Development of a selective and potent radioactive ligand for histamine H3 receptors: A compound potentially useful for receptor occupancy studies

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

“…as coupling partners to afford the cross-coupled products 4a-h in appreciable yields and high purity without the need for column chromatography (Scheme 3). The heterocyclic ring of the 2,3-dihydroquinazolin-4(1H)-ones has been found to undergo a different degree of unsaturation through dehydrogenation or aromatization to afford the potentially tautomeric quinazolin-4(3H)-ones or their quinazoline derivatives [28][29][30][31][32]. Quinazolin-4(3H)-ones are versatile building blocks in the synthesis of novel 2,3-disubstituted quinazolinones [28][29][30][31] and their 2,4-disubstituted quinazoline derivatives using the principles of lactam-lactim dynamic equilibrium phenomena [32].…”

“…The heterocyclic ring of the 2,3-dihydroquinazolin-4(1H)-ones has been found to undergo a different degree of unsaturation through dehydrogenation or aromatization to afford the potentially tautomeric quinazolin-4(3H)-ones or their quinazoline derivatives [28][29][30][31][32]. Quinazolin-4(3H)-ones are versatile building blocks in the synthesis of novel 2,3-disubstituted quinazolinones [28][29][30][31] and their 2,4-disubstituted quinazoline derivatives using the principles of lactam-lactim dynamic equilibrium phenomena [32]. Oxidants such as KMnO 4 [28], CuCl 2 [29], DDQ [30] and MnO 2 [31] have been employed before in stoichiometric or large excess to convert the 2,3-dihydroquinazolin-4(1H)-ones into their quinazolin-4(3H)-one derivatives.…”

“…Quinazolin-4(3H)-ones are versatile building blocks in the synthesis of novel 2,3-disubstituted quinazolinones [28][29][30][31] and their 2,4-disubstituted quinazoline derivatives using the principles of lactam-lactim dynamic equilibrium phenomena [32]. Oxidants such as KMnO 4 [28], CuCl 2 [29], DDQ [30] and MnO 2 [31] have been employed before in stoichiometric or large excess to convert the 2,3-dihydroquinazolin-4(1H)-ones into their quinazolin-4(3H)-one derivatives. In this investigation, we opted for the use of molecular iodine which has been used before as an oxidant to effect the oxidative aromatization of α,β-unsaturated cyclic compounds and the analogous 2,3-dihydroquinolin-4(1H)-ones [24].…”

Synthesis and Photophysical Property Studies of the 2,6,8-Triaryl-4-(phenylethynyl)quinazolines

“…The potentially tautomeric quinazolin-4(3H)-one moiety itself is readily accessible via dehydrogenation of the corresponding 2,3-dihydroquinazolin-4(1H)-one precursors using oxidants such as KMnO 4 [10], CuCl 2 [11], DDQ [12] and MnO 2 [13] in stoichiometric or large access. The 2-substituted quinazolin-4(3H)-ones have also been synthesized directly from anthranilamide and aldehydes using NaHSO 3 [14], DDQ [15], CuCl 2 (3 equiv.)…”

Copper‐Catalyzed Self‐Condensation of Benzamide: Domino Reactions towards Quinazolinones

“…[2] The quinazolinone derivatives exhibit a wide range of pharmacological activities such as anticancer, anti-microbial, anti-inflammatory, antitubercular, antiviral, [1,[3][4][5][6][7] and are core structures in several marketed drugs such as Methaqualone, Etaqualone, Afloqualone, Chloroqualone, Quinethazone, Fluproquazone, Tiacrilast, Raltitrexed etc. [8,9] The stability of the quinazolinone nucleus towards the oxidation, reduction and hydrolysis reactions has motivated researchers to introduce many bioactive moieties to this nucleus and create new potential medicinal agents. [8,9] The stability of the quinazolinone nucleus towards the oxidation, reduction and hydrolysis reactions has motivated researchers to introduce many bioactive moieties to this nucleus and create new potential medicinal agents.…”