A novel protocol for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from 2-aminobenzamides and aldehyde derivatives catalyzed by KOH/DMSO suspension has been developed. The present transition metal free methodology is operationally simple, scalable and varieties of 2,3-dihydroquinazolin-4(1H)-one derivatives were obtained in good to excellent yields in short reaction times.
2,3-Dihydroquinazolin-4(1H)-one derivatives have been synthesized via one-pot reaction of isatoic anhydride, aromatic aldehyde, and ammonium acetate catalyzed by FeCl3/neutral Al2O3 in tert-butanol under reflux conditions. Inexpensive and easily available reagents, convenient work-up procedure, reusable catalyst, and moderate to good yield are the salient features of this protocol.
New conditions for synthesis of (±)-2-monosubstituted and (±)-2,2-disubstituted 2,3-dihydro-4(1H)-quinazolinones from 2-nitro- and 2-aminobenzamide
作者:Richard A. Bunce、Baskar Nammalwar
DOI:10.1002/jhet.672
日期:2011.9
An efficient synthesis of (±)‐2‐monosubstituted and (±)‐2,2‐disubstituted 2,3‐dihydro‐4(1H)‐quinazolinones has been developed using a dissolving metalreduction‐condensative cyclization strategy. Treatment of 2‐nitrobenzamide and an aldehyde or ketone with iron powder in refluxing acetic acid affords high yields of the title compounds. More complex ring systems are available by incorporating additional
2-Phenyl-2,3-dihydroquinazolin-4(1H)-one derivatives were synthesized for the first time in water under neutral conditions by the reaction of aldehyde, and anthranilamide mediated by beta-cyclodextrin in high yields. beta-Cyclodextrin can be recovered and reused with a small loss of catalytic activity. (C) 2012 Elsevier Ltd. All rights reserved.
One-pot B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> catalyzed cascade synthesis of 2-substituted-2,3-dihydroquinazolin-4(1<i>H</i>)-ones
作者:Achut R. Shinde、Yogesh D. Mane、Dnyanoba B. Muley
DOI:10.1080/00397911.2019.1679539
日期:2020.1.2
A new and efficient B(C6F5)(3) catalyzed domino strategy has been developed for the synthesis of 2-substituted quinazolinones. The reaction utilizes 2-aminobenzamide and aldehydes for a one-pot protocol. A wide range of substrate scope, functional group tolerance, and operational simplicity with excellent yield are synthetically useful features.