Condensation of 2-(4-fluorophenyl)-1-(4-pyridyl)ethanone (I) with dimethylformamide-dimethylacetal gives the enamino ketone (II). This is cyclized with thiourea (III) in the presence of NaOEt to produce the pyrimidine-2-thione (IV). Finally, S-alkylation of (IV) with 2-(methylsulfinyl)benzyl chloride (V) yields the target compound.