Dihydropyrimidinone as a precursor in the synthesis of BODIPY: Study of photophysical properties and DNA interaction

The development of molecules that combine relevant photophysical properties with the ability to interact with biological targets has gained increasing prominence due to their potential in bioanalytical and therapeutic applications. In this study, a novel fluorophore was synthesized: a boron-dipyrromethene (BODIPY) core functionalized at the meso position with a quinazoline moiety, a heterocyclic system with well-established and widely reported biological activities in the literature. The synthetic route was accomplished in six steps, using a dihydropyrimidinone (DHPM) scaffold as a key precursor. All intermediates, as well as the final BODIPY derivative, were characterized by 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectrometry (HRMS) and density functional theory (DFT) calculations. The final compound was obtained in 43% isolated yield and exhibited good chemical stability. Favorable photophysical properties were observed, with a fluorescence quantum yield (Φ) of 9.6% and a molar absorptivity (ε) value of (4.38 ± 0.02) × 10 4 L·mol -1 ·cm -1 . UV–Vis titration studies with salmon sperm DNA (ssDNA) indicated non-covalent interactions, consistent with an intrinsic binding constant ( K b ) of 1.10 ± 0.08 ×10 4 L mol -1 . The experimental findings were supported by molecular docking, which corroborated a minor-groove binding mode. Overall, the quinazoline–BODIPY hybrid is proposed as a promising platform for the development of functional fluorophores for bioanalytical applications, including biomolecule detection, quantification, and monitoring, while also supporting its potential in therapeutic contexts. • Synthesis of a novel quinazoline–BODIPY fluorophore. • Full structural characterization by experimental and theoretical methods. • Hybrid design modulates photophysical properties and enables DNA recognition. • Spectroscopic studies and molecular docking reveal minor groove binding. • Provides a strategic platform for biologically relevant BODIPY-based probes.