Porphyrinogens and porphodimethenes, intermediates in the synthesis of <i>meso</i>‐tetraphenylporphins from pyrroles and benzaldehyde

Abstract

Abstract The reaction between pyrroles and benzaldehyde in refluxing acetic acid 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.