Patents by Inventor Junning Lee

Junning Lee 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).

  • Process for the stereospecific synthesis of azetidinones
    Patent number: 5306817
    Abstract: This invention provides an improved process for producing azetidinones. More particularly, this invention provides the steps of producing an trans-azetidinone represented by the formula ##STR1## from a carboxylic acid R.sup.2 -D-CH.sub.2 -COOH, an aldehyde R.sup.1 -A-CHO and an amine RNH.sub.2, by the steps of: (a1) converting a carboxylic acid to the corresponding acid chloride; (b1) deprotonating a chiral oxazolidinone and treating the resulting anion with the product of step (a1); (c1) enolizing the product of step (b1) and condensing with the aldehyde; (d1) hydrolyzing the product of step (c1); (e1) condensing the product of step (d1) with the amine; and (f1) cyclizing the product of step (e1).Alternatively, the process comprises (a2) enolizing the product of step (b1) and condensing, in the presence of a Lewis acid, with a Schiff's base prepared from the aldehyde and the amine; and (b2) cyclizing the product of step (a2).
    Type: Grant
    Filed: October 19, 1992
    Date of Patent: April 26, 1994
    Assignee: Schering Corporation
    Inventors: Tiruvettipuram K. Thiruvengadam, Chou-Hong Tann, Junning Lee, Timothy McAllister, Anantha Sudhakar
  • Process for preparing albuterol, acetal, hemi-acetal, and hydrates of arylglyoxal intermediates thereof
    Patent number: 5283359
    Abstract: The preparation of arylethanolamines, and in particular albuterol (salbutamol), together with their novel boron, acetal and hemi-acetal intermediates is described.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: February 1, 1994
    Assignee: Schering Corp.
    Inventors: Chou-Hong Tann, T. K. Thiruvengadam, John Chiu, Michael Green, Timothy L. McAllister, Cesar Colon, Junning Lee