Tris(hydroxymethyl)methane ammonium hydrogensulphate as a nano ionic liquid and its catalytic activity in the synthesis of bis(indolyl)methanes

In this study, tris(hydroxymethyl)methane ammonium hydrogensulphate [(THA)(HSO4)] was synthesized as the first nanoaliphatic ammonium-based ionic liquid via a simple chemical route in water. The [(THA)(HSO4)] ionic liquid was characterized by various techniques such as XRD, SEM, TEM, AFM, H-1 NMR, C-13 NMR, FT-IR, MS, TG, DTG and elemental analysis and successfully applied as an eco-friendly and recyclable catalyst for the synthesis of bis(indolyl)methane derivatives at room temperature under solvent-free conditions. Taking the environment and economy into consideration, the work presented here has the merits of environmental friendliness, high yields, simple work-up, easy operation and the avoidance of the organic solvents and inexpensive catalysts. In this work, some bis(indolyl)methane derivatives were synthesized and reported for the first time. (C) 2016 Elsevier B.V. All rights reserved.