Abstract:
Ball-milling technique as a solvent-free and an alternative green process was investigated for the eco-benign synthesis of bis(indolyl)methanes (BIMs) from various aldehydes and selected ketones with indoles in high yields. The present methodology has several advantages such as simple procedure, good yields, mild conditions, and reduced environmental consequences. The silica gel acts both as a grinding medium and an acid catalyst. The utility of this technique was demonstrated by synthesizing library of 17 BIMs including two natural products trisindoline and tris(1H-indol-3-yl)methane.