Convenient synthesis of bis(indolyl)alkanes by dithiocarbohydrazone Schiff base/Zn(ClO4)2·6H2O catalyzed Friedel–Crafts reaction of indoles with imines
Friedel–Crafts reaction of indoles with imines in the presence of dithiocarbohydrazone Schiff base/Zn(ClO4)2·6H2O as a highly stable, effective and readily available catalyst is described. Moderate to good yields (up to 99% yield) were obtained with both substrates for imine derivatives. This procedure is simple, practical and economic.