Synthesis of sulfonamide-substituted phthalocyanines

The synthesis and characterization of new phthalocyanines bearing eight N-alkyl or N-aryl sulfonamide groups is described. The synthetic route involves the chorosulfonation of 4,5-diphenoxyphthalonitrile with chlorosulfonic acid and reaction of the resulting 4,5-bis(p-chlorosulfonylphenoxy)phthalonitrile with amines. The sulfonamide-substituted phthalonitriles are then cyclotetramerized to yield the title compounds in good yields (50–83%).