Synthesis, structural characterization, Hirshfeld surface, DFT calculation and antifungal activity of novel quinoline carbonothioate compounds

Three quinoline carbonothioate compounds were synthesized using o-fluoroaniline and ethyl 2-methylacetoacetate as starting materials via multi-steps. The structures of three compounds were confirmed using ¹H NMR and HRMS. The structure of O-ethyl S-(8-fluoro-2,3-dimethylquinolin-4-yl) carbonothioate (3a) was further determined through X-ray single-crystal diffraction. Single-crystal X-ray diffraction analysis indicated that compound 3a crystallizes in the monoclinic space group C2/c, with unit cell parameters: a = 14.3284(6) Å, b = 19.2857(8) Å, c = 10.3990(5) Å, β = 108.1220(10)°, V = 2731.0(2) ų. In addition, the physicochemical properties of compound 3a were calculated and discussed using molecular electrostatic potential, frontier molecular orbital and Hirshfeld surface analysis. The antifungal activity of the three compounds was evaluated at 50 μg/mL, with compound 3b exhibiting good activity (75.8%) against R. solani.