Abstract
A fast and efficient Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-ones (or thiones) by the reaction of aromatic aldehydes, β-dicarbonyls, and urea/thiourea using NaHSO4·H2O/ultrasound system is presented. The reactions were carried out in refluxing n-hexane/CH3CN (2.5:0.5 mL) to afford the products in excellent yields.
GRAPHICAL ABSTRACT
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Acknowledgments
The authors gratefully appreciate the financial support of this work by the Research Council of Urmia University.