Photochromic naphthacenequinones, process for their preparation and the use thereof

US5177227A · kind A · utility

Assignee

• Ciba-Geigy · US

Inventors

• Walter Fischer · Reinach, CH
• Evelyn Fischer · Weil am Rhein, DE
• Ernst Minder · Sissach, CH
• Manfred Hofmann · Hettstadt, DE
• Jurgen Finter · Glückstadt, DE
• Heinz Spahni · Frenkendorf, CH

Key dates

• Filing date: Jan 10, 1991
• Grant date: Jan 5, 1993
• Expiry date: Jan 10, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2603/44
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Compounds of formula I or V, or mixtures thereof, ##STR1## wherein R is unsubstituted C.sub.6 -C.sub.14 aryl or C.sub.6 -C.sub.14 aryl which is substituted by C.sub.1 -C.sub.12 alkyl, C.sub.1 -C.sub.12 alkoxy, C.sub.1 -C.sub.12 alkylthiol, phenyl, benzyl, --CN,--CF.sub.3, halogen or --COOR.sub.5, and R.sub.5 is H, C.sub.1 -C.sub.18 alkyl, cyclohexyl, cyclopentyl, phenyl, C.sub.1 -C.sub.12 alkylphenyl, benzyl or C.sub.1 -C.sub.12 alkylbenzyl, and at least one of the substituents R.sub.1 to R.sub.4 is an organic thiol, sulfoxyl or sulfonyl group, and the other members R.sub.1 to R.sub.4 are H, F, Cl or Br, are reversible photochromic systems which can be used for contrast formation or light absorption.