Process for the preparation of oligophenyls dihalogenated in the 4,4'-position

US5053566A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Artur Botta · Krefeld, DE
• Hans-Josef Buysch · Krefeld, DE
• Lothar Puppe · Burscheid, DE

Key dates

• Filing date: Aug 23, 1990
• Grant date: Oct 1, 1991
• Expiry date: Aug 23, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C17/12
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Oligophenyls dihalogenated in the 4,4'-position, of the formula ##STR1## can be prepared by catalyzed halogenation of oligophenyls of the formula ##STR2## wherein, in the formulae, X.sup.1 and X.sup.2 independently of one another represent chlorine or bromine, preferably chlorine, PA1 X.sup.3 denotes hydrogen, chlorine or bromine, preferably hydrogen or chlorine and particularly preferably hydrogen, PA1 R.sup.1, R.sup.2 and R.sup.3 independently of one another represent hydrogen, C.sub.1 -C.sub.4 -alkyl (preferably methyl or ethyl and particularly preferably methyl), C.sub.1 -C.sub.4 -alkoxy (preferably methoxy or ethoxy and particularly preferably methoxy), fluorine, chlorine or bromine and PA1 a assumes the value zero or one, with halogenating agents, the preparation being carried out in the presence of methylene chloride or solvent mixtures essentially containing methylene chloride and in the presence of zeolites of the L structure type which contain metal cations.