Green Protocol for the Synthesis of Bisindolylmethanes and Evaluation of Their Antimicrobial Activities

A simple, efficient, and ecofriendly procedure for the preparation of bis(indolyl)methanes via electrophilic substitution reactions of 2-phenylindoles with aldehydes is described. The reaction takes place in the presence of glacial acetic acid and a catalytic amount of anhydrous ferric chloride. All the synthesized compounds have been characterized by elemental analysis and spectral data (IR and ¹H NMR). They have also been evaluated for their antibacterial and antifungal activities, and some of them have shown promising results against S. aureus, E. coli, A. flavus, and A. niger.