<i>meso</i>‑Tetraphenylbenzoporphyrin‑2²,2³‑dicarboxylic Anhydride: A Platform to Benzoporphyrin Derivatives

Abstract

A method to synthesize <i>meso</i>-tetraphenylbenzoporphyrin-2²,2³-dicarboxylic anhydride is reported. This compound reacts with alkylamines and arylamines to afford the corresponding “phthalimides” in moderate to excellent yields. The reaction of the title compound with benzene-1,4-diamine or with benzene-1,3-diamine yields the corresponding <i>N</i>,<i>N</i>′-(phenylene)­bisphthalimides, whereas with benzene-1,2-diamine or naphthalene-1,8-diamine it affords heterocyclic-fused porphyrins. Molecular mechanics simulations elucidates the multiplicity of signals observed in the NMR spectra of the <i>N</i>,<i>N</i>′-(1,4-phenylene)­bisphthalimide <b>11</b>. This molecule exhibits two preferential conformations corresponding to a coplanar and an almost perpendicular arrangement of the benzoporphyrin units relative to the central benzenic ring