N-Alkylation of 1-(3-methylphenyl)piperazine with 3,6-dichloropyridazine in dimethylformamide as a solvent and in the presence of sodium carbonate afforded 3-chloro-6-[4-(3-methylphenyl-1-piperazinyl]pyridazine. The reactive chlorine atom in this intermediate was replaced by a methoxy group, by refluxing the compound in methanol containing an excess of sodium methoxide. After addition of water to the cooled reaction mixture the product crystallized. Recrystallization from 2-propanol produced pure 3-methoxy-6-[4-(3-methylphenyl)-1-piperazinyl]pyridazine.