Facile synthesis of novel fluorescent thiazole coumarinyl compounds: Electrochemical, time resolve fluorescence, and solvatochromic study

In this study, Benzocoumarin-Thiazoles-Azomethine derivatives with bioactive scaffolds were synthesized and characterized. The present investigation is concerned with the multistep synthesis of thiazole coumarinyl derivatives (5a-k), which were accomplished from naphthaldehyde, ethyl acetoacetate, and thiosemicarbazide. The formation of newly synthesized derivatives was confirmed by ¹H NMR and ¹³C NMR spectroscopic studies. Thiazole coumarinyl derivatives were subjected to UV-Visible studies in different solvents such as ethanol, ethyl acetate, and DMF for solvatochromic studies. The synthesized coumarinyl thiazole compounds showed absorption in the range of 332-390 nm. Electrochemical studies were performed in DMSO and redox behavior was offered by thiazoles. Fluorescence of coumarinyl thiazole compounds were examined in ethanol, ethyl acetate, and DMF to visualize the solvent effect on the emitting ability of compounds. Fluorescence spectra of coumarinyl thiazoles expressed a sharp emission in the range 436-550 nm.