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:
Dec. 05, 2000
Filed:
Oct. 28, 1999
Viesturs Lesins, Tonawanda, NY (US);
Arthur H Morth, Grand Island, NY (US);
Frank P Bermel, Orchard Park, NY (US);
David Y Tang, East Amherst, NY (US);
Mark E Lindrose, Buffalo, NY (US);
William L Rueter, Niagara Falls, NY (US);
Dean R Lagerwall, Amherst, NY (US);
Pravin M Khandare, Amherst, NY (US);
Hang-Chang Bobby Chen, Amherst, NY (US);
Mark F Lechner, Sanborn, NY (US);
Occidental Chemical Corporation, Dallas, TX (US);
Abstract
Disclosed is a method of making high purity 2,4- and 3,4-dichlorotoluene from parachlorotoluene that contains some metachlorotoluene. About 0.0001 to about 5 wt % of a Friedel-Crafts catalyst and about 0.5 to about 10 equivalents of a brominating agent are added to the parachlorotoluene. The metachlorotoluene is brominated, but most of the parachlorotoluene is not brominated. Without separating the brominated products from the unbrominated products, about 0.5 to about 1.5 equivalents of a chlorinating agent are added, whereby only the unbrominated products (i.e., the parachlorotoluene) are chlorinated. The resulting 2,4-dichlorotoluene and 3,4-dichlorotoluene can be separated by distillation.