Patents by Inventor R. Donald Clark

R. Donald Clark 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 the preparation of 2-amino-6-nitrobenzothiazole
    Patent number: 4447617
    Abstract: Disclosed is a novel process for the preparation of 2-amino-6-nitrobenzothiazole which comprises contacting 2-mercapto-6-nitrobenzothiazole with hydrogen peroxide in the presence of ammonia. The reaction is conveniently conducted in an aqueous medium. The mole ratio of hydrogen peroxide to mercaptan is preferably about 4:1 and the reaction is conducted at a temperature of about 50.degree. to 100.degree. C.
    Type: Grant
    Filed: April 14, 1982
    Date of Patent: May 8, 1984
    Assignee: Eastman Kodak Company
    Inventor: R. Donald Clark
  • Preparation of 2-aminobenzothiazoles
    Patent number: 4363913
    Abstract: Disclosed is a process for the preparation of 2-aminobenzothiazoles by the oxidative ring closure of an arylthiourea which comprises contacting the arylthiourea with sulfuric acid and a catalytic amount of a bromine compound.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: December 14, 1982
    Assignee: Eastman Kodak Company
    Inventors: R. Donald Clark, Herman S. Pridgen