The epindolidione compounds of the general formula (I) in which A′, R2 and A have the meanings given in claim 1, are outstanding pigments which are notable in particular for better migration, light and solvent fastnesses, better heat stability and enhanced colouring power and also better dispersibility and capability to be brought into pigment form. The invention also relates to a process for preparing these epindolidione compounds and to their use a colorants for colouring polymer compositions or paper pulps, as colorants in electrophotographic toners and developers, as colorants in ink-jet inks, as colorants in the coatings industry, as colorants for textile printing or as a printing ink in the graphical industry, as colorants in cosmetics.