The synthesis of symmetrical peripheral and non-peripheral octa-substituted metal-free phthalocyanines: simpler, better, faster, cheaper

Phthalocyanines are important not only as industrial pigments, but also in photodynamic cancer therapy, catalysis and various other fields. Despite the huge demand, synthetic routes to Pcs are tedious and the yields poor. In this paper, we report on modifications to the syntheses of symmetrical octa-substituted metal-free phthalocyanines (H2Pc). H2Pcs with peripheral or non-peripheral alkyl substituents were prepared in less steps and in higher yields than previously reported, whereas the yields of H2Pcs with alkoxy substituents (peripheral or non-peripheral) were improved considerably.