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:
Jun. 26, 1990
Filed:
Nov. 20, 1989
Applicant:
Inventors:
Lawrence B Fertel, Buffalo, NY (US);
Neil J O'Reilly, Grand Island, NY (US);
Assignee:
Occidental Chemical Corporation, Niagara Falls, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562479 ;
Abstract
4,5-Difluorphthalic anhydride and 4,5-difluorophthalic acid may be decarboxylated in high yield to 3,4-difluorobenzoic acid by heating in N-methyl-2-pyrrolidone or dimethyl acetamide using copper, copper oxide, copper salts, or halides and salts of Zn, Cd, Ag and Ni as a catalyst.