Synthesis of a Combinatorial Library of Amides and Its Evaluation against the Fall Armyworm, Spodoptera frugiperda

The fall armyworm Spodoptera frugiperda is a polyphagous pest that causes important damage in different regions of America and mainly affects corn crops in both tropical and subtropical areas. Currently, control relies on both transgenic plants and/or chemical pesticides. In this work we describe the preparation of an indexed combinatorial library of amides and its toxic effect by contact against S. frugiperda. (E)-1-(1-Piperidinyl)-3-[4-(trifluoromethoxy)phenyl]-2-propen-1-one was the most active compound with an LD50 = 0.793 μg mg−1 of larva. This amide was also evaluated by ingestion and at the lowest concentration (1 mg kg−1) achieved 83.3% mortality.