Synthetic studies on condensed-azole derivatives. V. Synthesis and anti- asthmatic activities of ω-sulfamoylalkyloxy[1,2,4]triazolo[1,s-b]pyridazines

Article abstract of DOI:10.1248/cpb.45.1447

A series of novel ([1,2,4]triazolo[1,5-b]pyridazin-6- yl)oxyalkylsulfonamides was synthesized and evaluated for the ability to inhibit platelet activating factor (PAF)-induced bronchoconstriction in guinea pigs. The compounds bearing a gem-dialkyl or a cycloalkylidene group at the 2 position of the sulfamoylpropyloxy group in the side chain and a methyl group at the 7 position were found to have potent activity. Among them, 2,2-diethyl-3-(7-methyl[l,2,4]-triazolo[1,5-b]pyridazin-6- yl)oxypropanesulfonamide (13) showed excellent anti-asthmatic activity. Compouds 13 may be of significant value in the treatment of asthma and other respiratory diseases. The structure-activity relationships in this series of compounds are discussed.