Derivatizable novel β-tetra 7-oxycoumarin-3-carboxylate substituted metallophthalocyanines: Synthesis and characterization

In this study, a novel phthalonitrile, ethyl 7-(3,4-dicyanophenoxy)coumarin-3-carboxylate (1), was prepared and characterized. The metallophthalocyanines (3–6) were prepared by cyclotetramerization of 1 with the corresponding metal salts {Zn(OAc)2·2H2O, Co(OAc)2·4H2O, Cu(OAc)2, Ni(OAc)2·4H2O} in 2-chloronaphthalene. Reaction of 3 with aqueous hydrochloric acid gave the coumarino-zincphthalocyanine (3a) carrying carboxyl groups at the 3-position of all the coumarin moieties. Treatment of compound 3a with aqueous NaOH./AgNO3 or aqueous NaOH in N,N-dimethylformamide (DMF) gave the expected silver (3c) or sodium (3d) salts, respectively. The four carboxylic groups in coumarino-zincphthalocyanine (3a) and the four carboxylate groups in 3d make the compounds have good solubility in water. Heating of the acyl chloride derivative of 3 with morpholine in DMF yielded the corresponding 3-carboxymorpholinamide (3b). The newly prepared compounds, phthalonitrile and metallophthalocyanines, have been characterized by FT-IR, UV–Vis, MALDI-TOF and 1H NMR spectroscopies.

Graphical abstractThe metallophthalocyanines (MPcs, M = Zn, Co, Cu, Ni) (3–6) were prepared by cyclotetramerization of ethyl 7-(3,4-dicyanophenoxy)coumarin-3-carboxylate (1) with the corresponding metal salts in 2-chloronaphthalene. Reaction of 3 with H3O+Cl− gave coumarino-phthalocyanine (3a), carrying carboxyl groups at the 3-position of all the coumarin moieties. Treatment of compound 3a with aqueous NaOH./AgNO3 or aqueous NaOH in DMF gave the expected silver (3c) or sodium (3d) salt, respectively. The four carboxylic groups in coumarino-ZnPc (3a) and the four carboxylate groups in 3d make the compounds have good solubility in water. Heating of the acyl chloride derivative of 3 with morpholine in DMF yielded the corresponding 3-carboxymorpholinamide (3b). The newly prepared compounds, phthalonitriles and Pcs, have been characterized by FT-IR, UV–Vis, MALDI-TOF and 1H NMR spectroscopies.Figure optionsDownload full-size imageDownload as PowerPoint slide