Patents by Inventor John R. Duchek

John R. Duchek 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).

  • Processes for the Preparation of Modafinil and Analogs Thereof
    Publication number: 20080319227
    Abstract: The present invention generally relates to an improved process for preparing modafinil and analogs thereof. The process minimizes impurities and improves the overall yield by oxidizing a modafinil intermediate compound in a reaction mixture including an alcohol and an organic acid at a ratio of from about 1:1 to about 80:1 (by volume).
    Type: Application
    Filed: November 27, 2006
    Publication date: December 25, 2008
    Inventors: Sidney Liang, John R. Duchek, Carl J. Schaefer
  • Process for preparation of (+)-p-mentha-2,8-diene-1-ol
    Patent number: 7323607
    Abstract: A process for preparing (+)-p-mentha-2,8-diene-1-ol comprising reacting (+)-limonene oxide with at least one amine in the presence of at least one Lewis acid to form amine adduct intermediates. The amine adduct is then oxidized to form an N-oxide that is pyrolized to form (+)-p-mentha-2,8-diene-1-ol.
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: January 29, 2008
    Assignee: Mallinckrodt Inc.
    Inventors: Hong Gu, J. Kendall Killgore, John R. Duchek
  • Synthesis of compounds useful in the manufacture of ketorolac
    Patent number: 6559319
    Abstract: A multi-step method of synthesizing ketorolac, an analgesic compound, is shown. Several of the reactions and intermediate compounds are novel. The reaction sequence begins with the known compound N-2-bromoethylpyrrole.
    Type: Grant
    Filed: September 3, 2002
    Date of Patent: May 6, 2003
    Assignee: Mallinckrodt Inc.
    Inventors: Douglas C. Caskey, John R. Duchek, Henry J. Buehler
  • Synthesis of compounds useful in the manufacture of ketorolac
    Publication number: 20030036660
    Abstract: A multi-step method of synthesizing ketorolac, an analgesic compound, is shown. Several of the reactions and intermediate compounds are novel. The reaction sequence begins with the known compound N-2-bromoethylpyrrole.
    Type: Application
    Filed: September 3, 2002
    Publication date: February 20, 2003
    Inventors: Douglas C. Caskey, John R. Duchek, Henry J. Buehler
  • Synthesis of compounds useful in the manufacture of ketorolac
    Patent number: 6489491
    Abstract: A multi-step method of synthesizing ketorolac, an analgesic compound, is shown. Several of the reactions and intermediate compounds are novel. The reaction sequence begins with the known compound N-2-bromoethylpyrrole.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: December 3, 2002
    Assignee: Mallinckrodt Inc.
    Inventors: Douglas C. Caskey, John R. Duchek, Henry J. Buehler
  • Synthesis of compounds useful in the manufacture of ketorolac
    Publication number: 20020137945
    Abstract: A multi-step method of synthesizing ketorolac, an analgesic compound, is shown. Several of the reactions and intermediate compounds are novel. The reaction sequence begins with the known compound N-2-bromoethylpyrrole.
    Type: Application
    Filed: February 5, 2002
    Publication date: September 26, 2002
    Inventors: Douglas C. Caskey, John R. Duchek, Henry J. Buehler
  • Synthesis of compounds useful in the manufacture of ketorolac
    Patent number: 6376681
    Abstract: This invention relates to the drug, ketorolac and the synthesis of compounds useful in the manufacture of ketorolac. Ketorolac tromethamine is a pharmaceutical compound useful as an analgesic.
    Type: Grant
    Filed: December 6, 2000
    Date of Patent: April 23, 2002
    Assignee: Mallinckodt Inc.
    Inventors: John R. Duchek, Henry J. Buehler, Douglas C. Caskey
  • Method of preparing D-propoxyphene
    Patent number: 5312970
    Abstract: D-propoxyphene can be prepared by reacting d-oxyphene and propionic anhydride. Preferably, an excess of propionic anhydride is used. The reaction easily proceeds at temperatures of 70.degree. to 80.degree. C. and produces yields exceeding 95 percent of theory. The free base d-propoxyphene can easily be converted in high yields to its hydrochloride or napsylate salts, both analgesics.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: May 17, 1994
    Assignee: Mallinckrodt Specialty Chemicals Company
    Inventor: John R. Duchek
  • Resolution of 3-dimethylamino-2-methylpropiophenone (3-DAMP)
    Patent number: 5227526
    Abstract: In a process for resolving 3-dimethylamino-2-methylpropiophenone (3-DAMP) material, a methanol solution containing a mixture of both 1- and d-enantiomers of 3-DAMP is formed. To this solution, ditoluyl-(L)-tartaric acid or ditoluyl-(D)-tartaric acid is added, so as to precipitate either the 1- or d-enantiomer of 3-DAMP as a salt. The precipitate then is isolated as a salt of a substantially pure enantiomer of 3-DAMP.
    Type: Grant
    Filed: June 16, 1992
    Date of Patent: July 13, 1993
    Assignee: Mallinckrodt Specialty Chemicals Company
    Inventor: John R. Duchek