CONDENSATION OF MUSCIMOL OR THIOMUSCIMOL WITH AMINOPYRIDAZINES YIELDS GABA-A ANTAGONISTS

Ten analogs of muscimol and thiomuscimol in which the amino function was delocalized in an amidinic system were prepared by N2 alkylation of 6-aryl-3-aminopyridazines with (chloromethyl) isoxazole or (chloromethyl)isothiazole derivatives. These muscimol and thiomuscimol derivatives show potent binding properties for GABA-A receptors (they displace [H-3]GABA and [H-3]gabazine) and provoke convulsions after iv injections. They fit well with the model pharmacophore proposed by our group for the GABA-A antagonists and show similar structure-activity profiles to that of the pyridazinyl-GABAs.