Discovery, research and development of axalion® active insecticide: dimpropyridaz†

Abstract

Dimpropyridaz is a novel insecticide active ingredient (a.i.) for the control of piercing and sucking pests. The discovery of dimpropyridaz included the synthesis of thousands of compound analogs which were investigated for their potential efficacy and registrability. Dimpropyridaz is the sole representative of the pyridazine pyrazolecarboxamide class, Insecticide Resistance Action Committee (IRAC) Group 36. The novel mode of action is characterized by disrupting the function of an insect's chordotonal organs in a way that is distinctly different from IRAC Groups 9 and 29. Dimpropyridaz demonstrates translaminar and systemic effects as well as high selectivity, providing both application flexibility and, when applied according to the label, beneficial organism, and environmental compatibility. Dimpropyridaz, powered formulations will be available in select markets, covering a broad range of vegetable, fruit, row crop, and ornamental production segments. Dimpropyridaz also has commercial registered name: Axalion Active. This review will focus on a broad outline of the chemical preparation, regulatory overview, and select biological performance and represents a summary of the information shared during the invited lecture at the 15th IUPAC (International Union of Pure and Applied Chemistry) International Congress of Crop Protection Chemistry held in New Delhi, India in March 2023. © 2024 BASF. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Keywords: IRAC Group 36; chordotonal organs; dimpropyridaz; residual activity; systemicity.

Figure 1

Abridged evolution from first insecticidal hit to dimpropyridaz. 1, First patent filing structure, exploration of initial chemistry class activity; 2, establishment of field testing paired with higher tier regulatory testing; 3, process development led to increased patent portfolio with replacement of pyrazole with pyridazine moiety and resulted in consistent whitefly activity; 4, excellent field activity against both whiteflies and aphid species; 5, improved systemicity and establishment of business case and lead analog; 6, dimpropyridaz.

Figure 2

Diagrammatic representation of the effects of CO modulator insecticides Groups 9, 29, and 36; of which Groups 9 and 29 directly and indirectly activate TRPV channels, respectively, while Group 36, dimpropyridaz silences CO neurons at an upstream target site.

Figure 3

Dimpropyridaz whitefly life stage control: adults, eggs, second to fourth instar. Application while adults are present, or expected, controls the adult population. Application while eggs are present, or newly emerged crawlers, controls the first instar crawler population. Application during second to fourth instar nymphal development provides control at adult emergence. Based on internal BASF trial data.

Figure 4

Image of untreated compared with dimpropyridaz, referenced within image as Axalion® Active Insecticide treated bell pepper, 14 days after treatment. Dimpropyridaz pepper plant was treated at 54 g a.i. ha⁻¹ rate, 300 L ha⁻¹ water volume. Once dried both plants were infested with Myzus persicae, from established laboratory colony. Each leaf was infested. Plants were reinfested with > 50 aphids to the crown in an interval of every 7 days.