Patents by Inventor Fengrui Lang

Fengrui Lang 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).

  • Method for preparing efficiently synthetic sitafloxacin intermediate (7S)-5-azaspiro[2.4]heptane-7-yl tert-butyl carbamate
    Patent number: 10358417
    Abstract: The present invention discloses a preparation method for efficient synthesis of sitafloxacin intermediate (7S)-5-azaspiro[2.4]heptane-7-yl-tert-butyl carbamate, comprising the following steps: reacting to obtain reacting to obtain reacting to obtain and reacting to obtain In the present invention, a single compound with a relatively high ee value can be obtained, the unnecessary waste of materials is avoided, the yield is significantly improved, the operation is simple, the industrial scale-up is easy, and the production cost is reduced.
    Type: Grant
    Filed: April 25, 2017
    Date of Patent: July 23, 2019
    Assignee: Chen-Stone (Guangzhou) Co., Ltd.
    Inventors: Yingjie Lai, Dabing Ye, Fengrui Lang, Xiangtian Long
  • METHOD FOR PREPARING EFFICIENTLY SYNTHETIC SITAFLOXACIN INTERMEDIATE (7S)-5-AZASPIRO[2.4]HEPTANE-7-YL TERT-BUTYL CARBAMATE
    Publication number: 20180370914
    Abstract: The present invention discloses a preparation method for efficient synthesis of sitafloxacin intermediate (7S)-5-azaspiro[2.4]heptane-7-yl-tert-butyl carbamate, comprising the following steps: reacting to obtain reacting to obtain reacting to obtain and reacting to obtain In the present invention, a single compound with a relatively high ee value can be obtained, the unnecessary waste of materials is avoided, the yield is significantly improved, the operation is simple, the industrial scale-up is easy, and the production cost is reduced.
    Type: Application
    Filed: April 25, 2017
    Publication date: December 27, 2018
    Inventors: Yingjie Lai, Dabing Ye, Fengrui Lang, Xiangtian Long
  • Diastereoselective preparation of Michael adducts
    Patent number: 6479672
    Abstract: Michael addition conducted in the presence of a zinc-amine complex and additional amounts of the amine component results in product with high diastereomeric excess.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: November 12, 2002
    Assignees: Merck & Co., Inc., Banyu Pharmaceutical Co., Ltd,
    Inventors: Ioannis Houpis, Ralph P. Volante, Fengrui Lang, Ilias Dorziotis, David Tschaen, Shinji Kato, Toshiaki Mase
  • Process for the preparation of arylamines
    Publication number: 20010047013
    Abstract: Arylamines are prepared from aryl halides/methanesulfonates using ammonia and copper reagent under mild reaction conditions.
    Type: Application
    Filed: March 5, 2001
    Publication date: November 29, 2001
    Inventors: Fengrui Lang, Ioannis Houpis