Synthesis and bioactivity of novel 3-(1-hydroxyethylidene)-5-substituted-pyrrolidine-2,4-dione derivatives

Ten novel 5-substituted derivatives of 3-(1-hydroxyethylidene)pyrrolidine-2,4-dione were synthesized. The compounds were confirmed by IR, 1H NMR, MS and elemental analysis. The bioassay indicated that these compounds showed noticeable herbicidal activities, and compounds 6f and 6j exhibited excellent inhibitory activities against the stalk of Echinochloa crusgalli, with EC50 values of 94.4 and 72.7 mg/L, respectively.