Synthesis of 3‐nitrophthalonitrile and tetra‐α‐substituted phthalocyanines

An efficient synthesis of phthalocyanines prepared from ortho ‐substituted phthalonitriles is described. The precursor to these phthalocyanines, 3‐nitrophthalonitrile, is a key reagent for syntheses of phthalonitriles substituted at the 3‐position by means of nucleophilic aromatic substitutions. An example of this type of phthalocyanine, prepared from 3‐(4‐cumylphenoxy)phthalonitrile, is compared with the phthalocyanine derived from 4‐(4‐cumylphenoxy)phthalonitrile. Substitution of the phthalocyanine at this more sterically crowded site causes a 20 nm bathochromic shift of the Q‐band (π‐π* transition).