A new azo compound was prepared via the azo coupling reaction between 4-(ethoxycarbonyl)-3-methyl-1H-pyrazole-5-diazonium chloride and 8-hydroxyquinoline (oxine). The ester functional group of the obtained compound was hydrolyzed and thus a new chemical structure with a carboxylic functional group resulted. The structures of the new compounds were fully characterized by: UV–Vis, FT-IR, 1D and 2D NMR spectroscopy, and HRMS spectrometry.

A new azo compound was synthesized via an azo coupling reaction between 4-(phenyldiazenyl)benzenediazonium chloride and 8-hydroxyquinoline (8-Hq). The new diazene compound can be used to synthesize metal complexes as a derivative of 8-Hq. The structure of the new compound was characterized using UV–Vis, FT-IR, and 2D NMR spectroscopic methods.