Preparation of quinophthalone derivatives

US5342950A · kind A · utility

Assignee

• BASF SE

Inventors

• Gerhard Kilpper · Battenberg, DE
• Helmut Hoch

Key dates

• Filing date: Feb 27, 1992
• Grant date: Aug 30, 1994
• Expiry date: Feb 27, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B25/00
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Quinophthalone derivatives of the formula I ##STR1## where the group A completes substituted or unsubstituted heteroaromatic rings and the group B completes a substituted or unsubstituted aromatic ring, are prepared by reacting a methyl-substituted heterocyclic compound of the formula II ##STR2## with an anhydride of an aromatic dicarboxylic acid of the formula III ##STR3## or the corresponding free dicarboxylic acid (IIIa) in the presence of an acid and of an organic solvent, the organic solvent used being an alkyl benzoate.