Patents Examined by Raymond Povington
  • Process of producing anthraquinones in one step
    Patent number: 5041571
    Abstract: A process for the preparation of anthraquinone compounds comprises reaction of phthalic anhydride with a benzene derivative in a reaction mixture containing HF and BF.sub.3 as catalyst at a first temperature up to about 30.degree. C. and, subsequently, at an elevated temperature.
    Type: Grant
    Filed: March 29, 1990
    Date of Patent: August 20, 1991
    Assignee: Hoechst Celanese Corporation
    Inventors: Mohammad Aslam, Hans-Joachim Metz