Patents by Inventor Zhongli Gao

Zhongli Gao 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: 5734062
    Abstract: This invention relates to a process for the preparation of a product of the formula ##STR1## wherein R is loweralkyl; R.sub.1 is hydrogen, loweralkyl, lowercycloalkyl, lowercycloalkylloweralkyl, lowerbicycloalkyl, aryl or arylloweralkyl; Rs is loweralkyl, lowercycloalkyl, lowercycloalkylloweralkyl, lowerbicycloalkyl, aryl or arylloweralkyl; or R.sub.1 and R.sub.2 taken together with the nitrogen atom to which they are attached form a group of the formula (Ia) ##STR2## wherein Y is hydrogen or loweralkyl and Z is hydrogen, loweralkyl, halogen, loweralkoxy or hydroxy; X is loweralkyl, loweralkoxy, halogen or trifluoromethyl; and m is 0, 1 or 2; or a pharmaceutically acceptable salt thereof; which process comprises(a) contacting a compound of formula (II) as defined herein with fortified hydrogen bromide to afford a compound of formula (III) as defined herein; contacting the reaction mixture containing a compound of formula (III) with either (1) an isocyanate of formula R.sub.
    Type: Grant
    Filed: May 20, 1997
    Date of Patent: March 31, 1998
    Assignee: Hoechst Marion Roussel, Inc.
    Inventors: Thomas B. K. Lee, Zhongli Gao
  • Patent number: 5677457
    Abstract: The present invention relates to a novel process for the preparation of physostigmine carbamate derivatives and to pharmaceutically acceptable salts thereof. The present invention further relates to a novel process for the preparation of eseroline derivatives and to pharmaceutically acceptable salts thereof.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: October 14, 1997
    Assignee: Hoechst Marion Roussel, Inc.
    Inventors: Thomas B. K. Lee, Zhongli Gao, Barbara S. Rauckman
  • Patent number: 5665880
    Abstract: This invention relates to a process for the preparation of a product of the formula ##STR1## wherein R is loweralkyl; R.sub.1, is hydrogen, loweralkyl, lowercycloalkyl, lowercycloalkylloweralkyl, lowerbicycloalkyl, aryl or arylloweralyl; R.sub.2 is lower alkyl, lowercycloalkyl, lowercycloalkylloweralkyl, lowerbicycloalkyl, aryl or arylloweralkyl; or R.sub.1 and R.sub.2 taken together with the nitrogen atom to which they are attached form a group of the formula (Ia) ##STR2## wherein Y is hydrogen or loweralkyl and Z is hydrogen, loweralkyl, halogen, loweralkoxy or hydroxy; X is loweralkyl, loweralkoxy, halogen or trifluoromethyl; and m is 0, 1 or 2; or a pharmaceutically acceptable salt thereof; which process comprises(a) contacting a compound of formula (II) as defined herein with fortified hydrogen bromide to afford a compound of formula (III) as defined herein; contacting the reaction mixture containing a compound of formula (III) with either (1) an isocyanate of formula R.sub.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: September 9, 1997
    Assignee: Hoechst Marion Roussel, Inc.
    Inventors: Thomas B. K. Lee, Zhongli Gao