p-​Toluenesulfonic acid (p-​TSA)​-​catalyzed efficient synthesis of bis(indolyl)​methanes under grindstone method

摘要

An efficient reaction of indole with various aldehydes and ketones using catalytic amt. of p-​TSA to afford the corresponding bis(indolyl)​methanes, e.g., I (R = H, MeO, Me, NO2, Cl)​, under grindstone method in the absence of solvent is reported. The products are obtained in excellent yields.