16285-32-8Relevant articles and documents
Direct synthesis of quinazolinones via the carbon-supported acid-catalyzed cascade reaction of isatoic anhydrides with amides and aldehydes
Zhang, Xiangyu,Luo, Chujun,Chen, Xiaoyong,Ma, Weilin,Li, Bin,Lin, Zirui,Chen, Xiuwen,Li, Yibiao,Xie, Feng
, (2021/02/20)
A novel catalytic system is reported for the construction of quinazolinones via the carbon-supported acid-catalyzed cascade coupling of isatoic anhydrides with amides and aldehydes. Subsequent selective hydrosilylation of the quinazolinones using a hydrogen-transfer strategy was also explored to provide dihydroquinazolines with structural diversity. The developed methodology proceeds with a broad substrate scope, excellent functional group tolerance, and utilizes a reusable catalyst and air as a green oxidant.
One-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones by Fe3O4@SiO2-imid-PMAn nano-catalyst under ultrasonic irradiation and reflux conditions
Esmaeilpour, Mohsen,Javidi, Jaber,Zahmatkesh, Saeed,Fahimi, Nafiseh
, p. 947 - 956 (2017/04/14)
Abstract: Fe3O4@SiO2-imid-PMAn 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.]
Experimental and theoretical investigations into the stability of cyclic aminals
Sawatzky, Edgar,Drakopoulos, Antonios,R?lz, Martin,Sotriffer, Christoph,Engels, Bernd,Decker, Michael
, p. 2280 - 2292 (2016/11/17)
Background: Cyclic aminals are core features of natural products, drug molecules and important synthetic intermediates. Despite their relevance, systematic investigations into their stability towards hydrolysis depending on the pH value are lacking. Results: A set of cyclic aminals was synthesized and their stability quantified by kinetic measurements. Steric and electronic effects were investigated by choosing appropriate groups. Both molecular mechanics (MM) and density functional theory (DFT) based studies were applied to support and explain the results obtained. Rapid decomposition is observed in acidic aqueous media for all cyclic aminals which occurs as a reversible reaction. Electronic effects do not seem relevant with regard to stability, but the magnitude of the conformational energy of the ring system and pKa values of the N-3 nitrogen atom. Conclusion: Cyclic aminals are stable compounds when not exposed to acidic media and their stability is mainly dependent on the conformational energy of the ring system. Therefore, for the preparation and work-up of these valuable synthetic intermediates and natural products, appropriate conditions have to be chosen and for application as drug molecules their sensitivity towards hydrolysis has to be taken into account.
