Imidazo[1,2-B]pyridazines. IX. Syntheses and Central Nervous System Activities of Some 3-Alkoxy-6-(o-alkoxy, o-methylthio- or o-fluoro-phenoxy)-2-arylimidazo[1,2-b]pyridazines

Abstract

Syntheses are reported for a series of 6-(o-methoxy -, o-ethoxy -, o-methylthio - and o-fluoro-phenoxy )-3-( methoxy and ethoxy )-2- phenyl(substituted phenyl and pyridin-3″-yl) imidazo [1,2-b] pyridazines . IC₅₀ values are reported for the displacement of ³H-diazepam from rat brain membrane by each of these compounds.

The most active compounds were found to be 3-ethoxy-2-(p- fluorophenyl )-6-(o- methoxyphenoxy )-, 3-methoxy-6-(o- methoxyphenoxy )-2-(m-nitrophenyl )- and 3-methoxy-6-(o- methoxyphenoxy )-2-(3″,4″-methylenedioxy ) imidazo [1,2-b] pyridazines with IC_5O values of 15, 18 and 19 nM respectively.