Synthesis and insecticidal activity of benzoheterocyclic analogues of N ′‐benzoyl‐ N ‐( tert ‐butyl)benzohydrazide: Part 2. Introduction of substituents on the benzene rings of the benzoheterocycle moiety

A series of N′ ‐benzoheterocyclecarbonyl‐ N ‐ tert ‐butyl‐3,5‐dimethylbenzohydrazide analogues possessing a variety of substituents on the benzene rings of the benzoheterocyle moieties were synthesized and tested for their insecticidal activity. The introduction of a methyl group at the R 1 position of the benzoheterocycle moiety strongly increased the insecticidal activity. Among the analogues synthesized, N′ ‐ tert ‐butyl‐ N′ ‐(3,5‐dimethylbenzoyl)‐5‐methyl‐6‐chromanecarbohydrazide showed the highest insecticidal activity (LC 50  = 0.89 mg litre −1 ). © 2002 Society of Chemical Industry