Structure-activity Relationships of <i>N</i>-Aryl-4-carboxy- and <i>N</i>-Aryl-4-hydroxy-phthalimides in Control of <i>Plasmodiophora</i> Disease

Abstract

Sixty-five N-aryl-4-carboxy-and N-aryl-4-hydroxy-phthalimides having various substituents on the N-aryl moiety were prepared, and their preventive activity against clubroot of Chinese cabbage caused by Plasmodiophora byassicae was examined. Among these compounds, only 2, 6-dialkyl derivatives showed high preventive activity, which depended on the position-specific substituent effect, and both the presence of the ce-branching and the number of carbon atoms in the alkyl groups on the N-aryl ring.