Synthesis, insecticidal activities and DFT study of pyrimidin-4-amine derivatives containing the 1,2,4-oxadiazole motif

Abstract

Twenty six novel pyrimidin-4-amine derivatives containing the 1,2,4-oxadiazole motif were synthesized. Their chemical structures were confirmed by 1 H nuclear magnetic resonance (NMR), 13 C NMR, and highresolution mass spectrography. The insecticidal activity results indicated that some of them possessed excellent insecticidal activity (100%) against Mythimna separate, especially for compounds 6d, 6f, 6o, 6w, 6y and 6z. These compounds exhibited no activity against the insects Aphis medicagini and Tetranychus cinnabarinus. The structureinsecticidal activity relationships are discussed. Density functional theory analysis can potentially be used to design more active compounds. These results provide useful insecticide design information for further optimization.

Novel Dioxolane Ring Compounds for the Management of Phytopathogen Diseases as Ergosterol Biosynthesis Inhibitors: Synthesis, Biological Activities, and Molecular Docking

“…Heterocycles with nitrogen atoms are important structural units in many pesticides − or pharmaceuticals. − Among them, 1,2,4-triazole is an important five-membered nitrogen-containing heterocycle, which has led to the discovery of many commercial drugs, especially antifungal drugs used for invasive infections such as fluconazole, ravuconazole, viroconazole, and intraconazole and agricultural fungicides used for crop protection such as propiconazole, tebuconazole, propiconazole, and cyproconazole (Figure ). Triazole fungicides have high activity, broad spectrum, strong systemic conductivity, and adequate half-lives. , Most triazole fungicides can prevent diseases , and regulate plant growth. , After some triazole fungicides are used, plants cannot synthesize auxin and gibberellin (GA), thereby inhibiting plant growth .…”

Synthesis and pesticidal activity of new 1,3,4-oxadiazole thioether compounds containing a trifluoromethylpyrazoyl moiety

“…In the last two decades, 1,3,4-oxadiazoles have emerged as the one of the most promising pharmacophores exhibiting important biological activities like anti-tumor [ 20 ], ketol-acid reductoisomerase inhibitors [ 21 ], antiproliferative [ 22 ], anti-SARS-CoV-2 [ 23 ], insecticidal [ 24 ], fungicidal activities [ 25 ], cardioprotective agents [ 26 ], nematocidal activity [ 27 ], anti-TMV activity [ 28 ] and anti-Alzheimer agents [ 29 ]. The hybridization of 1,3,4-oxadiazole unit with several other heterocycles like benzimidazole [ 30 ], coumarin [ 31 ], pyridine [ 32 ], glycosyl [ 33 ], and triazole [ 34 ] has empowered to develop various molecular hybrid displaying excellent activity.…”

Design, synthesis and biological activities of 1,2,4‐triazolo[1,5‐a]pyrimidine‐7‐amine derivatives bearing 1,2,4‐oxadiazole motif

“…Plant diseases and insect pests are important factors affecting the yield and quality of food crops, vegetables, and fruits; and among them, M. separate, A. medicagini, and T. cinnabarinus are common pests and P. cubensis and E. cichoracearum are one of the most serious diseases of plants. In our previous work, two series of pyrimidine-7-amine derivatives [10,26] bearing a trifluoromethyl-1,-2,4-oxadiazole moiety were synthesized, and some of them exhibited excellent insecticidal activity against M. separate, A. medicagini, and T. cinnabarinus, and fungicidal activity against P. cubensis, respectively. In this article, a new series of 1,2,4-triazolo[1,5-a]pyrimidine-7-amine derivatives were designed and synthesized based on our previous work [10,26] in order to discover high active compounds with insecticidal and fungicidal activity.…”