Fe³⁺‐Montmorillonite as Effective, Recyclable Catalyst for Paal–Knorr Pyrrole Synthesis Under Mild Conditions

Abstract Fe3+‐montmorillonite clay catalyst was used for the first time for pyrroles preparation by Paal–Knorr condensation. The features of this catalytic system are improved yields, mild conditions, a simple procedure, and high catalytic efficiency. The catalyst could be easily recycled and reused for three times without visible losing of activity.