Novel Aryl Thioamides Derivatives as Insect Growth Regulators Analogues against Spodoptera littoralis (Lepidoptera: Noctuidae): Design, Synthesis, Insecticidal Activity and Biochemical Impacts

Abstract

A significant reason for developing innovative insecticidal active agents is the exponential rise in resistance to traditional chemical pesticides. Exploring new classes of insecticidal compounds with distinct mechanisms of action is one way to address this difficulty. So that, novel aryl thioamides derivatives 3‐15 has been synthesized viaone‐pot, three‐component reaction of aroyl chloride, ammonium thiocyanate, and aromatic amines in dry acetone. The newly synthesized compounds' structures were validated by various spectroscopic methods, including elemental analysis, 1H NMR, 13C NMR, and infrared spectroscopy. Under laboratory circumstances, the synthesized compounds showed good and broad‐spectrum insecticidal activities toward S. littorali. When compared to other synthetic target compounds, 2,4‐dichloro‐N‐[(3‐fluorophenyl)carbamothioyl]benzamide 11, 2,4‐dichloro‐N‐[(3‐fluorophenyl)carbamothioyl]benzenecarbothioamide 13 showed good insecticidal activity, with 46.33 mg/L and LC50 values of 49.25 mg/L for 2nd instar larvae. Furthermore, the compound 3 was the least toxic in controlling the second and fourth instar larvae of S. littoralis on tomato leaves. Additionally, several histopathological and biochemical features of the some synthesized compounds under laboratory circumstances were also examined.