Twenty-seven novel pyrrolidine-2,4-dione derivatives containing N-substituted phenylhydrazine moiety were synthesized. Their structures were confirmed by 1H NMR, 13C NMR and MS. The half effective concentration (EC50) values of the title compounds against the phytopathogenic fungi Rhizoctonia cerealis were evaluated. Compounds 6l and 6q displayed good bioactivity with EC50 values of 1.626 and 2.043 μg/mL, respectively. The 3D quantitative structure activity relationship(3D-QSAR) model of CoMFA was established with reliable cross-validated correlation coefficient q2 value of 0.585 and Noncross-validated correlation coefficient r2 value of 0.971. This model provided a tool for guiding further design and synthesis of novel pyrrolidine-2,4-dione derivatives with high fungicidal activity.

(E)-Methyl-2-(2-(bromomethyl)phenyl)-3-methoxyacrylate was reacted with substituted 1-acetylpyrrolidine-2,4-diones and 3-(1-(hydroxylamino)ethylidene)pyrrolidine-2,4-diones respectively to synthesize two series of β-methoxyacrylate derivatives containing the pyrrolidine-2,4-dione moiety. The structures of the targeted compounds were confirmed by IR, 1H NMR, 13C NMR, MS and elemental analysis. The fungicidal activity against Rhizoctonia solani, Botrytis cinerea and Fusarium graminearum was evaluated. The bioassay results demonstrated that these compounds showed visible fungicidal activity.Two series of β-methoxyacrylate derivatives containing the pyrrolidine-2,4-dione moiety were synthesized. These compounds showed visible fungicidal activity against phytopathogenic fungi.

A series of 3-(1-(2-(substituted phenyl)hydrazinyl)alkylidene)furan-2,4(3H,5H)-diones were designed and prepared using two synthetic routes. Their structures were confirmed by FT-IR, 1H NMR, 13C NMR, MS, elemental analysis and single-crystal X-ray diffraction. Their bioactivity was evaluated against Botrytis cinerea in vitro. Most target compounds exhibited remarkable antifungal activity. Two compounds 7f and 7h were highly effective and their EC50 values were 0.241 μg/mL and 0.167 μg/mL, respectively, close to that of the control drug procymidone. 3D-QSAR studies of CoMFA and CoMSIA were carried out. Models with good predictive ability were generated with the cross validated q2 values for CoMFA and CoMSIA being 0.565 and 0.823. Conventional r2 values were 0.983 and 0.945, respectively. The results provided a practical tool for guiding the design and synthesis of novel and more potent tetronic acid derivatives containing substituted phenylhydrazine moiety.A series of novel tetronic acid derivatives containing substituted phenylhydrazine moiety were synthesized. Most target compounds exhibited remarkable antifungal activity. The 3D-QSAR study involving CoMFA and CoMSIA were generated to provide a tool for guiding further structure modification.