Patents by Inventor Karl W. Thiem

Karl W. Thiem 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: 4552981
    Abstract: The present invention is directed to a process for preparing 5-nitro-acet-2,4-xylidine comprising:(a) dissolving acet-2,4-xylidine in an aqueous sulfuric acid solution, said aqueous solution containing from 86 to 92% by weight of sulfuric acid, the weight ratio of sulfuric acid to acet-2,4-xylidine being from 3.5:1 to 6.5:1;(b) nitrating the resultant solution at a temperature of from 0.degree. to 15.degree. C. in a mixed acid containing nitric acid, sulfuric acid, and from 10 to 25% by weight water; and(c) recovering 5-nitro-acet-2,4-xylidine.
    Type: Grant
    Filed: November 27, 1981
    Date of Patent: November 12, 1985
    Assignee: Mobay Chemical Corporation
    Inventors: Karl W. Thiem, Daniel P. Vanderpool
  • Patent number: 4341902
    Abstract: The present invention is directed to a process for preparing 5-nitro-acet-2,4-xylidine comprising(a) dissolving acet-2,4-xylidine in an aqueous sulfuric acid solution,(b) nitrating the resultant solution with a mixture of nitric acid and sulfuric acid,(c) adding the resultant nitration mixture to an aqueous sulfuric acid solution containing from 25 to 45% by weight of sulfuric acid, while maintaining the temperature at from 20.degree. to 50.degree. C. to thereby produce a slurry containing sulfuric acid in a concentration of from 30 to 50% by weight based solely on the weight of water and sulfuric acid, the total amount of sulfuric acid in said slurry being such that the molar ratio of sulfuric acid to the nitro-acet-2,4-xylidine isomers is from 53:1 to 10:1, and(d) recovering 5-nitro-acet-2,4-xylidine.
    Type: Grant
    Filed: June 26, 1981
    Date of Patent: July 27, 1982
    Assignee: Mobay Chemical Corporation
    Inventors: Karl W. Thiem, Daniel P. Vanderpool