Rothemund Reaction

Abstract

The one‐pot synthesis of porphine or isoporphine by the thermal condensation of aldehydes with pyrroles is generally referred to as the Rothemund condensation. Currently, this reaction being used for the synthesis of porphyrins, especially for 5,10,15,20‐, (or α,β,γ,δ‐) tetrasubstituted hindered meso ‐porphyrins. All the favourable conditions for the reaction have been discussed to enhance the final outcome. Many current preparations of porphyrin derivatives have been carried out in heterocyclic base, such as 2,4,6‐collidine. Furthermore some of the drawbacks of the reaction have also been addressed, such as formation of other analogues and the difficulty in isolation of porphyrin. This reaction has been considered as the primary method for the preparation of porphyrin derivatives and their analogues.