Synthesis and Insecticidal Activity of Thiacloprid Derivatives against Helicoverpa armigera (Hub)

Thiacloprid (1) was converted to the corresponding amide (2) and acid (4) by alkaline hydrolysis. Amide (2) was reacted with phenyl isocynate to give the corresponding urea derivatives (3). The esterification of acid yielded an ester, (5) which was converted to hydrazide (6) with hydrazine hydrate. The thiacloprid was reduced by stannous chloride in dry HCl, and hydrolyzed to get aldehyde (7) and further reduced by Na in absolute alcohol to yield primary amine (8) (Scheme-1). The efficacy of these compounds was studied on Helicoverpa armigera (Hub), the test compound thiacloprid (1.28–1.40%), 6 (1.03–1.21%), 3 (1.25–1.40%), 7 (1.06–1.83%), 8 (0.851.73%) and novaluron (1.51–1.61%) at 200–600 mg L⁻¹, showed higher glycogen content. The amount of protein, lipid and chitin were measured and compared with their chitin inhibition property. Thiacloprid showed the highest mortality (50%, 4^th day) at 600 mg L⁻¹.