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

Abstract

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. KEY WORDS: 2-Amino-3,5-dibromobenzamide, 2-Aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1H)-ones, Suzuki-Miyaura cross-coupling, 2,6,8-Triaryl-2,3-dihydroquinazolin-4(1H)-ones, 2,6,8-Triarylquinazolin-4(3H)-ones Bull. Chem. Soc. Ethiop. 2014, 28(1), 81-90. DOI: http://dx.doi.org/10.4314/bcse.v28i1.10