Heterocyclic polynuclear pigments and process for preparing same

Abstract

New compounds are disclosed having the general formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 may be the same or different and are selected from the class consisting of H, Cl and OCH.sub.3. They are useful as pigments. They are prepared by reacting a substituted or unsubstituted 1-aza-2-hydroxybenzanthrone with 2,3-dichloro-1,4-naphthoquinone, in the presence of pyridine, at a temperature between 80.degree. and about 120.degree. C.

Dependencies are inferred from the claim text.