Preparation Of Nitro Dihydropyridine Derivatives Via Condensation-Cyclization Reactions And Their Biological Activities

Neonicotinoids are a major class of insecticides with excellent insecticidal activity having a specific affinity towards the nicotinic acetylcholine receptors (nAChRs) of the insects and have been recognized as one of the most important research areas in the finding of new green insecticides. In this dissertation, a series of nitro dihydropyridine compounds with primary amide, substituted amide and primary thioamide substituents were designed based on the bioisosterism and recent structural innovation in neonicotinoid insecticides. Thirty-two new candidate compounds were prepared through Knoevenagel condensation and cyclization. All the synthesized compounds were confirmed by NMR, HRMS and IR spectroscopy. Bioassays showed that some of compounds exhibited insecticidal activities against cowpea aphids(Aphis craccivora Koch), while one of these compounds was endowed with excellent insecticidal activities. The LC50 value of this compound against cowpea aphids(Aphis craccivora Koch) was determined as 1.01mg/L.