Patents by Inventor Dongchao Wang

Dongchao Wang 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).

  • Preparation of one intermediate for pyrethroids
    Patent number: 7312366
    Abstract: Methods for preparing 2,3,5,6-tetrafluorodimethylolbenzene, an intermediate for the preparation of pyrethroids, are disclosed. A method for preparing 2,3,5,6-tetrafluorodimethylolbenzene includes the reduction of tetrafluoroterephthalate. Various reduction processes are disclosed, which are simple and safe and can afford the product in high yield and purity. Processes for preparing tefluthrin from 2,3,5,6-tetrafluorodimethylolbenzene, by halogenation, hydrogenation, and esterification, are also disclosed.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: December 25, 2007
    Assignee: Jiangsu Yangong Chemical Co., Ltd.
    Inventors: Dongchao Wang, Youfa Jiang
  • Preparation of one intermediate for pyrethroids
    Publication number: 20070055075
    Abstract: Methods for preparing 2,3,5,6-tetrafluorodimethylolbenzene, an intermediate for the preparation of pyrethroids, are disclosed. A method for preparing 2,3,5,6-tetrafluorodimethylolbenzene includes the reduction of tetrafluoroterephthalate. Various reduction processes are disclosed, which are simple and safe and can afford the product in high yield and purity. Processes for preparing tefluthrin from 2,3,5,6-tetrafluorodimethylolbenzene, by halogenation, hydrogenation, and esterification, are also disclosed.
    Type: Application
    Filed: January 13, 2004
    Publication date: March 8, 2007
    Applicant: Jiangsu Yangnong Chemical Co., Ltd.
    Inventors: Dongchao Wang, Youfa Jiang