Silica Sodium Carbonate as an Effective and Reusable Catalyst for the Three-Component Synthesis of Pyrano Coumarins

Silica sodium carbonate (SSC) has been prepared, characterized and then used as a valuable silica-supported catalyst for the preparation of a range of known and novel pyrano coumarins via the three-component reactions of aryl aldehydes, active methylene compound (malononitrile or ethyl cyanoacetate), and hydroxycoumarin (5,7-dihydroxy-4-substituted coumarins or 4-hydroxycoumarin). The heterogeneous catalyst showed much the same efficiency when employed in following reaction runs.