First synthesis of tetrapyrrolylporphyrin

[reaction: see text] N-alkyl-substituted meso-tetrapyrrolylporphyrin (TPyrP) and its derivatives were synthesized for the first time via an acid-catalyzed condensation between N-alkyl-2,4-diformylpyrrole and unsubstituted pyrrole and a subsequent deformylation reaction. X-ray structural analysis of formyl-substituted TPyrP shows the tilting of meso pyrrole rings ca. 60 degrees to the porphyrin plane. Formyl groups of meso pyrrole rings were removed by treatment with trifluoroacetic acid (TFA) in pyrrole.