Approaches Towards the Synthesis of a 2,9,16,23-Tetrasubstitutedphthalocyanine as a Pure Isomer

摘要

Treatment of 4-neopentoxyphthalonitrile with hydrogen sulfide gas yielded 1-imino-6-neopentoxy-3-thioisoindoline and 1-imino-5-neopentoxy-3-thioisoindoline, which on alkylation with iodomethane gave 1-imino-3-methylthio-6-neopentoxyisoindolenine and 1-imino-3-methylthio-5-neopentoxyisoindolenine. The methylthioisoindolenines readily condensed at room temperature to a mixture of tetrasubstituted phthalocyanines and a series of linear open-chained purple compounds characteristic of isoindigos, while condensation at -20 C in the presence of zinc acetate gave, in at least one experiment, 2,9,16,23-tetraneopentoxy phthalocyanine as a pure isomer. The low temperature formation of phthalocyanines is remarkable and the syntheses described herein provide guidelines for the synthesis of pure isomers of 2,9,16,23-tetrasubstitutedphthalocyanines. The purple and red compounds are shown to have isoindigo structures rather than a ring opened phthalocyanine structure as previously reported. Keywords: Phthalocyanine, Synthesis(Chemistry), Indoles. (mjm)