4-Cyclohexyl-1-substituted-4H-[1,2,4]triazolo [4,3-a] quinazolin-5-ones: novel class of H1-antihistaminic agents.
A series of novel 1-substituted-4-cyclohexyl-4H-[1,2,4]triazolo [4,3-a] quinazolin-5-ones were synthesized by the cyclization of 3-cyclohexyl-2-hydrazino-3H-quinazolin-4-one with various one carbon donors. When tested for their in vivo H1-antihistaminic activity on guinea-pigs, all the test compounds protected the animals from histamine induced bronchospasm significantly. The compound 4-cyclohexyl-1-methyl-4H-[1,2,4]triazolo[4,3-a] quinazolin-5-one (II) emerged as the most active compound of the series and it is more potent (72.96% protection) when compared to the reference standard chlorpheniramine maleate (71.00% protection). The compound II shows negligible sedation (9%) when compared to chlorpheniramine maleate (30%). Hence, it could serve as prototype molecule for further development as a new class of H1-antihistamines.
Alagarsamy
V
V
Meena
S
S
Ramaseshu
K V
KV
Solomon
V Raja
VR
Kumar
T Durai Ananda
TD
D000818:Animals; D001986:Bronchial Spasm / Q000139:chemically induced / Q000188:drug therapy; D003510:Cyclohexanes / Q000138:chemical synthesis* / Q000494:pharmacology; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists / Q000138:chemical synthesis / Q000494:pharmacology; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects; D052999:Quinazolinones / Q000138:chemical synthesis* / Q000494:pharmacology; D014230:Triazoles / Q000138:chemical synthesis* / Q000494:pharmacology
D003510:Cyclohexanes; D006634:Histamine H1 Antagonists; D006993:Hypnotics and Sedatives; D052999:Quinazolinones; D014230:Triazoles