Isoquinolinone Dyes. II – Synthesis and Properties of Some Coloured Isomeric Unsymmetrically Disubstituted Derivatives of 10,11-Dimethylbenzimidazo[2,1-a]benz-[de]isoquinolin-7-one

The purpose of this letter, which is a continuation of studies on the influence of structure on the physico-chemical and colour properties of isoquinolinone dyes, is to report on the synthesis of some unknown and so-far undescribed coloured isomeric unsymmetrically disubstituted derivatives of 10,11-dimethylbenzimidazo[2,1-a]benz[de]isoquinolin-7-one