Design, Synthesis and 3D‐QSAR of New Quinazolin‐4(3H)‐one Derivatives Containing a Hydrazide Moiety as Potential Fungicides

Abstract A series of quinazolin‐4(3 H )‐one derivatives containing a hydrazide moiety were designed, synthesized and characterized in detail via FT‐IR, 1 H NMR, 13 C NMR and HRMS spectra. The antifungal activities against Rhizoctonia solani ( Rs ) and Fusarium graminearum ( Fg ) were evaluated in vitro . The bioassay results indicated that most of the title compounds exhibited significant antifungal activities against Rs and Fg . Strikingly, the EC 50 values of some title compounds against Rs are obviously superior to that of the positive control carbendazim. Based on the antifungal bioassay results against Rs , the comparative molecular filed analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) models were generated to investigate the structure‐activity relationship of title compounds against Rs . The analytical results indicated that these two models exhibited good predictive accuracies and could provide significant structural insights for the design of bioactive quinazolin‐4(3 H )‐one derivatives containing a hydrazide moiety.