Abstract A number of structural analogues of the known toxicant para-aminopropiophenone (PAPP) have been prepared and evaluated for their capacity to induce methemoglobinemia— with a view to their possible application as humane pest control agents. It was found that an optimal lipophilicity for the formation of methemoglobin (metHb) in vitro existed for alkyl analogues of PAPP (aminophenones 1–20; compound 6 metHb%= 74.1±2). Besides ...