Patents by Inventor Junji Shiraiwa

Junji Shiraiwa 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 production of N-substituted carbazoles
    Patent number: 5254700
    Abstract: There is disclosed a process for the production of N-substituted carbazoles with high efficiency, in which a carbazole compound is reacted with an appropriate halogenated compound in an inert solvent in the presence of an acid-removing agent and an amine without using any quaternary ammonium salt which is required in the conventional process.
    Type: Grant
    Filed: February 19, 1993
    Date of Patent: October 19, 1993
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Masashi Kamitamari, Takashi Kamikawa, Osamu Maruyama, Shinzaburo Masaki, Junji Shiraiwa