Discovery of novel insecticidal 3-aminopyridyl ureas

Commercial compound databases represent rich sources of potential starting points for pharmaceutical and agrochemical product development. Routine insecticidal screening of compounds ordered from these sources led to the identification of a 3-aminopyridyl urea with activity against Myzus persicae (Sulzer) (green peach aphid). Based on this activity and its structural novelty, further exploration of the chemical space around this hit was initiated.

A series of ureas based on the structure of the initial hit were synthesized and screened for insecticidal activity. A broad range of tail groups derived from cyclic secondary amines were explored, and many of these compounds were found to be insecticidally active. However, only compounds featuring a 3-aminopyridine or 4-aminopyridazine head group exhibited significant insecticidal potency. Although activity against M. persicae was consistently observed, these ureas were largely inactive against another key sap-feeding insect pest, Bemisia tabaci (Glennadius) (sweetpotato whitefly).

Follow-up of an insecticide hit identified from commercial compound acquisition led to the discovery of a novel class of ureas with activity against M. persicae. Despite considerable effort to identify related compounds with additional insecticidal spectrum, however, activity on other important pests remains limited. © 2019 Society of Chemical Industry.