The synthesis and antiallergy activity of 1-(aryloxy)-4-(4-arylpiperazinyl)-2-butanol derivatives

A series of 1-(aryloxy)-4-(4-arylpiperazinyl)-2-butanol derivatives were prepared and evaluated for antiallergy activity in the passive foot anaphylaxis (PFA) assay in rats. Twenty-seven derivatives had activity equal to or greater than the parent, alpha-(phenoxymethyl)-4-phenyl-1-piperazinepropanol. Six derivatives that possessed greater activity in the PFA than the parent compound were then tested in the guinea pig anaphylaxis (GPA) assay. Five of the derivatives were more potent than the parent (PD50 = 40 mg/kg) in the GPA with alpha-(4-fluorophenoxy)methyl]-4-(4-fluorophenyl)-1-piperazinepropan ol (PD50 = 3 mg/kg) having the greatest potency.