Design and Synthesis of Pyridine and Thiazole Derivatives as Eco-friendly Insecticidal to Control Olive Pests.

Abstract

Treatment of p-tosyloxybenzaldehyde (1) with ethyl cyanoacetate afforded ethyl 2-cyano-3-(4-{[(4-methylphenyl)sulfonyl]oxy}phenyl)acrylate (2) which reacted with some active methylene derivatives under microwave irradiation in presence of ammonium acetate yielded pyridine derivatives 3-7. On the other hand, when treatment of compound 1 with thiosemicarbazide gave 4-tosyloxybenzylidenethiosemicarbazone (8), which allowed to react with some active methylene compounds, such as: ethyl bromoacetate, chloroacetonitrile or phenacyl bromide derivatives gave thiazole derivatives 9-13. The structure of all products were confirmed by elemental and spectroscopic analyses such as IR, 1 H-NMR, 13 CNMR and mass spectra. The advanced of this method are short reaction time (3-7 min), excellent yield, pure products, and low-cost processing. In the final category, the toxicological characteristics of all compounds were tested towards Saissetia oleae (Olivier, 1791) (Hemiptera: Coccidae). With respect to the LC50 values. It has been found that compound 3 possesses the highest insecticidal bioefficacy compared with other products, with values of 0.502 and 1.009 ppm, for nymphs and adults female, respectively. This study paves the way towards discovering new materials for potential use as insecticidal active agents.