Abstract
Dual solvent-catalytic activity of 1,1′-butylenebis(3-sulfo-3H-imidazol-1-ium) chloride was studied for the synthesis of coumarins under mild conditions. In addition, the catalytic efficiency of some mono- or di-cation ionic liquids containing same counter anion viz. chloride were studied for the model reaction under optimized conditions. The results showed that 1,1′-butylenebis(3-sulfo-3H-imidazol-1-ium) chloride was superior in the yield of the desired product.