Synthesis and Fungicidal Activity of (E)-5-[1-(4-Phenyl-2-oxo-1-oxaspiro[4.5]dec-3-en-3-yl)ethylidene]-2-aminoimidazolin-4-one Derivatives

Abstract

(E)-5-[1-(4-Phenyl-2-oxo-1-oxaspiro[4.5]dec-3-en-3-yl)eth­yl­idene]-2-aminoimidazolin-4-one derivatives, as novel fungicidal agents, are designed and synthesized in moderate to excellent yields in four steps from (1-hydroxycyclohexyl)(phenyl)methanone and diketene as the starting materials. The products are characterized by 1H NMR and HRMS (ESI) analysis. An in vivo bioassay shows that some of the products exhibit good to excellent inhibition against P. cubensis and C. lagenarium, whilst up to 94.7% inhibition against P. capsici and up to 78.1% inhibition against B. cinerea is demonstrated in the in vitro bioassay. EC50 values of 3.40 and 5.86 μg/mL are demonstrated against P. capsici and B. cinerea.