Sulfonylbis(1,4-Phenylene)Bissulfamic Acid (Spsa): Introduction of An Efficient and Reusable Catalyst For the Synthesis of Bis(Indolyl)Methanes

A simple, efficient and convenient route is described for the synthesis of bis-indolyl methanes by using recyclable catalyst sulfonylbis (1,4phenylene)bissulfamic acid (spsa). in this procedure, we synthesize a bis-indolyl methane derivative via the three component reactions of two equivalent indoles with one equivalent of various aromatic aldehydes in the presence of 10 mol% sbsa as a heterogeneous catalyst under solvent-free conditions at 110 °c for the convinced reaction times (30–60 min). the advantages of this protocol towards the synthesis of bis-indolyl methane derivatives are: i) use of solvent-free conditions, ii) inexpensive catalyst, iii) using commercially available precursors, d) reusability of sbsa up to several cycles without much loss in reactivity, iv) simple work-up, v) high yields of pure products, vi) short reaction times. the structure of all bis(indolyl)methane derivatives were confirmed by melting point, ft-ir, 1h nmr spectra and were compared with reliable references.