Patents by Inventor Karl Hubert Agback

Karl Hubert Agback 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).

  • 4-(4-Hydroxy- or acetoxy-3-carbomethoxyphenylazo)-benzenesulphonyl chloride
    Patent number: 4045429
    Abstract: A method for the preparation of 2-[4-(4-hydroxy-3-carboxyphenylazo)-benzenesulfonamido]-pyridine by reacting 4-diazobenzenesulfonic acid with an ester of salicyclic acid having the formula ##STR1## in the presence of an alkali metal hydroxide to form a first reaction product having the formula ##STR2## reacting said first reaction product with an acylating agent to form a second reaction product having the formula ##STR3## treating said second reaction product with thionyl chloride in the presence of a tertiary formamide to form a chlorinated compound having the formula ##STR4## reacting said chlorinated compound with 2-amino-pyridine under water-free conditions in the presence of an acid binding agent, to form a third reaction product having the formula ##STR5## treating said third reaction product with alkali metal hydroxide in the presence of water to hydrolyze off the R and R.sub.1 groups, and recovering 2-[4-(4-hydroxy-3-carboxyphenylazo)-benzenesulfonamido]-pyridin e.
    Type: Grant
    Filed: April 25, 1975
    Date of Patent: August 30, 1977
    Assignee: Pharmacia Aktiebolag
    Inventor: Karl Hubert Agback