Synthesis of Tetrahydrobenzo[a]xanthene-11-one Derivatives Using ZrO2–SO3H as Highly Efficient Recyclable Nano-catalyst

Abstract

The catalytic effect of Zirconia Sulfuric Acid (ZrSA) nanoparticle which is synthesized from the<br />reaction of ZrO with chlorosulfonic acid has been investigated in the synthesis of<br />tetrahydrobenzo[a]xanthene-11-ones by one-pot three-component reaction of β-naphthol,<br />aromatic aldehydes, and dimedone. Different reaction conditions were studied in the presence of<br />ZrSA nanoparticle as catalyst. The results showed that ZrSA exhibited high catalytic activity<br />towards the synthesis of tetrahydrobenzo[a]xanthene-11-ones, with the desired products being<br />formed in high yields. Furthermore, the catalyst was recyclable and could be reused at least three<br />times without any discernible loss in its catalytic activity. Overall, this new catalytic method for<br />the synthesis of tetrahydrobenzo[a]xanthene-11-ones provides rapid access to the desired<br />compounds under solvent-free conditions at 110 °C following a simple work‐up procedure, and<br />avoids the use of harmful organic solvents. This method therefore represents a significant<br />improvement over the methods currently available for the synthesis of<br />tetrahydrobenzo[a]xanthene-11-ones.<br /><br />