Patents by Inventor Benjamin Shifman

Benjamin Shifman 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 preparing environmentally safe dicofol and its formulations
    Patent number: 5118881
    Abstract: The present invention provides for an improved practical process for producing DDTr-free p,p'-dicofol and its formulations substantially free of the practically inactive o-p'-dicofol comprising either directly recrystallizing technical dicofol from a suitable solvent such as acetic acid or alkanes, or alternatively preparing the p,p'-dicofol by the steps of (a) dehydrohalogenating technical DDT to give DDE; (b) chlorinating DDE to give Cl-DDT; and (c) hydrolyzing Cl-DDT to dicofol, wherein the technical DDT is initially recrystallized from a suitable solvent such as lower alkyl alcohols and then recrystallizing the ressulting p,p'-dicofol from a suitable solvent such as acetic acid or alkanes.
    Type: Grant
    Filed: November 8, 1990
    Date of Patent: June 2, 1992
    Assignee: Agan Chemical Manufacturers, Ltd.
    Inventors: Bernard Vaisbuch, Benjamin Shifman, Michael Pikarski