Zr-MCM-41 Nanoreactors: A Highly Efficient, Reusable and Novel Catalyst for the Synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-ones under Solvent-Free Conditions

A new green protocol has been developed for the synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-ones via a three component, one-pot condensation reaction of dimedone, naphthols and aromatic aldehydes using Zr-MCM-41 nanoreactors as a reusable and novel catalyst at 80 oC under solvent-free conditions. Various aromatic aldehydes containing electron-withdrawing and electron-donating substituent at ortho, meta or para-positions show equalease towards the product formation in high to excellent yields. Operational simplicity, mild reaction conditions, enhanced rates, environmentally benign, high isolated yields of the pure products and purification of products by non-chromatographic methods are significant advantages of the protocol presented here. The catalyst could be recycled and reused without a noticeably decrease in its activity

Keywords:

Naphthol , xanthenes , aldehyde , dimedone , Zr-MCM-41