Preparation of alkoxy(iso)violanthrenediones

US4882095A · kind A · utility

Assignee

• BASF SE

Inventors

• Reinhard Helwig · Ludwigshafen, DE
• Helmut Hoch

Key dates

• Filing date: Sep 19, 1988
• Grant date: Nov 21, 1989
• Expiry date: Sep 19, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B3/36
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of bisalkoxy(iso)violanthrenediones involves alkylating the corresponding bishydroxyl compounds in an organic reaction medium with methyl benzoate as the reaction medium. The ester can easily be regenerated and is stable under the reaction conditions.