Novel chromophoric heterocycles based on maleimide and naphthoquinone

Abstract 1‐Phenyl‐3,4‐dichloromaleimide, 1‐ n ‐propyl‐3‐bromomaleimide, and 2,3‐dichloro‐1,4‐naphthoquinone have been condensed with various mono‐ and bis‐nucleophiles to yield a range of novel dyes and pigments. Their visible absorption spectra are discussed.