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. 04, 2000
Filed:
Jul. 13, 1999
Bruce C Berris, Baton Rouge, LA (US);
Chi-Hung Cheng, Baton Rouge, LA (US);
Albemarle Corporation, Richmond, VA (US);
Abstract
Impure tetra(dihydrocarbylamino)phosphonium halide is contacted with a liquid cyclic ether to dissolve the phosphonium halide and leave at least a portion of the impurities comprising at least quaternary ammonium halide or an amidophosphoxide remaining in the solid state. The solids and the liquid phase are separated from each other, an anhydrous non-solvent for the tetra(dihydrocarbylamino)phosphonium halide is mixed with the separated liquid phase to precipitate the tetra(dihydrocarbylamino)phosphonium halide, which is then separated from the liquid phase. The so-treated tetra(dihydrocarbylamino)phosphonium halide is more efficient as a catalyst for halogen exchange reactions than the original untreated tetra(dihydrocarbylamino)phosphonium halide.