Carbazole containing benzopyrans

US4841050A · kind A · utility

Assignee

• BASF SE

Inventors

• Andreas Guentner · Bischofswerda, DE
• Udo Mayer · Bischofswerda, DE
• Andreas Oberlinner · Ludwigshafen, DE

Key dates

• Filing date: Mar 12, 1987
• Grant date: Jun 20, 1989
• Expiry date: Mar 12, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D417/06
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Benzopyrans of the formula ##STR1## where X is a radical ##STR2## and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and the ring A have the meanings stated in the description, a process for their preparation, and their use in pressure-sensitive or heat-sensitive layers.