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:
Oct. 24, 1989
Filed:
Feb. 27, 1989
Deanne M Nowak, Depew, NY (US);
Henry C Lin, Grand Island, NY (US);
Occidental Chemical Corporation, Niagara Falls, NY (US);
Abstract
2,4,5-trifluorobenzoic acid is prepared by converting 4,5-di-fluoroanthranilic acid to the corresponding amine salt, converting the amine salt to the corresponding diazonium tetrafluoroborate and decomposing the tetrafluoroborate in a Schiemann reaction. In a preferred preparation, the 10 percent HCl is added to solid 4,5-difluoroanthranilic acid in sufficient amount to dissolve the solid at 70.degree. C., the amine salt is isolated, aqueous NaNO.sub.2 is added to the isolated amine salt at 0.degree. C., followed by addition of 40 to 50 percent aqueous HBF.sub.4 at 0.degree. C., followed by separation of the tetrafluoroborate by cooling and filtering and then drying, and the dried separated tetrafluoroborate is thermally degraded to 2,4,5-trifluorobenzoic acid by heating at 125.degree. to 140.degree. C.