Patents by Inventor Joerg Redeker

Joerg Redeker 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).

  • Patent number: 4197250
    Abstract: In a process for the manufacture of 1-amino-2-bromo-4-hydroxyanthraquinone by hydroxylating previously prepared and isolated 1-amino-2,4-dibromoanthraquinone in sulfuric acid in the presence of boric acid at from 110.degree. to 130.degree. C., the improvememt that 1-aminoanthraquinone is brominated (from 1.5 to 2.1 moles of bromine per mole) in sulfuric acid of from 50 to 85 percent strength at from 80.degree. to 130.degree. C., the reaction mixture is brought to a concentration of from 96 percent strength sulfuric acid to 5 percent strength oleum by adding oleum; and the dibromo compound is then hydroxylated in the presence of boric acid. Very pure 1-amino-2-bromo-4-hydroxyanthraquinone, which can be used for all purposes, is obtained in a high yield.
    Type: Grant
    Filed: March 16, 1978
    Date of Patent: April 8, 1980
    Assignee: BASF Aktiengesellschaft
    Inventors: Joerg Redeker, Heinrich Hiller, Enno Spohler