Patents by Inventor Donald S. Hetzel

Donald S. Hetzel 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).

  • Preparation of citraconic anhydride
    Patent number: 4100179
    Abstract: The preparation of citraconic anhydride by continuous vapor phase oxidation of mesityl oxide, isomesityl oxide or mixtures thereof is disclosed.
    Type: Grant
    Filed: January 7, 1977
    Date of Patent: July 11, 1978
    Assignee: Pfizer Inc.
    Inventors: Rudolph G. Berg, Donald S. Hetzel