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:
Sep. 30, 1980
Filed:
Feb. 22, 1979
Donald J Perettie, Lake Jackson, TX (US);
Norman L Dean, Lake Jackson, TX (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Substantially pure 2,3,5,6-tetrachloropyridine is recovered from a mixture of chlorinated pyridines containing initially 2,3,5,6-tetrachloropyridine and other chlorinated pyridines in an improved process which comprises (a) reacting by contacting a first mixture of chlorinated pyridines with chlorine in the presence of a strong Lewis acid catalyst to thereby obtain a second mixture consisting essentially of 2,3,5,6-tetrachloropyridine and pentachloropyridine, and (b) recovering the 2,3,5,6-tetrachloropyridine from said second mixture. The reaction is normally conducted at a temperature of from about 150.degree. C. to about 300.degree. C. by pressurizing chlorine into a molten mixture of the chlorinated pyridines and maintaining such conditions until substantially all of the isomers have been converted to the symmetrical tetrachloropyridine or pentachloropyridine.