Several methods for the synthesis of metal-free phthalocyanine (Pc or PcH2)
and copper phthalocyanine (PcCu) from urea and phthalic anhydride, phthali
mide, 1,3-diiminoisoindoline (1,3-D), and phthalonitrile have been studied.
The results show that the nature of the solvent is the most important fact
or in the conventional chemical and direct electrochemical synthesis of the
final products. Different routes for phthalocyanine preparation are discus
sed.