Porphyrinogens and Porphodimethenes, Intermediates in the Synthesis of meso-Tetra-phenylporphins from Pyrroles and Benzaldehyde
J. Heterocycl. Chem.
The reaction between pyrroles and benzaldehyde in refluxing HOAc gives meso-tetraphenylporphins and chlorins. The initial condensations give a porphyrinogen which undergoes an acid catalyzed autoxidation to porphyrin via a porphodimethene. The chlorin is shown to be derived from the reduction of porphyrin.