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. 06, 1999
Filed:
Nov. 12, 1997
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
A process for the purification of tertiary phosphine oxides obtained in a Wittig synthesis as a contaminated by product resulting from the reaction of the corresponding tertiary phosphines, especially triphenylphosphine. The contaminated tertiary phosphine oxides coming from this Wittig synthesis have the formula I ##STR1## in which R.sup.1, R.sup.2, and R.sup.3 denote C.sub.1 -C.sub.12 alkyl, C.sub.5 -G.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.20 aralkyl, or C.sub.7 -C.sub.20 alkylaryl. The contaminated phosphine oxide I or phosphine oxide I-containing mixtures, optionally in an inert solvent, are first caused to react with an inorganic or organic acid at temperatures of from 0.degree. to 150.degree. C. to form a crystallized acid salt. The resulting salt crystals are then treated in a purifying step with water or an inorganic base or an organic base to again form the tertiary phosphine oxide. This reformed oxide is then extracted with an inert organic solvent from which the purified tertiary phosphine oxide is finally liberated.