2-Aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1h)-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. © 2014 Chemical Society of Ethiopia.