Tandem Synthesis of Piriqualone and Analogues Using Deep Eutectic Solvents: Photophysical and Theoretical Insights

Abstract

This study presents a sustainable chemical approach for the tandem synthesis of Piriqualone a sedative and anxiolytic drug and its analogues using a green protocol. The research investigates the ability of deep eutectic solvents (DESs) to act as catalysts as well as solvent in a tandem reaction involving transition metal‐free dehydrogenation and sp³ C−H bond functionalization, leading to the formation of styryl‐heterocyclic compounds (7a–p). These styryl derivatives were thoroughly characterized through spectral analysis and photophysical property evaluation. The relationship between chemical structure and AIE properties was particularly examined for compound 7n. Additionally, the experimental findings were corroborated by density functional theory (DFT) calculations. The structures of compounds 7j, 7p and 7fa were further validated through single crystal X‐ray diffraction (XRD) analysis.