Sawdust-SO3H: A Highly Efficient, Cheap and Recyclable Solid Acid Catalyst for the Synthesis of Quinoline Derivatives under Neat Conditions

Sawdust as a biomass waste material was treated with chlorosulfonic acid and sulfonated sawdust (SD-SO3H) was prepared which characterized with a variation of methods containing TGA, SEM and elemental analysis. This solid acid showed excellent catalytic activity for the synthesis of various quinolines derivatives through the Friedlander condensation of 2-aminoaryl ketones with cyclic and acyclic β-diketone, β- keto esters and cyclic ketone compounds under solvent-free conditions with high yields (70-95%). This new method offers some benefits such as simple procedure, short reaction times, high yields and use of a green, cheap and reusable catalyst.