Synthesis of new highly organosoluble metallophthalocyanines with 1,8-dioxo-octahydroxanthene substituents

New highly organosoluble metallophthalocyanines (M = Zn, Co, Ni and Cu) bearing four [4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenoxy] substituents at peripheral positions have been prepared by tetramerization of 4-[4-(3,3,6,6-tetramethyl-1,8-dioxo-dodecahydro-1H-xanthen-9-yl)phenoxy]phthalonitrile in 2-(dimethylamino)ethanol using microwave irradiation or conventional heating. Ni(II), Co(II), and Cu(I) chloride were employed in order to synthesize the corresponding metal phthalocyanines and Zn(OAc)₂ was used for the preparation of the zinc phthalocyanines. 4-[4-(3,3,6,6-Tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenoxy]phthalonitrile was obtained by nucleophilic displacement of the nitro group in 4-nitrophthalonitrile with 9-(4-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7-tetrahydro-2H-xanthene-1,8(5H,9H)-dione. 9-(4-Hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7-tetrahydro-2H-xanthene-1,8(5H,9H)-dione was synthesized efficiently from dimedone and 4-hydroxybenzaldehyde. All the phthalocyanines are soluble in DMSO, DMF, CHCl₃, THF, CH₂Cl₂, and CH₃CN. The new compounds were characterized by IR, NMR, and UV–vis spectroscopy, elemental analysis, and thermogravimetric analysis.