Based on molecular probes, that have favourable optical properties for use in fluorescence microscopy and favourable binding affinity towards protein tau aggregates 4-(4-((4-(ethyl(2-fluoroethyl)amino)phenyl)diazenyl)phenyl)-6-methyl-2-oxo-2H-pyran-3-carbonitrile was designed. Synthesis plan was chosen in accordance with literature data on the synthesis of building blocks present in the designed molecule. It included reactions of Cleisen condensation, diazotation, azo coupling, fluorination and Knoevelagel condensation. In this work, syntheses of intermediary compounds used for to obtain the final molecule are presented. The synthesis of the final compound was unsuccessful under the chosen conditions.