Synthesis, Characterization, Insecticidal Activities, and <i>in Silico</i> Molecular Docking Study of Some New Norfloxacin Analogues Based on 5-Spiro-1,2,4-Thiadiazoles

The significant problems with the use of pesticides have made the use of safe substitutes essential. Consequently, families of new, ecologically safe norfloxacin series that are effective in killing insects were found using 5-substituted 1,2,4-thiadiazoles. If the thiadiazole ring were isosterically added to the norfloxacin ring, more potent biological activity and/or a greater variety of sap-feeding bugs were anticipated. The target synthesized compounds will undergo both modern elemental and characterization analyses (IR,¹H NMR,¹³C NMR) to confirm their structure. The second category involved testing the generated chemicals on <i>Aphis gossypii</i>, the cotton aphid, nymphs, and adults. The most impacted synthetic chemical, compound <b>1</b>, had an LC₅₀ of 0.907 mg/L, according to the available information, whereas the LC₅₀ of commercial thiacloprid was 0.255 mg/L. Molecular docking studies confirmed these findings, with compounds <b>1</b>, <b>4</b>, <b>7</b>, and <b>10</b> displaying significantly stronger binding affinities to the hydrolase enzyme (−7.90, −7.70, −7.80, −7.70 kcal/mol) compared to the reference compound thiacloprid.