Bronchodilation and Structure-Activity Relationship Studies on New 6-Substituted Benzimidazo[1,2-c]quinazolines

Abstract

Two series of 6-substituted benzimidazo[1,2-c]quinazolines (Ia-p and IIa-l) have been synthesized and characterized. The compounds were evaluated for their bronchodilator activity, in vitro and in vivo. All the test compounds exhibited good activity both in vivo and in vitro methods. The structure-activity relationships based on the results obtained for these series have also been studied. In the 6-alkyl substituted compounds II, a longer alkyl chain and a 4-substitution by an electron-withdrawing group in compounds I, showed more activity. The presence of halogens altered the biological activity in both series. Among the compounds tested, 10-iodo-6-(n-propyl)-benzimidazol[1,2-c]quinazoline (II) was found to be the most potent (% protection = 75%; relative activity = 1.1).

Oxidation of some benzyl substituted fused quinazoline derivatives

“…Fused quinazoline derivatives were frequently described as a potential class of biologically active agents. [1][2][3][4][5][6][7] Thus, the chemical modifications of such compound are highly desirable.…”

The Conversion of 4-Anilinoquinazoline- and 3-Aryl-4-imino-3,4-dihydro-quinazoline-2-carbonitriles into Benzo[4,5]imidazo[1,2-c]quinazoline-6-carbonitriles via Oxidative and Nonoxidative C–N Couplings

“… Not surprisingly, benzo­[4,5]­imidazo­[1,2- c ]­quinazolines display a wide array of biological activities. Some act as DNA interchelators and show antitumor, anticancer, antiviral, and antimicrobial activities, while others act as anticonvulsant agents or as bronchodilators . Metal chelates with ruthenium­(II), tin, and lead have also been studied.…”

Synthesis, Characterization and Biological Activity Studies on 6-p-Dimethylaminophenyl-5,6-dihydrobenzoimidazo[1,2-c]quinazoline: Crystal Structure of the Title Compound and Comparative Study with Related Derivatives

“…Benzimidazoquinazolines have been reported to exhibit virucidal properties and antifungal effects against dermatophytes [20]. Benzimidazo [1,2-c]quinazolines with 6-alkyl substitution have been evaluated for their bronchodilator activity [21].…”