Discovery and Chemical Exploration of Spiro[Benzofuran-3,3'-Pyrroles] Derivatives as Innovative FLT3 Inhibitors for Targeting Acute Myeloid Leukemia.

Aims: This study aimed at the synthesis of several spiro[benzofuran-3,3'-pyrroles] derivatives by a three-component reaction conducted by mixing DMAD, N-bridgehead het-erocycles, and benzofuran-2,3-diones in dichloromethane at room temperature for 24 h. Moreover, in vitro evaluation of their cytotoxicity affinities against FMS-like tyrosine kinase 3 was carried out.

Objectives: The objective of this study was to use a one-pot, three-component reaction to synthesize a novel set of spiro[benzofuran-3,3'-pyrroles] derivatives.

Methods: A novel set of spiro[benzofuran-3,3'-pyrroles] ((11-13)a-e) was synthesized by a one-pot three-component reaction involving dimethyl acetylenedicarboxylate, N-bridgehead heterocycles and benzofuran-2,3-diones in dichloromethane at room temperature for 24 h. The compounds were analyzed using NMR 1H, 13C, 2D-NMR (COSY, HMQC, HMBC), and HRMS. Docking simulations were conducted to elucidate the anticancer activity of synthe-sized compounds on FLT3 protein, with Gilteritinib as a reference for comparison.

Results: This study demonstrated the successful design, synthesis, and biological evaluation of spiro[benzofuran-3,3'-pyrroles] derivatives as FLT3 inhibitors for AML treatment. The synthesized compounds demonstrated promising binding affinities and significant inhibitory activity against FLT3 kinase. The inhibitors (11a, 11b, 11c, 12d, and 12e) exhibited excellent selectivity profiles against FLT3. Particularly, compound 12e showed strong binding affinity and potent inhibitory activity (IC50 = 2.5 μM).

Conclusion: Fifteen new synthetic spiro[benzofuran-3,3'-pyrroles] were prepared, character-ized, and evaluated for cytotoxicity affinities against FMS-like tyrosine kinase 3. Compound 12e showed strong binding affinity and potent inhibitory activity (IC50 = 2.5 μM), making it a promising candidate for further development as a therapeutic option for AML treatment. These findings lay the groundwork for further optimization and development of spiro[benzo-furan-3,3'-pyrroles] derivatives as potential therapeutics for AML treatment. Further studies are needed to explore their efficacy and safety profiles in preclinical and clinical settings.