Synthesis and insecticidal activity of lipophilic amides. Part 1: Introductory survey,and discovery of an active synthetic compound

A group of naturally occurring isobutylamides and related compounds exhibit a range of biological properties including activity against insects. Their potential as a starting point for developing new insecticides, needed to control pests resistant to other classes of insecticides, is discussed, following an extensive survey of known structures and activities. Few of the known compounds were sufficiently active and well characterised to point to sound structure-activity relationships, so synthetic analogues were examined. One of these [(2E,4E)-N-(2-methylpropyl)-6-phenylhexa-2,4-dienamide] was sufficiently active, and prompted the investigations reported here and in subsequent papers in the series. Analogues of this compound designed to establish areas where structural variation is possible are also described.