A selective and convenient synthesis of gemini surfactants over heterogeneous basic catalyst

Tri-ethanolamine (C6H15O3N) and fatty acid (C10H20O2, C12H24O2, C14H28O2 and C16H32O2) using MgO–ZrO2 selectively gave the corresponding 2-(bis(2-hydroxyethyl)amino)ethyl alkanoate in good yield. Further the reaction of 2-(bis(2-hydroxyethyl)amino)ethyl alkanoate with epichlorohydrin or 1,2-dichloroethane (in the presence of the 2-(alkanoyloxy)-N,N-bis(2-hydroxyethyl)ethanaminium chloride) over same heterogeneous catalysis to afford novel N,N-bis(2-(alkanoyloxy)ethyl)-N,N,N,N-tetrakis(2-hydroxyethyl) propane-1,3-diaminium or N,N-bis(2-(alkanoyloxy)ethyl)-N,N,N,N-tetrakis(2-hydroxyethyl)ethane-1,2- diaminium (gemini surfactants), respectively. The ease of the diaminium reaction was found to be due to the neighboring-group participation (NGP) in the quaternization step. Results of esterification and diaminium reactions, reported herein were optimized for several catalytic effects to understand the probable mechanism. The catalysts can be easily separated from reaction and showed good recyclability.