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:
Jul. 26, 1988
Filed:
Dec. 11, 1986
Heinz U Blank, Odenthal, DE;
Erich Wolters, Cologne, DE;
Bernhard Beitzke, Bergisch-Gladbach, DE;
Karlfried Wedemeyer, Cologne, DE;
Michael Herzhoff, Much, DE;
Karl-Wilhelm Henneke, Leverkusen, DE;
Guido Steffan, Odenthal, DE;
Otto Neuner, Bergisch-Gladbach, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
In the preparation of 3,5-dichloro-.alpha.-methylstyrene by isopropylation of an m/p-dichlorobenzene mixture, isomerization of the resulting alkylation mixture, subsequent side chain bromination of the alkylation mixture and dehydrobromination of the resulting bromination mixture, the improvement which comprises reacting an excess of an m/p-dichlorobenzene mixture which contains at least 50% by weight of m-dichlorobenzene with isopropyl halide, isomerizing the resulting alkylation mixture under pressure in the presence of aluminum chloride until thermodynamic equilibrium has been attained, separating off the isomerized alkylation mixture from the unreacted m/p-dichlorobenzene mixture, and recycling the unreacted mixture for further reaction.