One-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones by Fe<inf>3</inf>O<inf>4</inf>@SiO<inf>2</inf>-imid-PMAⁿ nano-catalyst under ultrasonic irradiation and reflux conditions

Abstract

© 2016, Springer-Verlag Wien. Abstract: Fe 3 O 4 @SiO 2 -imid-PMA n efficiently catalyzes the condensation reaction of isatoic anhydride, aldehydes, and primary amines or ammonium salts to afford the corresponding 2,3-dihydroquinazolin-4(1H)-one derivatives under ultrasonic irradiation or reflux conditions. This method gives notable advantages such as operational simplicity, excellent yields, short reaction times, and absence of any tedious workup or purification. In addition, the excellent catalytic performance and the easy preparation, thermal stability, and separation of the catalyst make it a good heterogeneous system and a useful alternative to other heterogeneous catalysts. Also, the aforementioned nanocatalyst can be easily recovered by a magnetic field and reused for subsequent reactions for at least six times without noticeable deterioration in catalytic activity and reaction yield. Graphical abstract: [Figure not available: see fulltext.]