Utility of 5,5′‐Methylenebis(2‐hydroxybenzaldehyde) – cyanoacetohydrazide Hybrid as Scaffold for the Synthesis of Bis‐Heterocyclic Moieties and Study of Their Insecticidal Activity

Abstract The cotton leafworm, Spodoptera littoralis Boisd. is a serious pest attacking a wide range of ornamentals and many field crops. It is well documented that some heterocyclic systems have efficient insecticidal activities. So novel hydrazide‐hydrazone namely, N ′, N ′′′‐((methylenebis(6‐hydroxy‐3,1‐phenylene))bis(methanylylidene))bis(2‐cyanoacetohydrazide) 3 was exploited as a target to synthesize bis‐heterocyclic moieties such as furan, pyridone, coumarin, thiazole and isoxazole, and also some bis‐heteroarylidenes including heterocycles as indole and pyrazole. The chemical structures of the synthesized compounds were established on the basis of elemental analyses and some spectroscopic tools. All the synthesized compounds were screened for the insecticidal efficacy against the 4 th larval instar of Spodoptera littoralis (cotton leafworm). Manifestly, the data showed that compounds 9 and 14 possess remarkable potency but the rest of compounds showed no pronounced activity against cotton leafworm.