Silica supported sodium hydrogen sulfate and Indion 190 resin: An efficient and heterogeneous catalysts for facile synthesis of bis-(4-hydroxycoumarin-3-yl) methanes

4-Hydroxy coumarin on electrophilic substitution reaction with carbonyl compound in the presence of heterogeneous catalysts (NaHSO4 center dot SiO2/Indion 190 resin) offers bis-(4-hydroxycoumarin-3-yl) methanes in good to excellent yields. (C) 2011 Production and hosting by Elsevier B.V. on behalf of King Saud University.