2-Aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1H)-ones as substrates for the synthesis of 2,6,8-triarylquinazolin-4-ones

• Main Authors: M. J. Mphahlele, M. M. Maluleka, T. A. Khoza
• Format: Article
• Language: English
• Published: Chemical Society of Ethiopia 2014-01-01
• Series: Bulletin of the Chemical Society of Ethiopia
• Subjects: 2-Amino-3; 5-dibromobenzamide; 2-Aryl-6; 8-dibromo-2; 3-dihydroquinazolin-4(1H)-ones; Suzuki-Miyaura cross-coupling; 2; 6; 8-Triaryl-2; 8-Triarylquinazolin-4(3H)-ones
• Online Access: http://www.ajol.info/index.php/bcse/article/view/100079

Direct bromination of 2-aminobenzamide was achieved using N-bromosuccinimide in chloroform-carbon tetrachloride mixture at room temperature for 3 h to afford 2-amino-3,5-dibromobenzamide in high yield and purity. 2-Amino-3,5-dibromobenzamide was, in turn, condensed with benzaldehyde derivatives in the presence of boric acid to afford novel 2-aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1H)-ones. Suzuki-Miyaura cross-coupling of the latter with arylboronic acids yielded the corresponding 2,6,8-triaryl-2,3-dihydroquinazolin-4(1H)-ones. These triarylquinazolin-4(1H)-ones were dehydrogenated using iodine (2 equiv.) in ethanol under reflux to yield the potentially tautomeric 2,6,8-triarylquinazolin-4(3H)-ones. DOI: http://dx.doi.org/10.4314/bcse.v28i1.10