The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 18, 1989
Filed:
Feb. 29, 1988
Applicant:
Inventors:
John C Little, Concord, CA (US);
Charles A Wilson, Pittsburg, CA (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
546345 ;
Abstract
Alpha, beta-difluoropyridine compounds are prepared by contacting a 2,3-dihalopyridine compound or suitable precursor thereof 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.