The condensation of 2-(1-benzylpiperidin-4-yl)ethanol (I) with 4-hydroxybenzoic acid ethyl ester (II) by means of triphenylphosphine and diazenedicarboxylic acid diethyl ester in THF gives 4-[2-(1-benzylpiperidin-4-yl)ethoxy]benzoic acid ethyl ester (III) as fumarate salt. This compound is debenzylated by hydrogenation with H2 over Pd/C in ethanol, yielding the free product (IV), which is finally condensed with 3-chloro-6-methylpyridazine (V) by means of K2CO3 in DMF.