An efficient synthesis of quinazoline-2,4(1H,3H)-dione from CO2 and 2-aminobenzonitrile using [Hmim]OH/SiO2 as a base functionalized Supported Ionic Liquid Phase Catalyst

A simple base functionalized Supported Ionic Liquid Phase Catalyst using 1-hexy1-3-methyl imidazolium hydroxide ionic liquid supported on silica, (11-Imim1OH/SiO2) was used as an efficient, heterogeneous catalyst for the synthesis of quinazoline-2,4(1H,3H)-diones motif through the carboxylative coupling of CO2 with 2-aminobenzonitriles. The reactions give good to excellent yield under optimized reaction condition. The catalyst, [Hmim]OH/SiO2, was synthesized by physical adsorption phenomenon and was characterized by different techniques such as FT-IR and BET (Brunauer-Emmett-Teller) surface area analysis. The influences of different reaction parameters such as catalyst loading, reaction time, solvent, temperature and pressure on the reaction system were investigated. The developed methodology described a simple one step approach for the synthesis of a wide variety of substituted quinazoline-2,4(1H,3H)-diones with excellent yield of a desired products. Furthermore, the catalytic system was found to be recyclable up to four consecutive cycles with marginal decrease in yield after third recycle. (C) 2014 Elsevier Ltd. All rights reserved.