Solvent-free Synthesis of Novel and Known Octahydroquinazolinones/thiones by the Use of ZrOCl2.8H2O as a Highly Efficient and Reusable Catalyst

A solvent‐free reaction between urea/thiourea, dimedone and aromatic aldehydes in the presence of catalytic amounts of zirconium (IV) oxychloride octahydrate (ZrOCl2.8H2O) as a powerfull Lewis acid leads to octahydroquinazolinone/thione derivatives in good yields. This method has advantages such as avoidance of the organic solvents, production of pure products without any by‐product, short reaction times and simple operation. For the condensation of urea/thiourea, dimedone and aromatic aldehydes under solvent‐free conditions, zirconium (IV) oxychloride octahydrate was found to be an efficient and reusable catalyst. The high yield of the pure products has allowed the synthesis of several octahydroquinazolinones/thiones via this methodology.