Process for isolating M-dichlorobenzene from mixtures of dichlorobenzene isomers

US5436377A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Michael Pies · Duisburg, DE
• Kai Rohlk · Bensberg, DE
• Helmut Lahr · Bad Kreuznach, DE
• Helmut Fiege · Leverkusen, DE

Key dates

• Filing date: Sep 2, 1994
• Grant date: Jul 25, 1995
• Expiry date: Sep 2, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C17/392
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

In a particularly advantageous process for isolating m-dichlorobenzene from mixtures of dichlorobenzene isomers by crystallization as eutectic crystals using a processing aid, the processing aid used is a compound of the formula (I) ##STR1## in which R.sup.1 to R.sup.6 are, independently of one another, hydrogen, halogen, C.sub.1 -C.sub.4 -alkyl, hydroxyl, NH.sub.2 or R--CO-- having R=C.sub.1 -C.sub.4 -alkyl, with 1-bromo-4-chlorobenzene and 1,4-dibromobenzene being excepted.