The discovery of indoxacarb: oxadiazines as a new class of pyrazoline-typeinsecticides

The evolution of the insecticidal pyrazoline moiety that was originally dis covered in 1972 has led to the discovery of a new crop insecticide, indoxac arb, which is the first commercialized pyrazoline-type sodium-channel block er. Both monocyclic and fused-tricyclic pyrazolines and pyridazines, as wel l as structurally related semicarbazones were examined prior to the discove ry of analogous tricyclic oxadiazines which had similarly high activity as well as favorable environmental dissipation rates and low toxicity to non-t arget organisms. The eventual leading candidate, DPX-JW062, was originally obtained as a racemic molecule, but a chiral synthesis was developed which produces material that is 50% ee in the insecticidal (+)-S-enantiomer (DPX- MP062, indoxacarb). (C) 2001 Society of Chemical Industry.