Patents Represented by Attorney Herlin B. Davey
  • Patent number: 4973698
    Abstract: 2,3-Difluoro-5-(trifluoromethyl)pyridine is prepared by contacting a 2,3-dihalo-5-(trifluoromethyl) pyridine with an effective amount of KF or CsF in a polar aprotic solvent (diluent) at an elevated temperature under substantially anhydrous conditions with removal of the difluoropyridine products essentially as they are formed. The starting material may optionally be added as the reaction proceeds to minimize decomposition. The reaction is also optionally conducted in the presence of an acid scavenger and/or a crown ether or other phase-transfer catalyst.
    Type: Grant
    Filed: January 23, 1989
    Date of Patent: November 27, 1990
    Assignee: The Dow Chemical Company
    Inventors: John C. Little, Charles A. Wilson