. A method of condensing a nitrile with a primary or secondary amine to form an imine involves the reaction of a nitrile with diisobutylaluminum hydride; and then reacting the resultant compound with a primary or secondary amine to form the imine. The process is especially useful for producing enantiomerically pure chiral imines, and, ultimately, amines. Typical such imines have the formula: ##STR1## wherein R, R.sub.1, R.sub.2 and R.sub.3 are independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, aryl and aralkyl.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 15, 1997
    Assignee: NPS Pharmaceuticals, Inc.
    Inventors: Bradford C. VanWagenen, Steven R. Duff, William A. Nelson, Thomas E. D'Ambra
  • Patent number: 5633404
    Abstract: A method of making ( R)- N-[1-(3-methoxyphenyl)ethyl]-3-(2-chlorobenzene)propanamine which involves reducing the appropriate amidyl or iminyl precursor with an appropriate reducing agent. The appropriate amidyl or iminyl precursor is made from a synthesis involving the use of ( R)-3-methoxy-.alpha.-methylbenzylamine. A method of condensing a nitrile with a primary or secondary amine to form an imine involves the reaction of a nitrile with diisobutylaluminum hydride; and then reacting the resultant compound with a primary or secondary amine to form the imine. The process is especially useful for producing enantiomerically pure chiral imines, and, ultimately, amines. Typical such imines have the formula: ##STR1## wherein R, R.sub.1, R.sub.2 and R.sub.3 are independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, aryl and aralkyl.
    Type: Grant
    Filed: April 19, 1996
    Date of Patent: May 27, 1997
    Assignee: NPS Pharmaceuticals, Inc.
    Inventors: Bradford C. VanWagenen, Steven R. Duff, William A. Nelson
  • Patent number: 4948883
    Abstract: Bismuth salts of phosphorylated and/or sulfonated saccharides are prepared from a corresponding metal salt reactant, a water soluble organic acid, and a bismuth substance. For example, a complex salt of bismuth hydroxide sucrose octasulfate can be prepared in high yield and good purity from potassium sucrose octasulfate, trichloroacetic acid, trifluoracetic acid or 4-methylbenzenesulfonic acid, and bismuth hydroxide. Corresponding hydrogen phosphorylated and/or sulfonated saccharides may be intermediate products.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: August 14, 1990
    Assignee: Marion Laboratories, Inc.
    Inventor: Steven R. Duff
  • Patent number: 4940786
    Abstract: Bismuth salts of phosphorylated and/or sulfonated saccharides can be prepared in one reaction vessel from a corresponding metal salt reactant, a water soluble organic acid, and a bismuth substance. For example, a complex salt of bismuth hydroxide sucrose octasulfate can be prepared in high yield and good purity from potassium sucrose octasulfate, trifluoracetic acid, and bismuth hydroxide.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: July 10, 1990
    Assignee: Marion Laboratories, Inc.
    Inventor: Steven R. Duff