Abstract
A series of novel 3-(4-chlorophenyl)-2-(3-substituted propyl) quinazolin-4-(3H)-ones have been synthesized and tested for their in vivo H1-antihistaminic activity on conscious guinea pigs. All the test compounds have protected
the animals from histamine induced bronchospasm significantly. Compound 3-(4-chlorophenyl)-2-(3-(4-methylpiperazin-1-yl)
propylthio) quinazolin-4(3H)-one (PC5) emerged as the most active compound (77.53% protection) of the series when compared
to the reference standard chlorpheniramine maleate (70.09% protection). Compound PC5 shows negligible sedation (6.16%) compared to chlorpheniramine maleate (29.58%).
Therefore, compound PC5 can serve as the lead molecule for further development into a new class of H1-antihistaminic agents.
Key words
quinazolin-4-ones - sedation - H
1-antihistaminic activity