L-proline catalyzed one-pot synthesis of benzoxanthenes in aqueous medium

An operationally simple, cost-effective, and environmentally benign method has been described for the synthesis of various polysubstituted benzoxanthenes via L-proline-catalyzed three-component condensation of β-naphthol, aromatic aldehydes, dimedone, or 2-hydroxy-1,4-naphthoquinone in aqueous medium. This process has additional benefits such as simple product isolation and purification techniques, good to higher yields, and above all, efficient catalyst reusability. The addition of sodium dodecyl sulfate is an extra benefit to speed up this reaction.